In 1864 James Clerk Maxwell published his essay, A dynamical Theory of the Electromagnetic Field, which contained what are now known as Maxwell’s equations: the four basic equations of the electromagnetic field. In doing so he bought to a satisfactory pause an intense period of experiment and theorizing on the nature of electricity and magnetism. This period, I suggest, started in 1800 with the invention, by Alessandro Volta, of the voltaic pile, enabling, for the first time, the production of a continuous electric current. The following six decades were a fascinating montage of experiments and theories. This essay is not going to address the nature or ontology of the various fluid, wave, and field theories that emerged, and were argued over, in this period. I am going to discuss the speculation and experiments on electricity and magnetism carried out by three people: Hans Christian Ørsted (pictured above), André-Marie Ampère, and Michael Faraday, whose work launched a second industrial revolution, based on electric motors, generators, and the use of ‘electricity’.
Prior to this period a change occurred, particularly in France, Germany, and Scotland, where experimental science was developed with an emphasis on quantitative and mathematical approaches. In France this became a dominant orthodoxy led by Antoine-Laurent Lavoisier and, in particular, Pierre-Simon de Laplace. In response to this arose ‘Romantic’ approaches to natural philosophy. The Romantic Movement, particularly those influenced by the Naturphilophie of Frederich Schelling, believed (amongst a number of key concepts) that speculation, not just mathematical reasoning, was a crucial part of experimental science. This essay will explore this role of speculative theorizing in the experimental pursuits of Ørsted, Ampère, and Faraday, with the intention of illustrating how these three very different personalities arrived at their great discoveries through ‘disciplined speculation’.
Ørsted and the ‘Unity of Nature’: a Discovery by chance?
There is a substantial argument in the literature whether Kant’s philosophy or Schelling’s Naturphilosophie had the greater impact on Ørsted’s scientific work. While this essay is not intended to address this unresolved discussion it is relevant to understand both these influences. Hans Christian Ørsted and his younger brother Anders Sandøe Ørsted had immersed themselves in Kantian philosophy as undergraduates at the University of Copenhagen. After graduating in Pharmacy, including practical training in his father’s shop, Hans Christian submitted a doctoral thesis critiquing Kant’s Metaphysical Foundations of Natural Science, coming out in favour of his dynamical theory; the universe was a product of polar forces in perpetual interplay, and against the atomic theory of the world being constructed out of substantial entities (atoms). Ørsted’s thesis was not totally in agreement with Kant’s, his disagreement rested on Kant’s tracing his main concepts from empirical observation:
Kant had stopped at the outermost limit of reason: the mechanical-mathematical concept of matter was empty, but scientifically productive; the dynamical system by contrast offered concepts that made sense but were unable to be scientific.”
By 1799 Ørsted had already defined his life’s scientific project; going on step further than Kant and making the dynamical theory scientific.
Ørsted spent three periods during 1801-2 with the German physicist Johann Wilhelm Ritter. This near six weeks of discussing galvanism and conducting experiments together laid the foundation of a friendship for life. Ritter was a self-made scientist, influenced by, but not an acolyte of, Schelling, “who can be and in fact was in his time the prototype of a Romantic physicist,” who nonetheless made significant contributions to science. He developed the accumulator, proved the existence of ultra-violet light after speculating that it must exist, because of nature’s polarity, and the recent discovery of infra-red light by Herschel, and demonstrated the unification of electricity and chemical changes – creating the new science of electrochemistry. While Ritter’s experimental work was providing plausibility for the philosophical work of the Romantics, his continual imaginative, and in some cases wildly biased, speculations stimulated both excitement and caution in Ørsted.
After spending 1803 in Paris, Ørsted returned to Copenhagen in 1804 and was appointed a professor at the University in 1806. Ørsted continued to develop his experimental techniques as well as his theoretical ideas: in 1806 he published his theory of the “conflict of electricities”, in 1812 a book, Consideration of the Physical Laws of chemistry Deduced from the New Discoveries, which by analogy linked his “conflict” theory with the polarity of magnetism and chemical affinities work of Ritter, and in 1816 he developed a new, high current, galvanic cell, which he subsequently used in all his experiments.
Ørsted’s discovery was made during a series of lectures he gave from November 1819 to May 1820. The audience were not casual passers-by, rather they were men, advanced amateurs, with a sound foundation in natural philosophy – familiar with his thought experiment that strong electrical forces may affect a magnet. In the April lecture, he took a risk, and tried the experiment to the live audience. His thought experiment was vindicated when the switching on of the galvanic circuit deflected the magnetic needle. Once he managed time to confirm his results in July 1820, his results were published in a brief article, Experimenta, in the Danish journal Hesperus. This he then sent to a selection of scholars in Europe to claim his priority over the discovery. The primary account of these events come from Observations on Electro-magnetism, an 1821 article that was simultaneously published in journals in London, Nuremburg, Geneva, and Paris.
By the first week in September Biot and Arago in Paris could report complete verification of Ørsted’s results. Already Ampère had begun to build on Ørsted’s discovery, and on September 25 had announced to the Academie his discovery of the mutual forces between two parallel electric currents. On the first Monday in December, Ampère announced his theoretical description of the effect. As a consequence of his lack of mathematical training, Ørsted neither understood nor appreciated Ampère’s contribution. With uncharacteristic sarcasm, he later wrote:
The ingenuity with which this clever French mathematician has gradually changed and developed his theory in such a way that it is consistent with a variety of contradictory facts is very remarkable.
What Ørsted was reacting to was Ampère’s own speculative nature. Never a follower off the dominant Laplacian orthodoxy that “electrical and magnetic phenomena are due to two different fluids which act independently of each other,” Ampere had now found a question worthy of his attention.
In a manner similar to Ørsted’s discovery Ampère’s theoretical description was a result of a near lifetime of mental preparation. Ampère is generally acknowledged, despite Ørsted’s admonition, as the man who created the science of electrodynamics. His achievements however are deeply rooted in his broader philosophical interests. Ampère was not representative of his era, particularly in French scientific circles. His idiosyncratic approach to his professional life meant that he had little impact on the society in which he lived. This is in marked contrast to both Ørsted and Faraday whose impact went far beyond their immediate contributions to science.
Born in Lyon on January 20, 1775, Ampère had an idyllic youth, growing up between the commercial bustle of Lyon and rural life of the small village Poleymieux where the family moved to in 1782. His father, Jean-Jacques Ampère, was guided partially by Rousseau’s educational philosophy, and Andre-Marie had no formal education (except in Latin), instead he was allowed to “learn from things and to do so according to spontaneous interest.”
Contrary to Rousseau’s advice Andre-Marie was given early access to his father’s library and early impressions were made by French Enlightenment masterpieces such as Georges-Louis Leclerc, comte de Buffon’s Histoire naturelle, générale et particulière, Rousseau’s popular essays on botany, developing an interest in science and mathematics from Antoine Leonard Thomas’ Éloge de René Descartes and Denis Diderot and Jean le Rond d’Alembert’s Encyclopédie. His early felicity in Latin and Italian enabled the young Ampère to master the works of Leonhard Euler and Daniel Bernoulli and Joseph Louis de Lagrange’s Mechanique analitique. This intellectually invigorating childhood was bought to an end on November 23, 1792 when his father was guillotined during the Reign of Terror.
The next ten or so years were spent in provincial tutoring roles, marrying and starting a family. In 1802 Ampère was appointed professor of physics at the Bourg École Centrale. It was in these years that Ampere displayed his early gift for speculative experimentation, particularly in physics and chemistry. Immediately prior to his move he gave a lecture at the December 24, 1801 meeting of the Academie de Lyon reveals his speculative scope, which included a “sketch of a vast system that connects all parts of physics” “examination of the influence of electricity on affinities and on the theory of light and colors.” His ideas were highly speculative and underwent change when he moved to Paris in 1804, however they still retained the optimistic convictions of his youth. He believed that “scientific research would eventually reveal the true causal structure of nature” and that “science could at least reach a deeper level of reality than that described by phenomenological laws.” Ampère held a central philosophical and methodological attitude that a fundamental fact would emerge from a tentative “explicative hypothesis” followed by experimental confirmation. Ampère called this indirect synthesis, and demanded that this experimental confirmation should include and emphasize the prediction of new phenomena that might not have been noticed otherwise.
Between 1804 and 1820 Ampère advanced to the front in all three fields of mathematics, chemistry and physics, this despite being at methodological odds with the Laplacian mathematical and experimental program of science that dominated in France at the time. For example Ampère was one of the few French scientists to take seriously Avogadro’s 1811 hypothesis that equal volumes of gas contain equal number of particles. The doyen of French chemistry and co-chair with Laplace of the famous Societe d’Arcueil , Berthollet, resisted any atomic theory or speculation, maintaining that “for progress in [physics and chemistry]….to be real, one must bring to them a great deal of precision in facts.” Ampère’s interest in Chemistry was concluded in 1816 with a publication of his classification scheme for elements, all 48 of them, increased from the 33 in Lavoisier’s 1787 list, with light and caloric no longer recognised as elements.
Remembering that Arago repeated Ørsted’s experiment on September 4, 1820 to a sceptical French audience. The observation revealing two glaring exceptions to Laplacian physics; firstly electric and magnetic phenomena were not independent and secondly the perceived force acted tangentially to the current flow. In the same September and October Ampère produced attractions and repulsions between wires conducting electric currents. In 1826 Ampère produced a polished argument in his most influential publication, his Théorie des Phénomènes électro-dynamiques, describing the electrodynamic force.
Ampère was convinced that there existed two electric ‘fluids’, and argued that his theory was preferable to the Laplacian theory of Jean-Baptiste Biot and Siméon-Denis Poisson “because it could account for all magnetic, electromagnetic, and electrodynamic phenomena without postulating the existence of the magnetic fluids.” Driven by this speculation Ampère proceeded over the next six years in a frenzy of iterations of experiment, measure, speculate, report. In the years 1820-1822 this was nearly on a fortnightly basis to the Académie in a race with Biot and his protégé Félix Savart. Most notable here was that Ampère’s experimental activities were guided by predetermined goals, only with rare exceptions did Ampère experiment in pursuit of novelty for it own sake. After 1827 Ampère’s attention shifted to other topics, although he did take note of Faraday’s discovery of induction in 1831.
Speculative Theorizing at the Royal Institution; Michael Faraday the greatest Experimental Philosopher
Sir Humphrey Davy was in his day, a star, one of the most famous chemists of the nineteenth century and a captivating lecturer at the Royal Institution. Davy was also a Romantic Scientist. He was committed to the view that “mere organization of matter could not give rise to life” furthermore his lectures could only be understood in the context of the politics of the day: revolution and conservative reaction. This influence cannot go unnoticed when considering his successor at the Royal Institution; Michael Faraday. Faraday came from a poor background, but was nonetheless, akin to Ampère, a well- if self-educated man. By 1812 when he made Davy’s acquaintance he had well developed ideas on the nature of imponderable fluids and the nature of matter.
Faraday was undoubtedly a brilliant and extraordinarily persistent experimentalist and in contrast to Ampère was extremely organized in documenting his experiments. In the year following Orsted’s discovery he had repeated Orsted’s experiments and in doing so had, like Ampère, made his own discovery – that of electromagnetic rotation – leading to the invention of the electric motor in 1821. The value of these experiments lie as much in the speculation that Faraday made of them. For example in his diary he wrote:
The motion evidently belongs to the current, or what ever else it be, that is passing through the wire, and not the wire itself, except as the vehicle of the current.
From this point Faraday experimentally examined Ampère’s theory and, in addition, developed his own ideas on the nature of electricity. This led to his discovery in 1831 of the induction of electric current by magnetism in 1831. This discovery was not only the culmination of a long search it was the starting-point for almost thirty years of brilliant researches in electricity. These include his discovery of the ability of magnetic fields to change the polarization of light in 1845, which finally gave an experimental link to the unity of nature that was speculated on by for by Kant and Schelling. There is no doubt that Faraday was driven by a search for this unity of nature, as he wrote in 1845 :
I have long held an opinion, almost amounting to a conviction, in common I believe with many other lovers of natural knowledge, that the various forms under which the forces of matter are made manifest have one common origin; or in other words, are so directly related and mutually dependent that they are convertible, as it were, one into another, and possess equivalents of power in their action.
Like Ørsted and Ampère, Faraday’s speculations drove his experimental directions even when they at first, or in the end, appeared unfruitful (from July 19, 1850):
Here ends my trial for the present. The results are negative. They do not shake my strong feeling of the existence between gravity and electricity, though they give no proof that such a relation exists.
By examining the approaches of three key scientific figures, Ørsted, Ampère, and Faraday, I have attempted to illustrate the role that ‘disciplined’ speculation has played in the development of electromagnetism in the early half of the nineteenth century. In particular showing the influence of Kant and Schelling on all three physicists in conceptualizing their experiments, and at the same time illustrating that speculative science could be manifest in many nuanced forms as shown by the differing personalities and methods of the three examples given here.
 Maxwell, James Clerk, A Dynamical Theory of the Electromagnetic Field, ed. Thomas F. Torrance (1982), pp. 33-104.
 Torrance, Thomas F., Preface, in Maxwell, James Clerk, A Dynamical Theory of the Electromagnetic Field, ed. Thomas F. Torrance (1982), pp. xi-xii.
 Holten, Gerald, Foreword, in Brain, Cohen, and Knudsen (2007), pp. vii-viii.
 Frankel, Eugene, J. B. Biot and the Mathematization of Experimental Physics in Napoleonic France, (1977), pp. 34-47.
 Knight, David, Romanticism and the sciences, in Cunningham and Jardine (1990), pp. 13-24.
 Morgan, S. R., Schelling and the origins of his Naturphilosophie, in Cunningham and Jardine (1990), pp. 25-37.
 Nilsen, Keld and Andersen, Hanne, The influence of Kant’s philosophy on the young H. C. Ørsted, in Brain, Cohen, and Knudsen (2007), pp. 97-114.
 Stauffer, Robert C., Speculation and Experiment in the background of Ørsted’s Discovery of Electromagnetism, (1957), pp. 33-44.
 Christensen, Dan Charly, Hans Christian Ørsted: Reading Nature’s Mind, (2013), pp. 40-51.
 Christensen, Dan Charly, Hans Christian Ørsted: Reading Nature’s Mind, (2013), pp. 70-71.
 Christensen, Dan Charly, Hans Christian Ørsted: Reading Nature’s Mind, (2013), pp. 108-121.
 Wetzels, Walter D., Johann Wilhelm Ritter: Romantic physics in Germany, in Cunningham and Jardine (1990), pp. 199.
 Wetzels, Walter D., Johann Wilhelm Ritter: Romantic physics in Germany, in Cunningham and Jardine (1990), pp. 199-212.
 Ørsted, Hans Christian, facsimile of Experimenta front page ,in Christensen, Dan Charly, Hans Christian Ørsted: Reading Nature’s Mind, (2013), pp. 348.
 Ørsted, Hans Christian, Observations on Electro-magnetism, in Jackson, Jelved, and Knudsen (1998), pp. 430-449.
 Jelved, Karen and Jackson, Andrew D., The Other side of Ørsted: Civil Obedience, in Brain, Cohen, and Knudsen (2007), pp. 15.
 Wilson, Andrew D., Introduction, in Jackson, Jelved, and Knudsen (1998), pp. xvii.
 Hofman, James R., Andre-Marie Ampère, (1995), pp. 2.
 Hofman, James R., Andre-Marie Ampère, (1995), pp. 11.
 Hofman, James R., Andre-Marie Ampère, (1995), pp. 7-23.
 Hofman, James R., Andre-Marie Ampère, (1995), pp. 50-66.
 Hofman, James R., Andre-Marie Ampère, (1995), pp. 144-145.
 Hofman, James R., Andre-Marie Ampère, (1995), pp. 164.
 Frankel, Eugene, J. B. Biot and the Mathematization of Experimental Physics in Napoleonic France, (1977), pp. 34-47.
 Hofman, James R., Andre-Marie Ampère, (1995), pp. 192.
 Frankel, Eugene, J. B. Biot and the Mathematization of Experimental Physics in Napoleonic France, (1977), pp. 44-45.
 Hofman, James R., Andre-Marie Ampère, (1995), pp. 206-212.
 Hofman, James R., Andre-Marie Ampère, (1995), pp. 309-350.
 Hofman, James R., Andre-Marie Ampère, (1995), pp. 309.
 Lawrence, Christopher, The power and the glory: Humphry Davy and Romanticism, in Cunningham and Jardine (1990), pp. 213-227.
 Williams, L. Pierce, Michael Faraday, (1965), pp. 80-89.
 Faraday, Michael, Experimental Researches in Electricity, (1965).
 Williams, L. Pierce, Michael Faraday, (1965), pp. 151-168.
 Faraday, Michael, quoted in Williams, L. Pierce, Michael Faraday, (1965), pp. 165.
 Faraday, Michael, Experimental Researches in Electricity, (1965), (paragraph 2146), vol. 3, pp. 1-2.
 Faraday, Michael, Experimental Researches in Electricity, (1965), (paragraph 2717), vol. 3, pp. 168.
Brain, Robert M., Cohen, Robert S. and Knudsen, Ole, (editors), Hans Christian Ørsted and the Romantic Legacy in Science: Ideas, disciplines and practices, Springer, Dordrecht, 2007.
Christen, Dan C., Hans Christian Ørsted: Reading Nature’s Mind, Oxford University Press, Oxford, 2013.
Cunningham, A. and Jardine N., (editors), Romanticism and the Sciences, Cambridge University Press, Cambridge, 1990.
Faraday, Michael, Experimental Researches in Electricity Volumes 1&2 and Volume 3, Dover Publications Inc, New York, 1965.
Frankel, Eugene, J. B. Biot and the Mathematization of Experimental Physics in Napoleonic France, Historical Studies in the Physical Sciences, 8, (1977), pp. 33-72.
Hofman, James R., André-Marie Ampère, Blackwell Publishers, Oxford, 1995.
Jelved, Karen, Jackson, Andrew D. and Knudsen, Ole, (translators and editors), Selected Scientific Works of Hans Christian Ørsted, Princeton University Press, Princeton, 1998.
Maxwell, James Clerk, A Dynamical Theory of the Electromagnetic Field, ed. Thomas F. Torrance, Scottish Academic Press, Edinburgh, 1982.
Stauffer, Robert C., Speculation and Experiment in the background of Ørsted’s Discovery of Electromagnetism, Isis, 48(1), (1957), pp. 33-50.
Williams, L. Pierce, Michael Faraday, Chapman and Hall, London, 1965.
This essay was first presented in November 2014, by the author, as an assessment task for HPSC10001 “From Plato to Einstein” as partial requirements for the award of a Post Graduate Diploma Arts (History and Philosophy of Science) at the University of Melbourne.
What a time to ‘have to’ go and buy milk. Mid-morning Monday, July 21 1969, and my mother sends me up the street to get some milk. No big deal, you might say. However, a few hours prior to then, at 6:17 AEST that morning to be precise, a fragile craft, called the Eagle, had landed on the Moon – our Moon. Piloting it were two even more fragile beings, Neil Armstrong and Buzz Aldrin, and sometime that morning they would leave the Eagle and become the first people to ever walk on the Moon. The first people to ever walk on an other world – stop and think about that – what a stupendous human achievement – meanwhile I was running up the street to get the milk. Isn’t it interesting what we sometimes think of as important?
On that Monday I was home, special permission from the school because we had a television and my parents would be home, like so many others, to watch this historic event. All around Australia similar events were unfolding, those who could were at their homes watching, those who couldn’t were gathered together at schools to watch the event live. I can’t remember what others thought of the event at the time. I was enthralled, as were my close friends – despite living in suburban Australia, the space race was part of our intellectual growing-up.
By the completion of the first three (unmanned) Apollo missions on April 4, 1968 I was well engaged with the race to the moon. Interest in the American space program was a huge boost for my interest in science. This is despite the non-scientific nature of the Apollo program. Many scientists in the US decried the Apollo program as a waste of money. Instead there was a very vocal and influential support for unmanned, or robotic exploration, which could return greater scientific returns for less cost, and less risk. This debate culminated in the ‘forced’ inclusion of scientist-astronaut Harrison Schmitt on the final moon landing of the Apollo era. Of course this was a distinction that, as a primary school child, I was completely unaware.
As I, then safely returned from my milk expedition, watched, along with an estimated one-fifth of the world’s population, the moon-walk at 12:39 AEST, and heard those now famous words of Neil Armstrong’s it is safe to assume that I, amongst many others, was hooked by this spectacle. I was for ever changed in a very positive way. Cynics may deride what we gained from the moon race, or even the $25.4billion expenditure by the US to put 12 men on the Moon, and get them back safely. Some may even playfully question whether the the ‘eternal mystique of the moon could survive the onslaught of cold hard science.’ I still think that this was the greatest technological achievement in human history – one that will take some beating. In addition the view of the Earth from space, most famously photographed as ‘Earthrise’ by Bill Anders on board Apollo 8 on December 24, 1968 forever changed how we ‘see’ the Earth. This one image created an environmental awareness of the fragile Earth that has blossomed with time.
I will admit to feeling sorry for younger generations, living in a post Apollo world, without ever feeling the awe that this event.
Fifteen years on from the Apollo 11 landing I emerged from the subterranean bunker of the accelerator at Lucas Heights, home of the Australian Nuclear Science and Technology Organisation. It was dark, the stars were out, and Rob Elliman and I chatted as we clambered into a bright yellow jeep, a superannuated relic from Maralinga days, on our way to a dinner break before continuing a 48 weekend stint on the accelerator. “I wanted to be an astronaut,” I commented as I glanced up at the moon, “Yes, me too” says Rob, “Irony is probably so did most of our generation of physicists – and where did we end up?” “In a bunker pinging ions off semiconductor crystals,” I answer, “mmm,” completes Rob, as we roar off in the jeep. Impact is such a difficult concept to tie down.
Astrophysicists Robert Nemiroff and Teresa Wilson have undertaken what they consider to be the most sensitive and comprehensive search yet for time travelers from the future. The negative results they reported indicate that time travelers from the future may not amongst us.
Time travel has captured the public imagination for much of the past century. Modern fictional stories involving time travel to both the past and the future are not uncommon. Prominent examples are H G Well’s The Time Machine (1895), the Doctor Who television series (BBC, 1963 – present), Time Enough for Love (Robert Heinlein, 1974), The Flight of the Horse (Larry Niven, 1974) and the Back to the Future film trilogy (Steven Speilberg, 1985, 1989, 1990). These various stories present time travel as a technological problem to be solved – in the main ignoring, or skating over, the scientific and philosophic conundrums inherent in the concept of time travel.
Time travel at first seems reasonably plausible. Einstein’s theory of general relativity holds that we live in a 4-D world with time being just another dimension – like the other 3 familiar spatial ones. Then surely traveling in time is just technical matter – just like the other 3 dimensions?
Time travel to the future has a firm scientific footing – albeit an impractical one from the perspective of personally zipping to the future to check out how it will be. For example Special Relativity has clear sub-luminal solutions that correspond to time travel to the future. A famous example of this is Paul Langevin’s 1911 Twin Paradox. This was exploited fictionally by Robert Heinlein in his 1956 novel Time for the Stars, involving identical twins, one of whom makes a journey into space in a high-speed rocket aging far slower than the twin who remained on Earth. This twin paradox has been experimentally verified, for example, using precise measurements of atomic clocks flown on aircraft and satellites.
The science of time travel into the past however is far more controversial. The philosophy of time travel, when studied at anything greater than superficial level, is guaranteed to do your head in . This simple idea enthralls first-year undergraduate philosophy students as they grapple with time travel, freedom and deliberation. I will leave that comment for another time and instead will be challenging and suggest you read Ray Bradbury’s 1953 short story A Sound of Thunder, and answer, “How did they lay the path?”, then read Robert Heinlein’s 1959 short story By His Bootstraps, and answer “How did he start this causal loop?”, and finally be enthralled by Gregory Benford’s 1980 novel Timescape, which challenges the whole idea of determinism and time travel – brilliant reading.
Little, however, has been attempted to actually search for time travelers or evidence of them. I for one have always wondered why contemporary commentators of iconic historical events don’t include incredulous reports of unexpectedly large numbers of spectators or even participants. The Texas School Book Depository in Dallas, Texas, on November 22, 1963 would surely have been over run with time traveling tourists. As for the hill of Golgotha on April 7, 30AD – the crowds would be unimaginable.
However Michigan Technological University astrophysicist, Robert Nemiroff and physics graduate student, Teresa Wilson, have made a “fun-but-serious effort” to find travelers from the future by searching through internet records. They didn’t search for evidence of time travelers from the past; they couldn’t think of a test that would distinguish such a person, if they existed, from someone who has a knowledge of the past, which is most people. The authors also said that “to the best of our knowledge, human technology to create a time machine does not exist in the past, so that time travelers from the past must originate in the future, assuming such technology is ever developed.”
A time-traveler from the future might have left once-prescient content on the internet that persists today, or such information might have been placed there by a third party discussing something unusual they had heard. So they picked two events of unique significance that would remain well known into the future. The two events were the discovery of Comet ISON and the choosing of the papal name of the newly pope of the Catholic Church, Jorge Mario Bergoglio.
Comet ISON was discovered by the International Scientific Optical Network (ISON) on September 21, 2012. Therefore it came into public usage on this date. Furthermore histories of bright comets like ISON are generally well kept by astronomical societies and journals around the world, therefore it would be expected to remain memorable well into the future. Any discussions or even mentions of “Comet ISON” before September 21, 2012 could be prescient evidence of time travelers from the future.
Similarly on March 16, 2013 the term “Pope Francis” came into the public awareness when Bergoglio became the first pope to choose the name “Francis”. As papal histories are well-recorded by all manner of persons and organisations, for all manner of reasons, it again would seem reasonable that the term “Pope Francis” would remain ‘memorable’ well into the future. Again discussions or mentions before March 16, 2013 of Pope Francis might indicate the presence of time travelers from the future.
The researchers searched using Google, Google+, Facebook and Twitter to search for the terms “Comet ISON” #cometison, “Pope Francis” and #popefrancis. The terms were only found to exist post the dates that they entered the public awareness. The researchers also used Google Trends to ascertain whether any searches were made for these terms prior the events – this also proved negative. This allows the conclusion that if there were time travelers from the future they did not passively leave evidence on the internet.
What about an active response? here the researchers were not interested in conversing with time travelers, rather allowing them to indicate that time travel has become possible in the future. They did this by creating a post on a publicly available online bulletin board in September 2013, asking for one of two hashtag responses on or before August 2013. A message containing the term #ICannotChangethePast2 would indicate that time travel to the past is possible but that the time traveler believes that they do not have the ability to alter their past. Conversely a message containing the term #ICanChangethePast2 would indicate that the time traveler could change the past. Nemiroff and Wilson in their paper wisely steer away from the philosophical importance of these two stances and instead just look for the experimental results. At the time of writing no prescient tweets or emails were received.
The authors conclude:
Although the negative results they reported may indicate that time travelers are not amongst us and cannot communicate over the internet, they are not proof. It may be physically impossible for time travelers to leave any lasting remnants of their stay in the past, including even non-corporeal information remnants on the internet, or it may be physically impossible for us to find such information as that would violate some yet-unknown law of physics.
This could explain why there are no reports of huge crowds of time travelers at such historical events as the crucifixion of Christ or the assassination of President Robert Kennedy. Furthermore: “Time travelers may not want to be found, or may be good at covering their tracks.” Finally “our searches were not comprehensive, so that even if time travelers left the exact event tags […] we might have missed them due to human error.”
This is certainly a sensitive and comprehensive experiment and I think encouraging to others to develop and extend this to look for time travelers from the future.
An enduring image of an ‘astronaut’ was created for the public by NASA, Time magazine, and Tom Woolf’s The Right Stuff. These caricatures of the original seven American astronauts, the so-called Mercury-7, chosen to assert American supremacy over the communist threat of Sputnik have seemingly endured way past their use by date. A resurgence in interest in ‘astronauts’ was made almost single-handedly in the English speaking world by the Canadian Colonel Chris Hadfield. His much publicised exploits, through the media of YouTube, as commander of expedition 35 aboard the International Space Station made obvious a change from May 5, 1961 when Alan Shepherd rode Freedom 7 into the history books.
In his autobiographical An Astronaut’s Guide to Life on Earth, the now retired Hadfield provides one of the most readable and honest stories of his journey from being a glider in the Royal Canadian Air Cadets in 1975 to commanding the international space Station in 2013 – after ‘only’ 21 years of astronaut training. He candidly describes the effort and training to get to being a modern astronauts – studying, practicing, learning, waiting, preparing for the worst – then being flexible enough to deal with the unexpected. What I liked is his can do approach as explained in his response to the 1969 Apollo 11moon landing and wanting to become an astronaut:
I also knew, as did every other kid in Canada, that it was impossible. Astronauts were American. NASA only accepted applications from U.S citizens, and Canada didn’t even have a space agency.
I was old enough to understand that getting ready wasn’t simply a matter of playing “space mission” with my brothers in our bunk beds, underneath a big National geographic poster of the Moon. But there was no program I could enroll in, no manual i could read, no one to ask. There was only one option, I decided. I had to imagine what an astronaut might do if he were 9 years old, then do exactly the same thing.
His laconic, sometimes counter-intuitive advise is always presented with a wealth of evidence to support his lesson. His Frank assessment of the impact of his dream on the rest of his family make a good reminder for all the corporate males who neglect family events for yet another sales meeting.
Hadfield’s book is a great read and compares favorably with two of my other notable astronaut autobiographies.
At the age of five I was devastated when my mum said to me that I could not become an astronaut. She dashed my probably overly enthusiastic boyish exuberance regarding space exploration explaining that I would need to be both American and a military pilot. Despite this early reality check, and taking a different path to Hadfield, I followed the Apollo program with enthusiasm – racing home from primary school to watch the historic moon-walk of Armstrong and Aldrin.
Of those Apollo 11 voyagers only Michael Collins put pen to paper to capture his journeys as an astronaut in the vivid and captivating Carrying the Fire. Collins displays a fine writing style and wry sense of humor. He wrote from an earlier time than Hadfield. Collins was part of the “Apollo fourteen“, the third group of astronauts, after being unsuccessful for selection in the second group, the “New Nine”.
Collins adroitly describes his emergence as an astronaut, training for and flying on Gemini 10 with John Young and participating in the US’s third “space walk”. Collins was originally picked as part of the Apollo 8 crew. He was replaced by Jim Lovell when a bone spur was discovered on his spine, requiring surgery. He relates his feelings at losing this opportunity, Apollo 8 became the bold second manned Apollo flight all the way to circle the Moon, and then gaining his place in history as the Command Module Pilot of Apollo 11.
Other books from this era that deserve a mention are Deke Slayton’s Deke and John Glenn’s A Memoir. Both of these were of the Mercury 7. Glenn’s memoir is so straight that it strains the reader’s credulity. Extraordinarily enough it is all John Glenn – astronaut, married family man, US Senator – it is definitely one of an uncomplicated patriotic kind. Slayton was different, grounded with a heart irregularity and instead of flying became the first Chief of the Astronaut Corps and selected the crews who flew Gemini, Apollo and Skylab missions. His book, written as he was dying from cancer, covers the full space race period up to his retirement post the start of the Space Shuttle era.
Other books of note are books by Eugene Cernan The Last Man on the Moon, and John Young’s Forever Young.
My third must read astronaut autobiography though is Mike Mullane’s Riding Rockets.
This in my mind is a minor classic, again so different to both Collins and Hadfield. Mullane was part of the Space Shuttle generation of astronauts, the 1978 class of TFNGs (the Thirty Five New Guys), a group that included the first female NASA astronauts. This book contains an emotional level and cadence not pictured in other first hand astronaut memoirs.
Mullane, a self-confessed inhabitant from planet ‘arrested development’ shares his growing pains in recognising that women could be colleagues and brilliant astronauts at that. His brutally honest depiction of losing his friend Judy Resnik in the Challenger disaster due to NASA hubris. Mullane describes in vivid detail the subsequent appalling bureaucratic treatment of the family members who were present at the disastrous launch. His own experience prior to this when STS-27 suffered near catastrophic heat shield damage from launch damage makes this description all the more poignant.
The whole fateful uncertainty of the Space Shuttle era, the “glory and the folly” of this remarkable era in human exploration of near space is wittily and cuttingly told. If you aren’t both amazed and angered in reading this memoir than I suggest you go back and read it again.
Chris Hadfield | An Astronaut’s Guide to Life on Earth | Little Brown & Company | 2013 | ISBN 978-0-316-25301-7 | 295 pp | hardback
Michael Collins | Carrying the Fire | 1974 | 40th Anniversary edition 2009 | Farrar Straus and Giroux | ISBN 978-0-374-53194-2 | 478 pp | paperback
Mike Mullane | Riding Rockets | Scribner | 2006 | ISBN 978-0-7432-7683-2 | 382 pp | paperback
This review was first published on DragonLaughing here.
Forty years ago we last stepped foot on the Moon. Currently, with our occupation of the low-Earth orbit international space station, we are space residents. In the visionary Mission to Mars (National Geographic Society, 2013), moon-walker, space advocate, Gemini 12 and Apollo 11 astronaut, Buzz Aldrin, challenges us to take a further step and colonise Mars. Aldrin advocates bypassing the Moon and instead make progressive steps to mars via comets, asteroids and Mar’s moon Phobos. From Phobos astronauts using remote controlled robots will prepare the Mars landing site and habitats. Aldrin states that regular space travel to Mars would be too expensive with Apollo-style modular expendable components, instead favoring a gravity-powered spaceship cycling permanently between the Earth and Mars. Although strongly advocating for a US led enterprise Aldrin, thankfully, sees cooperation, rather than competition with China, Europe, Russia, India and Japan as being the way forward.
Currently we have the Dutch company Mars One are recruiting people to be part of a permanent human settlement on Mars by 2023; the US commercial firm SpaceX have their Red Dragon proposal to put a sample-return mission to Mars by 2018 (seen as a necessary precursor by NASA to a human exploration); the Chinese have a long term plan for non-crewed flights to Mars by 2033 and crewed phase of missions to Mars during 2040-2060. Although the funding mechanisms and motivations are different these plans all make use of one idea or more from book The Case for Mars (Free Press, 1996, 2011). Written by aerospace engineer and founder of the Mars Society, Robert Zubrin, it is a meticulous and plausible way to settle Mars. Aldrin’s book is more broad and his ideas fit well with current technologies, US aspirations for asteroid capture and exploitation, and NASA’s focus on the planet Mars.
The veteran Mars Exploration Rover, Opportunity, is still surprising us with its discoveries, more than nine years after the completion of its 90 day primary mission. While the sprightly youngster Curiosity is regularly rewriting and deepening our understanding of Mars – still only half-way through its three year primary mission.
Appreciating what it takes to get a scientific laboratory wheeling its way across Mars is enticingly portrayed in another new book Red Rover (Basic Books, 2013). This first-hand account is written by Roger Wiens, lead scientist for ChemCam – the laser zapping remote chemical analytical instrument onboard the rover Curiosity. It covers his involvement in robotic space exploration from his initiation in 1990 on the NASA Genesis probe to the joyous moment when Curiosity zapped its first rock in early 2013. If this piques your curiosity then the earlier Roving Mars: Spirit, Opportunity, and the exploration of the Red planet (Scribe, 2005) is well worth tracking down. A passionate insight into the 2004 twin rover Spirit and Opportunity mission by Steve Squyres, the mission’s scientific principal investigator.
These robotic missions are prudent preparatory steps to Aldrin provides and engaging overview of the technical, economic and political reasons for humanity to journey to Mars. It has been a self-professed vision of his since his return from the Moon. This books, though, represents Aldrin’s first attempt to put the whole of the puzzle, his Unified Space Vision, together in one place. For a more technical read on the settlement and exploration of Mars then Zubrin’s revised and updated The Case for Mars (Free press, 2011) and Marswalk One: first steps on a new planet (Praxis, 2005) by astronautical historian, writer and designers David Shayler, Andrew Salmon and Michael Shayler are also recommended. Mission to Mars though is a clarion call, essential reading for anyone interested in humanity’s next big step.
Curiosity; seen as a hazard to society in the classical world, early Christianity condemned it as a sin, and now, in the modern world, it is seen as an essential part of human nature. Somewhere between the late 1500s and 1700s attitudes in Europe changed. The change, according to Phillip Ball in Curiosity, was gradual and far from obvious. In this fascinating book Ball describes how curiosity was transformed over this period from a sense of ‘wonder’ through natural philosophy to the professional curiosity of modern day science.
The emphasis in Curiosity is not on some progress of science, gradual or otherwise, triumphing over the medieval church. Rather Ball presents a nuanced and almost chaotic extended period of change. The change is one from the ‘scholastic’ belief that truth was a “question of authority and status: a fact was verified if it could be found in an authoritative text, but otherwise it was mere hearsay” to experimental philosophers who imagined methods for turning facts into laws. These facts were either from observation of nature or via the startling new practice of ‘experiment’.
So we arrive at the modern world not by a straight line. Rather it is reached by a plethora of men (invariably) who held what from a modern perspective are competing and confounding ideas at the one time. The strength of Ball’s book lies in his ability to turn his research into astute and captivating observations of these people and what they perceived as they unwrapped nature. At the same time chronicling the how the invention and use of novel instruments, the telescope, microscope and the air-pump, rocked the beliefs about the world and what were the acceptable limits to curiosity.
Curiosity is a fascinating insight into what frames the questions that scientists ask, it is essential reading for anyone interested in understanding how science shapes, and is shaped, by society.
Philip Ball, Curiosity: how science became interested in everything | 2013 | Vintage| 465 pages | ISBN 9780099554271
Stephen Hawking: My brief history
Stephen Hawking’s memoir is a brief amble through his life from early childhood to date. Hawking’s memoir does cut through some of the hype that could surround someone who is “possibly the best-known scientist in the world.” At the same time he presents many of his remembrances with a quaint gentle sort of humor, that at the same time reminds you that this is no ordinary human. Two of my favorites are:
I was born on January 8, 1942, exactly three hundred years after the death of Galileo. I estimate, however that about two hundred thousand other babies were also born that day. I don’t know whether any of them was later interested in astronomy.
The first scientific description of time was given in 1689 by Sir Isaac Newton, who held the Lucasian chair at Cambridge that I used to occupy (though it wasn’t electrically operated in his time).
The memoir for me reflected almost two personalities. The first an almost languid bored life; that becomes more focused at the age of twenty-one when Hawking is told that he has motor-nurone disease and may only live a few more years.
Even as a child Hawking does not seem to demonstrate (at least not in the memoir) the genius that we now associate his name with. As an undergraduate at Oxford he claims to have worked about a thousand hours in the three years, an average of an hour a day. Affecting the air of complete boredom of the time and ascribing to the prevailing attitude at Oxford that was very anti-work.
You were supposed to be either brilliant without effort or accept your limitations and get a fourth-class degree.
The thought of an early death, a cloud hanging over his future were changed moving to graduate studies at Cambridge and there meeting and getting engaged to Jane Wilde. From this point on the memoir gather intellectual pace. Hawking takes us through being awarded a research Fellowship at Caius College, finishing his PhD, getting married, and his early work on gravity waves, the big bang and black holes.
The latter half of the book can seem cursory, focusing on Hawking’s work at Caltech and then back at Cambridge. During this period he had two more children and then eventually split with his first wife Jane, and marrying Elaine Mason his nurse. These personal stories were adequately covered – requiring none of the histrionic embellishments as you might find in a ‘celebrity’ autobiography. Hawking’s work stands as a singularly intellectual triumph.
This book is also fortunately light on obsessive detail that sometimes clouds the historical biography. Instead we have an enjoyable insightful memoir, accessible to all, of one of the most brilliant minds in modern times. I recommend it to all science buffs and those interested in those who have made a personal difference on a cosmological difference in our time.
Stephen Hawking, My Brief History: a memoir, (2013) Bantam Press, Sydney, ISBN 9780593072523.
Just on 30 years ago I came across an intriguing book, the then relatively unknown Gaia: A new look at life on Earth (OUP 1979) by an ‘independent scientist’, J.E. Lovelock. My earliest impression of it may seem surprising to many people now. I was infuriated. I was infuriated not by Lovelock’s hypothesis per se, but by what I impugned was his underlying purpose behind proposing this model.
Gaia was presented by Lovelock as a fifteen year quest to substantiate the model:
“in which the Earth’s living matter, air, oceans, and land surfaces form a complex which can be seen as a single organism and which has the capacity to keep our planet a fit place for life.”
That was an intriguing hypothesis. The infuriating part I found was the implication that thanks to Gaia our fears of pollution-extermination may be unfounded. In particular I found the logic of chapter 7 (Gaia and Man: the problem of pollution) to be pernicious. On the untested assumption that Gaia did exist, and in the form suggested by Lovelock, he proposed the idea “there is indeed ample evidence that pollution is as natural to Gaia as is breathing to ourselves and most other animals.” The philosopher in me took umbrage at his glib jibes at the various current environmental perspectives – chiding them for their naive perspectives.
It took at least another careful read of Gaia before I appreciated Lovelock’s perspective, which his follow-on books left the reader in no doubt. Gaia: a new look at life on Earth was followed by The Ages of Gaia in 1988 (both books were revised for 2nd editions in 1995), Lovelock’s autobiography Homage to Gaia: the life of an independent scientist (OUP, 2000) was followed by the more strident The Revenge of Gaia (Allen Lane, 2006) and The Vanishing Face of Gaia: a final warning (Allen Lane, 2009). There was still the unanswered question – does Gaia exist?
The reaction to the question of Gaia’s existence is one of the the great legacies of Lovelock’s book. Lovelock’s eloquence and novelty of hypothesis inspired many responses and continues to provoke fierce debate. It has taken some time for a concise critical scientific analysis, in a form accessible to the interested educated reader, of the major assertions and arguments underpinning the Gaia hypothesis to be written. Toby Tyrrell, Professor of Earth Systems Science at the University of Southampton has managed to deliver this.
In On Gaia: a critical investigation of the relationship between life and Earth (Princeton University press, 2013), Tyrell asks and answers the question: “Does the Gaia hypothesis hold up in court?”
Tyrrell gets down to business in a succinct manner. He distills the Gaia hypothesis to three main facts, or classes of facts that Lovelock has advanced in support of the hypothesis. They are:
- The environment is very well suited to the organisms that inhabit it
- The Earth’s atmosphere is a biological construct whose composition is far from expectations of (abiotic) chemical equilibrium, and
- The earth has been a stable environment over time, despite external forcings.
Tyrell reminds us that the Gaia hypothesis is not the only one that looks at the relationship between life and environment on Earth. So in his book he takes these three facts and examines the evidence for them in the light of two other competing hypotheses; the Geological and the Coevolutionary.
The Geological hypothesis was the dominant paradigm among geologists and other scientists at the time Gaia was written. According to this way of thinking life has been a passenger on Earth, helplessly buffeted around by a mixture of geological forces and astronomical processes. Life adapts to this environment but does not itself affect it.
The Coevolutionary hypothesis assumes that there is two way traffic: not only does the nature of the environment shape the nature of life, life also acts as a force that shapes the planetary environment. There is one obvious, although too easily missed, difference between the coevolution of life and climate and of two life forms; such as the interactions between predators and prey and between hosts and parasites for example. There is no equivalent cumulative evolutionary process that builds better-adapted oceans or atmospheres over time. This means that this hypothesis makes no claims about the wider outcomes of the interaction. The Gaia hypothesis suggest that the outcome of the interaction has stabilized the planet and kept it favorable for life; Coevolution is neutral about such claims.
Having carefully framed the questions, and presented some viable alternatives, Tyrell then very eloquently and elegantly (in that scientific sense) looks at the evidence for which hopythesis fits the facts best.
In doing this he takes us on quite an adventure. We look at extremophiles and life over the glacial and interglacial eons, because as Lovelock states “the most important property of Gaia is the tendency to optimize conditions for all terrestrial life”. In other chapters by examining, over time, deep sea plankton nitrogen and phosphorus ratios, and atmospheric oxygen and methane levels Tyrrell convincingly demonstrates that the earth’s atmosphere is a biological construct. Having established that life has the power to shape the Earth he then examines what are the environmental alterations are produced.
By carefully examining two evolutionary innovations that have most obviously shaken the world: (i) the evolution of oxygen-yielding photosynthesis, and (ii) the colonization of land by the first forests, we find that life has always changed to exploit and closely fit it, as it must because of evolution. Finally by examining the rocks, glaciation levels, seawater chemistry and the ups and downs of greenhouse gases for the past 500 million years Tyrell concludes that Gaia has not helped to keep the Earths environment stable – because the research shows that the environment has not been stable.
The final chapter is a masterful example of clear thinking. Tyrrell revisits the road travelled, weaves the strands together and draws his conclusion that Gaia is a fascinating but flawed hypothesis. Tyrrell does not stop there he proposes new “intriguing research topics” that have arisen as a consequence of evaluating the Gaia hypothesis. As well he reminds us why this evaluation is important: planetary management requires solid understanding, Gaia imbues undue optimism, and the need for an unbiased worldview.
On Gaia: a critical investigation of the relationship between life and Earth (Princeton University Press, 2013), is a great contribution to an important scientific, and human debate. Toby Tyrrell demonstrates both a fine grasp of science, and science communication. An intelligent reader will find this book rewarding, for both these reasons.
On Gaia: A Critical Investigation of the Relationship between Life and Earth
Cloth | 2013 | US$35.00 / £24.95 | ISBN: 9780691121581, 320 pp. | 6 x 9 | 16 halftones. 31 line illus. 12 tables.
The human brain has 100 billion neurons, connected to each other in networks that allow us to interpret the world around us, plan for the future, and control our actions and movements. Mapping those networks, creating a wiring diagram of the brain could help scientists learn how we each become our unique selves. Understanding the brain and all its connections is Connectomics – a word soon to become as familiar as ‘genetics’.
In three papers appearing in Nature, scientists report their first step toward this goal: Firstly using a combination of human and artificial intelligence, they have mapped all the wiring among 950 neurons within a tiny patch of the mouse retina. While a second group look at a classic problem of neural computation – the detection of visual motion – in the eye of a fruitfly.
The eye of the mouse
The retina is technically part of the brain, as it is composed of neurons that process visual information. Neurons come in many types, and the retina is estimated to contain 50 to 100 types, but they’ve never been exhaustively characterised. Their connections are even less well known. Neurons in the retina are classified into five classes: photoreceptors, horizontal cells, bipolar cells, amacrine cells and ganglion cells. Within each class are many types, classified by shape and by the connections they make with other neurons.
In this study, the research team focused on a section of the retina known as the inner plexiform layer, which is one of several layers sandwiched between the photoreceptors, which receive visual input, and the ganglion cells, which relay visual information to the brain via the optic nerve. The neurons of the inner plexiform layer help to process visual information as it passes from the surface of the eye to the optic nerve.
By mapping all of the neurons in a 117-micrometre-by-80-micrometre patch of tissue, researchers were able to classify most of the neurons they found, based on their patterns of wiring. They also identified a new type of retinal cell that had not been seen before. To map all of the connections in this small patch of retina, the researchers first took electron micrographs of the targeted section generating high-resolution three-dimensional images of biological samples.
Developing a wiring diagram from these images required both human and artificial intelligence. First, the researchers hired about 225 German undergraduates to trace the “skeleton” of each neuron, which took more than 20,000 hours of work (a little more than two years).
To flesh out the bodies of the neurons, the researchers fed these traced skeletons into a computer algorithm, which expands the skeletons into full neuron shapes. The researchers used machine learning to train the algorithm, known as a convolutional network, to detect the boundaries between neurons. Using those as reference points, the algorithm can fill in the entire body of each neuron.
The only previous complete wiring diagram, which mapped all of the connections between the 302 neurons found in the worm Caenorhabditis elegans, was reported in 1986 and required more than a dozen years of tedious labor.
Wiring diagrams allow scientists to see where neurons connect with each other to form synapses – the junctions that allow neurons to relay messages. By analyzing how neurons are connected to each other, researchers can classify different types of neurons.
The researchers were able to identify most of the 950 neurons included in the new retinal-wiring diagram based on their connections with other neurons, as well as the shape of the neuron. A handful of neurons could not be classified because there was only one of their type, or because only a fragment of the neuron was included in the imaged sample. In this study, the researchers identified a new class of bipolar cells, which relay information from photoreceptors to ganglion cells. However, further study is needed to determine this cell type’s exact function.
It should be noted, and is by the researchers, that this analysis provides contact information, but not synaptic strength. The absence of a contact always indicates a lack of synaptic connection. If our goal is to ‘learn how we each become our unique selves’ then synaptic strength is an important measure – an indication of cognitive abilities related to memory and learning.
The project of classifying types is not completed, but this work shows that it should be possible, in principle, if it’s scaled up to a larger piece of tissue. To analyse an entire mouse brain in this way would require several billion hours of human attention, that is 225 students for 200,000 years – suggesting that such a task is incredibly ambitious. The researchers are convinced, as are many other neurobiologists, that mapping and decoding the connectome will revolutionize brain research.
Ever tried to swat a fruitfly?
A fruitfly is effective at dodging predators and rapidly navigating during flight, so it is a perfect insect model for visual motion detection. It is easy to make simple models of motion detection: photoreceptor cells cannot detect direction but downstream (towards the brain) neurons, called tangential cells, do respond to the direction of movement. Somewhere in between lies the neural mechanism that creates this discrimination.
The authors here developed a semi-automatic method constructing a connectome of 379 neurons and 8,637 chemical synaptic contacts then matched these reconstructed neurons to cells types using light microscopy. Using this model and supportive evidence using some very elegant optical microscopy, which forms the third paper in Nature, the researchers identified the cells that constitute a motion detection circuit.
What these studies demonstrate is the power of connectomes to uncover key insights into the detail of the brain’s processing circuitry. At present the scales seem ‘mind-boggling’, any serious work would seem to be the province of well-heeled laboratories. However, as pointed out in a Nature News & Views article, “the researchers have stressed that the connectomic reconstructions will be public resources” making these invaluable resources for neuroscience.
Connectomics – a word to be remembered.
First published in Australian Science.
Since Erwin Schrödinger’s famous 1935 cat thought experiment, physicists around the globe have tried to create large scale systems to test how the rules of quantum mechanics apply to everyday objects. Scientists have only managed to recreate quantum effects on much smaller scales, resulting in a nagging possibility that quantum mechanics, by itself, is not sufficient to describe reality.
Researchers Alex Lvovsky and Christoph Simon from the University of Calgary recently made a significant step forward in this direction by creating a large system that displays quantum behaviour, publishing their results in Nature Physics.
Understanding Schrödinger’s cat
Quantum mechanics is without doubt one of the most successful physics theories to date. Without it the world we live in would be remarkably different: driving and shaping our modern world making possible everything from computers, mobile phones, nuclear weapons, solar cells and our everyday appliances. At the same time it presents us with conundrums that are at the far end of reason; challenging even the greatest minds to comprehend.
In contrast to our everyday experience, quantum physics allows for particles to be in two states at the same time — so-called quantum superpositions. A radioactive nucleus, for example, can simultaneously be in a decayed and non-decayed state.
Applying these quantum rules to large objects leads to paradoxical and even bizarre consequences. To emphasize this, Erwin Schrödinger, one of the founding fathers of quantum physics, proposed in 1935 a thought experiment involving a cat that could be killed by a mechanism triggered by the decay of a single atomic nucleus. If the nucleus is in a superposition of decayed and non-decayed states, and if quantum physics applies to large objects, the belief is that the cat will be simultaneously dead and alive.
Schrödinger’s thought experiment involves a (macroscopic) cat whose quantum state becomes entangled with that of a (microscopic) decaying nucleus. While quantum systems with properties akin to ‘Schrödinger’s cat’ have been achieved at a micro level, the application of this principle to everyday macro objects has proved to be difficult to demonstrate. The experimental creation of such micro-macro entanglement is what these authors successfully achieved.
Photons help to illuminate the paradox
The breakthrough achieved by Calgary quantum physicists is that they were able to contrive a quantum state of light that consists of a hundred million photons and can even be seen by the naked eye. In their state, the “dead” and “alive” components of the “cat” correspond to quantum states that differ by tens of thousands of photons.
While the findings are promising, study co-author Simon admits that many questions remain unanswered.
“We are still very far from being able to do this with a real cat,” he says. “But this result suggests there is ample opportunity for progress in that direction.”
Seeing quantum effects requires extremely precise measurements. In order to see the quantum nature of this state, one has to be able to count the number of photons in it perfectly. This becomes more and more difficult as the total number of photons is increased. Distinguishing one photon from two photons is within reach of current technology, but distinguishing a million photons from a million plus one is not.
Decoherence: the emergence of the classical world from the quantum
Why don’t we see quantum effects in everyday life? The current explanation is that it is to do with decoherence.
Physicists see quantum systems as fragile. When a photon interacts with its environment, even just a tiny bit, the superposition is destroyed. This interaction, could be as a result of measurement or an observation, or just a random interaction. Superposition is a fundamental principle of quantum physics that says that systems can exist in all their possible states simultaneously. But when measured, only the result of one of the states is given.
This effect is known as decoherence and it has been studied intensively over the last few decades. The idea of decoherence as a thought experiment was raised by Erwin Schrödinger, in his famous cat paradox. Unfortunately for non-physicists decoherence only provides an explanation for the observance of wave function collapse, as the quantum nature of the system “leaks” into the environment. It does not tell us where the line, if such one does exist, between the quantum and everyday is.
Although Schrodinger’s thought experiment was originally intended to convey the absurdity of applying quantum mechanics to macroscopic objects, this experiment and related ones suggest that it may apply on all scales.
If you are interested in the history and foundation of quantum mechanics then I highly recommend Quantum: Einstein, Bohr and the great debate about the nature of reality, by Manjit Kumar (2009), and The Age of Entanglement: when quantum physics was reborn, by Louisa Gilder (2008). Both are well-researched and captivating brilliant accounts of science science and scientists.
This article first published here in Australian Science.
Imagine, Lake Vostok is covered by more than 3,700 metres of Antarctic ice. Devoid of sunlight, it lies far below sea level in a depression that formed 60 million years ago, when the continental plates shifted and cracked. Few nutrients are available. Yet scientist, led by Scott Rogers, a Bowling Green State University professor of biological sciences, have found a surprising variety of life forms living and reproducing in this extreme environment. A paper published June 26 in PLOS ONE details the thousands of species they identified through DNA and RNA sequencing.
What lies sealed beneath the glacial ice?
Antarctica, 35 million years ago, had a temperate climate and was inhabited by a diverse plants and animals. About 34 million years ago, a huge drop in temperature occurred and ice covered the lake, when it was probably still connected to the Southern Ocean. This lowered the sea level by about 100 metres, which could have cut off Lake Vostok from the ocean. The ice cover was intermittent until a second big plunge in temperature took place 14 million years ago, and sea level dropped even farther.
As the ice crept across the lake, it plunged the lake into total darkness and isolated it from the atmosphere, and led to increasing pressure in the lake from the weight of the glacier. While many species probably disappeared from the lake, as indicated by Rogers’ results, some seem to have survived.
Rogers and his colleagues examined core sections from the ice above Lake Vostok that were extracted in 1998. At the time, no one had reached the actual lake, a feat that was achieved only last year. But the drilling had gone deep enough to reach a layer of ice at the bottom of the sheet that formed as lake water froze onto the bottom of the glacier where it meets the lake. The team sampled cores from two areas of the lake, the southern main basin and near an embayment on the southwestern end of the lake. The embayment appears to contain much of the biological activity in the lake.
By sequencing the DNA and RNA from the ice samples, the team identified thousands of bacteria, including some that are commonly found in the digestive systems of fish, crustaceans and annelid worms, in addition to fungi and two species of archaea, or single-celled organisms that tend to live in extreme environments. Other species they identified are associated with habitats of lake or ocean sediments. Psychrophiles, or organisms that live in extreme cold, were found, along with heat-loving thermophiles, which suggests the presence of hydrothermal vents deep in the lake. Rogers said the presence of marine and freshwater species supports the hypothesis that the lake once was connected to the ocean, and that the freshwater was deposited in the lake by the overriding glacier.
These results, however, are not without controversy.
Other claims and other lakes
Long before he began using these techniques to study the ice, Rogers and his team had developed a method to ensure purity. Sections of core ice were immersed in a sodium hypochlorite (bleach) solution, then rinsed three times with sterile water, removing an outer layer. Under strict sterile conditions, the remaining core ice was then melted, filtered and refrozen.
Sergey Bulat has doubts about the results, despite the careful sample preparation. Bulat, a Lake Vostok expert at the Petersburg Nuclear Physics Institute in Gatchina, Russia, is quoted as saying, “that it is very probably that the samples are heavily contaminated with tissue and microbes from the outside world.”
Quirin Schiermeier has noted in Nature News:
Bulat and Rogers have both studied Vostok ice samples taken in the 1990s by a consortium of Russian, French and US Antarctic researchers. In the past, the pair pondered a close collaboration. But their scientific relationship broke over enduring disagreement about the level of contamination of samples.
In March, Bulat himself faced criticism over an unknown species of bacterium his team had discovered in a Lake Vostok ice core drilled last year. Sceptics said that this finding was due to contamination from drilling fluid.
The two researchers’ claims are probably the first in what will no doubt be an interesting period of discovery in Lake Vostok and other Antarctic lakes. The first samples of water from Lake Vostok itself, collected in early 2013 are currently being analysed. The Russian team has said that it hopes to have results within the next year. Bacteria, of known species, have been recovered from the smaller Antarctic Lakes, Whillans and Vida. Lake Vida has been sealed off for around 2,800 years. Ice cores drilled in 2005 and 2010 have recently revealed life, but at about one-tenth of the abundance usually found in freshwater lakes in moderate climate zones. Similarly in Lake Whillans the bacteria levels were roughly one-tenth the abundance of microbes in the oceans.
These results are glimpses into the the sub-glacial world of Antarctica. Glimpses that may change how we not only view this continent but also providing clues to how extra terrestrial life may exist on icy moons such as Jupiter’s Europa and Saturn’s Enceladus.
This article was first published here on Australian Science.
The dwarf planet, Pluto, can still generate public interest – if the naming of its two recently discovered moons is anything to go by. After their discovery, the leader of the research team, Mark Showalter, called for a public vote to suggest names for the two objects. The contest, aptly named ‘Pluto Rocks!‘, concluded with the Vulcan as the outright favorite, after a William Shatner led push by Star Trek fans. The proposed names Cerberus and Styx ranking second and third respectively. The International Astronomical Union (IAU) has announced that the names Kerberos and Styx have officially been recognised for these fourth and fifth moons of Pluto. A decision that is probably correct, even if it proves not to be the most popular.
The moons of Pluto
The new moons were discovered in 2011 and 2012, during observations of the Pluto system made with the NASA/ESA Hubble Space Telescope. Their discovery increasing the number of known Pluto moons to five. Kerberos lies between the orbits of Nix and Hydra, two bigger moons discovered by Hubble in 2005, and Styx lies between Charon, the innermost and biggest moon, and Nix. Both have circular orbits assumed to be in the plane of the other satellites in the system. Kerberos has an estimated diameter of 13 to 34 kilometres, and Styx is thought to be irregular in shape and is 10 to 25 kilometres across.
The recent discoveries of the two small moons orbiting Pluto raise interesting new questions about how the dwarf planet formed. We now know that a total of four outer moons circle around a central “double-planet” comprising Pluto and its large, nearby moon Charon.
No home for Spock
The International Astronomical Union (IAU) is the arbiter of the naming process of celestial bodies, and is advised and supported by astronomers active in different fields. On discovery, astronomical objects receive unambiguous and official catalogue designations. When common names are assigned, the IAU rules ensure that the names work across different languages and cultures in order to support collaborative worldwide research and avoid confusion.
To be consistent with the names of the other Pluto satellites, the names had to be picked from classical European mythology, in particular with reference to the underworld — the realm where the souls of the deceased go in the afterlife. Showalter submitted Vulcan and Cerberus to the IAU where the Working Group for Planetary System Nomenclature (WGPSN) and the Committee on Small Body Nomenclature (WGSBN) discussed the names for approval.
After a final deliberation, the IAU Working Group and Committee agreed to change Cerberus to Kerberos — the Greek spelling of the word, to avoid confusion with an asteroid called 1865 Cerberus. According to mythology, Cerberus was a many-headed dog that guarded the entrance to the underworld. In keeping with the underworld theme the third most popular name was chosen — Styx, the name of the goddess who ruled over the underworld river, also called the Styx.
The IAU decided against the name Vulcan for a number of reasons: Vulcan had already been used for a hypothetical planet between Mercury and the Sun (although this planet was found not to exist), the term “vulcanoid” remains attached to any asteroid existing inside the orbit of Mercury, and finally Vulcan does not fit into the underworld mythological scheme. The Romans identified Vulcan with the Greek smith-god Hephaestus, and he became associated like his Greek counterpart with the constructive use of fire in metalworking.
In a press release the IAU has stated that it:
wholeheartedly welcomes the public’s interest in recent discoveries, and continues to stress the importance of having a unified naming procedure following certain rules, such as involving the IAU as early as possible, and making the process open and free to all. Read more about the naming of astronomical objects here. The process of possibly giving public names to exoplanets (see iau1301), and more generally to yet-to-be discovered Solar System planets and to planetary satellites, is currently under review by the new IAU Executive Committee Task Group Public Naming of Planets and Planetary Satellites.
It all began with Galileo
Naming moons is not a new controversy. No sooner had telescopes been developed – improving on viewing the heavens by eye – and naming rights were contested. Galileo Galilei discovered the four largest moons of Jupiter sometime between 1609 and 1610. Galileo initially named his discovery the Cosmica Sidera (“Cosimo’s stars”) in the hope of gaining patronage from a former student of his the Grand Duke Cosimo II of Tuscany. He changed this to the “Medician Stars”, which would honor all four brothers in the Medici clan, in his 1610 book Sidereus Nuncius (The Starry Messenger). Their present names (lovers of the god Zeus (the Greek equivalent of Jupiter)) were suggested by Johannes Kepler, to Simon Marius, who had discovered the moons independently around the same time as Galileo. Marius published the names: Io, Europa, Ganymede and Callisto, in his Mundus Jovialis, in 1614 .
Despite the firm hand of the IAU, naming even in the present day is still an art as much as a science. Charon was discovered in 1978 when astronomer James Christy noticed images of Pluto were strangely elongated. The direction of elongation cycled back and forth over 6.39 days – Pluto’s rotation period. Searching through their archives of Pluto images taken years before, Christy found more cases where Pluto appeared elongated. Additional images confirmed he had discovered the first known moon of Pluto. Christy proposed the name Charon after the mythological ferryman who carried souls across the river Acheron, one of the five mythical rivers that surrounded Pluto’s underworld. Apart from the mythological connection for this name, Christy chose it because the first four letters also matched the name of his wife, Charlene.
New Horizons, Pluto and the Kuiper Belt
Pluto’s origin and identity has long puzzled astronomers. Orbiting at a distance of between 4.4–7.4 billion kilometres from the Sun it has proved difficult to investigate. Pluto’s true place in the Solar System began to reveal itself only in 1992, when astronomers began to find small icy objects beyond Neptune that were similar to Pluto not only in orbit but also in size and composition. Astronomers now believe Pluto to be the largest member of the Kuiper belt, a somewhat stable ring of objects located between 30 and 50 AU from the Sun. Though Pluto is the largest of the Kuiper belt objects discovered so far, Neptune’s moon Triton, which is slightly larger than Pluto, is similar to it both geologically and atmospherically, and is believed to be a captured Kuiper belt object
The excitement for Pluto and its moons will be heightened in 2015 when NASA’s New Horizons spacecraft makes a flyby and then continues on to study the Kuiper belt objects in 2016-2020. It has already been suggested by Showalter that some of the names from the Pluto Rocks list, as well as some from Star Trek, may well names of craters and mountains, revealed on Pluto by New Horizons – this story is far from over.
This story originally published on Australian Science.
Trouble in Mind (Jenni Ogden, Scribe, $32.95, ISBN 9781922070562, July 2013)
I do not think I would be alone in fearing ‘losing my mind’. Even the common expression, “are you out of your mind?” gives solid form to what may seem a merely philosophical train of thought. At any given time most people will declare confidently that “I am in my ‘right mind’ and point to themselves as that ‘I’. The quandary is the ‘I’ of age eight is different to the ‘I’ of forty-eight; despite the continuity of of ‘I’ joining these two for example. Our mind then is one of those puzzling concepts at once both familiar and ephemeral. To lose ones mind, though, even partially, through trauma, disease, or disorder we would all agree is to lose some quintessential part of us. Trouble In Mind is a collection of real stories about people who have suffered just that – losing part of their minds.
The stories are from patients that the neuropsychologist author, Jenni Ogden, has worked with over her career in New Zealand, the USA, and Australia. Ten of the 15 patients portrayed in this book featured in Ogden’s 2005 textbook Fractured Minds. Trouble in Mind is neither text, nor assessment, nor treatment book. There are other books on the market that describe patients with a variety of neurological conditions. Many written by clinicians such as Ogden. Most I find fall short because the clinician writer is excited by the condition and fails to connect the human to that condition. In other examples non-clinicians often focus complete cures, without any reference to the many that underwent similar treatments – without success.
Ogden’s stories succinctly and clearly explain the medical conditions and engagingly present the human side of each in an empathetic and nuanced style. Whether talking about patients with car-crash brain trauma, rugby-induced concussion or suffering from Parkinson’s disease Ogden covers the personal, social and family elements with clarity that is often missing in clinical based non-fiction written by clinicians. In this respect Ogden writes with feeling like that of psychologist Oliver Sacks at his best.
These are stories that will have a resonance with most in our society. Three in particular I will mention as way of illustration of the breadth covered. Michael was a 24-year old motorcycle maniac. After a horrific accident, he left the critical care unit with a virtually ignored head injury; the surgeons had grappled with keeping him alive and the extensive orthopedic surgeries and specialist care. neither he nor his doctors realised that he was cortically blind. This resolved itself after two years – leaving him with object agnosia – the inability to recognise what he was seeing. Ogden then describes he many years work with Michael, his trials, tribulations and treatments to living 24 years later is a life with a most interesting disability. Amongst this we also get Ogden’s motivation – her clinician’s ‘delight’ in being asked to work with such an unusual case. Yes her delight, her excitement; those real human emotions not hidden behind neutral, banal psychology speak.
In another chapter Ogden looks at the bizarre neuropsychological disorder of hemineglect – ignoring visual stimuli in the side of space opposite to the side of their brain that is damaged. In this case though the patient is a chirpy 50 year-old female, Janet. The chapter is fascinating and the description of janet’s sessions with Ogden are sometimes, well, hilarious. But this is real-life not Hollywood. Janet’s hemineglect is caused by a brain tumor. Janet dies, four long and difficult years following her diagnosis. Ogden doesn’t just end the chapter, she humanely discusses the impact on Janet’s husband and close family and friends of her treatment and death. She also assesses the effectiveness of the treatments, looking at other cases, from her own and others’ casebooks.
The final chapter is aptly called “The Long Goodbye: coming to terms with Alzheimer’s disease.” This chapter follows Sophie’s diagnosis and cognitive decline from Alzheimer’s disease. I learnt a lot about the disease from reading this chapter. I equally learnt how it would be to watch a person who “was once active, independent, intelligent, humorous and loving gradually lose her mind”.
This collection of stories is eminently readable. I recommend it to readers with either; a specific, perhaps personal, topic of interest or those more generally who are curious and interested in how our minds work, particularly when they go awry due to damage to that squishy grey organ inside our skull.
The colorful and polished launch of Shenzhou 10 confirms that China has come of age as a spacefaring nation. At 19:40 AEST on Tuesday June 11 (17:40 local time) three ‘yuhangyuan’, Chinese astronauts, embarked on China’s sixth crewed space mission. This second mission to Tiangong 1, the Chinese space station, is a credible step in mastering the art and engineering of space exploration. It was also a public relations success.
Shenzhou 10 crew
Announcing in early April, that Wang Yaping, a 35 year old Major in the PLA Air Force, was one of the 3-person Shenzhou 10 crew, silence then descended on the identity of the other crew members. Wang was named as the in-flight instructor. She becomes China’s second female and 9th astronaut to have flown.
Building the suspense the Chinese finally announcing the other two the names of the three person crew yesterday. Along with Wang the Shenzhou 10 crew are: Nie Haisheng (48) Commander of Shenzhou 10, a veteran of Shenzhou 6 in 2005, and a Major General in PLA Air Force, and Zhang Xiaoguang, 47 Assistant Pilot of Shenzhou 10, backup crew of Shenzhou 9 (along with Wang) and a Senior Colonel of PLA Air Force.
This places the Chinese astronaut corps as a modern, relatively, gender balanced operation. Zhang and Nie both hale from the 1996 second astronaut selection. As have all male yuhangyuan to date including Yang Liwei, China’s first astronaut. The first group of astronauts were selected in 1971 in a hopelessly ambitious and quickly abandoned attempt to put astronauts into space in the 1970s. Wang, along with Liu Yang, China’s first female yuhangyuan, comes from China’s 2010 third group of yuhangyuan. The Chinese, at least to the outside world, have not followed the more memorable and colourful NASA lead of allowing astronaut groups to pick their nick-names.
The heavenly palace
With the launch a success, Nie will now chase, rendezvous and dock with an orbital laboratory, Tiangong (a mandarin word meaning “heavenly palace”), which was launched nearly two years ago on September 29, 2011.On November 2, 2011 China successfully docked the unmanned Shenzhou 8 with Tiangong. It remained docked for 14 days and then undocked and repeated the docking maneuver – proof that the first was not a fluke. It then was undocked, leaving Tiangong to its solitary orbit 370km above the earth’s surface.
On June 18, 2012 a second craft docked with Tiangong. This time it was the crewed Shenzhou 9. The space station was then declared operational. China had joined Russia and the USA in having the capability to become space residents. The three person crew on Tiangong conducted experiments and aclimatised to the prolonged weightlessness for their 10 day mission.
The normal pattern was for two to sleep in Tiangong and one to sleep in Shenzhou. At only 10.4m in length, Shenzhou is smaller than the 1971 Russian Salyut (13.1m) and the 1973 US Skylab (36.1m) space laboratories. Like these other first space laboratories Tiangong is designed with a limited lifespan. The current mission, Shenzhou 10, will be the last to Tiangong 1.
As is the norm now the Shenzhou launch was covered live by the Chinese media. providing pictures, expert commentary and graphics depicting what was going on at the various stages of the launch. Shenzhou 10 is now safely in orbit and will spend the next few days approaching a suitable orbit for docking. The Shenzhou 10 will dock with the orbiting lab module Tiangong 1 several times.
“The three astronauts will stay in orbit for 15 days, including 12 days when they will work inside the coupled complex of the Shenzhou 10 and Tiangong 1,” said Zhou Jianping, head designer of China’s manned space program. It is expected that they will set a Chinese record for time in orbit.
The interesting point is that the mission profile for Shenzhou 10 is opaque. Although it is expected that the craft will be put through it’s docking paces – not something to be dismissed lightly – the scientific and engineering goals of this mission are less obvious that the recent Shenzhou missions.
As the in-flight instructor Wang will give lectures to middle and elementary school students from orbit. This could be seen as mimicry of recent astronauts on the International Space Station; the everyday science experiments of Don Pettit and most recently Chris Hadfield. These were experiments designed by US High School students and carried out in space by the astronauts. What Wang will demonstrate and whether it will be released to the West are at present questions – without answers.
This will be the last Chinese human space mission for quite some time. The next Shenzhou missions are expected to fly to the Tiangong 2 laboratory. This will be an expanded version of Tiangong 1, similar in design to the Russian 1986 Mir space station. It is expected to be able to sustain 20-day visits. It will probably not be launched until around 2015 or possibly later. The gap between the flight of Shenzhou 10 and Shenzhou 11 could ultimately prove to be the longest hiatus in Chinese human spaceflight to date.
How will the Chinese promote this current mission once it is completed? Its success, or otherwise, will not necessarily aid any military space activities, nor directly any Chinese commercial space activities. It does provide a compelling message, I suggest, to its regional competitors. Human exploration is possibly the most expensive and prestigious space activity. I think we will find China promoting this expedition to its fullest. It has large domestic appeal: pride in national achievement as well as motivating and driving high technology industry development. From the perspective of an “Asian Space race” China has an audacious program of robotic missions to the Moon over the next few years. Fully intending to continue its long march to put humans onto the Moon and Mars in the next few decades.
This was first published on Australian Science.
As the most visible man-made object in the night sky the International Space Station (ISS) is of significance to humankind. It takes humans from being explorers of space to being residents of space.
The Russians launched Zarya, the first module of the ISS, on November 20, 1998. It has grown considerably since then and has been continuously inhabited since November 2, 2000.
Science and the space station
Understanding the response of the human body to low and microgravity is critical for space exploration. Astronauts undergoing long periods of weightlessness – such as in flights to and from Mars – will need to understand the impact of this on their ability to carry out tasks, both routine and emergency.
The space station provides an ideal environment to study many aspects of humans in space, including: balance, digestion, muscle and bone retention and heart behaviour.
It also provides a unique window on the earth and sun – one in which scientists can use their understanding to respond to opportunities as they arise as well as conduct scheduled experiments and observations.
As a solar observatory, the space station is clear of Earth’s atmosphere, giving a unique perspective on terrestrial weather and atmospheric science.
The four laboratory sections house experiments selected on their scientific merit or educational and industrial interest. These include understanding how microgravity effects animal and plant growth, and understanding and developing novel industrial processes.
The AMS has been in operation and collecting data since June 27, 2011 and has an expected operational lifetime in excess of ten years.
A tour of the International Space Station
Its most visible features are the eight solar arrays. They generate 84 kilowatts of power and have a wingspan of 73 metres, wider than a Boeing 777. They, along with the array of habitable modules, are supported by a central truss.
This is the space station control and services centre, containing the Russian guidance and navigation computers.
It’s also the sleeping and hygiene quarters for two of the cosmonauts. In an emergency it can support all six of the crew.
Back through Zarya you’ll come to the US-built Unity node, a galley where it is possible for all the crew to gather and eat together.
With its six side windows and a top window the Cupola gives observers a Millenium Falcon-type view of Earth below.
You wind your way back to Unity then through the truss structure (that supports the solar arrays and the Canadarm2) to the Destiny Laboratory – the primary US research facility. Continuing on from here, you reach Harmony.
You note the Destiny and Harmony nodes are square, rather than round like the older modules. This gives four usable working “walls” – there is no up or down, so no floor or ceiling.
Besides velcroing objects to every available “wall” space, the next noticeable thing is the total absence of chairs.
Harmony is home to four crew. The sleeping berths radiate into each “wall”. Each is about the size of a phone booth and have a sleeping bag-type arrangement as well as computer and space for personal effects.
Sleeping on the ISS is a novel experience. The station orbits Earth every 90 minutes, which means there is a sunrise and sunset every hour and a half.
The Harmony node also houses sanitary (yes, that is your toothbrush and toothpaste velcroed to the wall) and exercise facilities. A treadmill, gym and seatless exercise bike are part of the necessary exercise regime to ensure muscle does not waste away in the microgravity environment of the space station.
And … that’s it! This is your world for the next six months, all 388 cubic metres of it – about half the interior space of a Jumbo jet.
The international space residents
The first expedition of William Shepherd (US), Yuri Gidzenko (Russia) and Sergei Krikalev (Russia) was launched on a Russian Soyuz on October 31, 2000 and returned on the space shuttle Discovery on March 21, 2001.
At the moment, the ISS is hosting a six-person expedition, #35. Current commander Chris Hadfield (Canada) and flight engineers Tom Marshburn (US) and Roman Romanenko (Russia) docked on December 21, 2012.
Chris Cassidy (US), Alexander Misurkin (Russia), and Pavel Vinogradov (Russia), also flight engineers, docked on March 28, this year, replacing then-commander Kevin Ford (US) and flight engineers Oleg Novitskiy (Russia) and Evgeny Tarelkin (Russia).
You can watch the ISS crew live when they’re on duty.
Expedition #35 is an all-male crew, but 31 women have flown to the space station – including Expedition 16 commander Peggy Whitson, the station’s first female commander. In all, there have been nationals from 15 countries, including seven tourists.
- a laboratory in space, for the conduct of science and applications and the development of new technologies
- a permanent observatory in high-inclination orbit, from which to observe Earth, the Solar System and the rest of the Universe
- a transportation node where payloads and vehicles are stationed, assembled, processed and deployed to their destination
- a servicing capability from which payloads and vehicles are maintained, repaired, replenished and refurbished
- an assembly capability from which large space structures and systems are assembled and verified
- a research and technology capability in space, where the unique space environment enhances commercial opportunities and encourages commercial investment in space
- a storage depot for consumables, payloads and spares
- a staging base for possible future missions, such as a permanent lunar base, a human mission to Mars, robotic planetary probes, a human mission to survey the asteroids, and a scientific and communications facility in geosynchronous orbit
In the 2010 US National Space Policy, the ISS was given additional roles of serving commercial, diplomatic and educational purposes.
The ISS has acted as an example and vehicle for international co-operation, but the US has vetoed China’s participation. China, as a result, is now pursuing its own space laboratory program.
The US Administration will fund the ISS until 2020. With continued interest from the international community, the space station should continue as a vehicle for fruitful science and demonstration of international co-operation for at least this decade.
The development of commercial spacecraft also provides a second string to the station’s future. SpaceX has demonstrated its capability to deliver cargo and possibly crew to supplement the ageing Russian Soyuz capability.
Only time will tell whether the US allows the addition of China and India, Asia’s space-capable nations, to the ISS fraternity.
Kevin Orrman-Rossiter does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.
Animal Wise: the thoughts and emotions of our fellow creatures, by Virginia Morell, Black Inc. Books, 2013.
Laughing rats, name-calling wild parrots, archer-fish with a sense of humour, and educated ants; the naturalist Charles Darwin would have loved this book. The philosopher Rene Descartes would equally have found it deeply troubling. Both with good reason.
In Descartes’ dualist philosophy the mind and body are two separate entities. There is the material body and the immaterial mind or soul. The latter linking humans to the mind of God, making us, in his philosophy, different to animals. Descartes famously reasoned animals are composed only of material substances and therefore have no capacity to reason. More importantly for how we see animals, Descartes wrote that a human person, such as you or I, is something distinct from that person’s body. Therefore an animal, being material only, could in this way of thinking, never have a mind – never have a concept of “I”.
This stance was extended by the behaviorist paradigms of the mid 20th century associated with the psychologist B F Skinner.
Darwin on the other hand thought differently. He was a natural philosopher who got up out of his armchair and voyaged the world, most notably aboard the Beagle. Darwin attributed emotions to many animals and even argued that earthworms are cognitive beings. In his classic The Descent of Man he argued, most persuasively, that we and the other animals differ in our mental powers by degree, not in kind.
Today the discussion is no different, researchers still debate not only advanced claims of intelligence in animals but also how to test whether their abilities reflect human-like cognition.
This brings me to what I liked so much about this book.
Each chapter focuses on an animal in a particular observational or experimental setting. Virginia Morell introduces us to the scientist and the animals, explaining the studies, the results and some of the trials and triumphs along the way to building an understanding of what the scientists find. The animal and settings we may already have a prejudice about; captive dolphins, elephant memories, chimpanzees and language, dogs and humans, are very carefully presented to ensure that the most compelling results are well presented. The more novel animals, ants and fish for example, are also carefully presented, their novelty makes for an easier presentation. For example I had no preconceived ideas regarding the ability of ants to teach – with no mental hurdle of my to overcome – that chapter was very illuminating. The examples and researchers chosen for these chapters succinctly illustrate what we have learnt about the emotions and intelligence of these animals.
Yes I did say chosen. It does not pretend, nor claim to be, encyclopaedic, academic nor ‘balanced’ presentation of the entire field. This is a lively, non-fiction tour of the cutting edge of animal cognitive science. Virginia Morell translates the scientific jargon of the field into words that all can engage with.
Each chapter is a separate story, reflecting that some of the chapters were adapted from previously published articles from 2008 to 2012. These are neatly book-ended with chapter that frame these quite succinctly. This I think is a strength of the book. Each chapter, each story, is self-contained that you can read it, look at the references and ponder what the researchers and Virginia are conveying to you. Not only do you get an appreciation of the scientific significance of the various studies – you get that rare glimpse into the scientific process and personality that is often missed in science communication writing.
For example, consider the archer-fish and neuroscientist Stefan Schuster. I learnt that Stefan has spent more than forty years investigating how fish think and make decisions. I learnt that the idea of seeing life from the mind of a fish was something that grabbed him as a child. Stefan’s story is more than just his careful experimentation on fish behaviour. Along the way he has made key discoveries about the sophisticated mental abilities of the archer-fish. The archer-fish is well-named for it is the sharpshooter of the piscine world.
In the chapter discussing his work I learnt that Schuster owes his success to curiosity, fun and serendipity – as well as careful experimentation. Schuster and his students had discovered that archer-fish learnt how to shoot at difficult and novel targets by watching another skilled fish perform the task. That means they had taken the viewpoint of the other fish. Did they copy or imitate? Let the philosophers debate the definitions. What the archerfish do involves cognition. Although we don’t understand the relationship between cognition and sentience, scientists know that one informs the other.
Each chapter is replete with great stories, good science and probing philosophy. Morell displays her ability to write engagingly for a general audience, while presenting the science at a suitably intriguing level. If you view animals the same after reading this book – then give it a second read – it will be worth it.
I’ll leave the last words to the late Douglas Adams:
Man had always assumed that he was more intelligent than dolphins because he had achieved so much – the wheel, New York, wars and so on – while all the dolphins had ever done was muck about in the water having a good time. But conversely, the dolphins had always believed that they were far more intelligent than man – for precisely the same reasons.
NASA’s Kepler space telescope has witnessed the effects of a dead star bending the light of its companion star. The findings are among the first detections of this phenomenon — a prediction of Einstein’s general theory of relativity — in binary, or double, star systems.
The dead star, called a white dwarf, is the burnt-out core of what used to be a star like our sun. It is locked in an orbiting dance with its partner, a small “red dwarf” star. While the tiny white dwarf is physically smaller than the red dwarf, it is more massive.
This white dwarf is about the size of Earth but has half the mass of the sun. It’s so hefty that the red dwarf, of roughly the same mass though 50 times larger in diameter (about half our sun’s diameter), is circling around the white dwarf. These findings are to be published April 20, in the Astrophysical Journal.
The Kepler space telescope’s primary job is to scan stars in search of orbiting planets. As the planets pass by, they block the starlight by miniscule amounts, which Kepler’s sensitive detectors can see.
“The technique is equivalent to spotting a flea on a light bulb 3,000 miles away, roughly the distance from Los Angeles to New York City,” said Avi Shporer, co-author of the study.
Muirhead and his colleagues regularly use public Kepler data to search for and confirm planets around smaller stars, the red dwarfs, also known as M dwarfs. These stars are cooler and redder than our yellow sun. When the team first looked at the Kepler data for a target called KOI-256 (Kepler Object of Interest), they thought they were looking at a huge gas giant planet eclipsing the red dwarf.
“We saw what appeared to be huge dips in the light from the star, and suspected it was from a giant planet, roughly the size of Jupiter, passing in front,” said Muirhead.
To learn more about the star system, Muirhead and his colleagues turned to the Hale Telescope at Palomar Observatory near San Diego. Using a technique called radial velocity, they discovered that the red dwarf was wobbling around like a spinning top. The wobble was far too big to be caused by the tug of a planet. That is when they knew they were looking at a massive white dwarf passing behind the red dwarf, rather than a gas giant passing in front.
The team also incorporated ultraviolet measurements of KOI-256 taken by the Galaxy Evolution Explorer (GALEX), a NASA space telescope now operated by the California Institute of Technology in Pasadena. The GALEX observations, led by Cornell University, Ithaca, N.Y., are part of an ongoing program to measure ultraviolet activity in all the stars in Kepler field of view, an indicator of potential habitability for planets in the systems. These data revealed the red dwarf is very active, consistent with being “spun-up” by the orbit of the more massive white dwarf.
The astronomers then went back to the Kepler data and were surprised by what they saw. When the white dwarf passed in front of its star, its gravity caused the starlight to bend and brighten by measurable effects.
“Only Kepler could detect this tiny, tiny effect,” said Doug Hudgins, the Kepler program scientist at NASA Headquarters, Washington. “But with this detection, we are witnessing Einstein’s general theory of relativity at play in a far-flung star system.”
One of the predictions of Einstein’s general theory of relativity is that gravity bends light. Astronomers regularly observe this phenomenon, often called gravitational lensing, in our galaxy and beyond. For example, the light from a distant galaxy can be bent and magnified by matter in front of it. This reveals new information about dark matter and dark energy, two mysterious ingredients in our universe.
Gravitational lensing has also been used to discover new planets and hunt for free-floating planets.
In the new Kepler study, scientists used the gravitational lensing to determine the mass of the white dwarf. By combining this information with all the data they acquired, the scientists were also able to measure accurately the mass of the red dwarf and the physical sizes of both stars. Kepler’s data and Einstein’s theory of relativity have together led to a better understanding of how binary stars evolve.
By Kevin Orrman-Rossiter, University of Melbourne
Nobel prizewinner Samuel Ting, early this morning (AEDT), announced the first results from the Alpha Magnetic Spectrophotometer (AMS) search for dark matter. The findings, published in Physical Review Letters, provide the most compelling direct evidence to date for the existence of this mysterious matter.
In short, the AMS results have shown an excess of antimatter particles within a certain energy range. The measurements represent 18 months of data from the US$1.5 billion instrument.
The AMS experiment is a collaboration of 56 institutions, across 16 countries, run by the European Organisation for Nuclear Research (CERN). The AMS is a giant magnet and cosmic-ray detector complex fixed to the outside of the International Space Station (ISS).
Dark matter matters
The visible matter in the universe, such as you, me, the stars and planets, adds up to less than 5% of the universe. The other 95% is dark, either dark matter or dark energy. Dark matter can be observed indirectly through its interaction with visible matter but has yet to be directly detected.
Cosmic rays are charged high-energy particles that permeate space. The AMS is designed to study them before they have a chance to interact with Earth’s atmosphere.
An excess of antimatter within the cosmic rays has been observed in two recent experiments – and these were labelled as “tantalising hints” of dark-matter decay.
One possibility for the excess antimatter, predicted by a theory known as supersymmetry, is that positrons (antimatter electrons) could be produced when two particles of dark matter collide and annihilate.
Assuming that dark matter is evenly distributed, these theories predict the newly reported observations.
But the AMS measurement cannot yet entirely rule out the alternative explanation that the positrons originate from pulsars (rotating neutron stars) distributed around the galactic plane.
Supersymmetry theories also predict a cut-off at higher energies above the mass range of dark matter particles, and this has not yet been observed. Over the coming years, the AMS will further refine the measurement’s precision, and clarify the behaviour of the positron fraction at higher energies.
The AMS idea dates back to 1994. At that time NASA was desperate to develop a “sexy” science project that would endear the US scientific community to the ISS.
Enter Ting and his idea of a space-borne magnet that would sift matter and antimatter.
By 1995 Ting had NASA’s agreement. The US Department of Energy would fund the detector, and NASA would provide space on the ISS and a shuttle to fly it there. Ting would obtain the foreign involvement needed to build the instrument.
By 2008 the detector was complete but the shuttle flight schedule was a shambles. With delays after the 2003 Columbia disaster and the probable 2010 retirement of the shuttles, no flights were available to deliver the device to the space station.
Ting persisted and, through lobbying, got Congress to authorise one more shuttle flight, STS-134 – the second last ever.
On May 16, 2011 the final flight of NASA’s youngest shuttle, Endeavour, the spectrophotometer was launched. It has been in operation and collecting data since June 27, 2011 and has an expected operational lifetime in excess of 10 years.
There is a second scientific aim of the AMS. Experimental evidence indicates that our galaxy is made of matter. But the Big Bang theory assumes equal amounts of matter and antimatter were present at the origin of the universe.
So what happened to all the antimatter? The observation of just one antihelium nucleus would provide evidence for the existence of a large amount of antimatter somewhere in the universe.
With a sensitivity three orders of magnitude better than previous experiments, the Alpha Magnetic Spectrophotometer will be searching for the existence of this primordial antimatter.
Amazingly we have come to recognise that we know little about what makes up 95% of our universe.
Today’s AMS results mark a precision start to an audacious experiment to redress that ignorance.
Kevin Orrman-Rossiter does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.
Long distance weather reports are now a commonality. The report for 2MASSJ22282889-431026 is somewhat unusual. It forecasts wind-driven, planet-sized clouds, with the light varying in time, brightening and dimming about every 90 minutes. The clouds on 2MASSJ22282889-431026 are composed of hot grains of sand, liquid drops of iron, and other exotic compounds. Definitely not the first place to spend a summer holiday.
Not that 2MASSJ22282889-431026 (or 2M2228 as it is known in The Astrophysical Journal Letters) will appear on a travel itinerary anytime soon. For 2M2228 is a brown dwarf, 39.1 light years from earth. Brown dwarves form out of condensing gas, as stars do, but lack the mass to fuse hydrogen atoms and produce energy. Instead, these objects, which some call failed stars, are more similar to gas planets, such as Jupiter and Saturn, with their complex, varied atmospheres. Although brown dwarves are cool relative to other stars, they are actually hot by earthly standards. This particular object is about 600 to 700 degrees Celsius.
The atmosphere of 2M2228
Astronomers using NASA’s Spitzer and Hubble space telescopes have probed the stormy atmosphere of this brown dwarf, creating the most detailed “weather map” yet for this class of cool, star-like orbs. “With Hubble and Spitzer, we were able to look at different atmospheric layers of a brown dwarf, similar to the way doctors use medical imaging techniques to study the different tissues in your body,” said Daniel Apai, the principal investigator of the research at the University of Arizona in Tucson.
But more surprising, the team also found the timing of this change in brightness depended on whether they looked using different wavelengths of infrared light.
These variations are the result of different layers or patches of material swirling around the brown dwarf in windy storms as large as Earth itself. Spitzer and Hubble see different atmospheric layers because certain infrared wavelengths are blocked by vapors of water and methane high up, while other infrared wavelengths emerge from much deeper layers.
The new research is a stepping-stone toward a better understanding not only of brown dwarves, but also of the atmospheres of planets beyond our solar system.
Into the red: the Spitzer space telescope
The Spitzer Space Telescope is the final mission in NASA’s Great Observatories Program – a family of four space-based observatories, each observing the Universe in a different kind of light. The other missions in the program include the visible-light Hubble Space Telescope, Compton Gamma-Ray Observatory, and the Chandra X-Ray Observatory.
The Spitzer Space Telescope consists of a 0.85-meter diameter telescope and three cryogenically-cooled science instruments which perform imaging and spectroscopy in the 3 – 180 micron wavelength range. Since infrared is primarily heat radiation, detectors are most sensitive to infrared light when they are kept extremely cold. Using the latest in large-format detector arrays, Spitzer is able to make observations that are more sensitive than any previous mission. Spitzer’s mission lifetime requirement was 2.5 years, then extended this to 5-years. Spitzer .
Launched on August 25, 2003 Spitzer is now more than 9 years into its mission, and orbits around the sun more than 100-million kilometers behind Earth. It has heated up just a bit – its instruments have warmed up from -271 Celsius to -242 Celsius. This is still way colder than a chunk of ice at 0 Celsius. More importantly, it is still cold enough for some of Spitzer’s infrared detectors to keep on probing the cosmos for at least two more years; the project funding has been extended to 2016.
Spitzer is the largest infrared telescope ever launched into space. Its highly sensitive instruments allow scientists to peer into cosmic regions that are hidden from optical telescopes, including dusty stellar nurseries, the centres of galaxies, and newly forming planetary systems. Spitzer’s infrared eyes also allows astronomers see cooler objects in space, like brown dwarves, extrasolar planets, giant molecular clouds, and organic molecules that may hold the secret to life on other planets.
Instead of orbiting Earth itself, the observatory trails behind Earth as it orbits the Sun and drifts away from us at about 1/10th of one astronomical unit per year.
This innovative orbit lets nature cool the telescope, allowing the observatory to operate for around 5.5 years using 360 litres of liquid helium coolant. In comparison, Spitzer’s predecessor, the Infrared Astronomical Satellite, used 520 litres of cryogen in only 10 months.
This unique orbital trajectory also keeps the observatory away from much of Earth’s heat, which can reach 250 Kelvin (-23 Celsius) for satellites and spacecraft in more conventional near-Earth orbits.
More scientific duets: the asteroid belt of Vega
Like a gracefully aging rock star Spitzer is reveling in duets. It has also teamed up with the European Space Agency‘s Herschel Space Observatory. Using data from both astronomers have discovered what appears to be a large asteroid belts around the star Vega, the second brightest star in northern night skies.
The data are consistent with the star having an inner, warm belt and outer, cool belt separated by a gap. The discovery of this asteroid belt-like band of debris around Vega makes the star similar to another observed star called Fomalhaut. Again this formation is similar to the asteroid and Kuiper belts in our own solar system.
What is maintaining the gap between the warm and cool belts around Vega and Fomalhaut? The results strongly suggest the answer is multiple planets. Our solar system’s asteroid belt, which lies between Mars and Jupiter, is maintained by the gravity of the terrestrial planets and the giant planets, and the outer Kuiper belt is sculpted by the giant planets.
“Our findings (accepted for publication in the Astrophysical Journal) echo recent results showing multiple-planet systems are common beyond our sun,” said Kate Su, an astronomer at the Steward Observatory at the University of Arizona, Tucson.
Vega and Fomalhaut are similar in other ways. Both are about twice the mass of our sun and burn a hotter, bluer color in visible light. Both stars are relatively nearby, at about 25 light-years away. Fomalhaut is thought to be around 400 million years old, but Vega could be closer to its 600 millionth birthday. For comparison our sun is 4,600 million years old. Fomalhaut has a single candidate planet orbiting it, Fomalhaut b, which orbits at the inner edge of its cometary belt.
The Herschel and Spitzer telescopes detected infrared light emitted by warm and cold dust in discrete bands around Vega and Fomalhaut, discovering the new asteroid belt around Vega and confirming the existence of the other belts around both stars. Comets and the collisions of rocky chunks replenish the dust in these bands. The inner belts in these systems cannot be seen in visible light because the glare of their stars outshines them.
It would seem that Spitzer has quite a bit more productive and novel scientific life, including duets, left in it yet.
By Kevin Orrman-Rossiter, University of Melbourne
NASA revealed Friday morning (AEST) that its Van Allen Probes have discovered a third, previously unknown, radiation belt around Earth. The belt appears to be transient, depending strongly on solar activity.
The Probes mission is part of NASA’s Living With a Star geospace program to explore the fundamental processes that operate throughout the solar system, in particular those that generate hazardous space weather effects near Earth and phenomena that could affect solar system exploration.
In what could perhaps be described as serendipitous, scientists had switched on key instruments on the the twin probes (which are described in detail in the second video below) just three days after launch from Cape Canaveral Air Force Station in Florida on August 30 last year.
That decision was made in order that observations would overlap with those of another mission, the Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX) – launched in 1992 – that was about to de-orbit and re-enter Earth’s atmosphere.
In practice it meant NASA’s mission scientists gathered data on the third radiation belt for four weeks before a shock-wave from the sun annihilated it.
The Van Allen Probes are studying an extreme and dynamic regions of space known as the Van Allen Radiation Belts.
These belts are critical regions of space for modern society. They are affected by solar storms and space weather and can change dramatically. They can pose dangers to communication and GPS satellites as well as humans in space – as I’ll discuss shortly.
Named after their discoverer, the late pioneering NASA astrophysicist James Van Allen, these concentric, donut shaped rings are filled with high-energy particles that gyrate, bounce, and drift through a region extending to 65,000 kilometres from the earth’s surface.
This belt is comprised mostly of high-energy protons, trapped within about 600-6,000 kilometres of Earth’s surface. Those particles are particularly damaging to satellites and humans in space. The International Space Station (ISS) orbits below this belt at 330-410 kilometres.
This larger belt is located 10,000 to 65,000 kilometres above Earth’s surface, and is at its most intense between 14,500 and 19,000 kilometres above Earth. The second belt is much more variable than the inner one. In addition to protons, it contains ions of oxygen and helium.
So what of the third belt? This new, outer zone is comprised mainly of high-energy electrons and very energetic positive ions (mostly protons). As reported today in the journal Science, this torus formed on September 2 last year and persisted unchanged in a height range of 20,000-23,000 kilometres for four weeks. It was then disrupted by a shock-wave from the sun.
Space weather impacts on Earth
The radiation belts are part of a much larger space weather system driven by energy and material that erupt off the sun’s surface and fill the entire solar system. Besides emitting a continuous stream of plasma called the solar wind, the sun periodically releases billions of tons of matter in what are called coronal mass ejections.
These immense clouds of material, when directed towards Earth, can cause large magnetic storms in the space environment around Earth, the magnetosphere and the upper atmosphere.
The term space weather generally refers to conditions on the sun, in the solar wind, and within Earth’s magnetosphere, ionosphere and thermosphere that can influence the performance and reliability of space-borne and ground-based technological systems and can endanger human life or health.
Most spacecraft in Earth orbit operate partly or entirely within the radiation belts. During periods of intense space weather, the density of particles within the belts increases, making it more likely that a shuttle’s sensitive electronics will be hit by a charged particle.
Ions striking satellites can overwhelm sensors, damage solar cells, and degrade wiring and other equipment. When conditions get especially rough in the radiation belts, satellites often switch to a safe mode to protect their systems.
When high-energy particles – those moving with enough energy to knock electrons out of atoms – collide with human tissue, they alter the chemical bonds between the molecules that make up the tissue’s cells.
Sometimes the damage is too great for a cell to repair and it no longer functions properly. Damage to DNA within cells may even lead to cancer – causing mutations.
During geomagnetic storms, the increased density and energy of particles trapped in the radiation belts means a greater chance that an astronaut will be hit by a damaging particle.
That’s why the ISS has increased shielding around crew quarters, and why NASA carefully monitors each astronaut’s radiation exposure throughout his or her career.
The advances in technology and detection made by NASA in this mission already have had an almost immediate impact on both basic science and the space-based technology we all depend on.
Kevin Orrman-Rossiter does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.
Being responsible for picking the week’s most interesting science stories is a fun and fascinating challenge. It pushes to me to look beyond my own interests and explore what others find compelling. So I trust you find my ‘science making news’ selection of interest and delight; explore the quantum, human, off-world and mathematical highs of the week.
On the human scale an international team of scientists has been investigating the antibiotic properties of sweat. More precisely they discovered how a natural antibiotic called dermcidin, produced by our skin when we sweat, is a highly efficient tool to fight tuberculosis germs and other dangerous bugs.
Their results could contribute to the development of new antibiotics that control multi-resistant bacteria.
The benefits of a good nights sleep once again are news. Researchers have shown that the disruption in the body’s circadian rhythm can lead not only to obesity, but can also increase the risk of diabetes and heart disease.
Our study confirms that it is not only what you eat and how much you eat that is important for a healthy lifestyle, but when you eat is also very important.
At the quantum scale, the particle physicists are at it again. Not content with discovering the Higgs Boson they are shedding light (pardon the pun) on a possible 5th force in nature. In a breakthrough physicists have established new limits on what scientists call “long-range spin-spin interactions” between atomic particles. These interactions have been proposed by theoretical physicists but have not yet been seen. If a long-range spin-spin force is found, it not only would revolutionize particle physics but might eventually provide geophysicists with a new tool that would allow them to directly study the spin-polarized electrons within Earth.
The most rewarding and surprising thing about this project was realizing that particle physics could actually be used to study the deep Earth.
The latest news from Mars is that curiosity has relayed new images that confirm it has successfully obtained the first sample ever collected from the interior of a rock on another planet.
Many of us have been working toward this day for years. Getting final confirmation of successful drilling is incredibly gratifying. For the sampling team, this is the equivalent of the landing team going crazy after the successful touchdown.
To wrap up with one further piece of geek excitement. On January 25th at 23:30:26 UTC, the largest known prime number, 257,885,161-1, was discovered on Great Internet Mersenne Prime Search (GIMPS) volunteer Curtis Cooper’s computer. The new prime number, 2 multiplied by itself 57,885,161 times, less one, has 17,425,170 digits. With 360,000 CPUs peaking at 150 trillion calculations per second, 17th-year GIMPS is the longest continuously-running global “grassroots supercomputing”project in Internet history.
Until next week’s Australian Science review, go geekily crazy and enjoy your weekend.
Massive objects moving at near light speeds do not occur naturally in the universe as we know it. If we detect such objects it is a reasonable to assume they are artificial artifacts from advanced intelligent life. This according to Garcia-Escartin and Chamorro-Posada, authors of a recent paper, is a low-cost, sure-fire way of searching for intelligent life outside earth.
Searching for life beyond earth is a grand and varied enterprise.
For a start we can look for exoplanets that fall inside the habitable zone of a star. A planet found in this zone may fulfill the requirements for life: liquid water, energy, elements and other nutrients, and appropriate physical conditions. Though we have located many exoplanets in recent times they are far from earth – many light years distant. For example one star system, Gliese 581, is 20.3 light years away (192,048,720,000,000 kilometres). With three planets in its habitable zone, we know nothing about conditions on them. The techniques used to find them can tell us nothing about their ecology – if any. being in a habitable zone does not guarantee life. It is only in recent years that we have realised how inhospitable Venus and Mars are to life – despite being in our habitable zone.
By looking for alien signals or transmissions, as in the SETI programme, we extend our search from ‘possible life’ to intelligent life. For advanced civilisations we look for artificial illumination or interstellar probes.
Let’s face it though, to know we are not alone will require quite good proof for most of us (apart from the misguided minority of UFO believers), and especially for the skeptical scientists.
The intriguing proposition of Garcia-Escartin and Chamorro-Posada is based on three ideas. The first is that anything travelling faster than 3.3% of light speed (5,935,890 kilometres per hour) is artificial. All known natural objects travel slower than this speed, as do our current space probes. This speed was chosen as it is the estimated speed of the nuclear propulsion ship proposed by Freeman Dyson in the Orion project. Although the propulsion technology is feasible today the technological and economic hurdle of creating such a craft is way beyond our current means. Although it is certainly not inconceivable to achieve such interstellar travel in the next 100 years.
You are possibly thinking about now; “Doesn’t the mass of an object increases massively as its speed approaches light speed?” You would be correct, this consequence of Einstein’s theory of special relativity is demonstrated quite satisfactorily in particle accelerators around the world. To cover this the authors next identify a consequence of relativity theory: relativistic effects amplify the light reflected from a body travelling at near light speed – in some key situations. Allowing for the detection of ‘small’ objects.
This brings in the authors third criteria. Interstellar travel will be from one star system to another. The reflected-light magnifying effect would be greatest for the cases where earth is almost in line with the departure stellar system and the destination stellar system.
The authors propose to limit the first search to star systems that are reasonably close to each other (no further than 10 light years apart) to maximise the probability of stellar travel opportunities. Considering that Gliese 581, for example, is greater than 20 light years distance from us, I suggest that this criteria is too limiting.
The paper is an interesting, if not compelling, proposition. The authors do calculate what size an artifact would need to be, travelling at their minimum speed (3.3% light speed), to be detected at the distance of one of our closer stellar neighbours. Could such an artifact be detected by the Hubble or James Webb space telescopes, for example? What is the probability of success of such an experiment, compared to say the SETI experiments?
One idea I did find interesting is by focusing on detecting light reflected from ships, we do not need to assume any intention by the interstellar travellers to communicate with us. The ‘signal’ is independent of alien psychology. It is also independent of propulsion technology – we aren’t looking for any ‘signature’ of any particular technology, known or unknown.
It is an interesting paper. I’m not sure they have presented a compelling enough case to convince a funding body – yet.
There is a dominant theme in the life of Nikola Tesla. His undoubted genius. Tesla pioneered, if not invented; AC motors, AC power generation and transmission, high voltage generation (Tesla coil), wireless transmission of power and information, radio controlled boats, cold discharge fluorescent lighting, and the ‘death-ray’.
It also meant that he was ahead of his time, in many cases unable or disdainful to translate what to him was now obvious to those of lesser vision or ability. This resulted in tempestuous clashes with entrepreneurial inventors in three major technologies, technologies that defined this as the ‘Age of Electricity’. Tesla’s was no ordinary progression in life and its colorful and quirky story continues to determine his eccentric place in history – from near invisibility to cult figure.
Two books: many stories
My prompt for this writing this essay was my recent reading of two books on Tesla’s life. His autobiography; My Inventions and other writings, first published serially in 1919 when he was 63, is a technicolour, frenetic meditation on his major discoveries and innovations. It is autobiographical, mixing his life stories with his inventions, the narrative leaping around in time and place as Tesla seemed to in real life. Worth reading to obtain some of the character of Nikola Tesla – even if coloured by his own deliberate self mythologizing.
The second book Wizard: the life and times of Nikola Tesla (by Marc Seifer) captures much of the excitement of this early age of electricity. This book is a chronology of Tesla’s life, informative in its research and illuminating with its vignettes drawn from contemporary memoirs. At the same time its chronological presentation provides a misleading sequential perception of his life.
Seifer also lacks the engineering or science competence to describe in simple terms the genius of Tesla’s inventions. An essential for a biography of someone whose whole life revolved around his work. In the concluding chapters Seifer’s writing starts to take on the ludicrous credulity of the conspiracy theorist – which is a pity the rest of the book is clear of this nonsense.
in defense of Seifer I think it would be challenge for any biographer to tell the whole Tesla story. Tesla was completely consumed by his ideas and inventions, eschewing most intimate contact – to the extreme of apparently being celibate his whole life. To make credible his fantastic life is a challenge. Furthermore, a modern reader, it most cases will struggle in comprehending the archaic technical descriptions and ideas.
The dawn of the Electric Age
This was an age when electricity and magnetism had only recently been linked by the arcane mathematics of James Clerk Maxwell and electricity was still thought to propagate by vibrations of an aether. Tesla was one of the few people alive who understood the physics of what we now call electromagnetism, and could also translate this into tangible inventions.
Tesla’s name is associated with the invention of the rotating magnetic field and the ability of such a field to produce an electric current. By 1882 Tesla had invented and patented the AC polyphase motor – giving the ability to transfer electrical energy into mechanical energy. The reverse of this creates a turbine that converts mechanical energy, from say a waterfall, into electrical energy.
Tesla’s move, in 1884, from Europe to the USA was to develop his own inventions and contribute to Edison’s commercial interests. This collaboration parted ways over what became the AC-DC power war. Edison’s commercial interests were firmly focused on his incandescent lamps and the use of DC power (direct current; such as we get from a battery). Tesla had correctly intuited from first principles that alternating current (AC power as we now operate our homes and industries on), as different to DC power, could be transported by wires over great distances with minimal power loss.
Ultimately Tesla was proved both scientifically and commercially correct. It was his turbine designs that Westinghouse used in the first major hydroelectric power station in the world – the 1894 powering of Buffalo by the might of Niagara falls.
This was a tumultuous period of commercial expansion. The ability to power industry by electricity rather than steam was arguably a bigger leap than from manual to steam power – certainly in commercial terms. The ensuing law-suits and counter-suits over patent precedence in motors, generation and transmission, roiled across the US and Europe, making and breaking reputations and fortunes. These actions bringing Edison General Electric to its knees and forcing it to join with others to become General Electric.
Westinghouse prevailed, at the same time neglecting to pay Tesla royalties that he deserved – despite he not bothering to ensure he had written agreements. This disdain for the corporate conventions of the time cost Tesla both wealth and reputation. He moved onto other new ideas whilst others claimed his inventions in the law and popular press.
Father of the wireless
This was repeated in the next huge modernisation trend – the invention of the wireless transmission of information. By 1893 Tesla was demonstrating the transmission of electric power by wireless means most notably at the Chicago World fair. He delighted in amazing audiences with fantastic high-voltage discharge displays, passing millions of volts through his body and remote lighting of fluorescent tubes by radio frequency.
Already in 1891 he had discussed his “wireless telegraphy” and demonstrated the technology required in 1892. It was 1894 before Guglielmo Marconi would begin his teenage tinkering in the wireless field. So why do we remember the name of Marconi as synonymous with radio? Why did he share the 1909 Nobel Prize with Karl Braun rather than with Tesla?
It would appear from historical evidence that Tesla, in his own mind, had already proved it – and moved on. Whereas the entrepreneur in Marconi, much like Edison, was tenacious in development of his inventions. Tesla at this time had formed a company with the financier Pierpont Morgan to commercialise his wireless technologies. Morgan knew their was a fortune in wireless telegraphy and fluorescent lighting; provided they were developed sufficiently to present to investors as near commercial realities.
To this end Morgan had tasked him with demonstrating the fluorescent light technologies and maturing their manufacture and demonstrating his wireless by covering off-shore yacht races. The latter would have been a tangible demonstration for both the rich and the Navy. Tesla did neither. he scorned the triviality of the public demonstration – despite his very public earlier electric demonstrations. This left the field of wireless telegraphy (radio) for Marconi and other to develop. instead Tesla squandered the Morgan money on his other big dream – providing wireless transmission of electric power by radio.
Radio power, transmission and weapons
Tesla’s greatest dream was sure to be one not funded by the likes of Morgan. He envisaged a world where power and information were transmitted world-wide – for free. To this end he he used the money from Morgan to plan and start building a gigantic transmission tower, Wardenclyffe, in 1902. His philanthropic ideals and profligate spending meant that by 1906 his funding from Morgan had dried up, and his dream never realised. The tower was destroyed in 1917 by US Government orders to ensure that it was not used by enemies of the state.
In developing this idea he correctly understood the physics of wireless transmission both through the atmosphere and the ground. Laying down the principles that would guide the subsequent invention of both AM and FM radio.
A combination of creditors, stock market upheavals, World War 1 and the stock market collapse of 1930 ensured that Tesla could never raise the money required to bring about this revolutionary idea. A idea revolutionary even by the social standards and upheavals of the time.
At the same time Tesla was a continuing fountain of new ideas. Perhaps given the turbulent times these included the world’s first radio controlled boat in 1898 which he continually and unsuccessfully tried to interest the US Navy in, improvements on dirigibles, a helicopter plane called a flivver and at the age of 78 a ‘death-ray’.
This latter ‘invention’ was never built nor even prototyped but harked back to experiments of Tesla in the 1890’s that were only a small step away from the invention of the laser. The ideas were sufficiently developed though to serve as mental prototypes for particle-beam weapons and strategic defense shields loved by science fiction writers and some politicians.
Apart from the tangible technological legacies left by Tesla’s prodigious genius there are also quixotically hare-brained modern legacies. These Tesla, if he were alive today, would scoff at. None more so than the Tesla “free-energy-generator”
This modern scam is based on the misrepresentation of Tesla’s laudable Wardenclyffe dream and his idea that you could use his generator as a receiver of the, at the time, newly discovered cosmic rays. The radio sophistication and development of radar during and subsequent to WW11 demonstrate the impracticality of large transmitters and receivers of radio power at the levels envisaged by Tesla. We now use networks of smaller powered repeaters (many of these satellites) to ensure uninterrupted radio/telephone/television coverage on a world-wide basis. As for cosmic rays, they are energetic, however of such low density (thankfully for life) that collecting sufficient power from them is impracticable.
That scams based on Tesla exist in this modern age is testament not to conspiracy theories as maintained by these swindlers. Rather it is testimony to Tesla being truly ahead of his time – a time of tumultuous technological growth, which he partially created without ever seeming to inhabit.
A complete biography of Nikola Tesla is still to be written. I believe it will require a writer who understands the science and engineering of Tesla’s age and who has the artistry to weave the many threads of his life into the dynamic, parallel genius of his life – teetering on the precipice of chaos – that was Nikola Tesla.
The 28th and last flight (STS-107) of the space shuttle Columbia was ten years ago. Launched on January 16, 2003 Columbia was destroyed at about 0900 EST on February 1, 2003 while re-entering the atmosphere after its 16-day scientific mission. The destruction of the shuttle killed all seven astronauts on board.
An illustrious career
Columbia was the first of the space shuttles to fly, it was successfully launched on April 12, 1981, the 20th anniversary of the first human spaceflight by Yuri Gagarin in Vostok 1, and returned on April 14, 1981, after orbiting the Earth 36 times. The first flight of Columbia (STS-1) was commanded by John Young, a Gemini and Apollo veteran who was the ninth person to walk on the Moon in 1972, and piloted by Robert Crippen, a rookie astronaut who served as a support crew member for the Skylab and Apollo-Soyuz missions.
Columbia has an illustrious career as part of the US space program, featuring many ‘firsts’. It was the first true manned spaceship. It was also the first manned vehicle to be flown into orbit without benefit of previous unmanned “orbital” testing; the first to launch with wings using solid rocket boosters. It was also the first winged reentry vehicle to return to a conventional runway landing, weighing more than 99-tons as it was braked to a stop on the dry lakebed at Edwards Air Force Base, California.
Its second flight, STS-2 on November 12, 1981 marked the first re-use of a manned space vehicle. A year later it became the first 4-person space vehicle – bumping this to six on its sixth flight (STS-9) on November 28, 1983. This flight also featured both the first flight of the reusable laboratory ‘Spacelab’ and the first non-American astronaut on a space shuttle, Ulf Merbold. STS-93, launched on July 23, 1999, was commanded by Eileen Collins, the first female Commander of a US spacecraft.
Space Shuttle Columbia flew 28 flights, spent 300.74 days in space, completed 4,808 orbits, launched 8 satellites and flew 201,497,772 km in total, including its final mission. Its penultimate flight (STS-109) was the third of the highly publicised servicing and upgrade flights to the Hubble Space Telescope.
The fatal flight
The rockets fire. Amidst the thundering fiery roar the shuttle lifts majestically from the launch pad. Unnoticed at the time, at 81.9 seconds after launch a foam insulating block disintegrates upon hitting the leading edge of the shuttles left-wing. The launch continues as scheduled. One hour after launch Columbia was in orbit and the crew began to configure it for their 16-day mission in space.
The next day, routine analysis of high-resolution video from the tracking cameras reveals the debris strike. Multiple groups within the mission team review the tapes. They assess the possibility of damage and decide that an image is required of the wing. They make a request to the NASA ground management for imaging of the wing in-orbit.
However, it was considered “of low concern” that the carbon matrix could be damaged by the foam block. The engineers were over-reacting. The Space shuttle Program managers declined to get the Columbia imaged – or alert the shuttle crew. In fact the crew were told that the impact was a “turn-around issue”, something they had seen before and would be a maintenance check only. Titanic-like the mission continued.
Scientifically the mission was great success. The shuttle crew worked around the clock to ensure that maximum scientific value was achieved. Including an investigation of the web-spinning abilities of the Golden orb spider under low gravity. An experiment designed by students from Glen Waverley Secondary College, in Melbourne Australia.
The morning of re-entry all appears calm and normal in the mission control room. As re-entry started the crew are seen to be in good spirits and looking forward to coming home.
Then while travelling at Mach 24.1, during the 10-minute fiery re-entry, when the leading edge reaches temperatures in excess of 1550 Celsius, the damaged thermal protection panels on the wing overheated – then failed catastrophically. The wing and shuttle disintegrating.
The nearly 84,000 pieces of debris from the shuttle are stored in a 16th floor office suite in the Vehicle Assembly Building at the Kennedy Space Center.
The seven crew members who died aboard this final mission were: Rick Husband, Commander; Willie McCool, Pilot; Michael Anderson, Payload Commander; David Brown, Mission Specialist 1; Kalpana Chawla, Mission Specialist 2; Laurel Clark, Mission Specialist 4; and Ilan Ramon, Payload Specialist 1.
Two other died in the search for the debris: Jules Mier (Debris Search Pilot) and Charles Krenek (Debris Search Aviation Specialist).
Is spaceflight perilous? Or an unforgiving adventure?
It is rather remarkable that NASA had launched men into space sixteen times during the the Mercury and Gemini programs without a casualty – although there had been some scary moments.
Compared to the cramped and tiny Mercury capsule the Apollo command module was, in spaceflight terms, a luxury liner. So when a spark ignited the oxygen atmosphere of the Apollo 1 capsule on January 27, 1967 killing three astronauts it was shocking for both NASA and the public. The last communication from the Apollo 1 capsule was not revealed for a long time to the public:
Fire! We’ve got a fire in the cockpit! We’ve got a bad fire…..get us out. We’re burning up…..
The last sound was a scream, shrill and brief. After this nothing at NASA would be quite the same again.
The fatal Apollo 1 fire was also unexpected. At the time of the fire the crew of Gus Grissom, John Young and Roger Chaffee were perched atop an empty Saturn V rocket involved in routine testing of the capsule control systems.
The 1986 Challenger disaster was equally shocking – and far more public. The explosion 73 seconds after lift off claimed shuttle crew and vehicle. The cause of explosion was determined to be an o-ring failure in the right solid rocket booster. Cold weather was determined to be a contributing factor. The subsequent investigation and changes delayed the next shuttle launch to late 1988.
You could say that space exploration in itself is not inherently dangerous. But to an even greater degree than aviation, it is terribly unforgiving of any carelessness, incapacity or neglect. Gus Grissom has been quoted as saying during the pioneering Mercury missions:
If we die we want people to accept it. We hope that if anything happens to us it will not delay the program. The conquest of space is worth the risk of life.
I’m not sure that Gus Grissom would have accepted these deaths as an acceptable risk of human spaceflight.
Christmas – whether you’re religious or not – is a time when people gather their families together to reinforce the bonds that make us human.
In the era of modern telecommunications, distance no longer separates people the way it once did. Whether you’re on another continent, another planet, or floating out in space, satellites enable us to talk to and see each other, to feel connected.
And speaking of Christmas and space, it turns out the two have a bit of a history.
An Apollo Christmas
Apollo 8 was a Christmas mission, the only one of all the Apollo missions. On December 21, 1968, astronauts Frank Borman, Jim Lovell and Bill Anders blasted off from Cape Kennedy on a Saturn V rocket.
Their Christmas gift to the world was an extraordinary photograph that became one of the icons of the 20th century.
As they orbited the moon a few days after launch, an unscheduled change in orientation suddenly brought the earth into their view. The astronauts scrambled to get their cameras working, and Bill Anders took the famous shot of the Earth rising over the lunar horizon.
For the first time we saw our whole world from the outside. The fragility and beauty of the blue-and-white globe floating in the sea of darkness ignited an awareness of how interconnected the people of Earth are.
The nascent environmental movement drew inspiration from this vision and people really began to appreciate that we are only a small part of a rather large universe.
The Apollo program provided more concrete presents as well. The crew of Apollo 17, the last men on the moon, made a December 19 splashdown loaded with a 100kg-Santa’s-sack-worth of lunar rocks – our biggest collection so far. Many of these moon rocks were given as goodwill gestures to other nations.
They’re now the most valuable rocks in the world; each lump may be worth millions, as we have no idea when we’ll have the opportunity to get some more. Unbelievably, quite a few of these precious rocks have gone missing!
Home and away
The Apollo missions demonstrated that humans could survive in space; what they couldn’t tell us was whether it was possible to actually live for an extended amount of time in space. This was the purpose of Skylab – the first US spacecraft to be designed as a living space, a home away from home.
Skylab was launched in 1973 and hosted three crews (Skylab 1 was unmanned) during its short working life. While in the space station, the astronauts enjoyed showers, a special dining area, and a sadly punishing toilet routine – everything that left their bodies had to be kept for future analysis.
The crew of the Skylab 4 mission celebrated Christmas in 1973 with a crafty piece of improvisation. Astronauts Gerald Carr, William Pogue and Edward Gibson made this charming Christmas tree out of empty food cans.
Wasting valuable mission time to make the tree may have been a passive act of resistance to having every minute of their waking days overplanned. Later in the three-month mission, the exhausted crew allegedly “mutinied” and chucked the first sickie in space.
On Earth and on the moon, space was quickly incorporated into Christmas traditions.
In 1947, Woomera in South Australia became the location of one of the earliest rocket launch sites in the world. The card shown below, with a Christmas greeting inside, depicts a V2-like rocket being launched over the desert.
Germany developed the V2 in WWII and it became the basis of Cold War space programs in the US, UK, France and Russia. Two ended up in Australia and are now at the Australian War Memorial in Canberra. The card seems to send a rather mixed message about war and peace …
Soviet Russia also got into the Christmas card action though not officially – the celebration of Christmas was not encouraged during the Soviet era.
That said, the card below, which depicts St Nicholas and three USSR spacecraft, leaves no doubt that the spirit of Christmas nonetheless endured. (Bonus points if you can identify the spacecraft!)
Not to be outdone on either the space or Christmas card race, NASA responded in style. In the shot below, the Apollo 14 crew of Alan Shepard, Ed Mitchell and Stuart Roosa, receive a Christmas card from James Loy, Chief, Protocol Branch for the KSC Public Affairs Office.
Note the crew peeping out from behind the Christmas tree on the card.
Every NASA mission generates merchandise and memorabilia – patches, t-shirts, mugs, etc. But did you know you could give your own Christmas tree a NASA makeover?
The image below, and the one above of Santa and an Apollo capsule, show souvenir Christmas tree ornaments from the Kennedy Space Centre.
2012 Christmas in space
This Christmas will be a quiet one in space. That said, on December 19 a crew of three flight engineers did launch from Kazakhstan to complete expedition 34 on the International Space Station.
NASA astronaut Tom Marshburn, Russian cosmonaut Roman Romanenko, and Canadian astronaut Chris Hadfield will get to celebrate Christmas twice – once on December 25, and again for the Russian Orthodox feast on January 7.
Like many modern families, the Mars Rover family – Curiosity, Opportunity and Spirit – will spend the Christmas period far from each other, albeit on the red planet. (For Santa to include them in his rounds, he may need to battle the Martians – or so they thought in this classic 1964 film).
Similarly, the twin Voyager spacecraft are moving ever further apart from each other on their missions to interstellar space.
But it’s not all bad. The same technologies which created the Mars Rover family and the Voyager twins led to our modern telecommunications network.
Human and robot alike are linked in a web of electromagnetic waves that keep us communicating and connected. In space, no-one need feel alone, particularly at Christmas.
The authors do not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article. They also have no relevant affiliations.
In a news conference at the American Geophysical Union NASA’s Curiosity mission team presented a measured, low-key and hype-free discussion about the first use of Curiosity’s full array of analytical instruments.
What they have found are chlorinated hydrocarbons – simple organic molecules made up of carbon, chlorine and hydrogen, sulphur-containing compounds, and calcium perchlorate.
Perchlorates are salts that, when dissolved in water, lower the freezing temperature of that water. The presence of those salts could enable water to stay liquid in the near-surface layers of martian soil. This could provide a possible habitat for Martian microbes.
The discovery of perchlorates supports the 2008 finding made by NASA’s Phoenix lander, which detected perchlorate salts in soil samples from Mars’s north polar region. Being a stationary craft, Phoenix could only take limited samples and used a simpler “wet-chemistry” analytical instrument.
Worth the wait?
The announcement of results from Curiosity comes after weeks of excited anticipation from scientists and the general public alike, following suggestions NASA was getting ready to announce the discovery of life on Mars.
Why? Well, on November 20, the Curiosity mission’s principal investigator John Grotzinger commented to NPR reporter Joe Palca:
The data is one for the history books. It’s looking really good.
This exuberant exclamation about the analysis of Martian soil samples, set off a frenzy of speculation on the internet and since then NASA has been working hard to lower expectations.
In the lead-up to this morning’s press conference NASA even revealed that no, they weren’t about to announce the discovery of life.
The search for life
It’s important to keep in mind that Curiosity never set out to find life. In fact it’s been suggested that, barring an alien waving at Curiosity’s many cameras, life would be more or less undetectable by the rover.
What Curiosity is trying to do is assess the habitability of Mars, both in the past and in the present. Has Mars got the required minerals and energy sources for primitive life to exist? Was there ever a water source that could have aided transport and delivery of these nutrients?
To this end, Curiosity is checking the Martian soil for organic molecules – carbon-containing chemicals and salts that could be ingredients for life. Just like the ones it has found.
Where and how?
The newly announced results follow Curiosity’s investigation of sandy soil at a site called “Rocknest”. This site was chosen to provide the first samples of “normal” soil (as if interplanetary soil could ever be normal).
Using a mechanism on its robotic arm, Curiosity dug up five scoopfuls of Martian soil, each from a pit roughly 4cm wide (see image above).
The first Rocknest scoop was collected on the mission’s 61st Martian day (also known as Sol 61) on October 7.
Fine sand and dust from that first scoopful and two subsequent scoops were used to scrub the inside of Curiosity’s sample-handling mechanism and to ensure they were analysing the right soil.
Samples from scoops three, four and five were then analysed by the chemistry and mineralogy instruments inside the rover.
Cause for excitement
These findings are exciting for scientists – they are repeatable and clear enough for the science history books. After all, they are the first well-characterised Martian soil samples. Scientists now have integrated chemical, mineralogical and visual data, which the couldn’t get from earlier landers and rovers.
That said, it might take something a little bit “sexier” than soil analysis before the mainstream media reports Curiosity’s findings with as much gusto as it did with the rover’s landing.
Many voiced frustration over the wait before today’s Curiosity announcement, but given past experience you can understand why NASA needed to scrutinise the results.
Of course, it’s never that simple.
Imagine you had worked for ten years on this rover, no doubt putting in very long work days (and nights) and making the necessary life sacrifices.
You’ve seen the ups and downs of the project and lived through the success of the terrifying landing earlier this year.
Now it’s really happening and the data you have anticipated for years is finally pouring in, with a level of detail you could only have dreamt about. Who wouldn’t be keen to share the results with the world?
It’s been a productive and trouble-free first three months for Curiosity and the mission team has completed most of its baseline data, instrument and rover testing.
A drilling test experiment is yet to be completed before Curiosity moves on. Curiosity can sample rocks and soil by both scooping and drilling. Now that NASA is sure the analytical instruments are working, they can check out the drill attachment.
Following the drilling test, Curiosity will rove slowly over to the 5.5km-high Mount Sharp via a site called Yellowknife Bay. Mount Sharp is the main investigative target of Curiosity’s primary mission and the point at which the science program gets into full gear.
Mount Sharp’s slopes are gentle enough for Curiosity to climb, analysing and sampling as it goes. As it climbs it will be sampling younger and younger strata of rocks – it really is a Martian areological timeline.
So as we wait for Curiosity to take the next steps (figuratively) on its mission to better understand the red planet, it’s worth remembering that we don’t need to find life for the mission to be both exciting and scientifically worthwhile.
- Just out of Curiosity, did life on Earth come from Mars? – Jon Borwein & Dave Bailey, The Conversation
The authors do not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article. They also have no relevant affiliations.
During the 20th century a powerful new idea gradually entered our consciousness and culture: cosmic evolution. We are all par of a huge narrative: a cosmos billions of years old and billions of light years in extent. It is this idea that caught my attention this month via the proceedings of the Sao Paulo Advanced School of Astrobiology SPASA 2011, published in the October International Journal of Astrobiology.
Although the question of extraterrestrial life is very old, the concept of full-blown cosmic evolution – the connected evolution of planets, stars galaxies and life on Earth and beyond – is much younger. In a rather breathtaking paper, Steven Dick formerly of the Aerospace History at the National Air & Space Museum places his arguments for cosmic evolution. Dick traces the idea from its roots in the 19th century theories of Pierre-Simon Laplace and Robert Chambers through its philosophical, astronomical, and biological upbringing to the present day. He examines evolution, the worldview that it had become in the 1950s and 1960s and how it had permeated culture in numerous ways and different cultures in diverse ways. Dick cautions us though noting “we need to remember that ‘culture’ is not monolithic and that ‘impact’ is a notoriously vague term.”
In addition to the impact of our new understanding on culture, cosmic evolution also provides a window on long-term human destiny, asserts Dick. He presents this idea via three scenarios, the: the physical , biological, and postbiological universe. Life is unique to earth in the physical universe scenario, and the options flow from this situation – think of Isaac Asimov’s Foundation series. We will certainly interact with extraterrestrials in the biological universe – here cosmic evolution commonly ends in life, mind and intelligence. Cultural evolution in a biological universe may replace biologicals with artificial intelligence creating what Dick calls a postbiological universe. We do not know yet, which of these is our reality, that is one of the challenges of astrobiology, maintains Dick.
In a second ‘big-picture’ paper Marcelo Gleiser presents his four ages of astrobiology. For Gleiser the influx of astrophysical data, particularly on the prevalence of exoplanets “indicates that there are plenty of potentially life-bearing platforms within our galaxy.” He then presents the ‘history’ of life in the universe in terms of the steps needed for matter to have sequentially self-organised into more and more complex structures. His sequence is best viewed as a prelude to the physical or biological universe scenarios of Dick. Gleiser’s fourth age, the Cognitive Age (the age of thinking biomolecules), really addresses whether we are unique or not i.e. which of Dick’s two scenarios, the physical or biological are reality. Gleiser’s first three ages: physical, the creation of stars and planets from atomic nuclei; chemical, in which elements organise into biomolecules; and thirdly biological, in which living creatures of growing complexity form from biomolecules. the papers by Dick and Gleiser are both papers heady and exhilarating conceptual reads.
Jorge Horvath and Douglas Galante accept the premiss that life exists, and then argue we need to take high-energy astrophysical events seriously. Scientists and the public account for meteor impacts in both academic studies, science-fiction writing and film – not so for events such as supernovae, gamma-ray bursts and flares. They show that these events are more frequent than asteroid strikes and that the effects are non-negligible (academic speak for potentially fatal to planet based species). They conclude that just because we have not yet been wiped out by such events can be seen as either a measure of earthlife’s resilience or a threat we are statistically yet to encounter.
My attention was captured by two other papers from the proceedings. Martin Brasier and David Wacey address the problem of studying life in deep space – comparing it to study of life remote in time. This view is pertinent, as it is non-trivial for scientists to determine what is a viable signal of extinct life. The authors develop a set of protocols and then apply these to earth samples, of varying ages. They do this to show how we could interpret similar samples, where much of the desirable information (the context) has been filtered out during the process of transmission (either physical or data) across vast distances of space, or time or both (as is likely on Mars). Even 10 years ago these questions were moot, but we have learned much over the recent past about metabolic pathways and living microbial systems. Brasier and Wacey conclude that there is still work required on pseudo-fossils, structures that arise naturally within complex physico-chemical systems, so that we can confidently agree on signs of life that are remote in space and time.
My final pick is an experimental paper that looks at the ExoMars mission. The European Space Agency and (initially NASA ) ExoMars mission is scheduled for launch in 2018 – specifically to detect life signatures on the surface and subsurface of Mars. This probe will carry, for the first time, a Raman spectrometer, a technique with proven ability to determine the spectral signals of key biochemicals. The authors support these assertions by assessing samples acquired from Arctic and Antarctic cold deserts and a meteorite crater. These terrestrial environments are similar to those found on Mars. The experimental results presented in this paper demonstrate that it will be possible using this technique to assess and detect spectral signals of extra-terrestrial (Mars in this case) extremophilic life signatures.
This article was first published on the Australian Sciencesite as: Does my science look big in this? The astrobiology edition
An international group of researchers announced in the journal Nature that they had succeeded in creating tin-100. This experiment helps us understand how heavy elements have formed. A few minutes after the Big Bang the universe contained no other elements than the lightest; hydrogen and helium.
We, the objects around us, the Earth and the other planets all contain heavier elements; carbon, oxygen, silicon, tin, iron etc. These elements came into existence later than hydrogen and helium. They formed through the fusion of atomic nuclei inside of stars. Elements heavier than iron owe their existence to gigantic stellar explosions called supernovas. Tin-100 is a very unstable, yet important, element for the understanding the formation of these heavier elements.
A multinational team headed by nuclear physicists from the Technische Universitat Munchen, the Cluster of Excellence Origin and Structures of the Universe and the GSI in Darmstadt carried out these precision experiments. They shot xenon-124 ions at a sheet of beryllium to create the tin-100 atoms. The subsequently measured the half-life and decay energy of tin-100 and its decay products using specially developed particle detectors.
What is our world made from?
The inspiration of creating new elements can be traced to alchemical traditions. Alchemy is an arcane tradition, that can be viewed as a proto-science, a precursor to chemistry and nuclear physics. It’s prime objective was to produce the mythical philosopher’s stone, which was said to be capable of turning base metals into gold or silver, and also act as an elixir of life that would confer youth and immortality upon its user.
It did bring to chemistry many ideas and provided procedures, equipment, and terminology that are still in use. It also provided the inspiration for the creation of new elements. Now we understand to create new elements requires a combination of precision equipment and experimental procedures coupled with a sound understanding of quantum theory.
So what is tin-100 and why is it useful to understand the astrophysics of heavy element formation?
Most people will recognise that matter around us is composed of atoms. Atoms of carbon, hydrogen, oxygen for example form the building blocks to make organic molecules and silicon and oxygen bond together to make common beach sand and are fused together to make glass. The familiar metals are solids made of one type of atom, for example gold and aluminium, or combinations, bronze being made of copper and tin atoms.
Atoms in turn are a central nucleus of protons and neutrons surrounded by a swarm of electrons. The number of protons distinguishes one element from another. This atomic number is used to designate an element 1 for hydrogen, 8 for oxygen and 50 for tin, for example. Stable tin comprises 112 nuclear particles – 50 protons and 62 neutrons. The neutrons act as a kind of buffer between the electrically repelling protons and prevent normal tin from decaying. Each atom will contain an equal number of electrons to its protons. Remove or add an electron and the atom becomes an ion, a charged particle.
The strange quantum world of the nuclei
Quantum mechanics which, amongst other things, explains how the electrons form into shells around the nucleus. Elements which have filled outer shells, helium, neon, argon, xenon are ‘noble’ gases, chemically inert – not the least reactive. Nuclei are also complex quantum objects.
As far as we know, nuclei are the smallest objects that can be split up into their constituents. They are therefore the smallest entities which emergent properties – patterns that arise from complexity – can be studied. Nuclear scientists study these emergent phenomena and are using them to decipher the nature of the nuclear force. In contrast to the structure of atoms, for which the fundamental interaction between the electrons and the nucleus – the electromagnetic force – is known with great precision, the interaction between the nucleons – the strong nuclear force – is not so well known.
In nature not all combinations of nucleons are stable. As a general rule the more protons present then more neutrons are required to stablise the nuclei. A useful graphical presentation of this is the Segre table of radionuclides.
If the shell structure of electrons was difficult at first for scientists to come to terms with, then the shell structure exhibited by nucleons is not only unexpected it is complex enough not to be discussed in many quantum physics texts. It was first thought that such densely packed and strongly interacting objects as the nucleons would exhibit a liquid-like behavior, much like the flow of electrons in a good conductor such as a metal.
That is what makes these experiments so exciting.
Stability and magic numbers
Magic numbers are the number of protons or neutrons that form full shells in an atomic nucleus. The term is thought to have been coined by the physicist Eugene Wigner. The model has been used to explain – at least for stable nuclei – the observed sequence of magic numbers: 2, 8, 28, 50, 82 and 126.
Nuclei that have a magic number of neutrons or protons are more tightly bound than there non-magic counterparts. This intrinsic simplicity makes them prime candidates for testing proposed models of nuclear structure. Even more attractive are the doubly magic nuclei. The lighter nuclei helium-4, oxygen-16 and calcium-40 do follow the magic number sequence.
However because of the repulsion between protons the line of stable nuclei veers away from the symmetry line. As a result tin-100 represents the largest nuclei to follow the sequence. It is bound but unstable. It is very close to the edge of nuclear stability, where the nuclear force between the protons and neutrons can no longer bind them into a nucleus. Unfortunately, what makes this nucleus so attractive to study is what also makes it so difficult.
How to make a new element
In nature elements heavier than iron come into being only in powerful stellar explosions – supernovas. These include, for example, the precious metals gold and silver and the radioactive uranium. The cauldron of a supernova gives rise to a whole array of high-mass atomic nuclei. these decay to stable elements via different short-lived intermediate stages.
There are two ways to create new elements in the laboratory. The first is is to fuse two nuclei in a manner that minimises the loss of protons or α-particles (helium-4 nuclei). The second is is more brutal, fragmenting a small part off a heavier nuclei in a collision.
In these experiments energetic xenon-124 is sheared by making it collide with a target beryllium foil leaving a residue that is composed of 50 neutrons and 50 protons. Out of the 120,000,000,000,000 xenon-124 accelerated in the experiment, only 259 tin-100 nuclei were identified. These results were sufficient though for the decay of tin-100 to be studied with great precision.
The results, excitedly for the researchers, demonstrated a ‘superallowed Gamow-Teller decay‘. This type of β-decay is beyond the scope of this essay to explain, needless to say it does provide new experimental depth to the models of nuclear chemistry. It is an important decay transition that occurs in the collapse of supernovae. It also is important in putting boundaries on the possible mass of the neutrino. Both of which are important validations of the current nuclear theories as well as providing real experimental data to fine tune the theoretical models.
This allows more real models of nuclear synthesis to be constructed. Allowing a deeper understanding of how the atoms that make up our universe were created.
Now other laboratories around the world will work on improving the production rates of tin-100 and other exotic nuclei, based on these experiments. Allowing the emergent properties of these nuclei can be studied in more detail. Giving us greater understanding of the forces that bind these particles together – to make us!