Lucid thoughts http://lucidthoughts.com.au/wordpress making complex science accessible Fri, 15 Apr 2016 08:41:53 +0000 en-US hourly 1 https://wordpress.org/?v=4.6.4 Living in a bubble: inflatable modules could be the future of space habitats http://lucidthoughts.com.au/wordpress/?p=1816 http://lucidthoughts.com.au/wordpress/?p=1816#respond Fri, 15 Apr 2016 08:41:53 +0000 http://lucidthoughts.com.au/wordpress/?p=1816 issThe astronauts of the International Space Station welcomed the arrival of what we call the “Bigelow Bungalow”, officially known as the Bigelow Expandable Activity Module (BEAM) on April 10.

If all goes to plan, the station’s robotic arm will install the module later this week. Although, according to NASA’s Kirk Shireman, it won’t be inflated until late in May. BEAM will then remain inflated for a period of two years.

Expandable Habitats and BEAM Installation Animation, NASA.

The arrival of the inflatable module is a significant achievement for the future of space habitation and exploration. It is a major achievement for private space enterprises, especially for Bigelow Aerospace, which built the module, and SpaceX, which delivered it.

It is also an extraordinary achievement for public-private partnership, the commercialisation of government-funded research and NASA’s strategy to stimulate the commercialisation of space.

And it shows that the perceived dichotomy of public and private in space is a false one. It certainly looks like the future of space exploration and exploitation lies in these cooperative ventures.

Why an inflatable habitat?

The idea of using inflatable habitats in space is not new. NASA’s first telecommunication satellite, Echo 1, was an inflatable Mylar balloon. And, in the early 1960s NASA developed the concept of an inflatable space habitat.

According to NASA:

[…] unlike many early space station concepts, this design actually made it out of the concept phase and into production, though no models were ever flown.

NASA’s inflatable habitat prototype from 1961.
NASA

Concepts for inflatable lunar bases were also drawn up, as with this one from 1989, replete with, “a small clean room, a fully equipped life sciences lab, a lunar lander, selenological work, hydroponic gardens, a wardroom, private crew quarters, dust-removing devices for lunar surface work and an airlock”.

Inflatable Moon Base. NASA concept art, 1989.
NASA

In the 1990s, NASA developed the Transhab concept. Transhab was originally proposed as living quarters for a Mars mission, then developed as a possible crew quarters for the ISS.

However, the program was cancelled in 2000 due to budget constraints. The close resemblance between the Transhab concept and BEAM is no coincidence; Bigelow’s inflatables have evolved directly from Transhub.

NASA’s Transhab concept.
NASA-JSC, Frassanito and Associates (graphics image)

Enter Robert T Bigelow, who made his money in the hotel industry, founded Bigelow Aerospace in 1998. Starting in 2002, NASA and Bigelow entered into the first of a series of Space Act Agreements with NASA. In 2003, Bigelow was licensed the NASA patents related to Transhab expandable habitats.

The company launched its first test modules, Genesis 1 and Genesis 2, aboard a Russian Dnepr rocket in 2006 and 2007. These modules are currently still in orbit and providing invaluable images, videos and data. They were the lowest-cost spacecraft fabrications and launches in aerospace history.

While astronauts aboard the ISS might wish to have the additional space of a new small bedroom approximately four metres long and 3.2 metres wide, the purpose of the installation is entirely experimental. So it will remain empty and uninhabited for the duration its deployment on the ISS.

The primary goal of BEAM’s two-year deployment is to test its safety for future occupation, including radiation protection and the various procedures for delivery and installation.

During the two-year test, it will be monitored for structural integrity, temperature control and resistance to micro-meteoroids and other sources of leaks.

NextSTEP: deep space exploration?

One of NASA’s current strategies “is to stimulate the commercial space industry” through Space Act Agreements and the more recent Next Space Technologies for Exploration Partnerships (NextSTEP) program.

NextSTEP aims to promote public-private partnerships for developing deep-space exploration capabilities, testing them “in around and beyond cislunar space — the space near Earth that extends just beyond the moon”.

Bigelow Aerospace and NASA have signed a NextSTEP contract to develop the B330 Habitat to “support safe, affordable, and robust human spaceflight missions to the Moon, Mars, and beyond”. The B330 habitat will provide a much more spacious habitat than the ISS: 330 cubic metres, hence the name. That is substantially larger than the 160 cubic metre Destiny module of the ISS.

Components for the ISS are currently limited in weight and volume. This is where the inflatable habitats provide a scalable future for extraterrestrial habitation, providing they pass safety and durability requirements. Their volume and shape will not be restricted by the launch capabilities of the available rockets.

David Parker Brown at Airline Reporter has some great photos of a walk through of a B330 mock-up here. The direct evolution from NASA’s Transhab is clearly apparent in the B330’s structure.

B330 clamshell
Bigelow Aerospace

On April 11, just a day after BEAM was delivered to the ISS, Bigelow Aerospace and United Launch Alliance announced a partnership to launch two B330 habitats. The plan is for the first module to be launched in 2019 and the second in 2020. The modules will provide the first commercial space habitat research facilities in orbit.

However, according to Robert Bigelow,:

We are exploring options for the location of the initial B330 including discussions with NASA on the possibility of attaching it to the International Space Station (ISS).

A Bigelow Habitat with Mars in the Background
Bigelow Aerospace

And, while the B330 stations will initially be tested in low-Earth orbit, one strategic long-term goal is clearly to use these modules to support deep-space missions to the moon and Mars.

Of course, commercial entities also want to turn a profit. And NASA is offering a helping hand through programs like Startup NASA. But the permissible commercial uses of space, and the future of space utilisation and exploitation are going to need active international political dialogue about what the Outer Space Treaty had declared the “province of mankind”.

In the meantime, I’m sure many of us would settle for a visit to a “Bigelow Bungalow” in low-Earth orbit, where we could happily sip champagne from a tube and enjoy a not-so-very-private room with a view.

The Conversation

Morgan Saletta, PhD, History and Philosophy of Science, University of Melbourne and Kevin Orrman-Rossiter, Graduate Student, History & Philosophy of Science, University of Melbourne

This article was originally published on The Conversation. Read the original article.

]]>
http://lucidthoughts.com.au/wordpress/?feed=rss2&p=1816 0
The long hunt for new objects in our expanding solar system http://lucidthoughts.com.au/wordpress/?p=1811 http://lucidthoughts.com.au/wordpress/?p=1811#respond Thu, 04 Feb 2016 11:01:41 +0000 http://lucidthoughts.com.au/wordpress/?p=1811 View from the surface of the remote Oort Cloud planetoid Sedna, looking back towards the Sun and the inner Solar System; sky calculated for April 5, 2004

View from the surface of the remote Oort Cloud planetoid Sedna, looking back towards the Sun and the inner Solar System; sky calculated for April 5, 2004

Kevin Orrman-Rossiter, University of Melbourne and Alice Gorman, Flinders University

Recognise these planet names: Vulcan, Neptune, Pluto, Nemesis, Tyche and Planet X? They all have one thing in common: their existence was predicted to account for unexplained phenomena in our solar system.

While the predictions of Neptune and Pluto proved correct, Nemesis and Tyche probably don’t exist. Now we have another contender, Planet Nine – the existence of which astronomers predicted last month – but we may need to wait ten or more years for it to be confirmed.

Compare this to Vulcan. While many claimed to have observed the predicted planet, it took 75 years and Einstein’s general theory of relativity to consign it to the dustbin of history.

Somewhere out there

Astronomers are finding new exoplanets in other parts of the galaxy all the time. So why is it so hard to pin down exactly what is orbiting our own sun?

One reason is that very different methods are used to identify planets in other solar systems. Most involve observing periodic changes in the star’s light as the planet swings around it, as intercepted by telescopes such as Kepler.

Inside our own solar system, we can’t see these effects when we’re looking out into the darkness rather than towards the sun. Instead, planet-hunters use indirect means. Slight wobbles and perturbations in the orbits of planets, comets and other objects may reveal the gravitational presence of ghostly neighbours we didn’t know we had.

This method has been used often over the past two centuries to predict new planets.

The planet that arrived late

In 1843, French mathematician Urbain Le Verrier published his provisional theory on the planet Mercury’s orbital motion.

Three years in the writing, it would be tested during a transit of Mercury across the face of the sun in 1845. But predictions from Le Verrier’s theory failed to match the observations. Mercury was late by 16 seconds!

A photomosaic of images collected by Mariner 10 as it flew past Mercury. But was there another planet nearby?
NASA

Le Verrier was not deterred. Further study showed that Mercury’s perihelion – the point when it’s closest to the sun – advances by a small amount each orbit, technically called perihelion precession.

But the amount predicted by classical mechanics differed from the observed value by a miniscule 43 arcseconds per century.

Initially, Le Verrier proposed that the excess precession could be explained by the presence of an asteroid belt inside the orbit of Mercury. Further calculations led him to prefer a small planet, which he named Vulcan after the Roman god of fire.

The search for Vulcan

It was a credible claim, as in 1845 Le Verrier had also successfully predicted the position of Neptune from perturbations of Uranus’s orbit. Now astronomers just had to find Vulcan.

As planet fever hit the popular press, professional and amateur astronomers reviewed solar photographs to see whether Vulcan transits had been mistaken as mere sunspots.

The first possible sighting came immediately. In 1859 Edmond Lescarbault, a country doctor and gentleman astronomer in France, claimed to have seen Vulcan transit across the sun.

Further sightings continued, and by the mid-1860s The Astronomical Register listed Vulcan as the innermost planet.

Vulcan’s moment in the sun came to a head in 1869. Observations of solar transits in March and April and a solar eclipse in August failed to see the elusive planet.

Not everyone was ready to give up, though. At the Sydney Observatory, astronomer Henry Chamberlain Russell watched the sun for three days in March 1877, according to a report in Sydney’s Evening News, on Friday March 23, which said:

No sign of Vulcan appeared all through the 20th and 21st. But in watching for this planet several interesting observations were made of the sun’s spots.

Newspaper report on the search Vulcan by Sydney astronomer H C Russell.
National Library of Australia/Evening News

The explanation for the missing seconds came from a completely different direction. After Einstein published his general theory of relativity in 1915, it was revealed that the discrepancy was caused by the sun’s distortion of spacetime.

Beyond Planet X

In 1905, the American astronomer Percival Lowell started hunting for a Planet X. He predicted it would lie beyond Neptune, just as Neptune lies beyond Uranus. His calculations led astronomers at Lowell’s namesake observatory to find Pluto in 1930.

Speculation about unsighted planets never entirely died down in the astronomical community, but decades passed without any major breakthroughs.

In the 1950s, though, the solar system potentially expanded to a distance 100,000 times further that Earth’s orbit. The Dutch astronomer Jan Hendrik Oort hypothesised the existence of a spherical distribution of icy bodies. The Oort Cloud is thought to be the source of long period comets, which have eccentric orbits and periods from 200 to many thousands of years.

In 1951 the Dutch-American astronomer Gerard Kuiper proposed that a similar belt of icy objects beyond Neptune’s orbit could account for short-period and short-lived comets. In 1992 astronomers David Jewitt and Jane Luu discovered the first of these Kuiper Belt Objects (KBO) – originally called “Smiley”, it is now catalogued more prosaically as 1992 QB1.

The most well-known KBOs are Eris, Sedna and the dwarf planet Pluto. After flying by Pluto on July 15, 2015, the New Horizons spacecraft is due to encounter KBO-2014 MU69 on January 1, 2019.

Speculation and measurement

Other predictions for new solar system objects came from looking at the terrestrial fossil record, rather than the skies.

On the basis of statistical analysis of mass extinctions, the America palaeontologists David Raup and Jack Sepkoski proposed in 1984 that they coincided with large-impact events. Independently, two teams of astronomers suggested that a dwarf star, later named Nemesis, passes through the solar system every 26 million years, flinging comets on a path to impact Earth.

Comets provide key evidence in these studies. Analysis of perturbations in comet orbits led astronomers to propose that a brown dwarf (bigger than a planet but smaller than a star) exists in the outer solar system. It is named Tyche, the good sister of Nemesis.

A search of the Wide-Field Infrared Survey Explorer (WISE) satellite data in 2014 ruled out the existence of both Nemesis and Tyche.

In 2003, the “Pluto killer” Michael Brown was part of a team that discovered what he called “the coldest most distant place known in the solar system”, which came to be known as Sedna. The discovery of this Kuiper belt object prompted further searches and much speculation as to its origin – particularly its strange orbit.

As more and more objects were identified in the Kuiper Belt, it was possible to observe orbital anomalies more precisely. The simplest way to explain them was another planet.

The 2016 orbital calculations by Konstantin Batygin and Mike Brown strengthen the concept of an unseen planet, which they call Planet Nine.

Planet Nine from Outer Space

What difference does it make if there is another planet lurking out there? We’re not likely to see it any time soon.

Artist’s impression: The distant view from Planet Nine back towards the sun.
Caltech/R. Hurt (IPAC)

At its closest approach to Earth, the predicted Planet Nine will still be 200 astronomical units (au) away (about 30 billion kilometres). Compare this to Pluto’s orbit, which is an average of 39 au from the sun (5.8 billion kilometres). We don’t even know where Planet Nine is right now, if it exists at all.

But everything we learn about the dark outer regions contributes to the story of how our solar system evolved, and, more importantly, how it will change in the future.

In 1957, journalist John Barbour quipped:

What with Russia’s Sputniks, and the gaudy possibilities of interplanetary travel to come, our solar system seems to be shrinking somewhat like the Earth did when aeroplanes came into use.

Now, it seems, the opposite is true: the mysterious trans-Neptunian region of the solar system has still much to surprise us.

The Conversation

Kevin Orrman-Rossiter, Graduate Student, History & Philosophy of Science, University of Melbourne and Alice Gorman, Senior Lecturer in archaeology and space studies, Flinders University

This article was originally published on The Conversation. Read the original article.

]]>
http://lucidthoughts.com.au/wordpress/?feed=rss2&p=1811 0
http://lucidthoughts.com.au/wordpress/?p=1807 http://lucidthoughts.com.au/wordpress/?p=1807#respond Thu, 16 Jul 2015 22:01:56 +0000 http://lucidthoughts.com.au/wordpress/?p=1807 Finding Pluto: the hunt for Planet X

This artist's impression shows one of the three newly discovered planets in the star cluster Messier 67. In this cluster the stars are all about the same age and composition as the Sun. This makes it a perfect laboratory to study how many planets form in such a crowded environment. Very few planets in clusters are known and this one has the additional distinction of orbiting a solar twin — a star that is almost identical to the Sun in all respects.

Kevin Orrman-Rossiter, University of Melbourne and Alice Gorman, Flinders University

Our solar system’s shadowy ninth (dwarf) planet was the subject of furious speculation and a frantic search for almost a century before it was finally discovered by Clyde Tombaugh in 1930. And remarkably, Pluto’s reality was deduced using a heady array of reasoning, observation and no small amount of imagination.

The 18th and 19th centuries were thick with astronomical discoveries; not least were the planets Uranus and Neptune. The latter, in particular, was predicted by comparing observed perturbations in the orbit of Uranus to what was expected. This suggested the gravitational influence of another nearby planet.

John Couch Adams and Urbain-Jean-Joseph Le Verrier calculated the orbit of Neptune by comparing these perturbations in Uranus’ orbit to those of the other seven known planets. Neptune was hence discovered in the predicted location in 1846.

Soon after this, French physicist Jacques Babinet proposed the existence of an even more distant planet, which he named Hyperion. Le Verrier wasn’t convinced, stating that there was “absolutely nothing by which one could determine the position of another planet, barring hypotheses in which imagination played too large a part”.

Despite that lack of evidence for perturbations in Neptune’s orbit, many predicted the existence of a ninth planet over the next 80 years. Frenchman Gabriel Dallet called it “Planet X” in 1892 and 1901, and the famed American astronomer William Henry Pickering proposed “Planet O” in 1908.

Comets, the law of vegetable growth and a conspiracy

In addition to the perturbations of known planets there were other hypotheses that foretold unknown bodies beyond Neptune.

In the 19th century, it was understood that many comets had highly elliptical orbits that swung past the outer planets at their farthest points from the sun. It was believed that these planets diverted the comets into their eccentric orbits.

Pluto is not only distant, but it’s small. That makes it very difficult to see from Earth.
NASA

In 1879 the French astronomer Camille Flammarion predicted a planet with an orbit 24 times that of Earth’s based on comet measurements. Using the same method, George Forbes, professor of astronomy at Glasgow University, confidently announced in 1880 that “two planets exist beyond the orbit of Neptune, one about 100 times, the other about 300 times the distance of the earth from the sun”.

Depending on how the calculations were done, the results predicted anything from one to four planets.

Other predictions were based on what can be described as numerical curiosities or speculations. One of these was the now-discredited Bode’s law, a sort of Fibonacci sequence for planets. The American mathematician Benjamin Pierce was not a fan, claiming that “fractions which express the law of vegetable growth” were more accurate than Bode’s law.

As well as these earnest astronomers, the trans-Neptunian planet idea attracted cranks and visionaries. An interesting contribution came in 1875 from Count Oskar Reichenbach, who accused Le Verrier and Adams of conspiring to conceal the locations of two trans-Neptunian planets.

The early photographic searches

Theories and calculations were all well and good, but many hoped to actually see the hitherto invisible planet(s). From the late 1800s new powerful telescopes equipped with the latest dry-plate photographic technologies were employed to search for undiscovered planets.

Pluto isn’t easy to spot. This 10 minute exposure shows the apparent magnitude of Pluto compared to some nearby stars.
Kevin Heider, CC BY-SA

Amateur astronomers such Isaac Roberts and William Edwards Wilson used the predictions of George Forbes to search the skies, taking many hundreds of photographic plates in the process. They found no lurking trans-Neptunian planets.

The professionals fared no better. Edward Charles Pickering, director of the Harvard Observatory and William’s brother, spent around ten years from 1900 searching using his own data and those of earlier astronomers such as Dallet, all to no avail.

Lowell’s approach

In 1906 a new approach was introduced by the veteran astronomer Percival Lowell. Although best known to us for his (mistaken) observations of canals on Mars, Lowell bought a new rigour to analysing the orbit of Uranus based on observational data from 1750 to 1903.

With these improved calculations, hope for a visual fix on the elusive planet was renewed. With the aid of the brothers Vesto and Earl Slipher, Lowell spend the rest of his life scanning photographic plates with a hand magnifier and finally with a Zeiss blink comparator.

In September 1919 William Pickering kicked off another search for “Planet O” based on deviations in Neptune’s orbit. Milton L Humason, from the Mount Wilson Observatory in California, started a search based on these new predictions as well as Lowell’s and Pickering’s 1909 predictions. This search again failed to find any new planets. Pickering continued to publish articles on hypothetical planets but by 1928 he had become discouraged.

Zeiss Blink comparator at Lowell Observatory used in the discovery of Pluto by Clyde Tombaugh in 1930
nivium/Wikimedia, CC BY

A planet among 160,000 stars

As part of Lowell’s legacy, the Lowell Observatory built a special astrographic telescope. It was completed in 1929, and under Vesto Slipher’s direction, a young assistant was assigned to take and examine the photographs of the farthest reaches of the solar system. His name was Clyde Tombaugh.

This was grim, unglamorous work. Each plate was exposed for an hour or more, with Tombaugh adjusting the telescope precisely to keep pace with the slowly turning sky. Today a computer would make the comparisons, but in 1929 they were made by eye, manually flicking between two images. Stars would remain motionless while other bodies would seem to jump between views. Some images would have 40,000 stars, others up to 1 million.

Nearly a year had elapsed when, on February 18, 1930, two images fifteen times fainter than Neptune were found among 160,000 stars on the photographic plates. The discovery was confirmed by examining earlier images. On February 20 the planet was observed to be yellowish, rather than bluish like Neptune. The new planet had revealed its true colours at last.

Announcing a discovery

Slipher waited until March 13 to announce the discovery. This was both Lowell’s birthday and the anniversary date of the discovery of Uranus. The announcement set off a worldwide rush to observe and photograph the new planet.

Now that astronomers, amateur and professional alike, knew what they were looking for, it turned out that Pluto had been hiding in plain view. Re-examination of Humanson’s plates showed four images of Pluto from his 1919 survey, and there were many others.

On March 14, an Oxford librarian read the news to his 11-year old granddaughter Venetia Burney, who suggested the name Pluto. It was also suggested independently in a letter by William Henry Pickering.

To complete the circle, some of Clyde Tombaugh’s remains are in a canister attached to the New Horizons spacecraft.

Most people alive today would not remember a universe without Pluto. And from 2015, its patterned surface will enter our visual vocabulary of the planets. Once seen, it can never again be unseen. Planet X, welcome to our world.

The Conversation

Kevin Orrman-Rossiter is Graduate Student, History & Philosophy of Science at University of Melbourne.
Alice Gorman is Senior Lecturer in archaeology and space studies at Flinders University.

This article was originally published on The Conversation.
Read the original article.

]]>
http://lucidthoughts.com.au/wordpress/?feed=rss2&p=1807 0
The search for life beneath the ice: why we’re going back to Europa http://lucidthoughts.com.au/wordpress/?p=1801 http://lucidthoughts.com.au/wordpress/?p=1801#respond Wed, 08 Jul 2015 23:30:35 +0000 http://lucidthoughts.com.au/wordpress/?p=1801 sdppbyvj-1436248520Morgan Saletta, University of Melbourne and Kevin Orrman-Rossiter, University of Melbourne

Last month NASA gave the “all systems go” for a new mission to Europa. But why go back? After all, we’re still sifting through the data from the Galileo probes fly-bys from more than a decade ago.

The short answer: it’s all about life.

The Jovian moons – named after Jupiter’s lovers by Simon Marius – have been a source of scientific speculation since Galileo trained his telescope on Jupiter in 1610, announcing his discovery in the Sidereal Messenger.

But the idea that Europa and other moons of Jupiter might harbour life is relatively new, as is the notion they might have hidden oceans beneath their icy surfaces. Indeed, these speculations demonstrate just how fast our conceptions of the solar system, and life, can change.

Speculative science, speculative fiction

A generation of space scientists and enthusiasts who grew up on Robert A. Heinlein’s “juveniles” will fondly remember Farmer in the Sky, written in 1950, when the Jovian moons were believed to be rocky, like our own Moon.

But in the late 1950s and continuing through the early 1970s, a growing body of telescopic data suggested that some of these moons, in particular Callisto, Ganymede and Europa, were covered in water ice. This speculation came from their high albedo, a measure of how much they light they reflect. With an albedo of 0.64, Europa is one of the most reflective bodies in the solar system.

In 1971, Carl Sagan suggested that the Jovian moons, including Europa, were of “major…exobiological significance”. In other words: they might harbour life.

Europa as seen by Voyager 2 during its close encounter in 1979.
NASA/JPL

The early 1970s also saw the first speculation that some outer moons of the solar system, including Europa, might hide an ocean beneath their surfaces. It was initially suggested this might be due to radiative heating, although it was later proposed that the heat might come from tidal forces induced by Jupiter, especially because of the synchronous orbits of the three innermost Galilean moons: Io, Europa and Ganymede.

The 1979 Voyager fly-bys confirmed that Callisto, Europa and Ganymede moons were covered in ice and that Io was extremely volcanic. The best images of Europa were taken by Voyager 2 from a range of 204,400 kilometres, showing Europa to be “billiard ball” smooth.

Not too hot, not too cold…

Things took a turn following the discovery by Robert Ballard’s 1977 expedition of entire ecosystems thriving near hydrothermal vents in the deep ocean. These vents existed in the “midnight zone”, without sunlight and photosynthesis, and changed the way we thought about life.

The discovery of life around deep ocean vents, like this one, raised the exciting prospect of life existing under the ocean on Europa.
P. Rona/NOAA

In 1980, scientists Gerald Feinberg and Robert Shapiro hypothesised that deep sea volcanism might support life on the Jovian moons. The Feinberg-Shapiro hypothesis is one of the major reasons for the current interest in Europa by astrobiologists.

In essence, it was proposed there might be a tidally heated habitable zone around giant planets, similar to the habitable, or “Goldilocks” zone around a star: where it’s not to hot, not to cold, and where liquid water and life can exist.

The idea of life on the Jovian moons was quickly picked up by science fiction writers. In Arthur C. Clarke’s 2010: Odyssey two (1982) and 2061: Odyssey three (1988), aliens transform Jupiter into a star kick-starting the evolution of life on Europa, transforming it into a tropical ocean world forbidden to humans.

In Bruce Sterling’s 1985 Nebula Award nominee, Schismatrix, Europa’s ocean is colonised by a group of genetically transformed post-human species.

Fire and ice

Europa and life were thus well and truly established in the minds of science fiction writers, planetary scientists, exobiologists and the public by the time NASA’s extraordinary Galileo mission began taking images of Europa in 1996.

This is the colour view of Europa from Galileo, taken in the 1990s, that shows the largest portion of the moon’s surface at the highest resolution.
NASA/JPL

By the completion of its primary mission on December 7 1997, Galileo had made eleven encounters with Europa. Galileo’s extended mission became one of “fire and ice”: its twin foci were Io’s vulcanism and Europa’s icy oceans. The Europa fly-bys took the probe to within a few hundred kilometres of the moon’s surface.

These extensive observations of Europa by the Galileo mission were compelling evidence for a liquid water ocean some 100 to 200 kilometres thick on which “floats” an outer shell of ice. Magnetometer measurements indicate the ocean is free flowing and salty.

Galileo also provided spectacular views of the icy terrain: ridges, slip faults and “ice-bergs”, all adding to the picture of a surface only 10-100 million years old, which is young by the four to five billion year age of the solar system.

The spacecraft, nearly out of fuel after an extended mission, was deliberately crashed into Jupiter on 21 September 2003 to protect Europa from possible contamination.

Europa Report

The data Galileo collected are still revealing new important finds. There evidence of clay-like minerals on the surface, possibly from asteroid or meteorite collision, and signs of sea salt, discoloured by radiation, making up some of the dark patches observed by both Voyager and Galileo.

A whole new generation of scientists is eagerly awaiting the data from the new mission. Astrobiology has become, since the early 2000s, a whole new science discipline. This “alien ocean” mission is clumsily named, at present, Europa Multiple Flyby Mission.

So the new mission, slated for a rendezvous with Europa in 2030, won’t involve a lander. And until we can send a probe into the icy depths of Europa’s sea, speculation about what might be lurking there, à la Sebastián Cordero’s Europa Report, will remain the domain of science fiction and scientists’ fantasy. Maybe one day, it will be science fact. Europa, here we come.

The Conversation

Morgan Saletta is Doctoral Candidate History and Philosophy of Science at University of Melbourne.
Kevin Orrman-Rossiter is Graduate Student, History & Philosophy of Science at University of Melbourne.

This article was originally published on The Conversation.
Read the original article.

]]>
http://lucidthoughts.com.au/wordpress/?feed=rss2&p=1801 0
From Newton to Hawking and beyond: a short history of the Lucasian Chair http://lucidthoughts.com.au/wordpress/?p=1793 http://lucidthoughts.com.au/wordpress/?p=1793#respond Fri, 19 Jun 2015 05:02:29 +0000 http://lucidthoughts.com.au/wordpress/?p=1793 96qmwvbz-1434600319Kevin Orrman-Rossiter, University of Melbourne and Morgan Saletta, University of Melbourne

On July 1 physicist Michael Cates will be the 19th person to sit in what is perhaps the most prestigious “chair” in science when he assumes the post of the Lucasian Professor of Mathematics at Cambridge University.

Although sometimes called “Newton’s chair” after its most famous holder, Sir Isaac was not the only brilliant mind, nor the most colourful individual, to occupy the post.

The Lucasian Chair was founded in 1663 at the bequest of Henry Lucas (1640-1648), who was a member of Parliament for Cambridge University. In his will, he provided “a yearly stipend and salarie for a professor […] of mathematicall sciences in the said Vniversitie” to “honor that greate body” and assist “that parte of learning which hitherto hath not bin provided for”.

The Lucasian Chair has been held by a fascinating procession of scientists, including

It also has the unusual distinction of having been held by a famous – though fictitious and wholly artificial person – Star Trek: The Next Generation’s Data, in the series’ final episode, “All Good Things…”. But that is another quantum timeline.

Smart seat

The first Lucasian Professor, Isaac Barrow, held both the Regius Professorship of Greek and Gresham Chair in geometry.

Sadly, Barrow’s early ardour for mathematics had waned by the time he took up the Chair in 1663. His “method of tangents”, though, was seen as ground breaking at the time. This proto-calculus set the scene for his brilliant successor: Isaac Newton.

Newton was elected to the Chair after his anni mirabiles of 1666. According to William Stukeley’s 1752 biography, that is the year Newton inferred the law of gravity by observing an apple falling in his orchard as he “sat in contemplative mood”.

While Lucasian Professor, Newton developed his most important contributions to science, in particular the masterpieces Philosophiae Naturalis Principia Mathematica (1687) and Opticks (1704).

At the time of Newton’s election in 1669, the Lucasian Chair was one of eight Chairs at Cambridge. The Lucasian Professor is elected, then as now. The election is made by the masters of the Colleges at Cambridge, with the vice chancellor able to break a deadlock if required.

An uneven history

Despite its prestige, the history of the Chair is not one of undiluted greatness.

The stories of the post-Newtonian Chairs of William Whiston (from 1702 to 1710), Nicholas Saunderson (1711 to 1739), John Colson (1739 to 1760), Edward Waring (1760 to 1798) and Isaac Milner (1798 to 1820) was largely one of translating, teaching, expanding and developing the great works of former Chair-holder, Newton.

In the latter half of the 19th century, as science became the arena of professional scientists rather than dilettante gentlemen, the Lucasian Chair was sometimes used as a stepping stone to more lucrative or important positions.

Robert Woodhouse (Chair from 1820 to 1822) lasted only two years in the post. He was rewarded for his “conformity” by securing the Plumian Chair of mathematics and the directorship of the Cambridge astronomical observatory.

His successor, Thomas Turton (from 1822 to 1826), described as “mathematically inert and utterly reliable”, departed to the more prestigious Regius Chair of Divinity (founded in 1540 by Henry VIII) and better paid dean-ships, eventually becoming the Bishop of Ely.

Dirac and the quantum age

Nevertheless, while the term might not apply to all holders of the Chair, Paul Dirac (from 1932 to 1969), was indisputably brilliant. In fact, Dirac personified the stereotype of the lone genius.

Paul Dirac was one of the more brilliant Lucasian Professors. He predicted the existence of antimatter before it was first detected.
Nobel Foundation

Einstein said of him: “This balancing on the dizzying path between genius and madness is awful.”

By the age of 26, Dirac had, in the period from 1925 to 1928, developed his own theory of quantum mechanics and relativistic quantum theory of the electron, as well as predicted the existence of antimatter.

Dirac, like Newton, also made significant contributions to science in his tenure as Lucasian Professor. According to John Polkinghorne, Dirac was once asked about his most fundamental belief, upon which, “he strode to a blackboard and wrote that the laws of nature should be expressed in beautiful equations”.

Hawking: the stopgap professor?

Of the more recent holders of the Lucasian Chair, it is the name of Stephen Hawking, who held the Professorship for three decades from 1979 to 2009, that has become most synonymous with the post – and a household name at that.

In an interview with Hélène Mialet, Hawking said he always assumed he was elected as a stopgap professor because he was not expected to live a long time and his “work would not disgrace the standards expected of the Lucasian chair”.

Nonetheless he confounded his doctors and held the chair until the retirement age of 67.

Hawking had, at the time of his election, hoped the Chair might go to a brilliant scientist who was not already affiliated with or educated at Cambridge. This would have been a remarkable change.

Holders of the Lucasian Chair have all been Cambridge graduates, in addition to being male and British. Only Dirac and Hawking have undergraduate degrees from a university other than Cambridge (Bristol and Oxford, respectively). Dirac alone was not of British birth – he was a Swiss national, though born in England in 1902 and acquiring British nationality in 1919.

The quality of Hawking’s scientific output puts this “stopgap professor” in the Lucasian top-three league, along with Newton and Dirac.

Incidentally, Stephen Hawking played a game of poker with Star Trek’s Data – the fictitious future Lucasian Chair – along with fellow Chair Isaac Newton and Albert Einstein (the latter played by actors, of course) in Star Trek: the Next Generation’s episode “Descent”.

Hawking was succeeded by Michael Green, who was Lucasian Professor from 2009 to this year. Green made long-term contributions to mathematics, including pioneering string theory in 1984.

What does the future of the chair hold?

Michael Cates is certainly no stopgap professor. Cates is an expert in the statistical mechanics of “soft materials”, examples of which are: colloids (paint); emulsions (mayonnaise); foams (shaving cream); surfactant solutions (shampoo); and liquid crystals (flat screen TVs).

His models capture the essential physics without including all the, at times confounding, chemical detail.

Prior to his election as Lucasian Professor, Cates held a Royal Society Research Professorship at Edinburgh. At age 54, he will likely hold the Chair for more than a decade. It will be fascinating to see what he contributes to mathematics and the ongoing Lucasian history during his tenure.

As for future chairs? If Star Trek is any indication, it will continue to be populated by some of the most brilliant minds in the known universe – although one wonders when it might be finally held by a brilliant woman.

The Conversation

Kevin Orrman-Rossiter is Graduate Student, History & Philosophy of Science at University of Melbourne.
Morgan Saletta is Doctoral Candidate History and Philosophy of Science at University of Melbourne.

This article was originally published on The Conversation.
Read the original article.

]]>
http://lucidthoughts.com.au/wordpress/?feed=rss2&p=1793 0
The emerging new astronomy of the 17th century: Comets were not that important http://lucidthoughts.com.au/wordpress/?p=1771 http://lucidthoughts.com.au/wordpress/?p=1771#respond Mon, 23 Mar 2015 02:47:54 +0000 http://lucidthoughts.com.au/wordpress/?p=1771 u9zyjihhpmzbxbz5dwsqIntroduction

Here I will be arguing that comets were not instrumental in the emergence of modern astronomy in the 17th century. This view, most notably propounded by Kuhn and Hellman , where observations of comets were of paramount importance in ushering in a post-Newtonian modern astronomy by the end of the 17th century. Heidarzadeh posits that the history of comets falls into four periods, the first two being most relevant to this discussion: from Aristotle to Brahe comets were assumed to be meteorological phenomena; from Brahe to Newton, comets were admitted as celestial bodies but with unknown trajectories; from Newton to Laplace, they were treated as members of the solar system; and the post-Laplacian period, in which the mass and density of comets was calculated to be much less than the planets.

The focus here is particularly on observations of the 1577 comet by Tycho Brahe and Michael Mästlin and the 1607 comet by Johannes Kepler and Edmond Halley. From their observations and subsequent explanations it is obvious that there was more than science involved in their arguments: their actions cannot be removed from the political, social and cultural context of their time. In agreement with Nouhuys and Schechner Genuth I find that in the contemporary 16th and 17th century view there was no distinction between magical and scientific ideas, and to assess the science without appreciating this leads to a misleading understanding of the role played by comets in this period. In Kepler’s extensive writing we also find concurrence; he found comets to be unimportant in his arguments for a new cosmology. In addition, the shared discourse of comet lore, into the 18th century, was for comets  still seen as agents of upheaval, renewal and divine justice.

A tour of the universe in 1577

By modern astronomy, I mean a world-view where the solar system is heliocentric, with planets and comets for example, having elliptical orbits, described by Kepler’s laws and Newtonian mechanics. In the late 16th – early 17th centuries though, there were a variety of opinions advanced regarding the universe: the shaping of ‘scientific’ ideas is marked by the adaptability of the Renaissance Aristotelians, the role played by humanism, as well as astrology and divinatory beliefs.

Aristotle (384-322 BC) presented a long lasting model of the universe. The key idea, for our purposes, was it comprised a terrestrial and celestial tier. The lower terrestrial tier, from the moon down to the centre of the earth, was composed of four elements: earth, water, air and fire. The celestial tier, containing the planets (which included the moon and sun) and the stars, was made of a fifth, non-material, element; aither. The upper tier was unchanging. The stars were fixed to an outer, perfect, sphere revolving around the centre of the universe, the earth. Likewise the planets were fixed to interlocking spheres that transported motion from planet to planet. A key idea here, and somewhat challenging to our modern sense of material and immaterial, is that these non-material spheres were hard and impenetrable, ‘adamantine’, solid enough to keep the planets fixed in their motions and ensure that the spheres did not overlap. The terrestrial tier was the home of all change and corruption. Here was where Aristotle placed comets – they were sub-lunar phenomena composed of hot dry exhalations. They are referred to in his text on “Meteorology”, not “On the Heavens”.

This, highly philosophical model of Aristotle, was complemented by the mathematical model of Claudius Ptolemy (c.100-c.178 AD). Here Ptolemy successfully incorporated 800 years of observational data into a geometric model based on Aristotle’s. By incorporating epicycles and equants Ptolemy successfully predict planetary motions. Ptolemy accepted Aristotle’s aither, but not his interlocking spheres that transmitted motion from the stars to each successive planet, finishing before the terrestrial realm. Along with its predictive accuracy another of its successes is its simplicity from the point of view of the earth-stationed observer .

The challenge to the geocentric model of Aristotle and Ptolemy by Nicolaus Copernicus (1473-1543) in his 1543 work De revolutionibus orbium coelestium is well documented. The fundamental objection that Copernicus had to geocentrism was directed against both Aristotle and Ptolemy. He found it strange that motion was imparted to the ‘fixed’ stars to make the planets move. Copernicus argued it is better to have the Earth in motion and to reduce the complexity of the epicycles, and remove the equants needed to describe the geocentric system. This argument was one contemporary to Aristotle – it was reworking a Stoic criticism. However comets did not appear in Copernicus’ universe. However they did make an appearance in 1577.

Brahe, Mästlin and the comet of 1577

On the afternoon of November 13, 1577 Tycho Brahe (1546-1601), Danish royal consultant on astronomical and astrological matters, noticed a bright star. When a long ruddy tail, stretching in the opposite direction from the sunset, grew visible Brahe realised it was a comet – at age 31, it was the first he had seen. For the next two and a half months he observed and recorded its position against the fixed stars. From these parallax measurements, Brahe concluded that the comet was about one third of the way from the earth to the stars. This was the first major comet post Galileo’s telescopic discovery of the moons of Jupiter. The parallax measurements, like Galileo’s moons, challenged the logicality of immutable heavens, both Aristotle’s celestial sphere and the existence of crystalline spheres supporting the planets, rather than the geocentric model. Brahe had been skeptical of Aristotle’s distinction between the celestial and terrestrial regions, a subject he had delivered a lecture series on in 1574-5. In addition he had witnessed a nova, the ‘new star’ of 1572, which revealed the heavens to be mutable.

tycho_1577comet

In 1578 Brahe wrote a brief manuscript on the 1577 comet in German. The 1577 comet had also stimulated him to develop a new model of the planetary system with a stationary Earth still as the centre of the universe, around which the sun and moon revolved, with the planets revolving around the sun. This model was developed by 1583 and published by Brahe in 1588 in De mundi aetherei recentioribus phaenomenis liber secundus. While the rejection of the crystalline spheres and the imperfection of the celestial region led Brahe to examine the Copernican model, they were not sufficient to overthrow the ancient models.

Politics and astrology were inextricably linked with the 1577 astronomical observations for Brahe. Within five weeks of the comet sighting a pamphlet had been produced by Jørgen Dybvad, a professor at the University of Copenhagen. He had first sighted the comet on November 11, 1577, whilst in the company of King Frederick of Denmark. His pamphlet, written for a public audience in the vernacular German and dedicated to the King, can be seen more as a political document than a scientific one. In it he delivered an apocalyptic message based on the “terrible great comet” including “2000 years of astrological and historical evidence” to bolster his assertions. Brahe’s pamphlet response was then as much to assert his own political credibility and influence with the King, as to develop his scientific endeavours. In his pamphlet on the comet Brahe states:

It is regrettable that this comet, no less than former ones, brings and arouses the same evil effects and misfortunes here on earth, so much the more so because this comet has grown so very much greater than others and has a saturnine, evil appearance, which was revealed by its pallid appearance and unclearly shining color like the star Saturn.

Brahe then went onto presage, for example, calamities for Europe west of Denmark, as the comet had “first let itself be seen with the setting of the sun.” The arena was more about astrology and royal influence than modern scientific debate.

Michael Mästlin (1550-1631), astronomer at the University of Tübingen and teacher of Johannes Kepler (1571-1630), also observed the 1577 comet. Voelkel claims “Mästlin was the only convinced Copernican teaching at a university in Europe when Kepler was a student.” Mästlin was another who concluded the comet being located beyond the moon. Mästlin’s most important contribution was subtle; he attempted to compute the comet’s orbit. With only limited orbital information available he was genuinely innovative in trying to find an orbit for this transitory phenomenon: assigning a circular heliocentric orbit, between that of Earth and Venus, for the comet. Mästlin used, in his published demonstratio, the Copernican model as a calculation tool, without directly supporting the model. Mästlin’s orbital results were overshadowed by Brahe’s study; however he greatly influenced his student, Kepler.

In addition to these astronomical innovations, the observations also changed the nature of augury. However, new models and instruments did not change comets remaining as portends, this despite the growing interest in physical models of comets. Mästlin, along with others including Brahe, proposed that the comet tales were produced as an optical effect caused by sunbeams shining through translucent spheres. In addition to Brahe’s politically motivated divinations others such as John Bainbridge, future Savilian professor of astronomy at Oxford, were still seeing evidence of divine providence in the comet of 1618, this comet lore starting to decline in learned circles by the end of the 17th century.

Kepler, Newton and Halley and the comet of 1607

Kepler first acknowledges his faith in the Copernican model arose from the studies of the 1577 comet by Mästlin. Kepler’s 1593 student disputation argued for the new order of the inferior planets and the dispensability of Aristotle’s adamantine spheres. This can be seen as a preference rather than necessity, as Kepler was also the first to demonstrate the geometrical equivalence of the Ptolemaic and Copernican models. Most importantly for my argument by 1604 Kepler had downplayed the influence of the observations of the 1577 comet and had decided that all comets had rectilinear paths. This is despite publishing the idea of elliptical orbits for the planets in his 1605 Astronomia Nova. By the 1621 second edition of his Cosmographic Mystery Kepler had decided that the comet had entirely outlived its original usefulness as an argument in support of his new cosmology.

In 1619 Kepler published his book De Cometis Libelli Tres which included a diagram of the 1607 comet, clearly identifying the comets path as rectilinear. In 1695 Edmond Halley used this and observation data from John Flamsteed (1646-1719), the first Astronomer Royal, to compute the path for the comet of 1680-81, and conclude that it was the same as the comets of 1607 and 1531. Working with Isaac Newton they found that the comets travelled in closed elliptical orbits, following Kepler’s descriptions and the soon to be published universal laws of Newton’s Principia. Furthermore Halley predicted the comet to reappear in 1758.

newton et halley

While this appears straight forward from the perspective of ‘progress’ in physics it was neither necessary nor sufficient for the acceptance of the Copernican model. Ariew has argued that the Aristotelian theory of comets, suitably modified, survived in text books and university theses well into the second half of the 17th century. For example by 1657 Aristotelians accepted comets as celestial objects, as stars not a fire, and therefore not sublunary; therefore not challenging the idea of a firmament, some adopting a view along the lines of a Tychonic or semi-Tychonic system on account of comets. Kepler, as argued, saw the comet as extraneous to his model, and both Newton and Halley “continued to see comets as harbingers of cataclysmic events and world reform.” Newton noted that the path of comets made them perfect to distribute “vital material” throughout the heavens as well collide with the sun or alter the solar system, Halley thought it possible that a comet caused the biblical flood.

Conclusion

I have focused particularly on observations of the 1577 and 1607 comets because their influence is most cited as being instrumental in the emergence of modern astronomy in the 17th century. What I have argued is that there was as much political and social reasoning behind their observation and explanation as there was science.  Kepler, who put Copernicus’ model together with Brahe’s observations to create his “new astronomy’, did not see the place for comets in this model; consigning them to traveling linear paths  rather than the elliptical orbits of the planets. Finally I have shown , into the 18th century, the shared discourse of comet lore was for them to be, in addition to being supra-lunary objects, agents of upheaval, renewal and divine justice.

Bibliography

Primary Sources

Aristotle, “On the Heavens”, in The complete works of Aristotle. Edited by Jonathan Barnes, 984-1120. Princeton: Princeton University Press (Revised Oxford Translation, One-volume digital edition), 2014.

Aristotle, “Meteorology”, in The complete works of Aristotle. Edited by Jonathan Barnes, 1217-1369. Princeton: Princeton University Press (Revised Oxford Translation, One-volume digital edition), 2014.

Brahe, Tycho, “On the comet of 1577”, in Tyco Brahe’s German treatise on the comet of 1577: A study in science and politics, by J. R. Christianson, Isis 70 (1979): 132-140.

Copernicus, Nicolaus. On the revolutions of heavenly spheres. (Translated by Charles Glenn Wallis, 1939) Amherst: Prometheus Books, 1995.

Halley, Edmond, “Synopsis of the astronomy of comets,” in The elements of physical and geometrical astronomy, by David Gregory, 881-905. London: D. Midwinter, 1726.

Kepler, Johannes. De cometis libelli tres. Augsburg: Andrea Apergeri, 1619. https://archive.org/stream/den-kbd-pil-130011021221-001#page/n16/mode/2up

Secondary Sources

Ariew, Roger. “Theory of comets at Paris during the seventeenth century.” Journal of the history of ideas 53 (1992): 355-372.

Barker, Peter, and Bernard R. Goldstein. “The role of comets in the Copernican revolution.” Studies in History and Philosophy of Science 19 (1988): 299-319.

Blair, Ann. “Tycho Brahe’s critique of Copernicus and the Copernican system.” Journal of the History of Ideas 51 (1990): 355-377.

Christianson, J. R. “Tyco Brahe’s German treatise on the comet of 1577: A study in science and politics.” Isis 70 (1979): 110-140.

Heidarzadeh, Tofigh. “A history of physical theories of comets, from Aristotle to Whipple.” New York: Springer, 2008.

Hellman, C. Doris. “The comet of 1577: Its place in the history of astronomy.” New York: Columbia University Press, 1944.

Moesgaard, Kristian Peder. “Copernican influence on Tycho Brahe” in The reception of Copernicus’ heliocentric theory, edited by Jerzy Dobrzycki, 31-55. Dordrecht: Springer, 1972.

Nouhuys, Tabitta van. “The age of two-faced Janus: The comets of 1577 and 1618 and the decline of the Aristotelian world view in the Netherlands.” Leiden: Koninklijke Brill NV, 1998.

Pask, Colin. “Magnificent Principia: exploring Isaac Newton’s masterpiece.” Amherst: Prometheus Books, 2013.

Rosen, Edward. “The dissolution of the solid celestial spheres.” Journal of the history of ideas 46 (1985): 13-31.

Schechner Genuth, Sara. “Comets, popular culture, and the birth of modern cosmology.” Princeton: Princeton University Press, 1997.

Voelkel, James R. “The composition of Kepler’s Astronomia nova.” Princeton: Princeton University Press, 2001.

Westman, Robert S. “The comet and the cosmos: Kepler, Mästlin and the Copernican hypothesis” in The reception of Copernicus’ heliocentric theory, edited by Jerzy Dobrzycki, 7-30. Dordrecht: Springer, 1972.

This is an expanded version of an essay submitted in March 2015, by the author, as an partial assessment task for HPSC20015 “Astronomy in World History” in the Post Graduate Diploma Arts (History and Philosophy of Science) program at the University of Melbourne.

halley2

]]>
http://lucidthoughts.com.au/wordpress/?feed=rss2&p=1771 0
Teleology in nature and culture http://lucidthoughts.com.au/wordpress/?p=1759 http://lucidthoughts.com.au/wordpress/?p=1759#respond Fri, 06 Mar 2015 04:27:30 +0000 http://lucidthoughts.com.au/wordpress/?p=1759 galapagos-439Introduction

In 1859 Charles Darwin published his now famous On the Origin of Species , which provided, a well researched and reasoned naturalistic explanation of species evolution through ‘natural selection’. In introducing natural selection did Darwin enable us to dispense totally with teleological explanations for purpose and design in biology? In this essay I will contend that he did not. He did remove from modern, informed discourse the presence of a ‘designer’. Still leaving the argument for teleology as a useful explanatory concept in the biological sciences. This result produces a conundrum, especially if teleology is granted ontological existence rather than just metaphorical, suggesting that biology is not reducible to chemistry and to physics. While fascinating in itself, that enticing discussion is not in the scope of this essay.

I will be approaching this essay by following Lennox’s argument for the necessity of selection-based teleology and its origin in Darwin’s writings. I will present counter arguments from Dawkins, Nagel and then Davies’s strong argument that teleology as a metaphor is not a necessity, but rather it is a conservative psychological clinging to metaphorical explanation. I will then provide the argument from Bedau that teleological metaphor does have a heuristic role in biological discussions, and as example look at how it can give rise to ‘value’ in biological organisms. Via Aristotle’s final causality, I will be arguing that the extension of this teleological argument, that humans are purposeful animals, holds also for human culture. I will develop the argument that teleology can be a substantive argument for both purpose and value in human cultural evolution. Establishing the conclusion that culture does not transcend nor contrast with nature in a modern sense of evolution by natural selection.

The roots of teleology and Darwin

In general, and for the purposes of this essay, a teleological explanation is one in which some property is said to exist, or some process is said to be taking place for the sake of a certain result, or consequence . Teleological thinking originates from three views, all having their roots in ancient Greece . First, is what Lennox calls the ‘unnatural teleology’ of Plato in the Timaeus and Laws. In this case explanation of natural phenomena is an artefact of a divine, supernatural, intelligent being. Secondly are the ‘natural teleological explanations’ from the Aristotelian view (motions of natural objects are explained by their intrinsic purpose, unless they were not subject to external interference) that were discredited by Galileo and Newton in all the natural sciences bar biology. Final is the anti-teleology view of the Greek atomists.

The story gets more complicated, particularly in the early modern period, after the unnatural ‘intelligent design’ model of Plato is melded into Christianity, and then the medieval commentators have added to Aristotle. Later Rene Descartes, Francis Bacon and Baruch Spinoza all argue against the legitimacy of teleology, but on different and contradictory grounds. In the seventeenth century Robert Boyle and John Ray developed a Christian version of teleology based on the Platonic ‘unnatural teleology’, which came to be known as natural theology. Charles Darwin, along with many naturalists of this era, studied this , in his time at Cambridge University, in the form of the Natural Theology writings of William Paley .

GTY_charles_darwin_jt_141109_16x9_992Lennox argues that Darwin’s explanations in his writings are teleological . In Darwin’s 1868 monograph, The variation of animals and plants under domestication, Lennox quotes Darwin providing teleological explanations, without theological backing, for variation in plants being “accidental but for the promotion of the organisms’ wellbeing.” Lennox argues convincingly that there is a value component to Darwin’s explanations, “those traits which provide a relative advantage […] to the organisms that have them are selectively favoured.”

Teleological explanation in biology today

In agreement with Lennox other authors have proposed that teleology, in one form or another, is indispensable to biology . To understand the complex morphological and behavioural traits of organisms it seems we must say what the traits are for, which is to give a teleological explanation of why organisms have them. Some have argued that this is not necessary. Dawkins for example argues that natural selection provides a statistical explanation for why organisms have the traits they do, obviating any need for teleological explanations. Dawkins argument is is in line with the contention made by Nagel that being controlled by a program, having a function, is not the same as being goal-directed.

Dawkins, however, was more contending the teleological argument from natural theology, as he provides a stark teleological explanation for his main theme, the selfish gene: “I shall argue that the fundamental unit of selection, and therefore of self-interest, is not the species, not the group, nor even, strictly, the individual. It is the gene, the unit of heredity.” Here Dawkins sees the genes as following a program, rather than being metaphorically ‘selfish’, as his hypothesis boldly states.

Dawkins does apply ‘selfish’ continually as a metaphor, furthermore giving them, what could be interpreted as, an Aristotelian final cause – the purpose of genes is to be “selfish replicators”. Other philosophers maintain that this power of purpose should be dismissed as a consequence of our psychology .

Davies argues strongly that the architecture of our minds are such that we see ‘purpose’ and conceptualise certain objects as minded agents . This ability may have had (and may still have) a selective advantage for our ancestors, however it presents us with an abundance of false positives. “We readily see – we cannot help but see – minded agents or telltale effects of minded agents at nearly every turn, even when none is present.” Davies has noted that Darwin did kill design by a deity; “the theory of evolution by natural selection explains the diversity and adaptiveness of living forms better than any form of theology.” Davies however rails against the “conservatism” and “stubborn insistence” that gives rise to the seemingly indispensable persistence of metaphor in the concept of design in modern biology . He instead proposes that we can formulate a concept of biological functions without the teleological metaphor of design .

However it would seem that there is a heuristic value in metaphor use – providing us with things in a manner in which we otherwise might not see.

Bedau argues that “sanitizing” teleology by assimilating it into some “uncontroversial” descriptive form of explanation, as Davies demands above, misses the essential role that teleology does play in biology. Bedau proposes that value plays some role in the analysis of teleology and furthermore this can be usefully distinguished into three grades of evaluative involvement in teleology. Most arguments have focussed on what he terms grade one, the good consequences approach, which has many limitations and counter arguments. He argues that value plays a role in grade two, and in particular grade three, explanations, and in grade three the role is an essential part of the explanation. Grade three explanations, Bedau, argues are defined as a pair of logically linked propositions; linking a means to an end to another proposition which states the goodness of that end. This has great explanatory power for mental agents , such as human behaviours, artefacts (a rock is sometimes used as a paperweight, and a carburettor is designed to mix air and petrol) , and selection processes , such as evolution by natural selection.

Final causality and teleology revisited

Having seen the explanatory usefulness of teleology in modern biology it is worth revisiting Aristotle, albeit briefly, to see whether his ideas can add anything to this post-Darwin debate on teleology. This is particularly relevant to man , as a mental agent, and our self-perception that we are goal-directed individuals.

Aristotle’s telos is not a purpose or plan, nor is it a cosmic telos . Aristotle was primarily interested in individual living things and his ‘final causality’ is the mode of causation characterising human actions. At the same time Aristotle also finds teleological causation at work in nature in living organisms. I will focus on human actions now, not because, as Francis Bacon argued that final causes are of value only in the study of human affairs, not in the study of nature; where they are “barren virgins”, rather acknowledging that Aristotle forms a vast topic beyond the scope of this essay. I do suggest, as does Gotthelf for example, that Aristotle is worth revisiting to illuminate the implications of biological teleology for human life.

A key concept that arises from a study of Aristotle is that living organisms have an inherent telos and good of their own. Millett interprets this as introducing value into the world. Furthermore this imposes a moral obligation of responsibility on moral agents. Accepting and exercising such responsibility, Millett maintains, is a virtue. This argument in my mind provides a natural platform linking teleology of all biological entities to a natural ethics. I don’t claim that this is either new or uncontroversial. Rather I am suggesting goal-directedness in man is, and should be seen as, natural.

Is culture purposeful? Is it natural?

Humans are organisms that have evolved by natural selection, as part of an evolutionary tree that extends back to the beginnings of life on earth. It must be appropriate then to view humans as we view all other living organisms. I can plausibly apply teleological explanations, even if only as a metaphor, for their development, and in addition plausibly argue for goal-directed behaviour by virtue of them being moral agents, as discussed above. Again I leave for other times the discussion on the existence or not of free-will, and the possible impact of desire, emotion and behaviour on this discussion, and work on the pragmatic premise that all humans have free-will to some extent. Humans do possess culture, which other organisms do not. Here I am defining culture as “cultivation of the soul” or the betterment and refinement of individuals, possibly by formal or informal education. Further, in agreement with Premack and Hauser, I contend that culture is more than trivial behaviours that become population characteristics by social learning over generations . Premack and Hauser argue that human culture has a purpose to: “clarify what people value, what they take seriously in their daily lives, what they will fight for and use to exclude or include others in their group.” The question is then whether cultural inheritance, this teleological behaviour, is natural or does culture transcend the natural selection I have been discussing above?

It can be seen how early humans may have developed cultural behaviours, morals in the most primitive sense, that would have provided a group selection advantage in their foraging existence. Boehm proposes these cultural behaviours could be; group suppression of alpha male dominance, facilitating the sharing of foraged food, and a culturally based method for resolving social problems. Boehm then proceeds to detail a plausible, if not necessarily falsifiable, hypothesis that relies on culture development as a key component in group-selection. These steps or components involve natural selection and culture development, with; first biological selection providing the precursor to moral behaviour, then secondly the appearance of egalitarian bands (in the sense that weapon and tool use spread individual utility away from brute force dominance) as a product of intentional cultural invention. These steps would have profoundly affected natural selection through breeding preferences. Finally evolved altruistic tendencies, within the group, would have provided positive reasons for inclusive behaviour, in addition to punitive measures of exclusion that Boehm hypothesises to have developed earlier.

machupicchuI would argue this hypothesis remains valid in the transition from foraging to early agricultural civilisations and to our present modern times. Environmental factors and cultural selection would have driven natural selection, culture becomes an additional part of the environment, where ill-fitting or non-adaptive cultural practices would have led to cultural extinction , as has been hypothesised for early middle-eastern and meso-american cultures.

Evolution by natural selection proceeds from gene inheritance from our parents. Does cultural inheritance transcend nature by learning from non-parents? It has been claimed that overall adaptive benefits of such learning outweigh the overall adaptive cost. Individuals in a population can copy a behaviour, which augments fitness. It has been suggested that prestige bias may be a suitably evolved heuristic that plausibly explains how on average adaptive, rather than maladaptive, behaviours will be copied from individuals who excel in at least one domain.

This relies on the supposition that those individuals will serve as cultural models and in formal civilisations will get themselves into prestigious positions. From these arguments it can be seen that culture neither transcends nor clashes with a modern sense of nature as evolving by natural selection.

This essay was first submitted in March 2015, by the author, as an assessment task for HPSC20002 “A History of Nature” as partial requirements for the award of a Post Graduate Diploma Arts (History and Philosophy of Science) at the University of Melbourne.

Bibliography

Primary Sources

Aristotle, The complete works of Aristotle. Princeton: Princeton University Press (Revised Oxford Translation, One-volume digital edition), 2014.

Darwin, Charles L., “On the origin of species by means of natural selection, or The preservation of favoured races in the struggle for life,” in From so simple a beginning: the four great books of Charles Darwin, edited by Edward O. Wilson, 441-760. New York: W. W. Norton & Company, 2006.

Dawkins, Richard. The selfish gene. Oxford: Oxford University Press, 1976.

Paley, William, Natural Theology: or evidence of the existence and attributes of the deity, collected from the appearances of nature. (edited with an introduction and notes by Matthew D. Eddy and David Knight) Oxford: Oxford University Press, 2006.

Secondary Sources

Bedau, Mark, “Where’s the good in teleology?” in Nature’s purposes: analyses of function and design in biology, edited by Colin Allen, Marc Bekoff, and George Lauder, 261-291. Cambridge: The MIT Press, 1998.

Boehm, Christopher, “Interactions of culture and natural selection among Pleistocene hunters” in Evolution and culture, edited by Stephen C. Levinson, and Pierre Jaisson, 79-103. Cambridge: MIT Press, 2006.

Davies, Paul Sheldon, Subjects of the world: Darwin’s rhetoric and the study of agency in nature. Chicago & London: The University of Chicago Press, 2009.

Dawkins, Richard. The blind watchmaker. Harlow: Longman Scientific & Technical, 1987.

FitzPatrick, William J. Teleology and the norms of nature. New York: Taylor & Francis Group, 2000.

Gotthelf, Alan, “Understanding Aristotle’s teleology,” in Final causality in nature and human affairs, edited by Richard F. Hassing, 71-82. Washington: The Catholic University of America Press, 1997.

Lennox, James G., “Darwin and Teleology,” in The Cambridge Encyclopedia of Darwin and Evolutionary Thought, edited by Michael Ruse, 152-157. New York: Cambridge University Press, 2013.

Levinson, Stephen C., “Introduction: the evolution of a culture in a microcosm” in Evolution and culture, edited by Stephen C. Levinson, and Pierre Jaisson, 1-41. Cambridge: MIT Press, 2006.

Lewens, Tim, “Cultural Evolution”, in The Stanford Encyclopedia of Philosophy (Spring 2013 Edition), edited by Edward N. Zalta, http://plato.stanford.edu/archives/spr2013/entries/evolution-cultural : accessed 30/1/2015.

Millett, Stephan. Aristotle’s powers and responsibility for nature. Berne: Peter Lang AG, 2011.

Premack, David and Marc D. Hauser, “Why animals do not have culture” in Evolution and culture, edited by Stephen C. Levinson, and Pierre Jaisson, 275-278. Cambridge: MIT Press, 2006.

Galapagos-Islands_Unique-wildlife_2454

]]>
http://lucidthoughts.com.au/wordpress/?feed=rss2&p=1759 0
Bloglovin http://lucidthoughts.com.au/wordpress/?p=1756 http://lucidthoughts.com.au/wordpress/?p=1756#respond Thu, 29 Jan 2015 22:44:37 +0000 http://lucidthoughts.com.au/wordpress/?p=1756 Follow my blog with Bloglovin

]]>
http://lucidthoughts.com.au/wordpress/?feed=rss2&p=1756 0
Romantic science’s electric moment: the speculative physics of Ørsted, Ampère and Faraday http://lucidthoughts.com.au/wordpress/?p=1740 http://lucidthoughts.com.au/wordpress/?p=1740#comments Sat, 27 Dec 2014 02:51:28 +0000 http://lucidthoughts.com.au/wordpress/?p=1740 In 1864 James Clerk Maxwell published his essay, A dynamical Theory of the Electromagnetic Field[1], which contained what are now known as Maxwell’s equations: the four basic equations of the electromagnetic field[2]. 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’.[3]

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.[4] In response to this arose ‘Romantic’ approaches to natural philosophy[5]. The Romantic Movement, particularly those influenced by the Naturphilophie of Frederich Schelling[6], 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[7] or Schelling’s Naturphilosophie[8] 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.[9] 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.”[10]

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[11]. 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,”[12] 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[13]. 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.[14] 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.[15]

1-1239115-radio-hans-christian-orsted-1400086434028By 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.[16]

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,”[17] Ampere had now found a question worthy of his attention.

Ampère’s Electrodynamics

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[18]. 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.”[19]

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.[20] 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.”[21] 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.”[22] 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.[23]

230_ff74d22e3eBetween 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[24] 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.[25] 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.”[26] 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.[27]

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[28].

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.”[29] 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”[30] 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.[31]

1833_1_1Faraday was undoubtedly a brilliant and extraordinarily persistent experimentalist and in contrast to Ampère was extremely organized in documenting his experiments[32]. 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.[33] The value of these experiments lie as much in the speculation that Faraday made of them. For example in his diary he wrote[34]:

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.[35]

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.[36]

Disciplined Speculation

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.

References

[1] Maxwell, James Clerk, A Dynamical Theory of the Electromagnetic Field, ed. Thomas F. Torrance (1982), pp. 33-104.

[2] Torrance, Thomas F., Preface, in Maxwell, James Clerk, A Dynamical Theory of the Electromagnetic Field, ed. Thomas F. Torrance (1982), pp. xi-xii.

[3] Holten, Gerald, Foreword, in Brain, Cohen, and Knudsen (2007), pp. vii-viii.

[4] Frankel, Eugene, J. B. Biot and the Mathematization of Experimental Physics in Napoleonic France, (1977), pp. 34-47.

[5] Knight, David, Romanticism and the sciences, in Cunningham and Jardine (1990), pp. 13-24.

[6] Morgan, S. R., Schelling and the origins of his Naturphilosophie, in Cunningham and Jardine (1990), pp. 25-37.

[7] 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.

[8] Stauffer, Robert C., Speculation and Experiment in the background of Ørsted’s Discovery of Electromagnetism, (1957), pp. 33-44.

[9] Christensen, Dan Charly, Hans Christian Ørsted: Reading Nature’s Mind, (2013), pp. 40-51.

[10] Christensen, Dan Charly, Hans Christian Ørsted: Reading Nature’s Mind, (2013), pp. 70-71.

[11] Christensen, Dan Charly, Hans Christian Ørsted: Reading Nature’s Mind, (2013), pp. 108-121.

[12] Wetzels, Walter D., Johann Wilhelm Ritter: Romantic physics in Germany, in Cunningham and Jardine (1990), pp. 199.

[13] Wetzels, Walter D., Johann Wilhelm Ritter: Romantic physics in Germany, in Cunningham and Jardine (1990), pp. 199-212.

[14] Ørsted, Hans Christian, facsimile of Experimenta front page ,in Christensen, Dan Charly, Hans Christian Ørsted: Reading Nature’s Mind, (2013), pp. 348.

[15] Ørsted, Hans Christian, Observations on Electro-magnetism, in Jackson, Jelved, and Knudsen (1998), pp. 430-449.

[16] Jelved, Karen and Jackson, Andrew D., The Other side of Ørsted: Civil Obedience, in Brain, Cohen, and Knudsen (2007), pp. 15.

[17] Wilson, Andrew D., Introduction, in Jackson, Jelved, and Knudsen (1998), pp. xvii.

[18] Hofman, James R., Andre-Marie Ampère, (1995), pp. 2.

[19] Hofman, James R., Andre-Marie Ampère, (1995), pp. 11.

[20] Hofman, James R., Andre-Marie Ampère, (1995), pp. 7-23.

[21] Hofman, James R., Andre-Marie Ampère, (1995), pp. 50-66.

[22] Hofman, James R., Andre-Marie Ampère, (1995), pp. 144-145.

[23] Hofman, James R., Andre-Marie Ampère, (1995), pp. 164.

[24] Frankel, Eugene, J. B. Biot and the Mathematization of Experimental Physics in Napoleonic France, (1977), pp. 34-47.

[25] Hofman, James R., Andre-Marie Ampère, (1995), pp. 192.

[26] Frankel, Eugene, J. B. Biot and the Mathematization of Experimental Physics in Napoleonic France, (1977), pp. 44-45.

[27] Hofman, James R., Andre-Marie Ampère, (1995), pp. 206-212.

[28] Hofman, James R., Andre-Marie Ampère, (1995), pp. 309-350.

[29] Hofman, James R., Andre-Marie Ampère, (1995), pp. 309.

[30] Lawrence, Christopher, The power and the glory: Humphry Davy and Romanticism, in Cunningham and Jardine (1990), pp. 213-227.

[31] Williams, L. Pierce, Michael Faraday, (1965), pp. 80-89.

[32] Faraday, Michael, Experimental Researches in Electricity, (1965).

[33] Williams, L. Pierce, Michael Faraday, (1965), pp. 151-168.

[34] Faraday, Michael, quoted in Williams, L. Pierce, Michael Faraday, (1965), pp. 165.

[35] Faraday, Michael, Experimental Researches in Electricity, (1965), (paragraph 2146), vol. 3, pp. 1-2.

[36] Faraday, Michael, Experimental Researches in Electricity, (1965), (paragraph 2717), vol. 3, pp. 168.

Bibliography

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.

]]>
http://lucidthoughts.com.au/wordpress/?feed=rss2&p=1740 1
Apollo 11: it was 45 years ago today http://lucidthoughts.com.au/wordpress/?p=1724 http://lucidthoughts.com.au/wordpress/?p=1724#respond Sun, 20 Jul 2014 08:37:30 +0000 http://lucidthoughts.com.au/wordpress/?p=1724 ig205_01_02

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.

090713-apollo11-40ann-02

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.

070628_moon_view_02

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.

]]>
http://lucidthoughts.com.au/wordpress/?feed=rss2&p=1724 0