Drawing Mars in Greenwich: recreating an experiment for Stargazing Live

Cross-posted from The H Word blog.

Filming for Stargazing Live at Queen’s House in Greenwich. Photograph: Marek Kukula

This week [NB This post was first published on 7 January 2013] sees the return of the BBC’s highly successful Stargazing Live. It starts on Tuesday, in an episode that follows last year’s biggest astronomy story by focusing on Mars.

In thinking about the search for possible life on Mars, the programme will include some of the historical observations and debates that I discussed in a previous post. I’m delighted that the programme gave us at theRoyal Observatory a chance to recreate a key Greenwich contribution to the story.

This was the 1903 experiment carried out by E. Walter Maunder, an assistant at the Observatory, exploring perception at the limits of vision. It was one element in his campaign against the then-dominant view that the Martian surface was covered with immensely long, wide and straight “canals”, thought by many to the work of an advanced civilisation.

Maunder was not alone, being joined by Eugène Michel Antoniadi andWilliam Campbell, together described in Michael J. Crowe’s The Extraterrestrial Life Debate as “the leaders of a wrecking crew” that demolished the Martian canals.

Maunder, with the assistance of the headmaster of the Royal Hospital School in Greenwich, asked a number of the school’s pupils to draw from different depictions of Mars, placed on a board at the front of the room.His results suggested that, particularly at certain distances, the eye tended to resolve indistinct waves and dots into straight lines, suggesting that the “canals” were an optical illusion rather than real surface features.

Ever since I heard about this experiment, I have wanted to recreate it. Asking people to undertake an exercise like this is a wonderful way to understand the problems and contingencies surrounding astronomical observation and recording (imagine not only peering at this small image, but it flickering in an unsteady atmosphere, and having to keep taking your eyes away in order to represent it on paper). I also wondered if it really worked as Maunder described.

Maunder claimed in his paper that the boys, aged around 12 to 14, were all “wholly and entirely ignorant of the appearance of Mars in the telescope, and of the discussions which have taken place as to the markings on his surface.” I have always wondered if this was true, given the widespread popularity of the Martian canal idea at this period.

Our guinea pigs were probably familiar with what Mars looks like when photographed today, but less likely than the 1903 schoolboys to think of drawings or canals. An interesting difference was their age and the fact that most of them were art students. This probably produced different results than had we picked people off the street but might compare interestingly with the naval cadets. The latter were encouraged by Maunder, and probably by their education, simply to draw what they could see. Our art students may have been more likely, despite my instructions, to attempt to interpret the image and to consider different graphic approaches to its re-depiction.

It is likely that the experiment took place in the school’s old gymnasium. This no longer exists, so the BBC team opted for another of the school’s former buildings – the beautiful Queen’s House. They set up the experiment pretty faithfully, with distances and scales as specified in Maunder’s paper. Told to draw, our students obliged, and demonstrated that their eyesight and drawing ability was a good deal keener than mine.

Did our results back Maunder’s? Sort of. I didn’t see the generation of any “canals” where little or nothing appeared on the original image, but there were certainly more straight lines. In our small sample, it also appeared that the middle rows were more likely to see these lines than those nearest (who saw more detail) or those furthest away (who saw little distinctly). It could be argued that these distances mimicked the experience of observing with particular-sized telescopes, creating the conditions where the eye tends to resolve indistinct detail into non-existent straight lines.

Maunder’s report of this experiment apparently brought a key ally to the campaign against Martian canals – the veteran Canadian-American astronomer Simon Newcomb. It was, however, just one of the arguments brought – one of the simplest being the point that if straight canals like those reported by Percival Lowell did exist on the curved surface of Mars, they ought to appear curved to the observer on Earth.

In his writings, Maunder focused on scientific evidence and his own experiences as an astronomical observer. He chose to stay clear of the philosophical and religious dimension of the debate, despite the fact that his popular writings in astronomy were usually framed with natural theology and Biblical references.

Religious beliefs could support either position in the debate about the existence of life on other planets. However, it was clear that Maunder, an active member of a small pentecostal, adventist sect, believed man’s relationship with God and place in the universe were unique. He could not countenance intelligent, canal-building Martians – and thus his scientific arguments were motivated by religious belief.

Watch on Tuesday to see how the experiment went and how it fits into the long history of observing Mars and the search for extra-terrestrial life. Also visit Alien Revolution a small, free exhibition at the Royal Observatory, opening in March.

In the end the section of the film that included the experiment wasn’t run live on Stargazing, due to lack of time. Happily, the whole thing was made available online and you can see it here.

Thomas Jefferson, science enthusiast

Cross-posted from The H Word.

Thomas Jefferson by Rembrandt Peale, 1800. Photograph: White House Historical Association/Wikimedia Commons

If you want to enter an alternative reality, all you need to do is type words like “Jefferson”, “religion” and “history” into Google. The American right wing’s attitude to some aspects of science is deeply troublesome, but so too is their rewriting of their national history. The Jefferson Lies: Exposing the Myths You’ve Always Believed About Thomas Jefferson, by David Barton, is a case in point. It is endorsed by Glenn Beck despite enormous criticism from historians and publishers.

In July, readers of History News Network voted it the Least Credible History Book in Print for its distortion of history and of Jefferson’s views. The particular issues are identified around religion, slavery and the relationship between church and state, which Barton presents among seven “lies” told about the third president of the United States.

Barton has little to say about Jefferson’s intense interest in science. He would have done if Jefferson had lived a couple of generations later, as the statesman then might have accepted the geological evidence of the Earth’s age (which he was not inclined to do in the first decade of the century, when there was much dispute among geologists) and Darwin’s theory of evolution, and Barton might have had an eighth “lie” to deal with.

But there is little in established 18th and early 19th century science that the Tea Party would feel the need to reject. This is a reminder of the fact that in Jefferson’s time there was no perception of a war between science and religion and, indeed, that the American right do not necessarily have a blanket “anti-science” approach, but theological, political and ideological issues with particular fields.

However, where Barton does bring up science, he goes rather wrong. The main passage focuses on this Jefferson quote:

Bacon, Locke and Newton, I consider them as the three greatest men that have ever lived, without any exception, and as having laid the foundation of those superstructures which have been raised in the Physical and Moral Sciences.

Quite rightly, of course, Barton can point to the religiosity of these heroes of science, but he glosses over Newton’s unorthodoxy, denies Locke’s and presents this quote as part of his argument against the “lie” that Jefferson promoted secular education. This is quite bizarre, turning a blind eye to Locke’s advocacy of religious tolerance and the separation of church and state. A quick read of Locke’s A Letter Concerning Toleration would put him right.

An interest in science and advocacy of secularism in public life were, and are, by no means necessary bedfellows. Likewise, the interest of leaders and politicians of all stripes in many or most aspects of science and technology, which underpin national and military success in so many areas, goes without saying. Yet Jefferson’s interest in science was part of his personal identity in a way that it is hard to imagine the likes of Glenn Beck celebrating.

This summer I visited the American Philosophical Society (APS) in Philadelphia, of which Jefferson was a key early member, to do some research into the Lewis and Clark Expedition across the American continent in 1804-06, a scientific and imperialistic venture that was Jefferson’s pet project.

What I found fascinating in reading about this expedition was not just Jefferson’s support for a prestige national project, but his close involvement in the scientific training of Merriweather Lewis, his secretary, in preparation, and ready input to discussions about instrumentation. Jefferson was, according to an article on the instruments of the expedition, “inordinately fond” of an equatorial theodolite he owned, made by London instrument-maker Jesse Ramsden, and thought they should take something similar.

At the APS I dipped into some of Jefferson’s correspondence withRobert Patterson, the professor of mathematics at Philadelphia. More than once he wrote to thank Patterson for copies of the Nautical Almanac (the small books of astronomical tables for navigation published by the British Board of Longitude), as well as other scientific tracts, and for advice on buying and repairing instruments.

On 21 March 1811 he added:

before I entered on the business of the world I was much attached to Astronomy & had laid a sufficient foundation at College to have pursued it with satisfaction and advantage. but after 40 years of abstraction from it, and my mathematical acquirement coated over with rust, I find myself equal only to such simpler operations & practices in it as serve to amuse me. but they give me great amusement, and the more as I have some excellent instruments…

I don’t suppose that there is anything here that would particularly challenge the Tea Partyers. It is not climate science or evolution, but an enthusiasm for tracking Jupiter’s satellites. In any case, Barton’s claims have already been thoroughly taken down by historians. And yet, throwing up an image of a Founding Father who enjoyed tinkering with precision instruments, perusing astronomical tables and corresponding with university professors seems as good a response as any to some of the painfully bad history being produced.

Martyr of Science

I wrote this introduction to David Brewster’s collected biography of Galileo, Tycho Brahe and Kepler, Martyrs of Science (1841), some time ago when there was a plan to republish it as part of a collected edition of popular 19th-century works on science and history of science. This never worked out but, given my recent discussions on popular history of science writing, and current anxieties about financial support for science, now seems as good a time as any to give it an airing.