Tuesday, June 21, 2016

Chasing Venus: The Race to Measure the Heavens, by Andrea Wulf

Today I'm taking a look at Chasing Venus, a book about the transits of Venus across the sun in the eighteenth century, which was a major astronomical event and a huge research opportunity. But I guess I should explain what a transit of Venus is. Basically once in a very long while the planet Venus comes between Earth and the Sun and so Venus can be observed travelling across the face of the sun from Earth. Due to the orbits of the respective planets involved, this always happens in pairs eight years apart, and these pairs are about a hundred odd years apart. So any astronomer lucky enough to be alive when a transit occurs will do almost anything to be able to observe one. (Also sorry everyone, the last ones happened in 2004 and 2012. We won't see another one until 2117.)

But why is this a big deal, and specifically why were the transits in 1761 and 1769 such a big deal? Well as Wulf explains you have to put everything into the proper context. The transits of Venus in the eighteenth century were smack dab in the middle of the Enlightenment era, where Europeans were sailing across the world, meeting new and interesting people, stealing their countries, and making breakthroughs in science including astronomy. Astronomy was particularly important because ocean navigation was incredibly tied up with utilizing the sun, moon, and stars to help find latitude. Longitude was somewhat trickier and would remain a problem, but scientists were busily working on that all through the 1700's. The transit of Venus across the Sun was simply one in a large number of astronomical events astronomers were eager to observe.

However, the transit was also important because astronomers could use it to calculate just how big the solar system was. Astronomers had already crunched the numbers and had a pretty good idea on the relative distances between the planets, measured in Astronomical Units (AU) which was defined as the distance between the Earth and the Sun. The problem, however, was nobody had more than a rough guess of exactly how bit an AU was. But astronomers knew if they took a variety of measurements of the transit and did some insane trigonometry, they might be able to get a better idea.

The chief challenge was getting astronomers in locations where they'd be able to make observations. Some locations, such as upper Scandinavia, were fairly close but still very difficult to get to. Other locations such as Siberia, Canada, India, St. Helena, and Tahiti were far more remote but observations from these locations would be absolutely essential if scientists were to determine the distance between the Earth and the Sun. And the amazing thing? They actually managed to do it.

There were numerous obstacles to this endeavor, as Wulf points out in her book. The first problem was getting scientists from all across Europe to cooperate in taking measurements and sharing their research data. (Although that was fairly simple by comparison, and I'll go more into that in a minute.) Furthermore astronomers had to go to remote locations, with complex and delicate instruments like telescopes, barometers, chronometers, and quadrants, all across the world and then take accurate measurements. Numerous astronomers actually died on their expeditions and in some cases it's amazing we got any results at all. It's truly a testament to human endeavor that scientists were able to work together in a great scientific cause.

The biggest problem I have with this book, though, is I feel like Wulf misrepresents the context of the eighteenth century. A very big deal is made of the Seven Year's War which hampered expeditions for the 1761 transit, especially between British and French scientists. Certainly the rivalry between Britain and France was deep rooted, by the competition in the eighteenth century was hardly ideological. The eighteenth century after all is the era of ''gentlemanly'' warfare, where today's enemy could be tomorrow's ally. After all, the British-French and Austrian-Prussian rivalries switched partners between the War of Austrian Succession (France and Prussia vs. Austria and Britain) and the Seven Year's War (Britain and Prussia vs. Austria and France.) So I don't think it should come as any surprise that European scientists were able to put national identities aside in the pursuit of a greater cause.

I think Wulf also could have done a better job of talking about how nations lavished funds on their scientific societies during the eighteenth century as well. Aside from their more practical benefits, scientific societies were a matter of prestige for a modern ''enlightened'' state. Wulf does a good job of explaining how Catherine the Great of Russia and the American colonies worked to promote their own scientific societies to prove they were not provincial backwaters but rather members of the club of ''civilized'' nations. The fact that great sums of money were spent by monarchs on scientific expeditions at this time should hardly come as a surprise. It was simply a matter of national honor and prestige to have a good scientific society. Much like how in the late nineteenth and early twentieth centuries it became a matter of national honor and prestige to have colonies and battleships. I think Wulf makes the decision to fund these expeditions far more incredible than it is if you look at the historical context.

Overall this book is okay. Personally I actually found it a little boring but I think that may have just been the reader who didn't seem to get terribly excited by anything happening in the book. It was all delivered in a rather flat monotone. If you're interested in astronomy this may be a good book to read, but I can't find anything really compelling about it.

- Kalpar

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