The transit of Venus, then and now

Yesterday was the last transit of Venus until 2117, making it a bona fide once- (or twice-, if you caught the last one in 2004) in-a-lifetime event. Only six other transits of Venus have been recorded, starting in 1639 with the observations of a young British astronomer named Jeremiah Horrocks. While Johannes Kepler predicted the transit of 1631, it wasn’t visible in Europe and it appears that no one observed it. Kepler thought we would have to wait another 130 years for the next chance to see Venus meander across the sun, but Horrocks caught an error in his hero’s calculations and realized it would happen again in 1639. (Now we know these transits always occur in pairs eight years apart.) Despite some inconvenient clouds, he managed to observe the event that year. Unfortunately, he wasn’t as lucky in his other endeavors, never formally graduating from Cambridge—making him something of an outsider scientist—and suddenly dying at age 22, just two years after observing the transit.

One of NASA’s many amazing pictures of the 2012 transit of Venus.

The next pair of transits happened in 1761 and 1769, and this time there were many more people watching the sky. Earlier in the century, Edmund “The Comet” Halley laid out a method to use data about the transit of Venus to calculate the distance between the Earth and the sun and, from there, the size of the solar system. (Here’s the best non-technical explanation I’ve found of how this worked.) His method depended on the transit being observed at different points around the world, so a bunch of European explorers set off for the ends of the earth with astronomers in tow in anticipation of the event. Read the rest of this entry »


Physics on the Fringe

I have a review of Margaret Wertheim’s wonderful new book Physics on the Fringe: Smoke Rings, Circlons, and Alternative Theories of Everything up today at Bookforum. Wertheim has been collecting examples of outsider theoretical physics for fifteen years, and in Physics on the Fringe she considers what drives people to try to piece together the laws of the universe entirely on their own. As she follows the life and work of the “fringe theorizer” Jim Carter, who, like many outsider physicists, rejects math-heavy field theory in favor of his own home-spun ideas, she examines the professionalization of physics, the rise of abstract mathematics, and the oft-ignored question of who has been left behind as we march toward a “theory of everything.” One of my favorite parts the book that I had to leave out of the review is Wertheim’s discussion of Michael Faraday. [Edited to add: a version of my discussion of Faraday is now included in the Bookforum review as well.]

Michael Faraday, experimentalist extraordinaire. Image courtesy of Wikipedia.

Michael Faraday, the experimental physicist who did pioneering work on electromagnetism in the early nineteenth century, walked the fine line between insider and outsider in a way that is nearly impossible to do today. Faraday grew up poor and began his scientific career as a bottle washer in a laboratory in London’s Royal Institution. Like Carter, he had no university education and puzzled through the mysteries of the universe largely on his own. Unlike Carter, he was eventually regarded as a genius and recognized as one of the greatest experimental scientists of all time. In fact, it was Faraday who first developed field theory after sprinkling iron filings near a magnet and observing the predictable patterns they formed. “Ironically,” Wertheim writes of Carter, “the one major figure in the history of physics whose life story in some respects paralleled his own had been the source of an idea he could not stomach.”

Faraday lived at a time when the boundaries between amateur experimentalist and professional scientist weren’t quite as rigid as they are today, but he, too, felt the sting of being ignored by the academy. It wasn’t until the more respected physicist James Clerk Maxwell turned the results of Faraday’s experiments into differential equations that the physics community embraced field theory, setting the stage for the industrial revolution, the telecommunications industry, home electricity, and quantum mechanics. Ironically, Faraday’s lack of a formal education meant that he couldn’t understand Maxwell’s equations; Wertheim tells us that he “died a hero, but an alien in the world he had helped create,” and it’s easy to imagine him sympathizing with Carter and the other outsider physicists who still feel left out of that world today.

Click here for more information about Physics on the Fringe. Margaret Wertheim also runs the very cool Institute for Figuring here in Los Angeles.