Life of the Mind
Sun Moon Earth: The History of Solar Eclipses from Omens of Doom to Einstein and ExoplanetsTyler Nordgren. Basic Books, 2016. 264 pages. $26.99.
American Eclipse: A Nation’s Epic Race to Catch the Shadow of the Moon and Win the Glory of the World by David Baron. Forthcoming from Liveright in 2017. 384 pages. $27.95.
In the Shadow of the Moon: The Science, Magic, and Mystery of Solar Eclipses by Anthony Aveni. Forthcoming from Yale University Press in 2017. 320 pages, 32 b/w illus. $28.00.
By Jay M. Pasachoff
This summer's August 21 (2017) will be remarkable throughout North America, Central America, and northern South America for the eclipse of the Sun. For the first time in 99 years, since the 1928 event, a total solar eclipse's path will sweep across the continental United States from coast-to-coast, with partial phases visible from regions far to the north and south. Twelve states will have substantial regions from which totality will be visible--from Oregon to Idaho to Wyoming to Nebraska, to Kansas to Missouri to Illinois to Kentucky to North Carolina to Tennessee to Georgia to South Carolina, with bits of Montana and Iowa also in the darkest part of the Moon's shadow, which is known as the umbra.
Twelve million Americans live within the path of totality, with over two hundred million more within a day's drive. The US Department of Transportation has already sent out a warning of traffic conditions on August 21.
Several books about solar eclipses and their place in history are being issued, as well as guidebooks specifically about observing the eclipse and where to go. This review deals with three of the major books that set this year's solar eclipse in the context of thousands of years of eclipse-watching. My website with maps and links, mounted on behalf of the Working Group on Solar Eclipses of the International Astronomical Union, which I chair, is at http://eclipses.info. The results of decades of cloudiness statistics, compiled by Canadian meteorologist Jay Anderson, are at http://eclipsophile.com, with northwestern sites statistically clearer on that day than southeastern sites. Totality will last about two minutes on the centerline in Oregon ranging up to two minutes forty seconds at the eclipse's peak in southern Illinois and Kentucky, though clear weather is more important than extra seconds of totality in a cloudy sky.
Tony Aveni of Colgate University, in In the Shadow of the Moon: The Science, Magic, and Mystery of Solar Eclipses, is an archaeoastronomer, one of those who defined that field, which brings together not only the science but also the links to locations and objects of the past, with Stonehenge being the most prominent example. Was Stonehenge a giant computer of eclipses from a pre-writing era? Aveni brings the power of cultural astronomy together with modern scientific insights to discuss the question and its likely answer. After his introductory material, his dozen chapters deal with individual topics.... such as the 1919 expedition to an island off the coast of Africa at which Arthur Eddington made observations that confirmed a strange set of ideas known as the general theory of relativity that had recently been advanced by a young scientist named Albert Einstein, rocketing the latter to worldwide fame. The reactions to the 1878 eclipse that went over Pike's Peak in Colorado and the 1925 eclipse whose southern limit was marked by observers along individual blocks on Manhattan's Upper West Side are among other interesting chapters.
In Aveni's section on Eclipses in the Ancient World, he discusses Stonehenge as an eclipse computer, Babylonian descriptions, Greek science including the Antikythera Mechanism, the link between eclipses and the Crucifixion, predictions in ancient China, predictions by the Maya, and the link between eclipses and Aztec Sacrifice. In the section on eclipses in the modern age, he discusses the rebirth of eclipse science in Islam and Europe, the New England eclipse of 1806, the Pike's Peak eclipse of 1878, and New York City's eclipse of 1925. He ends by discussing the effects of eclipses on animals, before his final personal comments.
Tyler Nordgren of the University of California at Redlands, in Sun Moon Earth: The History of Solar Eclipses from Omens of Doom to Einstein and Exoplanets, discusses many of the same topics but from his own point of view. He is especially lyrical about the glories of seeing a total solar eclipse and why one shouldn't miss seeing any. The tone is set by his dedication to "my father, who still feels terrible about me missing the 1979 eclipse. Don't worry anymore; it set me on the path to be the right person at the right place and right time for 2017." Many of us are working to convince 300 million Americans to travel into the zone of totality so that they aren't left grieving for a long time that they missed the main event.
Nordgren describes, among many other things, Alhazen's figuring out the camera obscura from the crescents seen projected from a hole in window coverage. He also discusses the Antikythera Mechanism from ancient Greece, whose interpretation is overturning our current understanding of the level of scientific understanding 2,000 years ago. His chapters each have an integrated set of discussions, including also the American eclipses seen from Pike's Peak in 1878 and from New York City in 1925 as well as many others, especially how Einstein's general theory of relativity was tested at the 1919 eclipse seen from an island off the coast of Africa. He winds up by showing how the Earth-Moon system was formed, and how long it will be before the Moon recedes so much that there won't be any more total eclipses seen.
David Baron, a former NPR reporter, in American Eclipse: A Nation’s Epic Race to Catch the Shadow of the Moon and Win the Glory of the World writes his whole book especially about the 1878 eclipse and how Thomas Edison brought a new invention to it. Edison stole a lot of the attention that should have been given to the astronomers--Maria Mitchell of Vassar College among them--and his device finally didn't work and, had it worked, would not even have given the result about the temperature of the corona for which his participation was set.
We also learn from Baron about the rivalry between a pair of astronomers seeking Vulcan, the putative planet inside the orbit of Mercury that was distorting Mercury's orbit by an amount eventually explained by Einstein. Indeed, each of the astronomers "saw" such an inner planet at the 1878 eclipse—but each sighting claimed a different location for the object and both were eventually dismissed.
The printed word cannot display the full glory of being outdoors during a total solar eclipse. Americans will have a convenient chance on August 21 to see one on home territory—the first total solar eclipse that crosses no other country but the United States since the 18th-century formation of our Republic. I hope that these books help convince you to make the attempt to get into the path of totality to experience the awesome sights of the diamond rings this summer.
Astronomer and author Jay M. Pasachoff is the director of Hopkins Observatory and Field Memorial Professor of Astronomy at Williams College. He is a Visitor in the Planetary Sciences Department of Caltech. Williams College is home to the Gamma of Massachusetts Chapter of Phi Beta Kappa.