13 of 14 people found the following review helpful
on May 17, 2012
This meticulously researched and well structured book focuses on the human element of the 18th century Venus transit expeditions. It reads like a novel and you are left with a sense of wonder that people could actually go to such extremes for a scientific objective. I rated it the second best transit book after Sheehan and Westfall, "The Transits of Venus", because Sheehan and Westfall have much more technical material about transit conditions and uses of the observations. The two books are complementary, with Sheehan/Westfall providing the astronomy and an overview of the main expeditions and Wulf supplying many interesting and previously unpublished details on the participants and what they went through. It's a wonderful book and a credit to the author.
19 of 23 people found the following review helpful
on June 3, 2012
I was disappointed. The book a very well researched and documented history of how the transit of Venus in 1761 and 1769 mobilized scientist worldwide in an extraordinary effort to determine the physical size of the solar system. BUT the most interesting aspects of this effort are missing. I wanted to know not only the adventures of the astronomers as they traveled to the far corners of the world to do the observations, but ALSO the method they used in their calculations. How did they actually calculate the distance between the earth and the sun? How did they take into the account that during the 6 hour transit the earth traveled in its orbit, the circumference of which they did not know? How did they determine the precision they needed to convince themselves that could indeed measure the distance to the sun with adequate accuracy? How did Hubble predict the transit of Venus to within a fraction of an hour at any place on the globe? The book would have been significantly more interesting if the author answered these and many similar questions.
7 of 9 people found the following review helpful
Next month the world will enjoy a rare astronomical treat. Venus will cross the face of the Sun; it did this in 2004, because these transits tend to come in pairs separated by eight years, but the paired events occur only about every 120 years or so. Of course astronomers all over the world will be looking carefully, and recording, and timing, and there will be an international effort to gather all possible data from the event. We take such scientific cooperation for granted now, but it did not always exist, and it was transits of Venus that started the tradition of worldwide scientific cooperation. In _Chasing Venus: The Race to Measure the Heavens_ (Knopf), Andrea Wulf has told the amazing stories of the transits of 1761 and 1769, and the expeditions made by intrepid astronomers all over the world to get some idea of the vastness of our solar system. Looking at the sky every night, documenting points of light and their changes might be considered dull; indeed, at the time Britain's Royal Observatory was looking for assistant astronomers and suggested that they be "obedient drudges." The picture here, however, is of adventurous and hardy men (which is not to say they never complained about the hardships) who ventured into the wilds, literally risking their lives for the sake of getting astronomical data. Wulf's entertaining book is a fine tribute to that admirable human trait of scientific curiosity.
The expeditions had been set in motion in 1716, when Edmond Halley suggested the worldwide scientific project, knowing that he himself would not be around for the transits. Halley knew that observers at different points on the globe would only have to measure the exact times that the disk of Venus entered and exited that of the Sun, and that such times could calculate an exact distance to the Sun, something we did not know. The French astronomer Joseph-Nicolas Delisle took up the challenge in 1760, calling for global measurements of the transit the next year, and then for 1769. And so a small army of astronomers, many of whom may have been drudges devoted to scanning the sky every night and going to their homes to sleep during the day, enlisted for the sort of work they could not have predicted when they started their careers. They were imperiled by the dangers of the sea, including the wartime activities of their respective nations. They endured disease (not every one successfully), hardships, foul weather, freezing temperatures, and the distrust of natives. The viewings of the first transit were generally unsatisfactory, but they pointed the way to doing better ones for the second transit. For instance, it was realized that positions that saw the transit with the Sun near the horizon produced less reliable data, because of atmospheric interference, than those seeing the Sun high in the sky, so that observation points for 1769 could be planned with this in mind. There were still inaccuracies; the astronomers were mystified by the display that showed that Venus did not show up as a simple black disk entering the large bright disk of the Sun, but seemed to distort and flow into the Sun, making the measurement of crossing times inexact. The newly calculated distance to the Sun was still not exactly agreed upon, but it was far closer than any that had come before.
It wasn't just that we got a better picture of our place in the universe from these expeditions. The hundreds of voyagers produced better charts of their observation points, as well as descriptions and specimens of plants, animals, geography, weather, and human activity from the regions they traversed. The great inspirational lesson, though, is from the heroic astronomers and crews who endured daunting hardships to work together on a shared goal. "Never before," writes Wulf, "had scientists and thinkers banded together on such a global scale - not even war, national interests or adverse conditions could stop them." This is an inspiring story. May the trust that nature could best be understood by reason, a cornerstone of the Enlightenment, continue to unite and embolden us.
5 of 6 people found the following review helpful
on May 15, 2012
Andrea Wulf has done it again - she has taken technical, historical scientific material and transformed it into a real page-turner. The author weaves a tale of an eighteenth century race against time and weather to observe and measure the rarely seen phenomenon - the transit of Venus. Furthermore, she explains in layman's terms how these measurements were used to not only calculate the distance from the earth to the sun, but also to catalyze an international community of scientists who elevated themselves above border disputes and wars.
For the reader who also enjoyed THE BROTHER GARDENERS, you will enjoy the tie-in to this book as you read more about Captain Cook's journey to Tahiti along with his passenger, Joseph Banks.
The only 21st century transit of Venus is occurring soon. Read CHASING VENUS now so you can appreciate this rare occurrence.
3 of 3 people found the following review helpful
on June 30, 2012
Prospective buyers should know how slight this book is. The hardcover edition is 336 pages, but in the Kindle edition, about half of it is notes. Most of the text is narrative of the principal astronomical expeditions of 1761 and 1769, concentrating on the difficulty of traveling by ship, carriage, and sledge. The math and science involved are almost totally absent. Nor is there much discussion of the instruments and techniques used by the observers. You could get more science from the Wikipedia article about the transit of Venus and related articles about the astronomers and their instruments. So, although the book is well written, I can't really recommend it.
on August 3, 2014
As most reviewers have pointed out, this book was meticulously researched, but that may also be its downfall. Ultimately, it reads like a well-executed term paper, or maybe a PhD dissertation. It does indeed provide accounts of the major expeditions mounted to time the transits of 1761 and 1769, but these accounts lie flat on the page as a list of factual details and descriptions of events. I read Richard Holmes' "The Age of Wonder" a few months before this book, and his account of Joseph Banks in Tahiti is engaging and riveting, bringing to life the collision of cultures that occurred, the personalities of those involved, and weaving it all into a page-turning story. The contrast was clear in this book's coverage of James Cook's expedition to bring Banks to the South Seas, where the facts are recounted without really bringing the characters to life in my mind.
The book also chooses odd, sometimes single-word, quotations from the source material (which is all referenced in the extensive notes). A typical example is on page 159: "The weather was glorious and Le Gentil rejoiced in the beauty of the mirrored surface of the water which, he wrote in his journal, was as smooth as a 'lake'." After a nice summary of the scene in the author's words, do we need to know that "lake" was the exact term used by Le Gentil? I couldn't help but think, either give us a whole sentence or phrase from Le Gentil's journal or simply reference the whole sentence as a paraphrase. The book is littered with these one- or two-word quotes that seem to be a replacement for footnotes rather than adding authenticity to the material.
Finally, I'm not sure the author is completely comfortable explaining the astronomy involved. The reason that timing Venus' transit would allow calculation of the distance between the Earth and the Sun is not clearly explained. And the modern explanation of the "black drop effect" that stymied their measurements is also not well covered. There are some simple factual errors that hint at this as well.
Ultimately, the material is inherently interesting as a series of important historical events. The body of the text only runs to page 205 (the rest are notes), so it's a quick read. However, it is an account of the events that transpired with less context, explanation, and narrative drive than I would have liked.
on January 17, 2014
This is a very interesting book about the world's first global scientific collaboration: the monumental efforts made in 1761 - and again in 1769 - to measure the transit-times of the planet Venus as it made two rare crossings of the sun. The book chronicles the difficulties and complexities involved with sending scientists and their instruments (weighing thousands of pounds) to various corners of the globe in the mid 1700s. It details the hardships, frustrations, and sacrifices of the scientists - some of whom journeyed for more than a year to get to their appointed viewing spots, only to find their views of the event obscured by clouds, and some of whom died for their data.
Because measuring the transit of Venus was a collaboration amongst many scientists from many nations, the history is complex. This book is enjoyable because it does not shy away from the complexity. Ms. Wulf details the individual journeys of many of the scientists who took part in the project, but also manages to weave their disparate stories together, by providing enough geographical and historical context to enable the reader to get a sense for what the world was like back then, and for how the science ultimately came together.
I wish I'd read this book a couple of years ago, because It turns out that transits of Venus are rare events; pairs of transits happen eight years apart, and then are not seen again for over one hundred years. The last two transits were in 2004 and 2012, and I missed them both. The next one won't be until 2117, and I'm afraid I'm going to miss that one too. If I'd known the lengths to which the people of the eighteenth century went to view the event, I would have made an effort to see it myself.
A transit of Venus is a kind of solar eclipse in which the planet Venus, rather than the Moon, crosses in front of the Sun. A century-long interval between transits makes the normal kind of solar eclipse seem like a frequent event. The transits occur in pairs separated by eight years, with over one hundred-year separations between the pairs. We were treated to the opportunity to observe transits of Venus in 2004 and 2012.
By contrast with total solar eclipses, which may be viewed only within a narrow corridor, a transit of Venus may be viewed from any place on the Earth that faces the Sun during the event. Edmond Halley, of comet fame, realized that observations of a transit of Venus from separate locations on the Earth could be used to establish a precision measurement of the distance between the Earth and the Sun. This is the yardstick by which we measure the Universe. Halley urged astronomers to pursue the transits of 1761 and 1769, which were to occur well after his death.
This is the story of the first example of scientific cooperation on a world-wide scale. The scope of the effort can be compared to the project by scientists from all over the world to search for the Higgs particle at the CERN LHC.
For 1761, expeditions were organized to the far corners of the Earth. Scientists traveled by ship to the tropics and overland to northern latitudes. Included in the observers were two from England, Mason and Dixon, whose ship was caught in a battle at sea. They later did some surveying in North America. In 1761, the results were not as precise as expected. Scientists were surprised by the black drop effect, limited by their instrumentation, and by knowledge of where they were, e.g., their longitude. The relative longitudes of Paris and London had not yet been established. The 1761 results put the Earth-Sun distance between 77,100,000 and 98,700,000 miles.
Life does not always provide a second chance. However, the transit of 1769 was a second chance. There were more observers from more countries sent to more locations. One notable was Captain Cook who sailed to Tahiti for the transit. Astronomers had better telescopes and better clocks. This time, the result was more precise, 93,726,900 miles, which can be compared to today's value of 92,960,000 miles, established by radar measurements.
The author tells a tale of danger, privation, and even death for the scientists who risked their lives to travel to barely-settled areas of the planet. The author's research is impressive. Indeed, there are ninety pages of notes at the end of the book. The story is well told.
In her previous books, "The Brother Gardeners" and "Founding Gardeners," Andrea Wulf demonstrated her unique ability to convert topics I was not particularly interested in into fascinating studies. In this volume, about the Transit of Venus scientific expeditions in 1761 and 1769, she has accomplished this once again.
These multi-national efforts to study and measure the passage of Venus across the sun the author characterizes as "the first global scientific project." This is because for the first time there were multiple national scientific teams working together to gather and collate data from these two events. This is especially true for the 1769 transit, where something like 250 scientists at some 130 locations around the world made (or tried to make) observations.
While the British and French took the lead, there were other important actors as well. Catherine the Great, in her determination to propel Russia into modernity and western European culture, supported Russian participation (which meant trekking to Siberia). Even the future U.S. got into the act, with the involvement of David Rittenhouse and Benjamin Franklin. Sweden also dispatched observers to the far north. Particularly as regards the 1769 transit, it is amazing, considering the limits of 18th century travel resources, how widespread the observers ended up scattering themselves. Often, observer teams had to leave 6 months in advance of the transit date to make their destinations. Such dedication is to be commended.
But collecting the data with 18th century instruments was only half the battle: the next challenge was to collate all this international data into meaningful numbers. For example, should all observations be accorded the same weight, or should some be discounted? Since there were many different data points, how could this all be collated into meaningful ranges. Remember, this was all before the modern computer made the scene. Yet, for all these challenges, the joint computations yielded remarkably accurate findings close to the data generated today.
What was all the fuss about? It would hoped that accurate measurement of the transit would enable these 18th century scientists to accurately estimate the size of the universe and resolve issues for example like the distance from the earth to the sun.
The author has organized and presented her extensive research findings in a pleasant and very cogent format. She discusses some expeditions in detail, others less so. The book is full of maps and helpful diagrams and documents relating to 18th century scientific technology. The author has included a helpful "dramatis personae" introducing the leading actors; complete lists of observers for both transits; a solid bibliography; and 43 pages of valuable notes. However, the main advantage of Wulf's books is that she can explain scientific concepts in a way that we non-scientific types can understand and benefit from. All around, just a very fine job.
on March 2, 2013
In the 1700s, astronomers determined that if one measures from several locations the time for Venus to cross the sun then one could determine among other things the size of the Solar System. This set off an international scientific race often supported by governments giving who for those days large sums of money to measure this. Although I have heard about this measurement of Venus but never realized how big this was at the time until I read this book. This the book discussed very well the political and scientists stories to get this measurement.
The problem with this book is that there is little explanation of the science involved. Some points I feel should have been discussed the instruments, how they were used and the accuracy they could expect with these. I would also like to have seen at least an appendix for those that have some scientific knowledge explaining the theory, which I imagine would be interesting to many of the readers on the theory involved. I had to do a net search to figure this out.
Also I thought the summing up was very bad, yes some people got some very good figures but what about the consensus view of scientists? We are left in the dark.
Another point that could have been discussed was this race had enormous significance in history because it led to Captain Cook trip to Australia and New Zealand. Did it have any other long term affect we are not told?