Latitude: How American Astronomers Solved the Mystery of Variation

By Bill Carter and Merri Sue Carter

Book Overview

For more than a century European astronomers grappled with the mystery surrounding a suspected variation in latitude that affected their careful observations. Where the best minds in Europe had... This description may be from another edition of this product.

• Format: Hardcover
• Language: English
• ISBN: 1557500169
• ISBN13: 9781557500168
• Release Date: January 2002
• Publisher: US Naval Institute Press
• Length: 168 Pages
• Weight: 1.00 lbs.
• Dimensions: 1.0" x 5.3" x 8.2"

Customer Reviews

An Early Review of Latitude

John R. Herman [...] , a retired geophysicist., 12/23/2002 For centuries astronomers have been concerned with mapping the stars and determining their motions across the sky. Their main purpose in the old days was to obtain information needed to cast accurate horoscopes for their sponsors, usually an emperor or a king. It soon became apparent that by comparing his observation of the position of the stars at a particular moment in time with a catalog of star positions, a navigator could fix his ship's latitude anywhere on the ocean. For a complete determination of location the longitude also had to be known, but the solution to this problem is described in the book "Longitude," by Dava Sobel. To provide an accurate star catalog to fix the latitude at any point, the astronomers of Europe spent years nightly observing the stars and recording their positions. Long term observations at a fixed location seemed to show that relative to the stars the latitude of the observer seemed to change with time. These variations were largely dismissed as measurement errors introduced by temperature and pressure effects on the observing instruments, yet they were observed at astronomical observatories throughout Europe in all seasons. The new book "Latitude" by Bill Carter and his astronomer daughter Merri Sue, gives a fascinating account of how an American amateur astronomer named Seth Chandler, Jr. showed that the variations are real and have a rational explanation. The book describes how Chandler painstakingly analyzed and re-analyzed mountains of astronomical data from English and German star observations, as well as those from the US Naval Obsrvatory in Washington DC. He argued that the Earth is not a rigid body because not only do the oceans move along with atmospheric highs and lows, but also the land itself is elastic. Thus, as the Earth rotates on its axis the crust slops around and disturbs the circular motion. The motion is further disturbed on a seasonal basis due to heavy winter snow covers in Siberia and North America and the foliage and moisture of summer. This introduces a complex wobbling of the axis causing the poles to shift in latitude relative to the position of the stars. He discovered there are several frequencies in the time-related variation which sometimes lead to a zero departure from the true latitude, a fact which for years had driven the European astronomers to distraction to the point where they refused to believe there was a true wobble. The Carters chronicle Chandler's struggles with the international astronomical community as well as some of his American colleagues who did not believe his results.They go to show how he overcame their opposition to be finally vindicated by being awarded the Gold Medal of the Royal Astronomical Society of London for "his discussion of the variation of latitude...." This book also gives us a revealing look at the difficulties scientists have encountered in trying to get funding for important scientifi

A Review: Latitude

Latitude presents an issue in geodesy and astronomy that perplexed scientists, astronomers, and surveyors for years. Early surveys and measurements of latitude exhibited a certain amount of error; the real question was, how much error is acceptable and what are the causes of such error. Latitude discusses in great detail the history and science behind these errors and one aspect of error in particular - polar motion. The authors of Latitude, a Father and Daughter combination, Bill and Merri Sue Carter both have a strong scientific background in astronomy and geodesy. With this understanding of their backgrounds I fully expected Latitude to delve deep into the science behind the phenomenon of variation in latitude; however, instead I found that they spent more time discussing history. The Carters did a remarkable job in depicting the history and lives of the scientists that made the discovery but they also went further and portrayed the lives of the scientists before them that shaped the way to making the discovery. The historical items discussed range from letters to parents while at sea, family photographs, locations of actual instruments used by scientists, to the homes where they resided. In the opening the Carters grab your attention with fictional prologue about a commercial airliner having to make a no visibility emergency landing. This landing was to take place several years ago when GPS landing systems were not commonly installed in planes. This introduction serves many purposes. First, it demonstrates what the GPS technology provides to its users and how today we take the highly technical system (that takes into account a huge amount of factors) for granted. This GPS technology is shown to give within a meter accuracy of the location of a receiver and as the book later goes on to show for a long time such accuracy was difficult to achieve. Secondly, it captivates the reader. I think the authors could have done a better job of explaining why this introduction is particularly relevant to the purpose of the book, but it comes out eventually. One topic of discussion that caught me by surprise was religion. Religion is discussed in different places throughout the book, but the entire first half chapter on Newcomb deals with his conflict with religion It does appear clear that the authors seem to share the beliefs of Newcomb on the subject by the way the topic is discussed. There exists an enormous amount of interest in this topic that would spark emotions across the spectrum and the Carters present a pretty good case in the brief time it is discussed. This particular topic, while widely disputed by the masses of the public, would potentially be an interesting book and if published would undoubtedly spark the interest of a wider populace than that of Latitude. During the course of the book the Carters show how Chandler was able to determine the shifting of latitude caused by the polar "wobble." It goes on to discuss h

And here's why your GPS works

We have learned how Global Positioning Systems affect our lives in astonishing ways, from directing smart bombs onto thugs in Iraq to turning Texas hunters into space shuttle accident investigators. GPS has hundreds of other uses, too, including keeping airliners on course, but none of it would be possible without an understanding of the variation in latitude, and there's a story behind that. That latitude varies, with respect to the distant stars, was suspected by the middle of the 18th century, but the measurements to prove it were almost impossibly delicate. Some of the finest scientific minds of the age considered it, including Leonhard Euler, but the actual solution did not come about until the 1890s, finally nailed down by Seth Chandler, a typical example of a New England Yankee tinkerer. Chandler was better educated than most boys in the 1850s, going to high school in Boston, but he never attended college. At age 15, he was hired by the leading American mathematician of the day, Benjamin Peirce, to be a "computer." That is, he ground out equations for astronomical summaries, work that today is done electronically. In those days, such solutions were done by mere stubbornness with pencil and paper. The Carters, father and daughter, are well qualified to tell this recondite story. Bill Carter is a former chief of the geosciences laboratory at the National Oceanic and Atmospheric Administration, Merri Sue Carter is an astronomer at the National Earth Orientation Service of the Naval Observatory. Together they manage to make understandable some very complicated geometry, and almost -- but not quite -- impart some of the thrill of reading a murder mystery into the hunt for variation of latitude. Drama there was, but mostly of a rather rarefied kind. It is not a simple story. European scientists on the hunt for proof of variation decided to set up observatories on opposite sides of the globe, and they chose Berlin and Waikiki. But though the Waikiki observatory was built, Chandler beat Europe's best to the answer, using marvelously sensitive instruments of his own design, and a feel for the wobble of the Earth that perhaps has never been surpassed. Chandler, scanning his pages of numbers, discovered that the variation of latitude has more than one component. In fact, he came to believe that Earth has three subtle wobbles that impart a complex behavior to its axis (and, consequently, to the apparent latitude, as measured against the fixed stars). With better instruments and vastly greater resources, modern scientists have confirmed two of Chandler's wobbles. The third is so subtle that even today, researchers are not sure it exists. If it does, evidence may become available by around 2010. For a few bucks, you can buy a cellular phone with GPS as one of a dozen features. There's a whole lot more to that feature than most of us imagine.

This works on several levels

Like many good books, this one works on several levels. Its primary focus is the story of Seth Carlo Chandler, an amateur astronomer who discovered the variation of latitude now called the Chandler Wobble. In a larger sense, it explores how a group of American scientists attempted to raise American science up to the standards and practices of Europe. But what makes this an especially good read is that the authors make the scientists come alive. We learn not only what these scientists did, but also why. The authors penetrate the minds and motives of the scientists, creating a story that is both historical and imaginativeAlthough this book should appeal to a general audience, it is especially of interest to professionals who work in geodesy, surveying, astronomy, geophysics, and related disciplines requiring precise positioning. These readers will find a wealth of information about the foundation and structure of present scientific organizations, Today, the Global Positioning System and related technologies are capable of providing a precise positioning capability quickly and easily. But these technologies owe much to the work of Chandler and other scientists of the late nineteenth century. This vivid telling of Chandler's personal and professional life provides perceptive insight into a world that eventually brought America to the forefront of science and space exploration.

I really enjoyed this book!

I bought this book after seeing the advertisement for it in Sky and Telescope. I'm an amature astronomer and enjoy reading about the history of science. I had never heard this story before, although I knew about many of the men (Newcomb, Gould, Airy, etc) who are included in it. I thought it was very easy to read and interesting. The authors (Father and Daughter, both scientists in this case!) clearly know a great deal about this subject and give plenty of detail. Nice pictures, plenty of good background material. I came away with a much deeper understanding of the problem of the variation of latitude as well as the problems faced by American scientists in the late 1800's.A true inspiration to an "amature" like me to keep plugging away and looking for answers that the "professionals" may have missed.