Longitude by Dava Sobel
Finished reading on November 21, 2012
I finished reading this book while trying to watch Star Trek the Original Series at the same time. Couldn’t get too far that way though, so I now all that’s stopping me from watching Star Trek is writing this blog post and the fact that it’s past 2 am.
Now, “Longitude” – it’s a nice sort of book – short, small and not too technical. And the content’s are fairly interesting also – the quest to find a solution to finding the longitude at sea.
If you’d read just about any book on the history of astronomy, they’ll usually mention it, and sometimes they’ll have a whole chapter about it. So now it was good to read a bit more about it, although, it didn’t seem as if I’d gotten much smarter by reading it.
John Harrison, his chronometers and Nevil Maskelyne are some of the main topics. Historically it had been suggested already in the 16th century that one could use observations of the Moon to find out their longitude. Unfortunately at the time there wasn’t many observations of the Moon and no-one really understood the Moon’s movements that well yet, to predict it’s position precisely enough to determine their longitude by observing it, unless there was a lunar or solar eclipse.
Now the Moon was just one of the possibilities, but there were also the moons of Jupiter, that could be used for the same purpose.
If you’ve heard the joke about Niels Bohr and the barometer, then Harrison’s method of solving the longitude problem was a bit like that. In the beginning of the 18th century, there was a foundation founded for finding the solution to determining the longitude. The founding members were mostly astronomers. And so the fact that Harrison could solve something, for which they (and foremost – Maskelyne) wanted an astronomical solution, by using mechanics, is easily understood as something the foundation wouldn’t want to recognize as prize-worthy.
As far as I’m concerned, then I see it as clever and sneaky at the same time. And the story is interesting precisely because of that.
There’s also a two-part film (you can watch the trailer here) made after the book. I haven’t seen it yet, but seems ok.