Geology Through Literature - Vanity Fair

The next up on my Geology Through Literature thread is Vanity Fair by William Thackeray. Vanity Fair was written in 1848 and follows a group of wealthy urbanites throughout the time period of Napoleon's reemergence from Elba and his eventual defeat at Waterloo. You can get my complete thoughts on the book/story over at my other blog - The Remnant, but for here I will just go into the geological or basic scientific aspects that are brought up in the story.

Chapter XXV

There was only one instance of geology brought up in the story but it was one I had not thought about before.

"Who'd think the moon was two hundred and thirty-six thousand eight hundred and forty-seven miles off?"

This made me question when we actually figured out the distance between the Earth and the Moon. This story was written in 1848 and that seems very early compared to our modern day scientific techniques.

According to Nasa, the Earth is an average of 238,855 miles away, not that far off of the 236,847 miles quoted in the novel. And actually the distance between the Earth and Moon changes depending on the orbit. It goes from 225,623 miles up to 252,088 miles away (Space.com). So in reality, the novels distance quote was spot on. 

The distance from the Earth to the Moon was determined way earlier than the 1800's. In 270 BC, Aristarchus derived the Moon's distances using a lunar eclipse. The Greeks had already known the Earth was a sphere and that the Moon orbited the Earth (since it was assumed everything orbited the Earth at that time). He used this information, along with the duration of one lunar orbit (~a month) and the time it takes to fully cross through the Earth's shadow during an eclipse to determine that the Moon is about 60 Earth's away from the Earth. Without the actual Earth radius though, this couldn't be more refined, until Eratosthenes determine the Earth's circumference a couple of decades later (as discussed earlier). 

More detail on the mathematics of Aristarchus' calculations can be found on Nasa's website: 

http://www-istp.gsfc.nasa.gov/stargaze/Shipprc2.htm

Another method was developed by Hipparchus to measure the distance between the Earth and the Moon using a total eclispe of the sun. You can read about his methods here:

http://www-istp.gsfc.nasa.gov/stargaze/Shipparc.htm

References

http://spaceplace.nasa.gov/moon-distance/en/

http://www.space.com/18145-how-far-is-the-moon.html

http://www-istp.gsfc.nasa.gov/stargaze/Shipprc2.htm

http://www-istp.gsfc.nasa.gov/stargaze/Shipparc.htm