October 22, 2012 12:42 AM Subscribe
posted by kaibutsu (17 comments total)
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Q: How many miles is it to the crab nebula? How does one even figure this out?
A: The cosmic distance ladder! Here's a talk by Fields medalist Terrence Tao
on methods for indirect calculation of distances to astronomical objects. Here's Tao's blog post
on the subject, including the slides for the talk
. And here's a Wikipedia page
For my part, I remember in high school asking exactly how
one could use star brightness to measure distance, given that we can't really measure absolute brightness of a star directly. Somehow I got pretty unsatisfactory answers from my high school science teachers; it's nice to fill in some blanks!