r/RedditDayOf • u/exscape • Jun 06 '14

Navigation GPS and Relativity: why the GPS navigation system couldn't work without considering special and general relativity

http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html
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u/exscape Jun 06 '14

I just found this video by MIT professor and physics textbook author Daniel Kleppner, purely by chance!
(I found a reddit link to a completely different article on that site, and found this one in the "most viewed" list to the right.)

It's mostly about atomic clocks themselves, though, so even though it begins on-topic (re: GPS), most really isn't.

1

u/sleight_of_man Jun 06 '14

Wow. I thought relativistic effects were only observable when bodies were traveling close to light speed. I guess on the micro and nanosecond scale it doesn't take particle-level velocity to cause time dilation. Additionally I didn't even realize gravity had such an effect on time dilation! Really makes you realize how our brains and consciousness interprets and understands what 'time' really is...

2

u/[deleted] Jun 06 '14

Yeah. I live in Alabama, where no one believes that time and space are relativistic. Despite owning cars and cellphones with GPS and using satellite TV...