Special Relativity states that a clock orbiting Earth will tick slower than one on the surface of Earth. General Relativity states the opposite - a clock will tick faster the further it is from a mass. Is there then a critical radius where these two effects cancel out? Ignore the rotation of Earth for this problem. State the radius in terms of r(adsbygoogle = window.adsbygoogle || []).push({}); _{c}=kr_{E}, where k is the number to be determined and where r_{E}is the radius of the Earth.

-This was the extra credit problem on my Relativity final which I really wish I could have solved. Anybody want to take a shot at it?

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Critical Radius of Special and General Relativity Effects on a Clock Orbiting Earth

**Physics Forums | Science Articles, Homework Help, Discussion**