MadSci Network: Physics

Re: does the earths movement impart a red shift on light?

Date: Tue Sep 28 20:01:01 2004
Posted By: Ken Wharton, Physics Professor
Area of science: Physics
ID: 1095444967.Ph

You bet!

Some of the people who have to take the Earth's movement into account are the hunters of extrasolar planets. They use Doppler shifts to look for very tiny deviations in the velocity of other stars, and therefore have to subtract out the motion of the Earth. While the detailed motion of the Earth is fairly complicated (if one takes into account the gravitational influence of all the other planets, tidal effects, rotation, etc.), it so happens that the Earth's motion can still be modelled very accurately.

For some of the extrasolar planets that they've discovered, the stars are only moving back and forth at about 10 meters per second (as a result of the gravitational perturbation from the orbiting planet). Certainly, to see this level of precision, one has to take into account the motion of the Earth. If this wasn't taken into account, the doppler shift imparted by the Earth's motion would dominate the analysis.

Current Queue | Current Queue for Physics | Physics archives

Try the links in the MadSci Library for more information on Physics.

MadSci Home | Information | Search | Random Knowledge Generator | MadSci Archives | Mad Library | MAD Labs | MAD FAQs | Ask a ? | Join Us! | Help Support MadSci

MadSci Network,
© 1995-2003. All rights reserved.