Adrogans Posted December 20, 2006 Share Posted December 20, 2006 I never understood how gravitational redshift works for an electromagnetic wave leaving the source of gravity. I don't see how the frequency of the wave can be changed by space-time warping. If the "path" is what changes, how can the wave that's travelling over the path be changed too? I could see it affecting gravitational waves, because those are ripples IN spacetime, but I don't get how it works for electromagnetic waves. Thanks Link to comment Share on other sites More sharing options...
timo Posted December 21, 2006 Share Posted December 21, 2006 I do not fully understand your question. Are you familiar with the redshift (e.g. could you calculate the redshift occuring when I point a laser pointer towards a satelite) and want to discuss the results or haven´t you seen the math, yet? Imho, redshift can be purely considered an effect of gravitational time dilatation leaving the EM wave (in a suitable coordinate system) basically unchanged but letting the observers do different measurements on it. I´m pretty fu... tired right now so I´ll not elaborate for now. I´ll setup a little explanation of gravitational redshift the next days unless you already know the math. Link to comment Share on other sites More sharing options...
Amos Schuman Posted December 22, 2006 Share Posted December 22, 2006 I never understood how gravitational redshift works for an electromagnetic wave leaving the source of gravity. I don't see how the frequency of the wave can be changed by space-time warping. If the "path" is what changes, how can the wave that's travelling over the path be changed too? I could see it affecting gravitational waves, because those are ripples IN spacetime, but I don't get how it works for electromagnetic waves. The wavelength (inversely, frequency) is also characterized by a time parameter as well as spatial ones, and remember that we're talking about a path through space-time. Link to comment Share on other sites More sharing options...
timo Posted December 22, 2006 Share Posted December 22, 2006 I set up a little explanation, there we go: http://www.wisci.org/wiki/Redshift#Gravitational_Redshift . Link to comment Share on other sites More sharing options...
Adrogans Posted February 27, 2007 Author Share Posted February 27, 2007 Ok, thanks a lot both of you. Everything is pretty clear now. Link to comment Share on other sites More sharing options...
Wearden Posted March 12, 2007 Share Posted March 12, 2007 Thanks, I also get it now Link to comment Share on other sites More sharing options...
patty144 Posted April 26, 2007 Share Posted April 26, 2007 The correct answer can be described conceptually, without the math. Take a look at chapter 3 in Melia's "The Black Hole at the Center of Our Galaxy." Link to comment Share on other sites More sharing options...
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