mareksjacino Posted May 20, 2015 Share Posted May 20, 2015 Is it posible to increse the speed of light,if light waves pases black hole,not too close,not too far.. just using black holes gravity?! Link to comment Share on other sites More sharing options...
Mordred Posted May 20, 2015 Share Posted May 20, 2015 No the speed of light is invariant. All observers will see the speed of light As the same value in a vacuum. Gravity does not alter c. 1 Link to comment Share on other sites More sharing options...
mathematic Posted May 20, 2015 Share Posted May 20, 2015 The black hole, like any massive object, will bend the light beam. Link to comment Share on other sites More sharing options...
Avalanche2001 Posted May 20, 2015 Share Posted May 20, 2015 The passage of any light through a black hole would, in no way, increase its maximum speed. To outside observers, it would actually appear as if the light was traveling more slowly, and, as it reached the singularity, it would seem to stop completely before disappearing after some time. Link to comment Share on other sites More sharing options...
Strange Posted May 20, 2015 Share Posted May 20, 2015 The passage of any light through a black hole would, in no way, increase its maximum speed. To outside observers, it would actually appear as if the light was traveling more slowly, and, as it reached the singularity, it would seem to stop completely before disappearing after some time. No one could see what happened inside the event horizon, so approaching the singularity is not observable. Link to comment Share on other sites More sharing options...
Spyman Posted May 21, 2015 Share Posted May 21, 2015 Is it posible to increse the speed of light,if light waves pases black hole,not too close,not too far.. just using black holes gravity?! No the speed of light is invariant. All observers will see the speed of light As the same value in a vacuum. Gravity does not alter c. I am not an expert on Relativity, but from my understanding a light ray would be slowed down if it passes close to a black hole as measured by a distant observer. Locally the speed of light is c but when measured from a different gravity field it is not. "The Shapiro time delay effect, or gravitational time delay effect, is one of the four classic solar system tests of general relativity. Radar signals passing near a massive object take slightly longer to travel to a target and longer to return than they would if the mass of the object were not present. The time delay is caused by the slowing passage of light as it moves over a finite distance through a change in gravitational potential." http://en.wikipedia.org/wiki/Shapiro_effect Link to comment Share on other sites More sharing options...
MigL Posted May 21, 2015 Share Posted May 21, 2015 Mordred is still right... All observers will measure the speed of light to be c, in their own frame. If you're going to measure it from a different frame, your results may vary. AFAIK, the speed of light doesn't change due to gravitational fields. Its wavelength, and therefore frequency, does. A BH is not black because light stops, but because its wavelength becomes infinite climbing out of the BH's gravitational well ( as predicted by gravitational time dilation ). I'll have to read up on the Shapiro time delay, Spyman. Link to comment Share on other sites More sharing options...
Mordred Posted May 22, 2015 Share Posted May 22, 2015 Light has to travel a further distance due to spacetime curvature following the null geodesic. This is mentioned under the Shapiro effect on the wiki page above. "Throughout this article discussing the time delay, Shapiro uses c as the speed of light and calculated the time delay of the passage of light waves or rays over finite coordinate distance according to a Schwarzschild solution to the Einstein field equations." "which is the extra distance the light has to travel. Here R_s is the Schwarzschild radius.hich is the extra distance the light has to travel. Here R_s is the Schwarzschild radius." Look under the metric section. The speed of light is still invariant. 2 Link to comment Share on other sites More sharing options...
Spyman Posted May 22, 2015 Share Posted May 22, 2015 I am sorry if I didn't express myself clearly, I never meant to say that Mordred was wrong or that gravity can pull light to a stop. It seems we all agree that a light ray propagates through space with the speed of c, and that gravity causes the light ray to take a 'detour' from the straight line an distant observer measures the traverse length along, such that when timed from far away it will be delayed. If we would send a light signal close to a black hole it would descend with the speed of c and then climb up on the other side with the speed of c, but the time for the light ray to pass through the gravity field will take longer than length/c as measured by a distant observer. (An observer close to the black hole would measure the same light ray to locally pass by with the speed of c.) BTW Congratulations Mordred to becoming a Resident Expert! (Somehow I have managed to miss when this did happen.) Link to comment Share on other sites More sharing options...
imatfaal Posted May 22, 2015 Share Posted May 22, 2015 BTW Congratulations Mordred to becoming a Resident Expert! (Somehow I have managed to miss when this did happen.) http://www.scienceforums.net/topic/30961-sfn-nominates-new-resident-experts/?p=868626#entry868626 Thanks for the reminder Link to comment Share on other sites More sharing options...
agent x Posted June 13, 2015 Share Posted June 13, 2015 it is possible to slow the speed of light. i am not sure about speeding it up though. http://www.bbc.com/news/uk-scotland-glasgow-west-30944584 Link to comment Share on other sites More sharing options...
J.C.MacSwell Posted June 15, 2015 Share Posted June 15, 2015 it is possible to slow the speed of light. i am not sure about speeding it up though. http://www.bbc.com/news/uk-scotland-glasgow-west-30944584 I have to be skeptical of the results or conclusions. Only a slight difference in speed (or time lapse on their "race track"), but if true, in one frame this would be a stationary photon. Link to comment Share on other sites More sharing options...
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