light and escape velocity

[rthmjohn]

Does the principle of escape velocity apply to light? I'm a physics dummy, so I apologize if this sounds like a dumb question.

[immortal]

Yes it does, we can see it working in a black hole, the space and time is curved so much that even light cannot escape from the black hole.

[DrRocket]

Does the principle of escape velocity apply to light? I'm a physics dummy, so I apologize if this sounds like a dumb question.

 

Not really though LaPlace did conceive of a black hole in very primitive way through just such an analysis, and formally that solution will give you the event horizon of a black hole.

 

However, classical Newtonian gravity does not apply to light. That requires general relativity.

 

Escape velocity is related to 1) a mass and 2) a distance from that mass. It is the velocity at which the kinetic energy is equal to the energy required to raise an object from the starting distance 2) to infinity against the Newtonian gravity of the mass.

[JohnStu]

Does the principle of escape velocity apply to light? I'm a physics dummy, so I apologize if this sounds like a dumb question.

 

 

Light gets affected by gravity as well, so yes.

[granpa]

light from a gravity well will appear to be redshifted due to gravitational time dilation.

[derek w]

redshift is an effect of a light source travelling towards or away from the observer,which decreases or increases the wave length relative to the observer.

Edited March 4, 2012 by derek w

[granpa]

http://en.wikipedia.org/wiki/Gravitational_redshift

 

In astrophysics, gravitational redshift or Einstein shift is the process by which electromagnetic radiation originating from a source that is in gravitational field is reduced in frequency, or redshifted, when observed in a region of a weaker gravitational field. This is as a direct result of Gravitational time dilation

[derek w]

Then we are back to Dr Rocket's point,Newtonian gravity or general relativity.

My question is would not the wave length return to normal when it leaves the gravity well (general relativity) or remain shifted by (Newtonian gravity) i am not sure that my understanding is correct?

[derek w]

Light entering a gravity well would gain energy and become blue shifted,but would lose energy on its way out and become red shifted.

energy of light in = energy of light out.

 

The question of of light and escape velocity,light only has one velocity = c

 

Unless you can consider space as moving at the speed of light,then light would not escape.Then light would have a wave length = 0 or at least the plank length.

 

Not sure that my understanding is correct,so any further explanation would be appreciated thank you.

Edited March 9, 2012 by derek w