Light entering a Black Hole and Hawking radiation

[Superposed_Cat]

Main Question or Discussion Point

Hi all, I was wondering if, when a beam of light is pulled towards a black hole , because it can't accelerate, it is blueshifted? Thanks in advance.

 

[tiny-tim]

Hi Superposed_Cat!

If two people with identical flashlights are stationary at the top and bottom of a mountain, shining the flashlights at each other,

the top person will see the light redshifted, and the bottom person will see the light blueshifted.

It's the same for stationary observers near a black hole …

the gravitational effect of a black hole is (outside the event horizon and outside the surface of the star) exactly the same as that of a star of the same mass.

 

[Superposed_Cat]

Thanks tiny-tim :). Good day fine sir.