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Why Can’t Light Escape a Black Hole?

-- Cardin | May 24, 2021

Question:

Is the reason light cannot escape a black hole more due to the relative stop in time within the EH rather than the gravity slowing down the speed of light? The light could still be travelling at c but since v is a function of t, the relative t elapsed to an observer is always zero.

-- Cardin

Answer:

Within the event horizon of a black hole space is curved to the point where all paths that light might take to exit the event horizon point back inside the event horizon. This is the reason why light cannot escape a black hole. Another way to look at it is that the escape velocity from the event horizon of a black hole is faster than the speed of light. Since nothing can travel faster than the speed of light, nothing escapes the event horizon of a black hole.

-- Jeff Mangum

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