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The Question

(Submitted March 14, 1997)

Just curious about Black holes, and I wanted to know if the gravitational field of a black hole would pull an object in faster than the speed of light. If I understand correctly objects cannot go faster than the speed of light our they would be going back in time. If the acceleration of a black hole is constant, would an object that got sucked into a black holes velocity increase beyond the speed of light the closer it got to the black hole?

The Answer

The answer to your question is that the motion of a particle near a black hole is not governed by Newton's laws of motion in the familiar sense. The correct equations for motion near a black hole predict that an object on a radial path into the hole will have a velocity which approaches the speed of light as the object approaches the event horizon. For more information, I can only refer you to a textbook on general relativity, such as the one by Steven Weinberg ("Gravitation and Cosmology..." 1972 (Wiley: New York).

I hope this is of some help.

Tim Kallman

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