# Having trouble understanding description of tidal forces acting on a body in a singularity.

In describing a black hole and its immense tidal gravity, how do you describe the forces acting on a body as it approaches the singularity?

Here is the phrase I am trying to understand:
"This creates a tension gradient across the object parallel to any radii colinear with both the object's center and the singularity."
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Principal Software EngineerCommented:
I think the best practical description of this is in Larry Niven's short story "There Is A Tide."

The gravity becomes so great that there is significant force trying to pull an object apart as it orbits.  The inner portion wants to orbit faster, the outer portion slower, and the result is that the object rips apart when the gravity becomes large enough.

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Commented:
Things are even simpler and really has nothing to do with a black hole. It is just that the effect is so much more important near a black hole, The gravitational force goes as 1/r^2. Your object has one side nearer the black hole  so it has a force acting on that side. The other side of your object is father away from the black hole so while it has a force acting on it as well, that force is less than the force on the closer side. That difference in forces is what is tending to tear the object apart.
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Commented:
For orbital calculations, the gravitational force on smaller object acts on its center of mass.  But the mass is distributed, not concentrated in the center.

So the particles and pieces of a smaller object would have a tendency to follow different orbits around a larger one, such as a black hole or Saturn.  Closer parts want to orbit faster than the average, and more distant ones slower.  This give rise to tidal forces, which can be larger than the cohesive gravitational forces holding a small object together.  A process like this presumably formed the rings of Saturn.
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