What is spaghettification, and what causes it near a black hole?

• A. Spaghettification is the tidal stretching of objects by extreme tidal forces near a black hole, caused by the gradient in gravitational pull across the object's length.
• B. Spaghettification is the heating of gas to emit X-rays near the event horizon.
• C. Spaghettification is the bending of light into curved rays around the hole.
• D. Spaghettification is the collapse of matter into a singularity at the center.

Answer: (A)

Spaghettification is the tidal stretching of an object by the strong gravitational gradient near a black hole. Gravity isn’t the same strength across the length of the object—parts closer to the hole feel a stronger pull than parts farther away—so the object gets stretched along the line pointing toward the hole and squeezed perpendicular to it. This tidal force grows as you get closer to the black hole, and is especially extreme for smaller black holes where spacetime curvatures change rapidly over short distances. This is different from heating of gas into X-rays, or light bending, or matter collapsing into a singularity; those phenomena arise from other aspects of black holes, whereas spaghettification comes from the differential gravity across an object.