We know this because general relativity is a classical field
theory which predicts that under certain conditions, infinities
will occur...called singularities. Here is a version of what happens to space near a blackhole
based on the mathematics first discovered in 1921 by the Nobel
prize-winner Alvar Gullstrand, and independently by the French
mathematician and politician Paul Painlevé. (credit: Univ. Colorado). It emphasizes a concept
called collapsing space. Any objects trapped in this space will literally be dragged through the event horizon and crushed at the Singularity.
All known singularities in the theory seem to be hidden behind
event horizons. At these locations, space-time curvature defined
by the magnitude of the so-called Riemann Tensor, goes to infinity
as the radius of the system goes to zero. It is expected that a
make-over of general relativity by a fully quantum mechanical
field theory (Superstrings, M-Theory, etc) will remove these
singularities and replace them by some as yet undefined quantum
condition, such as the finite graininess of space-time itself at the Planck Scale.
Return to Dr. Odenwald's Gravity
page at the Astronomy Cafe Blog.