Black holes are said to be composed of two parts:
- A singularity at the center, where all the mass of the black hole is condensed in a point of zero volume.
- A black and empty ball delimited by the event horizon.
Also, relatively to an observer outside the black hole, the time for a particle inside the black hole (inside the event horizon) is stopped/frozen.
Suppose we had a particle very similar to photons but which wasn't affected by the gravitational force. Using this particle as our light we could see inside the black hole.
What would we see? We would see that particles who fall in the black hole become slower and slower because the more we come close to the black hole and the more time slows down. And once particles reach the event horizon, they stop completely, as time freezes.
So my question is: How can particles reach the singularity if time stops at the event horizon?
Scientists always say that, when a star collapses into a black hole, all the matter will be compressed in a singularity... But how can this singularity form if time stops at the event horizon?