Inside a black hole, our current understanding of physics breaks down, and our knowledge is limited. However, based on theoretical models and calculations, scientists propose the following:

1. Singularity: At the center of a black hole, there exists a region called a singularity, where matter is crushed to infinite density and space-time curvature becomes infinite. Here, the laws of physics as we know them cease to be valid. It is a point of zero volume and infinite mass.

2. Event Horizon: Surrounding the singularity is the event horizon, which is the boundary beyond which nothing, not even light, can escape the gravitational pull of the black hole. Once you cross the event horizon, you are irrevocably drawn towards the singularity.

3. Spaghettification: As you approach the singularity, the tidal forces become incredibly strong. This phenomenon, known as spaghettification or the "noodle effect," stretches your body into long, thin strands. The difference in gravitational pull between your head and feet becomes so extreme that you would be torn apart.

4. Time Dilation: Due to the intense gravitational field near the black hole, time is significantly dilated. For an outside observer, time appears to slow down as you get closer to the black hole. However, for someone falling into a black hole, time would seem to pass normally until reaching the singularity.

It is important to note that the above description is based on general relativity, which provides a good understanding of black holes but does not account for quantum effects. The true nature of what lies inside a black hole can only be fully understood through a theory combining general relativity and quantum mechanics, which is yet to be developed (known as a theory of quantum gravity).

References:

• Hawking, S. W., & Ellis, G. F. R. (1973). The large scale structure of space-time. Cambridge University Press.
• Thorne, K. S. (1994). Black holes and time warps: Einstein's outrageous legacy. W. W. Norton & Company.
• Kip Thorne's lecture on "Black Holes & Time Warps" at the Perimeter Institute: https://www.youtube.com/watch?v=JWVshkVF0SY