Fortran and Black Holes

[JohnNichols]

My 14 year old daughter wants to know what the inside of a black hole looks like. 

There are several papers on Fortran and modelling black holes, several show just black images, but has Fortran ever been used to model the "color" inside a black hole, not the surface, but actually inside? 

We discussed it for several hours on a trip and to my statement that is black, she said but with all the energy how can the inside be black?

[jimdempseyatthecove]

It would (may) depend on the definition of "black hole": Do you mean the event horizon, or do you mean inside the singularity (if that in fact is what is inside then center of the black hole).

Your daughter asks an interesting question upon which leads to additional questions.

For example:

1) Consider a photon approaching a black hole normal to the event horizon. Seeing that the gravitational pull can bend the photon path, the question becomes: Can the gravitational pull on the considered photon accelerate the photon as well?

2) Consider a photon approaching a black hole tangent to the event horizon. Assuming the singularity inside the event horizon is some distance from the event horizon... Does the photon, once inside the event horizon, travel in a spiral manner until it reaches the singularity? Does it halt motion (does time stop advancing) and remain at the point of entry? Does it make a right angle turn and directly traverse to the singularity? If so, how long does it take (at least from the perspective of a distant observer)?

Many other questions can be asked.

Jim Dempsey

[jimdempseyatthecove]

>>but with all the energy how can the inside be black?

Just because the event horizon doesn't emit light (photons), what is there to inhibit the photons falling through the event horizon from taking a finite time to reach the singularity? If this be the case, then there would be "color" of sorts (though presumably no observer to report as to what is observed).

Jim Dempsey

[JohnNichols]

This is a 14 year old girl, who for reasons I do not understand is interested in K Pop and Black holes.  The K pop is for her, but the Black Holes she actually asks good questions.  

There cannot be infinite energy packed into the black hole.  So if the black hole has volume M, and the total Energy is E then the Energy density is approximated by E/M, but there must be energy transfers within the black hole between regions, and the singular point at the middle, math may say it is infinitely dense, but that is just not really possible, as that point has to be thermally vibrating.