# What is inside a black hole? **URL:** \ **Category:** Factual Questions\ **Created:** [January 29, 2009, 4:30pm UTC](https://boards.straightdope.com/t/what-is-inside-a-black-hole/483570 "2009-01-29T16:30:45Z")\ **Posts on this page:** 4\ **Page:** 3
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [January 31, 2009, 12:42am UTC](https://boards.straightdope.com/t/what-is-inside-a-black-hole/483570/41 "2009-01-31T00:42:07Z")
Assorted nitpicks: Quoth **Stranger on a Train** : > [@](#): > > We can’t really say what form mass takes in that form; indeed, a black hole can in many ways be considered a giant composite quantum particle. A giant _fundamental_ particle. Composite particles have hair. > [@](#): > > The singularity for a rotating black hole (and we can readily assume that all naturally created black holes will have some amount of rotational momentum conserved from the original matter it condensed from) is actually a ring rather than a point, though the size of the ring for a stellar mass black hole is immeasurably tiny, and the diver falling into such a hole would be torn to component atoms by the tidal shearing forces long before. Actually, if the hole is maximally rotating (believed to be a good approximation for almost all astrophysical black holes), then the ring is of order a kilometer in diameter, and there are geodesics which pass cleanly through it. You’re still going to hit it if you fall in, though: Any nonzero test mass will, as it’s falling, perturb the hole in such a way as to close up the ring just in time for the test mass to hit it. Quoth **Ring** : > [@](#): > > Actually I found that groking the math wasn’t as difficult as groking the notation, especially indicial notation. That shit almost killed me. I suspect that you didn’t have a very good teacher. Taught well, the index notation makes tensor problems far, far easier. I always cringe when I see engineers (who haven’t learned the Einstein summation convention) doing tensor problems the hard way. On white holes, meanwhile, there’s nothing in the laws of physics that says that they can’t _exist_, but they can’t _form_. So for a white hole to exist, it would have to have existed since the beginning of the Universe. Since our Universe apparently started without any white holes, without white holes it shall remain. ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [January 31, 2009, 12:57am UTC](https://boards.straightdope.com/t/what-is-inside-a-black-hole/483570/42 "2009-01-31T00:57:24Z")
> [@Chronos](#): > > On white holes, meanwhile, there’s nothing in the laws of physics that says that they can’t _exist_, but they can’t _form_. So for a white hole to exist, it would have to have existed since the beginning of the Universe. Since our Universe apparently started without any white holes, without white holes it shall remain. Could you expand on that without making most of our heads explode? ---
**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\ **Post date:** [January 31, 2009, 1:12am UTC](https://boards.straightdope.com/t/what-is-inside-a-black-hole/483570/43 "2009-01-31T01:12:22Z")
Or you could say that one white hole has existed since the beginning of the universe: the universe. ---
**Author:** ![Ring](https://avatars.discourse-cdn.com/v4/letter/r/6a8cbe/32.png) [@Ring](https://boards.straightdope.com/u/Ring)\ **Post date:** [January 31, 2009, 4:26am UTC](https://boards.straightdope.com/t/what-is-inside-a-black-hole/483570/44 "2009-01-31T04:26:51Z")
**Chronos** wrote: > [@](#): > > I suspect that you didn’t have a very good teacher. I have an electrical engineering degree and an MBA. Over the years I bought about a zillion dollars worth of physics and math texts and taught myself. So I can guarantee you that I didn’t have a very good teacher. In fact he sucked canal water. If it weren’t for sci.physics and the internet he and I would still be sucking it. [Previous page](https://boards.straightdope.com/t/what-is-inside-a-black-hole/483570.md?page=2)