# Early Universe a Black Hole? **URL:** \ **Category:** Factual Questions\ **Created:** [July 12, 2002, 1:45pm UTC](https://boards.straightdope.com/t/early-universe-a-black-hole/118616 "2002-07-12T13:45:21Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![SoarerV8](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@SoarerV8](https://boards.straightdope.com/u/SoarerV8)\ **Post date:** [July 12, 2002, 1:45pm UTC](https://boards.straightdope.com/t/early-universe-a-black-hole/118616/1 "2002-07-12T13:45:21Z")
This has been bugging me ever since I read ‘A Brief History of Time’. If the universe was very, very small at some point (the Cosmic Egg) would not it have been wholely within its Swartzchild radius - i.e. would it have been a Black Hole? If so, has it since expanded outside its Swartzchild radius (which should be impossible), or are we and all around us still living inside a universe-sized black hole? ---
**Author:** ![erislover](https://avatars.discourse-cdn.com/v4/letter/e/71e660/32.png) [@erislover](https://boards.straightdope.com/u/erislover)\ **Post date:** [July 12, 2002, 2:36pm UTC](https://boards.straightdope.com/t/early-universe-a-black-hole/118616/2 "2002-07-12T14:36:10Z")
Universe-sized black hole is possible, I believe, since no information can travel out of the universe. IANAP. ---
**Author:** ![Enola\_Straight](https://avatars.discourse-cdn.com/v4/letter/e/dec6dc/32.png) [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)\ **Post date:** [July 12, 2002, 4:24pm UTC](https://boards.straightdope.com/t/early-universe-a-black-hole/118616/3 "2002-07-12T16:24:48Z")
A black hole has a quantum singularity. The pre-Big-Bang universe was also a quantum singularity. However, a black hole’s Swartschild Radius is a function of space, time, and the speed of light, three quantities which did not exist before the Big Bang. ---
**Author:** ![bryanmcc](https://avatars.discourse-cdn.com/v4/letter/b/eada6e/32.png) [@bryanmcc](https://boards.straightdope.com/u/bryanmcc)\ **Post date:** [July 12, 2002, 5:47pm UTC](https://boards.straightdope.com/t/early-universe-a-black-hole/118616/4 "2002-07-12T17:47:27Z")
I’ve often wondered about this as well. **Enola Straight** , it’s not about _before_ the big bang. 10^-20 seconds after the big bang (or some other ridiculously small number) the entire universe would’ve been within the Swartzchild radius of all that mass-energy. So how was it possible for it to keep expanding? -b ---
**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:** [July 12, 2002, 6:23pm UTC](https://boards.straightdope.com/t/early-universe-a-black-hole/118616/5 "2002-07-12T18:23:37Z")
The simple answer is that it is not wise to enquire too deeply into some things. More complicated answers might be that gravity fuctioned differently (if at all) at that time, or that the “inflation field”, whatever that was, changed the size of the Schwartschild radius. Furthermore, it is conceivable that the Universe is, in fact, a black hole: Neglecting [symbol]L[/symbol], the condition for this turns out to be the same as the condition for a closed (Big Crunch) universe. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [July 12, 2002, 9:26pm UTC](https://boards.straightdope.com/t/early-universe-a-black-hole/118616/6 "2002-07-12T21:26:34Z")
**Enola Straight** has the right idea. The universe is all there is. It is not “inside” anything else, never was, never will be. (In terms of our laws of physics.) You can’t draw a circle/sphere around it. Going back to the overused and probably not appropriate balloon analogy. Try drawing a line _on_ a balloon that completely encloses the balloon. While the balloon can be enclosed in a larger sphere, that is completely outside our physical realm and not part of the laws of gravity. (And then one can also argue, since the balloon analogy is a Bad Idea, that the universe was [maybe] born infinite and never enclosable in anything finite in any set of dimensions.) And then … For a _subset_ of the universe back when: Energy does leak out of black holes. If you’ve read Hawkings you know about this. The “hotter” the black hole, the greater the leakage. Needless to say, the early universe was **hot**. Also, gravity didn’t exist initially. The basic particles with their associated forces took “some time” to form. And then there are some _really_ weird things to think about. The Schwartschild radius is for objects going “merely” the speed of light. Very far off galaxies from us are actually receding at a speed greater than the speed of light. (We can’t see them of course, never will.) Ask your physics prof. about this (and kiss that letter of recommendation goodbye).