Why didn't the universe develop into nothing but black holes ?

[Pippy]

If the density of the universe was so great in the early seconds. weeks, months, years etc, then why didn't it all just collapse / develop into a mass of black holes ?

What stopped it all doing so ?

[Pig]

Maybe it has and we are all inside one now

[Pippy]

5 minutes ago, Pig said:

Maybe it has and we are all inside one now

Then what are the things we are calling "black holes" if we're already in one ?

That would mean relativity still applies just as well deep within a black hole itself, would it not ?

[Pig]

Yes it would ... and they would be called black holes with universes inside them and so on etc etc

[Pippy]

sheeesh, the deeper we look, the stranger it gets

[Linda]

26 minutes ago, Pippy said:

If the density of the universe was so great in the early seconds. weeks, months, years etc, then why didn't it all just collapse / develop into a mass of black holes ?

What stopped it all doing so ?

Maybe the inflation of space happened with greater force than gravity that was holding the stuff together...

[gnomus]

40 minutes ago, Pippy said:

If the density of the universe was so great in the early seconds. weeks, months, years etc, then why didn't it all just collapse / develop into a mass of black holes ?

What stopped it all doing so ?

Well, it certainly would have been cheaper.

[Bonnylad]

Apparently, in those early moments, the laws of physics as we know them, break down. Something to do with infinite gravity and infinite density, and where space-time curves... infinitely.

Anybody's guess.

[ronin]

Because it didn't.

If it had we would not be here to ask, so whatever was the determining factor - strings or whatever - we are in a universe that is as it is.

If the density of the universe was so great in the early seconds. weeks, months, years etc, then why didn't it all just collapse / develop into a mass of black holes ?

What stopped it all doing so ?

Inflation seems to be the answer to this but it may be a "fudge". The universe got bigger = inflated. But did so sort of quickly, faster the the speed of light, but that may be OK as it was likely to have been space-time that inflated and that does not have the "c" speed limit. It is the stuff in space time that has the speed limit (apparently). So "inflation" is used as the term for that initial expansion. It is also a good way to get around our lack of understanding of what was going on at the very early time.

Also how "dense" was it? There wasn't mass until it expanded and cooled a bit, how dense is a big/small/intense lump of energy ?

However overall we are in a universe that is as it is, it turned out like this for some reason and it is likely chance, luck or something - just the right mix (cosmic cookery?).

No reason why other "big bangs" have not happened and they failed to "inflate" so collapsed back into whatever they originated from.

 

[Kropster]

1 hour ago, Linda said:

Maybe the inflation of space happened with greater force than gravity that was holding the stuff together...

Exactly. In the early Universe the force of the Big Bang spread matter with more force than Gravity could oppose it with.

[Tiny Small]

The more important question I think, is why is there matter at all, given that matter and antimatter annihilate, and in the transition from energy to matter/antimatter, they are created in equal amounts (IIRC). 

[Bonnylad]

4 minutes ago, Tiny Small said:

The more important question I think, is why is there matter at all, given that matter and antimatter annihilate, and in the transition from energy to matter/antimatter, they are created in equal amounts (IIRC). 

Toss of a coin - we exist or we don't. We got to exist.

I read an eloquently put argument on a debate forum some time ago where the author explained how we couldn't possibly not exist. Fascinating. (Forum since closed down.)

[Tiny Small]

7 minutes ago, Bonnylad said:

Toss of a coin - we exist or we don't. We got to exist.

I read an eloquently put argument on a debate form

Although there are some far stretched hypotheses out there that argue the fact that we exist, I think it's safe to say that we do. Which is nice. But it's still important to ask why. Certainly important enough for the people at CERN at any rate.

[Bonnylad]

1 minute ago, Tiny Small said:

Although there are some far stretched hypotheses out there that argue the fact that we exist, I think it's safe to say that we do. Which is nice. But it's still important to ask why. ertainly important enough for the people at CERN at any rate.

Perhaps we'll forever be asking the why. But as we're here, the 'how' in due course may lead to 'why.'

[Pippy]

1 hour ago, Bonnylad said:

Apparently, in those early moments, the laws of physics as we know them, break down. Something to do with infinite gravity and infinite density, and where space-time curves... infinitely.

I would argue that it's not the laws of physics that break down, EVER, ever ever ever. it's our interpretation of it all that must be wrong and / or incomplete in cases like that.

[Tiny Small]

I think that this is without doubt the correct interpretation of what we see going on.

[Knight of Clear Skies]

Basically, because the porridge of the universe was 'just right' to prevent recollapse. Astrophysicist Ethal Siegal covers this here:

https://medium.com/starts-with-a-bang/ask-ethan-50-why-didnt-the-universe-become-a-black-hole-f4da68466e21#.ddiy12o1b

Our universe is very nearly flat, which is thought to be a consequence of inflation.

[Pippy]

26 minutes ago, Knight of Clear Skies said:

Basically, because the porridge of the universe was 'just right' to prevent recollapse. Astrophysicist Ethal Siegal covers this here:

https://medium.com/starts-with-a-bang/ask-ethan-50-why-didnt-the-universe-become-a-black-hole-f4da68466e21#.ddiy12o1b

Our universe is very nearly flat, which is thought to be a consequence of inflation.

To have such a required extremely fine balance like that in order for the universe as we know it to exist must surely mean that this has probably happened countless times before, and failed. Just that in this particular re-run of events, things turned out just right then. yes / no ?

Either that, or having that extremely fine balance is somehow an inherent property of the cause of the universe ?

Either that, or we just got soooo improbably lucky first time round !

How strange.

[Kropster]

12 hours ago, Tiny Small said:

The more important question I think, is why is there matter at all, given that matter and antimatter annihilate, and in the transition from energy to matter/antimatter, they are created in equal amounts (IIRC). 

Very nearly equal amounts. The matter we see is the result of a slight imbalance in the ratio of matter to anti-matter.

The big question is why the imbalance? I believe that is being worked on.

[Kropster]

11 hours ago, Pippy said:

To have such a required extremely fine balance like that in order for the universe as we know it to exist must surely mean that this has probably happened countless times before, and failed. Just that in this particular re-run of events, things turned out just right then. yes / no ?

Either that, or having that extremely fine balance is somehow an inherent property of the cause of the universe ?

Either that, or we just got soooo improbably lucky first time round !

How strange.

If Universes are created an infinite number of times, then sooner or later we were bound to happen.