Wednesday, February 17, 2016

There's Nothing There - Part 15

Now, the problem with a universe, a brand new universe full of Space-Time, or made of Space-Time, is that it is a bit unstable.

Like, brand new babies. Like, here's your brand new baby. Isn't it cute? Don't you just want to cuddle it to pieces?

And then you find out that it poops and pees and cries and screams and squirms and doesn't sleep at night when YOU need to sleep, but it sleeps really well in the daytime when YOU need to go do stuff and grows up and becomes a screaming toddler and then suddenly a nasty old teen-ager who is completely and totally unstable and says that it hates you even though it really doesn't mean it. But, still. It hurts.

OK, that's not really a great analogy, but we got to use the word "unstable" in a sentence, because that's what a brand new universe might be.

Instability in a universe - very bad.

Because the universe could just ... collapse back in on itself and become, um, not a universe again. Nothing there. Not a nothing that might be mistaken for a something, but like the original nothing out of which the universe came in the first place.

Nasty teen-ager. OK, it's a metaphor. Apes don't sue.
When you put their pictures on the web without asking first.
That would be bad. No universe, no nothing, no order, no life, no you or me. No screaming babies or sullen teen-agers. Don't go there. Don't wish the universe would go away just because of a nasty old teenager. Tempting though it may be.

Or the universe could expand waaaaaay too much, and then you get an even more enormous, but entirely empty universe.

Because everything that the universe produces has to be close enough to everything else the universe produces in order for the universe to produce anything else, up to and including babies and teen-agers.

Because (and this is what started this whole "There's Nothing There - Part Infinity" [apparently it's never going to end]), it seems likely that what there is in the nothing that makes the nothing act like something is (wait for it) ... interactions. Relationships. And for things to interact, they have to be close enough together for the laws of physics to make them interact.

The laws of physics being Gravity (which is really weak and if things aren't close enough, Gravity is just useless.), and Electromagnetism (ditto), and the Strong Force (OMG, it only reaches across an atom, which is veeery small) and the Weak Force (which we still don't quite get yet, but take our word for it - things gotta be close).

Just to remind us - Gravity is an interaction between matter and space-time.

So here's another question: how hard is it to get a universe to be juuuuuust right? Like, it doesn't collapse and it doesn't get too big. Not too small. Not too big. Juuuuuust right. Goldilocks-ishly. We made that word up.

And the answer is (drum roll) really really hard.

If we were to give you the odds, it would 1 in 10**60th, which is 1 in 10 to the 60th, which is 1 in 10000000000000000000000000000 0000000000000000000000000000000th. If we counted all the zeroes right.

Gravity has to be exaccccctly right in order for that to happen. Well, it can be off by 1 part in 10**60th.

And it also has to be what we call "Flat", this universe. Which means it can't be bent one way or 'tother.

This is the Physics Girl. Way smart.
Those are the three possible shapes of the universe. On the right.
The scientists call this "The Flatness Problem". You could look it up. Good idea. Go do that.

Because it's a problem. The odds are not good. The universe should have been bent one way or 'tother. 

But it isn't.

What are the odds?

That would be 1 in 10**62nd, which is 1 in 10 to the 62nd, which is 1 in 1000000000000000000000000000000000000000000000000 0000000000000nd. If we counted all the zeroes right.

So the scientists looked around for a way around this problem. Three of them found a way. If you want to know their names, you can ask us and we'll tell you.

They came up with this idea called "Cosmic Inflation". It's very cool.

It says that the universe, which was already expanding pretty darn fast, all of a sudden started expanding super-dooper fast for a really really tiny amount of time.

We told you this before, but that's OK. We'll tell you again.

It expanded in 10**-35th of a second from the size of a nanometer to 250 million light years across. And then it all of a sudden slowed down again. 

Here's how fast: .00000000000000000000000000000000001 second.

Here's how big: call it 2,500,000,000,000,000,000,000 km.

The Milky Way, by the Way, is only 100,000 light years across. Like, 1,000,000,000,000,000,000 km. Way smaller. Waaaaay. 

Cosmic Inflation. It's a lovely idea.

With a problem.

Things needed once again to be juuuuuust right for Inflation to happen.
This is Goldilocks. Kinda bad-ass.


So in order for the universe to be just right in order for it to actually be able to do anything, it had to expand super-dooper fast for a tiiiny amount of time, and in order for that to happen, everything had to be juuuuuust right.

And then there are some other things that had to be pretty darn perfect. The Higgs, the Dark, and the Dark. Boson, Energy, and Matter, that is.

We should explain. We'll do that. Later.

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