Things ain’t all rosy for the Big Bang; it just don’t explain why the universe looks the way it does and the theoretical fixes proposed by them astrobods are a-crackin and a-crumblin.
Here’s one problem with the Big Bang. It involves these giant space thermometers like COBE and WMAP which tell us that wherever we look, the universe is the same temperature: it is in thermal equilibrium.
Now, the observable universe is about 28 billion light years across but only 14 billion years old. So there is no way that heat could have travelled between opposite sides of the cosmos–it’s just too far. So a thermal equilibrium ain’t possible. That leaves only the tiny possibility that the universe looks like it does by chance; and that makes them cosmobods all suspicious and sweaty.
So they did a lil a-dreamin and a-thinkin and in 1981 came up with an ah-dear called inflation. It goes like this. After the Big Bang, when the universe was just a fraction of a second old, it suddenly expanded in size. Not by a lil bitty amount but by a gigantic amount. Get this: by 26 orders of magnitude. That’s alotta expandin.
Inflation smooths out irregularities and makes the universe neat ‘n’ tidy, just as we see it today. It solves everything or so them astrobods thought.
But earlier this year, cosmologists calculated that the probability of inflation actually occuring in this universe is vanishingly small. And this week William “Half” Nelson at Kings College, London says that when yer take quantum cosmology into account (and who likes to leave that out), inflation is even more unlikely
So the problem of why the universe looks like it does raises its ugly head again. What could have caused such an unlikely an event as inflation? And if it weren’t inflation, what was it?
There’s gonna be a-plenty of hand-wringin’ over this one.
Ref: arxiv.org/abs/0708.3288: The probability of Inflation in Loop Quantum Cosmology