how bout a boltzmann KICK IN THA NUTZ
alright, that was too long and not engaging enough. How about this one. So here's the idea with the multiverse. The eternal/infinite inflation model is basically the following. Ignore the universe, and suppose all there is is an infinitely large vacuum. Turns out even empty space can have intrinsic field structure with energy density. E = mc^2, so this energy can theoretically be moved from the latent field energy into mass ==> go go infinitely many big bangs.
Now, inflation comes in by saying that this infinite vacuum is growing (it's infinite already. But it's like a loaf of bread that's rising in the oven. Suppose you have an infinitely large loaf. As it rises it still grows, but every nook and cranny inside of it expands. It's like if you took the number line and started shoving more numbers between every integer in equal proportion so it all expands equally). Anyway, this inflation will affect the energy density of the vacuum, which will in turn affect the sorts of mass that is spontaneously created. It will affect things in terms of the values of fundamental constants and such.
So basically, since this vacuum is infinite, if there's any chance at all that a certain segment of vacuum will be capable of spontaneously transferring some of its energy density into matter with the fundamental constants and such that we see in our universe, then it'll happen. In fact it'll happen an infinite number of times (as a consequence of dealing with an infinitely large vacuum).
As a side note for consistency, the spontaneous transfer of energy from the inflating vacuum into a bubble universe has the effect of plucking the engine which was making the vacuum space inflate, or expand like the loaf of bread. So the resulting bubble universe will still expand a bit, but not nearly to the same extent as the initial vacuum which created it. So we're not super likely to be running into any other bubble universes.
So this multiverse theory is appealing because it's consistent with inflation models, consistent with our knowledge of how our universe is currently expanding in a weird way. And it also fills in a gap of "where did we come from" or "what happened before, or what caused the big bang" type questions. And this "fertile vacuum" is eternal. So you can always say God lives in 2 temporal dimensions and created this if you wanna be like that (though at this level I'm thinking increasingly fewer people care about that sort of explanation).
Alright, great, BUT HERE'S THE RUB. In this multiverse set up, there will be infinitely many more boltzmann brain's (Boltzmann solar systems, Boltzmann universes even), than there will be bubble universes just like ours. Turns out Boltzmann brains are more durable than I had originally understood.
The idea is that this vacuum will create growing universes with fantastic amounts of heat energy running around (just like our early universe), and by sheer virtue of incredible numbers, statistically, some of this random super-hot plasma matter will form a brain just like mine in every way (except instead of being protected by a skull, it'll be coddled in superhot plasma which sill melt it in a trillionth of a second). That's a brain, but Boltzmann solar systems and universes can be created too with enough material. That is, a whole solar system or universe exactly like ours will be spontaneously created (infinitely many times) . Only instead of being surrounded by vacuum as we assume ours is, it'll be surrounded by superhot plasma which is moving at tremendous velocities to annihilate it back to standard chaotic thermal plasma status quo.
And how do we know that we're not in one of these universes? of course we have not the slightest bit of evidence to suggest that we are not. So here's the situation. We try to describe out current universal situation, and figure out a theory which will create our universe in a pleasing, sensible way. It even answers why are things the way they are for us. Only it then catches us with our backs turned and predicts that in all likelihood, our experiences are not being created by the bubble universe that we wanted (that we made the damned theory trying to describe its origin in the first place). But rather that we're probably in some ridiculous statistical abomination, on the verge of annihilation eventually.
So what to make of it? We surely can't say that its predictions are wrong can we? It's statistically overwhelming that we're not in a bubble universe by this multiverse model that was made to describe how our bubble universe could be constructed. So do we throw the theory out? On what basis? We don't LIKE its conclusions? We certainly COULD still be in a bubble universe just like we want to be in. The theory allows that. Infinitely many times even.
Hell I don't know what to think of it.
Now, inflation comes in by saying that this infinite vacuum is growing (it's infinite already. But it's like a loaf of bread that's rising in the oven. Suppose you have an infinitely large loaf. As it rises it still grows, but every nook and cranny inside of it expands. It's like if you took the number line and started shoving more numbers between every integer in equal proportion so it all expands equally). Anyway, this inflation will affect the energy density of the vacuum, which will in turn affect the sorts of mass that is spontaneously created. It will affect things in terms of the values of fundamental constants and such.
So basically, since this vacuum is infinite, if there's any chance at all that a certain segment of vacuum will be capable of spontaneously transferring some of its energy density into matter with the fundamental constants and such that we see in our universe, then it'll happen. In fact it'll happen an infinite number of times (as a consequence of dealing with an infinitely large vacuum).
As a side note for consistency, the spontaneous transfer of energy from the inflating vacuum into a bubble universe has the effect of plucking the engine which was making the vacuum space inflate, or expand like the loaf of bread. So the resulting bubble universe will still expand a bit, but not nearly to the same extent as the initial vacuum which created it. So we're not super likely to be running into any other bubble universes.
So this multiverse theory is appealing because it's consistent with inflation models, consistent with our knowledge of how our universe is currently expanding in a weird way. And it also fills in a gap of "where did we come from" or "what happened before, or what caused the big bang" type questions. And this "fertile vacuum" is eternal. So you can always say God lives in 2 temporal dimensions and created this if you wanna be like that (though at this level I'm thinking increasingly fewer people care about that sort of explanation).
Alright, great, BUT HERE'S THE RUB. In this multiverse set up, there will be infinitely many more boltzmann brain's (Boltzmann solar systems, Boltzmann universes even), than there will be bubble universes just like ours. Turns out Boltzmann brains are more durable than I had originally understood.
The idea is that this vacuum will create growing universes with fantastic amounts of heat energy running around (just like our early universe), and by sheer virtue of incredible numbers, statistically, some of this random super-hot plasma matter will form a brain just like mine in every way (except instead of being protected by a skull, it'll be coddled in superhot plasma which sill melt it in a trillionth of a second). That's a brain, but Boltzmann solar systems and universes can be created too with enough material. That is, a whole solar system or universe exactly like ours will be spontaneously created (infinitely many times) . Only instead of being surrounded by vacuum as we assume ours is, it'll be surrounded by superhot plasma which is moving at tremendous velocities to annihilate it back to standard chaotic thermal plasma status quo.
And how do we know that we're not in one of these universes? of course we have not the slightest bit of evidence to suggest that we are not. So here's the situation. We try to describe out current universal situation, and figure out a theory which will create our universe in a pleasing, sensible way. It even answers why are things the way they are for us. Only it then catches us with our backs turned and predicts that in all likelihood, our experiences are not being created by the bubble universe that we wanted (that we made the damned theory trying to describe its origin in the first place). But rather that we're probably in some ridiculous statistical abomination, on the verge of annihilation eventually.
So what to make of it? We surely can't say that its predictions are wrong can we? It's statistically overwhelming that we're not in a bubble universe by this multiverse model that was made to describe how our bubble universe could be constructed. So do we throw the theory out? On what basis? We don't LIKE its conclusions? We certainly COULD still be in a bubble universe just like we want to be in. The theory allows that. Infinitely many times even.
Hell I don't know what to think of it.