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sam_handelman writes "The nytimes has another astrophysics article up. Free subscription etc. It talks about how inflation predicts multiple universes, this week. Dennis Overbye wrote the article, which is nice if lightweight. More info on the theory of inflation. Inflation, which is harebrained on first examination, actually predicts stuff, giving it credibility. Want to be the Right Pinky of God? It may yet be possible."
Moreover, "fact" doesn't mean "absolute certainty"; there ain't no such animal in an exciting and complex world. The final proofs of logic and mathematics flow deductively from stated premises and achieve certainty only because they are NOT about the empirical world. Evolutionists make no claim for perpetual truth, though creationists often do (and then attack us falsely for a style of argument that they themselves favor). In science "fact" can only mean "confirmed to such a degree that it would be perverse to withhold provisional consent." I suppose that apples might start to rise tomorrow, but the possibility does not merit equal time in physics classrooms.
Evolutionists have been very clear about this distinction of fact and theory from the very beginning, if only because we have always acknowledged how far we are from completely understanding the mechanisms (theory) by which evolution (fact) occurred. Darwin continually emphasized the difference between his two great and separate accomplishments: establishing the fact of evolution, and proposing a theory - natural selection - to explain the mechanism of evolution.
- Stephen J. Gould, "Evolution as Fact and Theory"; Discover, May 1981
> 50 years from now high school physics students will laugh at us. "Ha, these idiots believed in all sorts of kooky stuff".
Do today's highschool physics students laugh at the scientists of 50 years ago?
> This theory is just that, a theory.
And that's all a theory is supposed to be.
Sheesh, evil *and* a jerk. -- Jade
Why is inflation harebrained on first examination?
It was originally proposed to address one of the big problems in the old big bang theory, namely that parts of the universe visible from Earth, that were so far apart that light couldn't have travelled between them since the big bang, looked pretty much the same. For this too happen, they must have been some sort of communication between them at some point in the past, but a fixed, unbreakable speed of light prevents this happening. This assumes that the universe has always been expanding, with the expansion being slowed by gravity only.
Inflation just says that if the universe initially expanded much much faster than the current rate suggests it did, then those parts of the universe that are too far apart to communicate now, might have been able to communicate in the past. All of the complexity of the theory is in producing the physics that allows for, and causes the inflation.
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CowboyNeal for president!
"Hit any user to continue."
universe here means the area of the universe that we can (possibly) see, communicate with, and/or do physics experiments in. Since physics is limited to that region of the universe in which we can do physics experiments, then it is conceivable that there exist regions of spacetime that are inaccessible to us, by virtue of distance or some other parameter.
Whether it is meaningful for physicists to talk amount these regions as _seperate_ universes comes down to what you think universe means, and what the values of the cosmological parameters are this week.
I didn't see the explanation in the article, but from what I've heard the explanation is pretty simple. I think I read it in A Breif History of Time or something like that. I probably don't remember it correctly but here goes nothing...
The trick is that the collapse from an inflationary situation to normal spacetime can't happen instantaneously. By the time the collapse has happened and created a universe of normal spacetime, the inflation has already created more than enough (inflating) space/spacetime/cosmicstuff to replace it. So there will always be inflating stuff left over. Eventually this new inflating stuff will start collapsing into pockets of normal spacetime, creating new universes each time. The point is that the inflating stuff inflates too quickly to be consumed by the collapse process, so the process continues indefinitely.
- Inflation is predicated upon certain conditions within the universe just a few planck times after the big bang (a planck time is on the order of 10^-32 or so seconds, I can't remember exactly off the top of my head).
- If these conditions hold, inflation will occur. People pretty much believe that inflation did occur, for there is no other current way to accurately explain the rapid expansion of the universe in the first few planck times after the big bang.
- Now, assuming inflation did occur, that means the conditions for inflation must have been met. Here is where "inflation=multiple universes" as you put, it comes into play. Those conditions necessary to create inflation exist in certain pockets of space-time (most notably at singularities, such as in the center of a black hole) in our universe.
- Hence, if the conditions for inflation are met, surley something must be inflating. But we can't see results of such inflation in our universe, and therefore it probably means that the inflation is occuring in another universe. This is where the article is weak, and you are probably having your problem. They did not speak about the theories which allow for "new" universes to be created with different laws of physics, and how the preconditions for inflation meet these criteria. These theories have been around for quite some time, and are generally regarded as possible. That said, conditions which would cause these new universes are theoretical, and whether or not they exist are under debate. It just so happens that inflation theory forces some of these alternate universes to exist.
- So if there are random points in our universe which cause inflation and the creation of new universes, then it is very possible that our universe is one such inflation due to circumstances within another universe. And so on, creating a "web" of inflated universes: the multiverse.
I hope I've done some justice to the theories (sorry for the lack of links, I'll rumage through my books and try and post a followup later). If I'm wrong, or remembering things poorly, don't flame me, just reply and set things straight.---
"Of course, that's just my opinion. I could be wrong." --Dennis Miller
Note to God: Remember to make English better in next universe.
He theorised that all of the universe's parameters (light, gravity, strong and weak nuclear etc) were self-tuned in much the same way that life is tuned for survival. Universes where the gravity was too strong, or the charge of a particle was too weak, didn't develop black holes. Our universe appears to have thousands of black holes, and we know for a fact our universe is tuned to support life, ergo, our universe will have "off-spring", with black holes being the mothers.
He's basically doing what Creationists do - merging biological evolutionary theory with cosmological evolution, something which most scientists are quick to separate. I think he might be onto something...
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By the very nature of the word, an atom cannot be divided.
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Unfortunately, the big-brained ones have now copped onto the Sci-Fi idea of these alternate universes
...)
I think you have a wrong picture: although the notion of different choices and their consequences is an ancient one, the notion of parallel universes came from science (everett interpretation, feynman-multiple-path approach to quantum mechanics) to SciFi and philosophy.
As usual, the ideas flow from science to science-fiction. I asume this is because usually, nature is more bizare than what our imagination can predict. (and also because the best scientists are among the most creative people
Working for necessity's mother.
to understand this theory, all you have to do is visit your favorite pr0n site using IE. you see the way your screen fills with an endless swarm of pop-up windows, each with their own content? think of those as little universes, each separate from the others, but united in their love of barely legal asian teens.
"You want a toe? I can get you a toe by three o'clock... with nail polish."
Multiverses?
You mean this might mean that somewhere in the multiverse there might be a universe comprised entirely of "people" that look exactly like Lance and Britney?
Excuse me while I (and the rest of the "me's" in the multiverse) go out and hang ourselves....
LongTail SSH Brute Force analysis tool is here!
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Some groups of people used to think they were the center of the world(e.g. Zhong Guo==Middle Kingdom)
- Bigger groups used to think that earth was the center of reality and everything literally revolved around humans.(A belief vigorously defended)
- Leewonhoek's microscope revealed a smaller scale of reality than we knew, and it was quite some time before people accepted it.
- Newton's theories seemed to describe how all reality worked until we realized different things were going on at very small and very large scales.
- Now we have a much greater understanding of things at the quantum scale and the universal scale, but it seems obvious that that is not the end of it.
Why do we seem to assume that the scale of reality is finite and coincidentally matches the same scale at which we exist? I think that based upon all of our prior fumblings we would be more likely to conclude that reality extends to a much smaller scale than the quantum and a much greater scale than that of the observible universe; even that it is infinite in both directions.