Slashdot Mirror
The Ending Of The Big Bang?
Pedrito writes "CNN is running a story here about a new theory that competes with the Big Bang. I figured it would already be up here. The theory goes that the universe "existed" before as a vacuous space, devoid of matter or energy. Two universes collided and the collision brought matter and energy to the void. The theory explains some things that the Big Bang doesn't. It's also partially based in String theory, of which I'm a big believer."
The Big Bang theory always sounded too biblical to me. I mean one event from a single point exploding to create everything? We see relatively tiny bangs every day from novas and planetary death - I see no reason to think the Big Bang wasn't just a particularly large version of these daily occurences.
The Big Bang was fundamentally different in a number of ways.
Normal explosions involve moving a lot of matter and radiation around through space.
The big bang involved a lot of matter *and* space coming out of nowhere as the result of a quantum fluctuation [to grossly oversimplify].
Yes, there might be other big bangs "outside" the universe, but as both space and time exist only within the universe, we'd have no way of reaching hypothetical other universes [under the classic big bang model; other models propose bangs happening within a universe creating a new bubble of space and time, and other models propose one universe in which pockets undergo inflation and *look* like new universes from the inside.]
Your local univerity's library should have a lot of information on the subject, filed under "cosmology".
Don't get me wrong...Mr. Hawking and his peers think more before breakfast than I do in an average year, but without falsifiable hypotheses, a lot of cosmology has more to do with faith than with fact. This is not necessarily a bad thing, but one has to realize it for what it is.
Models of the universe's creation actually do produce a surprising number of testable predictions.
We see space permeated by 3K blackbody radiation. The big bang model neatly explains this (the universe was once very hot and compact). Steady-state models don't. Scratch the steady-state models.
We see a universe that is apparently geometrically "flat" (Euclidean). This eliminates a wide range of big bang models, and suggests (among other things) that the universe may have started with zero net energy (and thus be the result of a quantum fluctuation).
We see matter clumping on a small scale, but amazingly uniform on a larger scale. The degree and patterns of clumping observed suggest a period of extremely rapid expansion while the universe was very small. Thus, the various inflationary models of the universe. Some produce predicted mass distributions that match the universe's; some don't. Scratch the ones that don't.
Our models of physics at the extreme temperatures and densities that the universe looks like it had in its youth are not well-defined. Some options suggest that we'd get zillions of black holes permeating space. Do we see any? No, so scratch that range of physics models. Other options suggest gigantic artifacts like "cosmic strings" or "great walls". Do we see any? No walls, and strings are inconclusive (putting an upper limit on the number present, if any). This narrows the range of physical theories even more, which in turn gives us a better idea of how the universe would have behaved under early conditions, which lets us refine our predictions of what an old universe would look like under a given model, which lets us further prune models according to observations.
In summary, while speculation indeed occurs, when a model is selected it's usually selected based on the testable predictions it makes.
Again, a library search will turn up most of this.
"I figured it would already be up here."... right, perhaps even on slashdot just over a week ago. Considering a search on "Big Bang" turns it up, it doesn't seem as if anyone looked very hard. (you too, Hemos)
--
"It's tough to be bilingual when you get hit in the head."
"I figured it would already be up here."... right, perhaps even
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"It's tough to be bilingual when you get hit in the head."
The truth about the story is much more mundane than CNN tried to make it sound. The primary proponante of this alternative came up with for the sole purpose of having an alternative should the Big Bang theory not work out, and cause he thinks the math involved is fun. The only advantage the Big Bump theory has over its predecessor is that space existed before hand and there is no need for some silly epoch of inflation. The nice thing about this is it attacks the big bang at a point of uncertainty and should make predictions that are quite different. I would think that the two theories would have quite different predictions about what the cosmic background radiation's fine scale structure would look like, for instance. Right or wrong, at least it's a good theory.
--Jimmy has fancy plans; and pants to match.
I suppose I can see how one might get that impression. But that's not really what the theory is about. It's a spare theory in case we break the current better theory. Sure, you can't drive the The Big Bump faster than 35 mph, or more than 100 miles; but it is better than having to walk to the nearest accredited cosmological institution. Oddly enough, the theory is specific enough in its assumptions, that it should produce quite different predictions that are testable not only through future observations, but even through projects like COBE.
The COBE homepage
Pictures of the ashes of the fires of creation
Woo early web based learning from MIT (umm Harvard).
Acctual instruction is left as an exercise for the reader.
Early results seem to support inflation IIRC, but I'm not a cosmotologist either. While I know you're not one, I was curious as to what you think the future of nail polish for men is? And I'm not talking about just Carson Daley BTW. I kid cause we're good like that.
--Jimmy has fancy plans; and pants to match.