Posted on 03/28/2004 4:53:18 AM PST by PatrickHenry
The Universe was not born in one Big Bang, it has been going through cycles of creation and annihilation for eternity, according to a controversial new mathematical model1.
It's a compelling claim. The new cyclic model removes a major stumbling block common to existing theories of the Universe - namely, that physics can't explain what came before the Big Bang.
Because the model relies on new mathematics, it is having some teething problems, admit its proposers. Indeed, most cosmologists are treating the hypothesis with interested scepticism. Some are vociferously critical.
Criticism is to be expected, concedes Neil Turok of Cambridge University, UK, who developed the cyclic model with cosmologist Paul Steinhardt of Princeton University in New Jersey. "We're taking on some very fundamental issues here," says Turok.
Strings attached
Steinhardt and Turok draw on the emerging science of string theory. This mathematical idea uses up to ten dimensions - instead of the usual four - to explain the weird behaviour of tiny things in physics called fundamental particles.
When applied to big things like cosmology, string theory invokes weird mathematical entities called membranes - branes for short. In the cyclic model there are two branes at any one time, one containing our Universe, the other a parallel Universe that is the mirror image of our own.
The researchers suggest that these branes regularly collide, as they did 15 billion years ago, resulting in the massive release of energy previously ascribed to the Big Bang. And just like the Big Bang, "this collision made all the radiation and matter that fills the Universe," says Turok.
The branes are then flung apart. The Universes on each brane expand outwards over billions of years, as ours is doing today.
According to the model, a fifth dimension that we can't see or travel through bridges the branes. As each Universe expands, its matter and energy spreads ever thinner and is diluted. When the spring-like fifth dimension overcomes this expansion energy it heaves the branes back together, they collide, and the whole process repeats. "It's just like reproduction in biology," says Turok.
As well as solving the problem of what came before the Big Bang, the cyclic model could explain numerous other cosmological conundrums, such as dark energy. Our Universe should contain more energy than can be measured, and there are no good theories to explain why. Turok and Steinhardt's model suggests that this is because energy, in the form of gravity, leaks across the fifth dimension between our Universe and its complementary braneworld.
No braner?
Steinhardt and Turok's idea sounds appealing, but fellow astrophysicists are not greeting it with open arms. "The community is very, very sceptical," says David Lyth, a cosmologist at the University of Lancaster, UK.
Others are more scathing. "It's a very bad idea popular only among journalists," says one of the chief critics of the cyclic model, Andrei Linde of Stanford University, California. "It's an extremely complicated theory and simply does not work," adds Linde, the originator of a rival model of the Universe.
String theory is still in its infancy, and applying it to cosmology stretches it to its limits, explains Cambridge University cosmologist George Efstathiou. "Its connection to fundamental physics is really rather weak," he says, so until string theory matures, models that use it will be flawed and misunderstood. But on the whole, he says, "the cyclic model is a cute idea and some elements of it may survive."
Steinhardt and Turok agree that problems with the mathematics could be their undoing. "There may be disasters waiting for us at higher levels of calculation," says Turok. But, if it does add up, their theory overturns many ideas about the Universe, they say - like time and space being created in a Big Bang.
Footnote 1: Steinhardt, P. J. & Turok, N. A. Cyclic model of the Universe.Science, published online April 25 (2002). |Link to Science online.|
Yes, with all matter uniformly spread out in a sea of molecules all at near absolute zero, you would think it would take something more than a new math to get things back into a dense hot discontinuity again. I believe it was in a Azimov short story when the Master Computer solved the problem and said, "Let there be light".
That's Everett's "many worlds" interpretation of things, formulated back in 1957: Many-Worlds Interpretation of Quantum Mechanics.
With science you can only have cause and effect and no way to explain the uncaused first cause. That is where God comes in.
This was discussed at great length then. There were a lot of threads, and probably this article, too. Can't say why search didn't find something, maybe the title changed.
jwalsh07 and beavus, y'all might be interested in this article:
The cyclic universe has roots in even more complex thoughts like so-called superstring theory, which suggests there are as many as 10 spatial dimensions, not just the three we know of. The seemingly inexplicable physics of a big crunch and a big bang might be explained with the aid of these extra dimensions, which are otherwise invisible to us, several theorists believe.
In fact, Steinhardt, Turok and others proposed last year that our universe might have sprung from the collapse of an extra dimension, an idea they called the Ekpyrotic Universe. The cyclic universe builds on this former work but, Steinhardt says, does a better job explaining observations of our present universe.
Other theorists are not quick to give up their standard model, so the concept of a cyclic universe faces an uphill battle for prominence. Even Steinhardt acknowledges that the prospect of unseating a well established cosmological theory "would seem extremely dim."
Meanwhile, the new concept is not free of cracks, either: Even the cyclic universe does not address when the cycles began, so "the problem of explaining the ‘beginning of time’ remains," the researchers say.
So I recall. I searched on cosmology, big bang, and on the two names of the authors (Steinhardt and Turok) separately. Nothing. If you can turn up one of the prior threads, give us a link. I'd hate to lose all that commentary.
If you ask about Zeus, he has a genealogy. And the Greeks also held some kind of fate (anagke) as prior and fundamental to the Olympian hierarchy. And the Ionians philosophers, in search of this fundamental substrate, suggested material substrates such as water. One of them suggested infinity (apeiron). In all of these, a stopping point is found. Everything and all configurations are a function of that. Also for Christianity, the question "what created God" is answered by their divine understanding of infinity--no eternal regress.
We should remember that there are kinds of infinity. The eternal recurrence that animistic religions held is different than a fundamental infinity that is anterior to that. Sometimes a duality is a function of a monistic feature behind it.
So a good starting point on this problem is to distinguish kinds of infinity. An eternal cyclical recurrence of oppositive forces must be a different kind of infinity than what gives rise to them.
Perhaps one kind of question must be asked whenever we posit a most fundamental infinity. Is it intelligent and personal as we are?
No infinite regress here. This must be the thread.
But, the argument went, if this "actual existence" is finite, something else must be anterior any series of motions. That's Aristotle, at least.
This distinction you make between infinity in mathematics or imagination is very important.
What kind of time? Theoretically, one kind of infinity consists in a cycle or series of beginnings and endings. In that sense, the "problem of explaining the beginning" hints at a misunderstanding that LogicWings pointed out.
I think you should "contemplate" putting that bong away.
One's concept of time has much to do with his other understandings, including his theology. This discussion on the religion forum is particularly engaging: TIME: What is time and when did time start?
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