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.|
1) If Universe's are bubbling up all the time into this one then, just as we see eccentric galaxies forming with the Hubble Telescope 10 Billion years ago, we would also see (from a distance) areas of the sky where this is/has happening(-ed). We don't.1) There's a difference between the universe (created at the bigbang and encompassing all we can see) and the cosmos (the background fabric from which different universes expand out of). We can't see outside of our universe because its expansion rate at the edges is near the speed of light and the expansion of the fabric itself (according to one form of Inflation Theory) is faster than the speed of light.2) I just can't rationalize different sets of constants occupying the same space/time. It makes no physical and intuitive sense to me whatsoever.
2) The physical constants are the same all throughout the universe. They were created at the bigbang and don't change throughout the life of this single universe. There is no conflict between the physical constants of one universe and those of another universe because there can be no communication between two universes (separated as they are by ftl expansion from each other).
I once signed up for Astronomy 101. It was my first class in the morning of the first day of my venture into "higher education."
The instructor/professor (whatever) launched into pontificating about the "Big Bang". He droned on and on for about 45 minutes, then asked the class if they had any questions. I was the first to stand up, and I asked; "What was there before the 'Big Bang'"?
He gave me this "look". A sort of "How DARE you question the Big Bang Theory!" (And he didn't answer my question; in fact, he said nothing, just gave me "the look".)
A few hours later that day, during lunch, I dropped the class. I didn't want to spend one more minute of my time "learning" from the goose-steping Astrono-Nazi.
If this is our future [he was discussing the end of the big bang's expansion, which he thought might result in a contraction], it presumably also is our past. The present expanding universe would be only the phase following the last contraction and bounce. (Indeed, in their 1965 paper on the cosmic microwave radiation background, Dicke, Peebles, Roll, and Wilkinson assumed that there was a previous complete phase of cosmic expansion and contraction, and they argued that the universe must have contracted enough to raise the temperature to at least ten thousand million degrees in order to break up the heavy elements formed in the previous phase.) Looking farther back, we can imagine an endless cycle of expansion and contraction stretching into the infinite past, with no beginning whatever. [Underling added by PH.]That's from his last chapter: Epilogue: The Prospect Ahead, which is on page 153 of my copy.
There are even parallel universes in which I am the president of the United States. I'm intrigued with that one and maybe someday the technology will exist to take me to one of those. Hopefully one in which I am a successful president.
Why did we end up in a universe where Bill Clinton became president? Well, at least we had Reagan. I guess there are worse universes.
That's a description of a cyclical closed Universe; it made sense when Weinberg wrote "The First Three Minutes" because at that time we had no definitive data on whether or not the Universe was open, closed, or flat.
Since that time, however, the data have pretty much shut the door on the closed Universe. The W-MAP data in particular indicate the matter density of the Universe is exquisitely close, if not exactly equal, to the critical value, which corresponds with a flat Universe that never collapses, especially when the accelerating expansion is considered.
An infinite number of them. And an infinite number where you make exactly the same mistakes.
I know, and I don't like it. A universe that starts, produces us, and then fades away with a long goodbye into the big sleep. That's all there is? What's it all about, Alfie? It bothers me that the universe is the cosmic equivalent of a one-night stand.
Well, to quote the "Shoveller" in "Mystery Men": "It looks like we've been served a sh*t sandwich, and we're all gonna have to take a bite."
Go placidly amid the noise and waste,
And remember what comfort there may be in owning a piece thereof.
Avoid quiet and passive persons unless you are in need of sleep.
Rotate your tires.Speak glowingly of those greater than yourself,
And heed well their advice, even though they be turkeys.
Know what to kiss and when.
Consider that two wrongs never make a right,
But that three lefts do.Wherever possible put people on "HOLD".
Be comforted that in the face of all aridity and disillusionment,
And despite the changing fortunes of time,
There is always a big future in computer maintenance.
Remember the Pueblo.Strive at all times to bend, fold, spindle and mutilate.
Know yourself. If you need help, call the FBI.
Exercise caution in your daily affairs,
Especially with those persons closest to you;
That lemon on your left for instance.Be assured that a walk through the ocean of most souls,
Would scarcely get your feet wet.
Fall not in love therefore; it will stick to your face.Carefully surrender the things of youth: birds, clean air, tuna, Taiwan,
And let not the sands of time get in your lunch.
For a good time, call 606-4311.Take heart amid the deepening gloom that your dog
Is finally getting enough cheese;
And reflect that whatever fortunes may be your lot,
It could only be worse in Sioux City.You are a fluke of the Universe.
You have no right to be here, and whether you can hear it or not,
The Universe is laughing behind your back.Therefore make peace with your God whatever you conceive him to be,
Hairy Thunderer or Cosmic Muffin.With all its hopes, dreams, promises, and urban renewal,
The world continues to deteriorate.
Give up.
Ah, love, let us be true-- Dover Beach, by Matthew Arnold
To one another! for the world, which seems
To lie before us like a land of dreams,
So various, so beautiful, so new,
Hath really neither joy, nor love, nor light,Nor certitude, nor peace, nor help for pain;
And we are here as on a darkling plain
Swept with confused alarms of struggle and flight,
Where ignorant armies clash by night.
I can do anything." -- Jim Morrison
Fred Hoyle is dead? I had no idea. Did the Black Cloud get him?
So then what came before the "Big Bang" was another Big Bang, and before that another Big Bang...and so on...for eternity...
Boy, that really solves the problem of what came previously.
So live, that when thy summons comes to join-- Thanatopsis, by William Cullen Bryant
The innumerable caravan which moves
To that mysterious realm, where each shall take
His chamber in the silent halls of death,
Thou go not, like the quarry-slave at night,
Scourged to his dungeon, but, sustained and soothed
By an unfaltering trust, approach thy grave
Like one who wraps the drapery of his couch
About him, and lies down to pleasant dreams.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.