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| According to one proposal, new universes could sprout like bubbles off a spacetime "foam" that's not unlike soap bubbles. (Courtesy Lawrence Berkeley National Laboratory) |
Posted on 04/02/2006 7:46:13 PM PDT by snarks_when_bored
One universe or many? Panel holds unusual debate
March 30, 2006
Special to World Science
Scientific debates are as old as science. But in science, “debate” usually means a battle of ideas in general, not an actual, politician-style duel in front of an audience.
Occasionally, though, the latter also happens. And when the topic is as esoteric as the existence of multiple universes, sparks can fly.
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| According to one proposal, new universes could sprout like bubbles off a spacetime "foam" that's not unlike soap bubbles. (Courtesy Lawrence Berkeley National Laboratory) |
Such was the scene Wednesday evening at the American Museum of Natural History in New York.
Museum staff put together five top physicists and astronomers to debate whether universes beyond our own exist, then watched as the experts clashed over a question that’s nearly unanswerable, yet very much alive in modern physics.
New universes may appear constantly in a “continual genesis,” declared Michio Kaku, a theoretical physicist at City College of New York and key supporter of the idea that there exist multiple universes, or a “multiverse.”
“The multiverse is like a bubble bath,” with a bubble representing each universe, he added. There are “multiple universes bubbling, colliding and budding off each other” all the time.
Another panelist backed the multiverse idea, but three more insisted there’s virtually no evidence for the highly speculative concept.
A brief history of other universes
Some versions of the many-universes concept date back to ancient Greece, said panelist and science historian Virginia Trimble of the University of California, Irvine. But scientific justifications for the idea began to appear in the second half of the 20th century, when U.S. physicist Hugh Everett proposed it as a solution to a puzzle of quantum mechanics.
Physicists in this field found that a system of subatomic particles can exist in many possible states at once, until someone measures its state. The system then “collapses” to one state, the measured one.
This didn’t explain very satisfactorily why the measurement forces the system into that particular state. Everett proposed that there are enough universes so that one state can be measured in each one. Each time someone makes a measurement, the act creates a new universe that branches off the pre-existing ones.
The “multiverse” theory later reappeared as a consequence of another theory of physics, that of “inflation,” developed by various physicists in the late 1970s and early 1980s.
The theory solved several gnawing problems in the Big Bang theory, the idea that the universe was created from an explosion of a single point of extremely compact matter, by postulating that this expansion was stupendously fast in the first infinitesimal fraction of a second, then slowed down.
As part of this initial superheated expansion, known as the inflationary period, the universe could have sprouted legions of “baby universes,” said Andrei Linde of Stanford University in Stanford, Calif., a panelist at Wednesday’s event and a developer of the inflation theory.
A third argument for the multiverse theory comes from string theory, seen by some physicists as the best hope for a “theory of everything” because it shows an underlying unity of nature’s forces and solves conflicts between Einstein’s relativity theory and quantum mechanics.
String theory proposes that the many different types of subatomic particles are really just different vibrations of tiny strings that are like minuscule rubber bands. The catch is that it only works if the strings have several extra dimensions in which to vibrate beyond the dimensions we see.
Why don’t we see the extra dimensions? A proposal dating to 1998 claims we’re trapped in a three-dimensional zone within a space of higher dimensions. Other three-dimensional zones, called “branes,” could also exist, less than an atoms’ width away yet untouchable. The branes are sometimes called different universes, though some theorists say they should be considered part of our own because they can weakly interact with our brane in some ways.
In part the question rests on definitions, noted Lisa Randall, a Harvard University physicist who was one of the panelists on Wednesday night. Different universes can be defined as zones of spacetime that interact with each other weakly or not at all, she said.
Where’s the evidence?
Marshalling their best evidence for extra universes, Kaku and Linde—the two panelists who back the notion—presented a variety of arguments, which all boiled down to two basic points.
One, explained Linde, is that the multiverse solves the problem of why the laws of physics in our universe seem to be fine-tuned to allow for life. “If you change the mass of the proton, the charge on the electron,” or any of an array of other constants, “we’d all be dead,” he argued.
Why is this so, Linde asked—“did someone create this special universe for us?”
Steering clear of the straightforward answer many religious believers would give, “yes,” Linde argued that the multiverse explains the problem without resorting to the supernatural. If there are infinite universes, each one can have different physical laws, and some of them will have those that are just right for us.
The second key argument they presented is the one based on inflation, a theory considered more solidly grounded than the highly speculative string theory and its offshoots. The equations of inflation, Kaku explained, suggest spacetime—the fabric of reality including space and time—was initially a sort of foam, like the bathtub bubbles.
New bubbles could have sprouted constantly, representing new universes, he added. Linde has argued that this occurs because the same process that spawned one inflation can reoccur in the inflating universe, beginning a new round of inflation somewhere else. This would occur when energy fields become locally concentrated in portions of the expanding universe.
Scientists might one day create a “baby universe” in a laboratory by recreating such conditions, Kaku said. This would involve resurrecting the unimaginably high temperatures of the early universe. A spacetime foam can be recreated by literally “boiling space,” he said, adding that a sort of advanced microwave oven could do the trick.
Experiments already planned could “test the periphery” of these ideas, he added including a super-powerful particle accelerator to switch on next year, the Large Hadron Collider in Switzerland.
Randall countered that the new accelerator won’t bring particles anywhere near the level of energy needed to recreate the spacetime foam envisioned by multiverse proponents. The energies attained will be lower by a factor of 10 followed by 16 zeros.
Lawrence Krauss, a physicist and astronomer at Case Western Reserve University in Cleveland, said the whole multiverse idea is so speculative as to border on nonsense. It’s an outcome of an old impulse, which also gave rise to the correct notion that other planets exist, he argued: “We don’t want to be alone.”
It also caters to our desire for stability, he added: the universe changes, but “the multiverse is always the same.” And if there are many universes, you don’t have to make any predictions that will subject your pet theory to awkward tests, “because there’s always one in which the answers work out.”
Krauss allowed that he might buy the multiverse idea if it’s a consequence of some new theory that also successfully accounts for many other unexplained phenomena. But otherwise, multiverse concepts “are extending into philosophy” rather than science, he added, “and may not be testable.”
A couple of references:
Oldest light shows universe grew fast, researchers say [inflationary cosmology gets a big boost]
Andrei Linde, "The Self-Reproducing Inflationary Universe" [PDF file]
As for the obligatory Lisa Randall pics, I trust they'll be forthcoming...
Yes, it's a ping...
Or something even worse than that ~ I am reminded of this old SciFi story where the folks discovered they were trapped in one of Philip Farmer's "Pocket Universes", and their space ships just bounced off the boundaries somewhere toward Pluto's orbit.
I like how bigger and bigger terms keep being invented to describe the same thing...
cosmos
universe
multiverse
theory-of-everything
(Others?)
"42"
Gotta wonder what the anti-Marty would be like.
Rich, probably.
Interesting that the latest theories keep tending toward the idea that what we see, isolated galaxies, linked by gravity in long chains, could very well be independent universes, and these could be interspersed with universes we can't see ~ black matter/black energy, and all of that encapsulated in a macro-universe that holds all of 'em.
I have to disagree with you on that. The universes of which Linde and Kaku are speaking are not visible to us, nor are they composed of dark matter contained in the visible portion of our universe. They're speaking of completely separate universes lying outside the inflationary bubble that we inhabit.
BTW, I didn't know about Farmer's 'pocket universes' stories. Alan Guth, one of the co-discoverers of inflationary cosmology, speaks of 'pocket universes' when describing separate cosmic bubbles.
an actual, politician-style duel
Perhaps they can bring in some South Korean legislators to show them how these things should be done.
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(chuckle) Democracy as fisticuffs...
"...Okay. That means that...our whole solar system...could be, like...one tiny atom in the fingernail of some other giant being....This is too much! That means...one tiny atom in my fingernail could be..."
"Could be one little..."
"...tiny universe...Could l buy some pot from you?"
BTW, when cosmologists refer to "pocket universes" they are usually familiar with Philip Farmer's use of the term ~ all interesting stories ~ I'm not exactly sure who Farmer got his science from, but he knew how to spin a yarn.
Take another look at Billy Pilgrim, the character in several of Kurt Vonnegut's stories. Recall, quickly, that for a long time Kurt and Phil were big buddies ~ until Phil wrote a story for Billy himself.
There you discover a theory of "time" that suggests multi-dimensionality for time in pretty much the same manner as Farmer's pocket universes are expanded out from the point of origin.
As I was saying, and you might not have picked up on it, the current most speculative theories of the Universe's structure are getting closer to some ideas worked out in literature in the 1960s and 1970s by two Indiana writers.
If you haven't read Farmer's stories, here's your chance for some provocative thought.
Definitely some science fiction going on!
The idea of a multiverse is not new. Hugh Everett did his dissertation on the many worlds interpretation of quantum mechanics in 1957. As I understood it, his idea was that all possible quantum states are expressed.
OK OK OK RichInOC hears a Who.
I guess if I had read a bit further in the article I would have seen in print what I attempted to point out.:-)
Would the bozos of that universe worship us a gods? Would they fight Holy Wars over balrog666 vs snarks_when_bored?
What delicious possibilities!
I especially enjoyed these two: Blackholes, Wormholes and the Tenth Dimension and Hyperspace and a Theory of Everything.
We know how far we can see, but that's not the same as the boundary of all the inflationary space there could be.
Correct. Check out Linde's article (referenced in post #1). There he mentions that some inflation theories suggest that the radius of our cosmic bubble could be as large as 101,000,000,000,000 centimeters—that's a 1 followed by a trillion zeros. By contrast, the part of our universe that we can currently see has a radius which is only about 1026 centimeters, exceedingly miniscule by comparison.
But, as I understand it, there's this difference: Everett's branching quantum universes are completely separate and have no physical contact of any kind; the multiple universes of which inflationary cosmologists speak are separate, but, in principle, they could come into physical contact (for example, one could start to expand directly into an adjacent one, that sort of thing). All of the inflationary bubbles would inhabit the same, physical multiverse, whereas the Everett universes are completely separate, alone, part of no larger entity.
Hey, it's a p a r a l l e l u n i v e r s e.
She's her own woman and he's straight as an arrow.
Heck, I was thinking DC comics already had this subject pegged with their Multiverse.
In the DC Multiverse there are 12 numerically designated Earths as well as Earths A,B,C,C-minus, D,S,and X. And for good measure there is also the Anti-Matter Universe of Qward.
God can create as many or few universes as is pleasing to Him, and His Sons and Daughters (some of you). I do know one thing, there will be no shortage of land due to overcrowded conditions in eternity.
It's worth noting that even before Everett the prospect of multiverses was raised in 'serious' physics by the Einstein-Rosen Bridge concept, wherein wormholes would connect our universe to parallel universes.
Would the bozos of that universe worship us a gods? Would they fight Holy Wars over balrog666 vs snarks_when_bored?
Maybe I'll send 'em a moon rock to worship...
Nah.
Al Gore can have his own universe if he wants
You guys playin cards?
Oh, good, somebody got the reference.
Is this question really any different from questions of religion? They both seem to be metaphysical questions that are virtually untouchable by empirical science.
So far, there doesn't appear to be any evidence for the existence of cosmic bubbles outside our own. But cosmologists are continually searching for ways to test these (and like) ideas. Read the thread referenced in my post #1 to see how recent WMAP data have supported the predictions of inflationary cosmology.
We don't know what the future will bring in the way of tests.
[Is this question really any different from questions of religion? They both seem to be metaphysical questions that are virtually untouchable by empirical science.]
BINGO.
ping
If she was Gene Roddenberry's mistress than I guess it really is good to be the king!
"By contrast, the part of our universe that we can currently see has a radius which is only about 10^26 centimeters, exceedingly miniscule by comparison."
That would be precisely one yottameter. I kid you not.
I thought I'd never actually get a chance to use that word.
-ccm
Why not, he invented it.
I do know one thing, there will be no shortage of land due to overcrowded conditions in eternity.
Well, all things considered, I reckon you won't be feeling my sharp elbows over yonder.
It's worth noting that even before Everett the prospect of multiverses was raised in 'serious' physics by the Einstein-Rosen Bridge concept, wherein wormholes would connect our universe to parallel universes.
I need to review that, AntiGuv. Were the Einstein-Rosen bridges thought (by Einstein and Rosen and others) to connect parallel universes? Or just different parts of our own universe? (I tend to think it's the latter, but I haven't checked.)
That would be precisely one yottameter. I kid you not.
Yotta, yotta, yotta...
First of all, we don't know whether a parallel universe 'can never be reached' from ours. Second, if there are multiple universes, then they very well may interact in some way, and if they do, then the interactions would be predictable and describable, and in that event, they may be of use to us. In other words, if other universes are interacting with our own, then we cannot fully describe the physics of our own without accounting for said interactions.These issues might not be of any immediate practical consequence for thousands or even hundreds of thousands of years, but that's beside the point. We won't know until we know.
If the scientists do succeed in creating a universe in a laboratory, are they not doing what the God of this universe did in Genesis/the Big Bang? Are they then worthy of worship by any life forms that develop in the new universe?
Well, my personal answer would be: No, in that "the God of this universe" is indistinguishable from a phenomenon that doesn't exist, and phenomena that don't exist don't do anything at all, which means there's nothing to emulate.However, if for no scientific reason at all one assumes the existence of God, then the answer is a qualified yes. The scientists would be equivalent to deist concepts of God, and moreover, would be as worthy of worship by any consequent lifeforms as a deist God would be worthy of worship by us.
If things go poorly in such an experiment, could the new universe somehow consume or damage our own? Would Brahma suddenly become Shiva?
Not from what I've gathered. Or to be more precise, the physics as we currently understand them say that the answer is no. Any such universe would spin off on its own spacetime plane of existence. In any case, long before we get to the stage where we might be spinning off universes, if that's actually doable, we should have a Theory of Everything that makes clear what would happen.I have an article somewhere in my bookmarks that discusses this specific question. I'll see if I can track it down and post the link.
Well, the hypothetical Einstein-Rosen bridges are, to day, a speculative concept, but so far as the equations go then it could be either. In short, wormholes could connect either different parts of our own universe or connect our universe to a parallel universe. It hardly means that parallel universes do exist; it just means that parallel universes do not at all contradict General Relativity. Einstein recognized this.
Personally, I wouldn't want to be their God. I'd just patent them.
What I find interesting is that even though these scientists
only deal with the "physical" world some of thing think
that "we" are trapped in a 3 dimensional world and cannot
perceive the other dimension...
Now just who is the "we"? Is it a being that can be
"trapped" in the physical world?
By using the term, "we" I believe they are implicitly,
and quite unobviously (to themselves) believing in the
idea that the "we" is NOT part of nature, and is separate.
Therefore they are not completely controlled by the physical world,
and by their own beliefs, show that there has to be
a supernature, or an "other than nature" (i.e. physical world)
quality about what we call life.
Kaku is of the ME philosophy, the universe revolves around ME. Einstein popped that self centered bubble long ago : the universe doesn't give a fig wheather you exist or not. He and Rosen also came up with this seemingly paradoxical situation : you pick a card(face down)and place it on a Voyager space probe. 10 years later you sift thru the deck and find the 9 of diamonds(the curse of scotland)missing, instantly you KNOW the exact card that is beyond pluto's orbit. And yet, NOTHING can travel faster than c = 3 x 10^8 kps; how can this be? It's a paradox, yes? No, it's self centered, anthropomorphic stupidity. The choice or "message" was made/sent when you picked the card. Wheather you knew what the card was, or just guessed what it was, is mox nix. You see, these kaku-idiots/everett-con artists deliberately confuse probability with actuality. Variable quantum states are no more than the deck of cards in which you draw one at a time. These clowns are just a modern version of the flim-flam man...who have matriculated many a gullible fool... Also, can you demonstrate a time event that is NOT a kinetic energy event? $1000 cash award if you can.
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