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One Big Bang, Or Many?
Posted by
Zonk
on Fri May 05, 2006 02:42 PM
from the boggles-the-mind dept.
from the boggles-the-mind dept.
butterwise writes "From the Guardian Unlimited: 'The universe is at least 986 billion years older than physicists thought and is probably much older still, according to a radical new theory. The revolutionary study suggests that time did not begin with the big bang 14 billion years ago. This mammoth explosion which created all the matter we see around us, was just the most recent of many.'"
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Physicist Claims Time Has a Geometry 447 comments
sciencenews writes to tell us that a physicist at Stanford has just recently published a peer review website for several physics lectures focusing on a single underlying idea that "time is not a single dimension of spacetime but rather a local geometric distinction in spacetime." The science is presented quite clearly and originally uses GPS systems as a point of focus. From the article: "Not too long ago, people thought the Earth was flat, which meant they thought that gravity pointed in the same direction everywhere. Today, we think of that as a silly idea, but at the same time, most people today (including most scientists) still think of spacetime as if it were a big box with 3 space dimensions and 1 time dimension. So, like gravity for a flat Earth, the single time dimension for the 'big box universe' points in one direction, from the Big-Bang into the future. A lot of lip service is given to the idea of "curved spacetime", but the simplistic 3+1 'box' remains the dominant concept of what cosmic spacetime is like."
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Whew! (Score:4, Funny)
And you know how quickly that kind of thing can ruin your day!
-1 for self-contradiction, -1 for lateness (Score:5, Informative)
From TFA (emphasis mine): And also from TFA (again, emphasis mine):
Now, I'm no cosmologist, but these two descriptions of the theory seem to be in conflict...does the matter in the universe come together in the Big Crunch, or does it fly off into space forever, replenished by subsequent Big Bang events?
If the Guardian Unlimited doesn't even know what the theory is proposing, why are they reporting it?
Fortunately, we needn't depend upon Guardian Unlimited for our cosmology news...Nature.com happens to have a much more informative article [nature.com] on the subject. What's especially amusing is that they've had this article since April 26th of 2002.
Re:-1 for self-contradiction, -1 for lateness (Score:5, Interesting)
Dimensions are weird things. Imagine a two-dimensional plane that goes on infinitely. For a finite, two-dimensional being on that plane, there can only be two-dimensions. As far as he can see, his Universe is the only one. But there can be a million other dimensions stacked onto his in the third dimension. He is just one page on the book, but he cannot observe that third plane. Brane theory observes that just because X dimensions exist, that does not mean we experience all of them.
Think about time as the fourth dimension. Basically, a n-dimension allows you to add an infinite amount of things on the same place in a (n-1)-dimension world. In a two-dimensional world, you can stack many lines onto each other in the second dimension along the plane. A two-dimension sheet can be stacked infinitely in the third-dimension, so many objects can share the same two-dimensional space along the third-dimension. Many objects can exist at the same three-dimension coordinates but at different times.
What if there are more than one time-dimensions? Or more than three-spatial dimensions? Is there any postulate that says we can observe them all if they exist? That's kind of the battle because there can be no direct "proof" of any other dimensions, if they exist. Yet the other dimensions can still affect our dimension. That's why cosmology seems to be so made: because it is.
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Re:Global Warming, Universe Competition (Score:5, Funny)
Where people hang out on dotslash.moc, a web site for intellectually average people with magnificent sex lives. News for normals. You look mahvelous.
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Better question... (Score:5, Interesting)
Well, if this property holds true for the universe, and eventually our universe will expand a whole lot and lead to a new bang, exactly where in the known universe will this bang occur?
Or, perhaps there IS a center to the universe. If this is true, what would this do for relativity, which states that ALL frames of reference are valid? If you could just fly in a rocket and see a bit red cement pole with "center of universe" painted on it, that would make a dandy absolute reference point.
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Re:-1 for self-contradiction, -1 for lateness (Score:4, Funny)
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Taking Numbers at Face Value (Score:5, Funny)
I always found it amusing when people take scientific estimates at face value. The article says something along the lines of "the universe could be up to a trillion years old," so, obviously, the universe is precisely 1 trillion years old.
Re:Taking Numbers at Face Value (Score:5, Funny)
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A more comforting theory (Score:5, Interesting)
It did trigger the beginnings of an idea for a science fiction novel. What if the current state of the universe was the result of tinkering from the previous big bang cycle? If you end up with constants that make life more difficult, blame those that came before. Sort of like global warming on a multi-universal scale.
See also... (Score:5, Informative)
So... (Score:5, Funny)
Never know! (Score:5, Funny)
Hindu Cosmology (Score:5, Interesting)
In short, Hindu scriptures accept the Big Bang (and for that matter Evolution), but believe that it is cyclical in nature. Destruction follows creation, to be followed by creation again. Similarly, "devolution" follows evolution, in a cycle to be repeated endlessly.
While there are many links to back this up, here's the most relevant one I found on Hindu Cosmology [atributetohinduism.com] (I'm not affiliated to it in any way, just happened to be one of the first sites that came up on a Google search). Among other prominent people, it also carries this quote from Carl Sagan [wikipedia.org]'s description of Hindu cosmology in his book Cosmos. To quote:
The late scientist, Carl Sagan, in his book, Cosmos asserts that the Dance of Nataraja (Tandava) signifies the cycle of evolution and destruction of the cosmic universe (Big Bang Theory).
"It is the clearest image of the activity of God which any art or religion can boast of." Modern physics has shown that the rhythm of creation and destruction is not only manifest in the turn of the seasons and in the birth and death of all living creatures, but also the very essence of inorganic matter.
For modern physicists, then, Shiva's dance is the dance of subatomic matter. Hundreds of years ago, Indian artist created visual images of dancing Shiva's in a beautiful series of bronzes. Today, physicist have used the most advanced technology to portray the pattern of the cosmic dance. Thus, the metaphor of the cosmic dance unifies, ancient religious art and modern physics. The Hindus, according to Monier-Williams, were Spinozists more than 2,000 years before the advent of Spinoza, and Darwinians many centuries before Darwin and Evolutionists many centuries before the doctrine of Evolution was accepted by scientists of the present age.
"The Hindu religion is the only one of the world's great faiths dedicated to the idea that the Cosmos itself undergoes an immense, indeed an infinite, number of deaths and rebirths. It is the only religion in which the time scales correspond, to those of modern scientific cosmology. Its cycles run from our ordinary day and night to a day and night of Brahma, 8.64 billion years long. Longer than the age of the Earth or the Sun and about half the time since the Big Bang. And there are much longer time scales still."
"The most elegant and sublime of these is a representation of the creation of the universe at the beginning of each cosmic cycle, a motif known as the cosmic dance of Lord Shiva. The god, called in this manifestation Nataraja, the Dance King. In the upper right hand is a drum whose sound is the sound of creation. In the upper left hand is a tongue of flame, a reminder that the universe, now newly created, with billions of years from now will be utterly destroyed."
Re:Hindu Cosmology (Score:4, Insightful)
Strange how this coincides with the theory of "Cosmic cycles" in Hinduism and other Vedic religions like Buddhism
It's not strange at all. With many different religions and each religion having many different sects, how scientists describe how our universe works will seem similar to some religion somewhere.
If you think about it, religion is one way for people to describe what is happening in the world around them.
Personally, I say keep your faith and your science seperate.
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Very Old theory (Score:5, Insightful)
986 billion exactly? (Score:5, Insightful)
Whether or not the theory will hold up in the future nobody knows but as for right now everyone needs to remember this is a theory like any and decieving people into thinking its otherwise is unfair.
It's no wonder people buy into Intellegent Design (Score:5, Interesting)
Re:It's no wonder people buy into Intellegent Desi (Score:5, Insightful)
You mean "tautology." If it's a scientific theory then by definition it cannot be proved, only disproved.
From the article it's hard to say whether this is a theory, a modification to an existing theory, or a hypothesis.
A theory isn't just an accepted hypothesis, it's a descriptive edifice that lets you make predictions. Those predictions are hypotheses.
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Guardian misses the point (Score:4, Informative)
The cyclic model has been around for several years, and there is plenty I don't understand about it, but it is distinct from the old big bang-big crunch ideas. The "cycle" is the repeated collision between two sub-universes, called branes. We live in one of these sub-universes. Each collision resets our sub-universe with a new big bang... Our universe is constantly expanding; there is no crunch.
Importantly, the cyclic theory has detectable differences from the standard big bang scenario. For example, primordial gravity waves, detectable through their influence on the polarization of the cosmic microwave background, are present in the standard big bang scenario and absent here. Thus their possible detection by a future microwave experiment could rule out this theory.
The purpose of this new work is to argue that the cosmological constant (the factor which make the expansion of the universe accelerate) is naturally small and positive in the cyclic model. This is as we observe it. The standard big bang theory does not make a prediction for the size of the cosmological constant (it's just a parameter), while in string theories the expected size of the constant is vastly larger.
Steinhardt has many materials (including a cartoon movie of the brane collision) on his homepage [princeton.edu].
Cosmological constant survives the Big Crunch? (Score:4, Informative)
a) Might diminish over time, and
b) Might be able to survive a Big Crunch/Bang cycle, and
c) Seems to be smaller than it "should" be if the universe was created 14 billion years ago.
From these, they propose that:
d) The universe is actually much older and has gone through many Big Crunch/Bang cycles, allowing enough time for the CC to shrink to its current level.
However, I'd like to see some hard evidence for a), b), and c) before I accept that d) might be true.
Re:God is one kinky SOB (Score:5, Funny)
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Re:God is one kinky SOB (Score:5, Funny)
** I hope I don't get smited for that
For some reason, when I conjugate the verb word "smite" in that context, I get "smut".
(Yes, I know, it should be "smitten", but that's hardly humorous.)
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Re:what? (Score:5, Insightful)
Then why, pray tell, did you bother to enlighten us with your "theories?"
Common sense told Aristotle that objects fall because they are trying to return to a natural state of rest. Common sense and intuition are ridiculously bad tools for scientific inquiry. Esthetically-pleasing deductions with no empirical evidence are even worse.
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Re:Time had a beginning? (Score:5, Interesting)
It works something like this: according to relativity, space and time are really linked together as 4 dimensional spacetime. Just as 2- and 3-dimensional objects can have shape, so can 4-dimensional objects like spacetime. When physicists try and get some idea of the shape of spacetime they find that it "narrows to a point in the time direction" - the big bang.
Perhaps an analogy is the best way to think about it. A sphere is a two dimensional surface in a particular shape - at any point of the surface of the sphere you can parameterise direction in terms of 2 perpendicular base vectors. We do exactly that with directions about the surface of the earth (though we call "negative east" west, and "negative north" south), so if you like you can think of north and east as the dimensions/directions on the surface of the earth. If you keep heading north, however, you find that the sphere narrows to a point in that directions - the north pole. You can't really talk about what is north of the north pole - the question doesn't really make sense. Of course you can only really see that by stepping outside and observing the 2-dimensional surface of the earth as it is embedded into 3-dimensional space; if we look at things in terms of a more easy to picture map projection into 2-dimensions (just as the surface is 2-dimensional) you might think "can't we just keep going up? Surely there's more north?"
In practice spacetime works roughly the same way except the "surface" is 4-dimensional instead of 2-dimensional. The key point is that heading back in the time direction is just like heading in the north direction of the sphere - eventually you reach a point, like the north pole, where "before" or "further back in time" doesn't make sense, in just the same way that "further north of the north pole" doesn't make sense. From our perspective inside spacetime that's harder to imagine, similar to the way the map projection tends to skew your thinking. It is made worse by the fact that we usually tend to think of time as something very separate to space rather than just another direction. The concept of time beginning with the big bang does make sense, it just requires you to break out of the standard intuitions about how space and time fit together.
Jedidiah.
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Re:What makes this really interesting... (Score:5, Interesting)
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