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Do We Live In a Giant Cosmic Bubble?
Posted by
CmdrTaco
on Wed Oct 01, 2008 11:20 AM
from the i-live-in-my-own-universe dept.
from the i-live-in-my-own-universe dept.
Khemisty writes "Earth may be trapped in an abnormal bubble of space-time that is particularly void of matter. Scientists say this condition could account for the apparent acceleration of the universe's expansion, for which dark energy currently is the leading explanation.
Until now, there has been no good way to choose between dark energy or the void explanation, but a new study outlines a potential test of the bubble scenario.
If we were in an unusually sparse area of the universe, then things could look farther away than they really are and there would be no need to rely on dark energy as an explanation for certain astronomical observations.
'If we lived in a very large under-density, then the space-time itself wouldn't be accelerating,' said researcher Timothy Clifton of Oxford University in England. 'It would just be that the observations, if interpreted in the usual way, would look like they were.'"
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I know I do (Score:5, Funny)
Re:I know I do (Score:5, Funny)
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Re:I know I do (Score:5, Funny)
6000 years ago, god farted in a Cosmic Bathtub.
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Re:I know I do (Score:5, Funny)
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I always wondered... (Score:5, Interesting)
If this was why the galaxies appear to rotate to quickly at the edges.
Would the greater density at the galactic cores cause time to go slower and effect the apparent speed as observed from the exterier of the system?
Re:I always wondered... (Score:5, Informative)
No. The gravitational forces required for time dilation to be that strong are many orders of magnitude stronger than what you'll find on the galactic scale.
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Re:You mean like... (Score:5, Informative)
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Re:You mean like... (Score:5, Informative)
that would slow down time in the area.
The point is, no, it would not, not to the degree you are thinking of. Look, we do know what a galaxy is! We know there's a lot of mass in there! And it's easy to calculate the time dilation it causes, and it is negligable.
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Being special (Score:5, Insightful)
Ok, I'll believe that there are regions of space that are more dense than others. I'll even believe that we are in one of them. ( This is no harder than believing in dark matter and dark energy, and it's before breakfast )
But what I find hard to believe is that we are in the exact center of such a region. So therefore, the universe should appear to have different properties in different directions. Has anybody seen that?
Re:Being special (Score:5, Funny)
Man you ain't kidding. Take a look at the Capitol Hill region of space. That is one ultra dense region of hot air, that isn't just warping space-time this is a region of space where the wildest of idea's are warped into reality.
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Re:Being special (Score:5, Interesting)
Except if such specialties make our sentient life possible (or much more probable).
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Re:The anthropic cop-out (Score:5, Insightful)
It's perfectly reasonable to think that, if sentient life requires unusual circumstances, then we will find ourselves in unusual circumstances.
It's already the case that we're in a rather odd location. Pick a random point in the universe. Does it happen to be on the surface of a planet? Of course not.
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Re:The anthropic cop-out (Score:5, Insightful)
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Re:The anthropic cop-out (Score:5, Insightful)
I may be wrong, but isn't the term anthropic principle essentially the opposite of what you're describing? IMHO the anthropic principle just states that there is nothing special about our particular environment beyond the fact that we happen to live here and there is not much else that we have experience with?
Sadly, religious nutjobs have completely turned around what was once an important scientific reasoning tool that existed to make sure our observations of nature are not biased towards human existence.
The anthropic principle is the mother of all cause-and-effect observations. The obvious cause here is that we live in a certain environment with a certain set of rules and random environmental factors, as a consequence of this, we have turned out the way we are now - including our way of interpreting the world around us. Now religious people, for whatever fucked-up reason, believe our environment was actually created by someone just for us to live in, and that the purpose of our universe is to support human life - thereby turning common sense on its head by confusing cause and effect.
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Re:The anthropic cop-out (Score:5, Funny)
I've always preferred the misanthropic principle, myself. "We see the universe the way we do because people are idiots."
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Re:Being special (Score:5, Interesting)
If you get far enough away from this universe, and I'm talking 'Douglas Adams' far, this universe would appear to be perfectly uniform. However, the closer your observation point becomes, the easier it is to distinguish the clumps, bumps, peaks, valleys, troughs, etc. in the density. At a very close, human-type scale, the density changes are very easy to spot. How dense is the space between the Earth and the Moon as compared to the Earth itself?
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Re:Being special (Score:5, Informative)
There's an unexplained anisotropy [wikipedia.org] in the cosmic microwave background. Hot and cold spots don't appear to be quite randomly distributed. Nobody's come up with a good explanation, and it might be an instrumentation error or due to some local gravitational anomaly - say, lensing around the next supercluster over - but at the moment it's very unclear.
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Re:Being special (Score:5, Insightful)
We need not be at the exact center. Closer to the center than to the edge would probably suffice.
Nor does ours need to be the only bubble: there could be billions of them. Thus we need not be unique: just not quite average (but then, being perfectly average would itself be unlikely).
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Re:Being special (Score:5, Interesting)
I think we really need to restructure our underlying philosophy of what existence is. I've been chewing on this concept for years:
This "universe" isn't infinite. It's a 4 dimensional object, with a large but quantifiable amount of mass/energy, and this mass/energy has permutations across x, y, z and t. You see a 3 dimensional object with dimensions x, y, z moving through t, but observed from outside the t dimension, it's a 4 dimensional object.
The big bang, the singularity, is significant because at the moment that the mass/energy of the universe is in the singular state, it is identical to all the other universes. It is at this point that it "connects" to all the other universes, like petals connecting together to make a flower.
Questions of religion, spirituality and what it means to be human start getting in your way once you start looking at things this way. Am I an aspect of this object that is my universe, or am I some sort of traveler within this object that is a universe?
I think there's a good possibility that the missing matter and forces we hypothesize to be acting upon our universe are actually other universes influencing our own, like petals on a flower bumping into each other. And, assuming that we are "souls traveling within the universe" as opposed to "4 dimensional objects that are aspects of the universe", it isn't outside the bounds of reason to imagine that we might one day be able to map the shape of these universes and achieve "time travel" by moving to other universes.
I expect that we will eventually find the concept of the "infinite universe" to be a false path, and that we will achieve great breakthroughs when we find a framework that doesn't rely upon its existence.
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Re:Being special (Score:5, Informative)
This is no harder than believing in dark matter and dark energy, and it's before breakfast
"Time is an illusion, lunchtime doubly so". -The Hitchhiker's Guide to the Galaxy
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Re:Occam's Razor? (Score:5, Interesting)
My favorite alternative is that we need someone to do to Einstein what Einstein did to Newton; that just like Newton's laws are near-perfect and beautiful at reasonable speeds, maybe there's something that happens at cosmically grand distances, masses, or propagation delays for Gravity that we're going to have to be awfully clever to ever hope to reliably detect.
Dark Matter and Dark Energy both felt like big hacks to me.
But, I am by no means a scientist, just an interest layman who hasn't done enough reading.
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Re:Occam's Razor? (Score:5, Informative)
I thought it was for deciding between two or more competing theories. I didn't think it could be used to reject all theories. If you have two theories, one makes two assumptions, one makes just one, it's more likely to be the one that just makes one. While both may be wrong, you can't use Occam's razor to throw BOTH of them out.
Furthermore, you don't use it at all, or if you did, you forgot to tell us the outcome. You actually just say both sound like deus ex machina, are both silly, and we're not right yet. Didn't even mention any underlying assumptions. That's not Occam's razor, or even rational argumentation. You just have a gut instinct that they're both wrong.
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Re:Bubble? (Score:5, Interesting)
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Re:Bubble? (Score:5, Funny)
Why does the first thing that comes to mind after reading just this headline, make me think of that one episode on Star Trek Voyager
Wow, our minds just totally work differently. I thought of J-Lo's ass.
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Obvious Answer (Score:5, Funny)
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