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Do We Live In a Giant Cosmic Bubble?
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.'"
Like, cosmic, man.
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?
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?
At least as far as gas and dust are concerned. The Standard Model explanation is that a 'nearby' star (the pulsar Geminga) went supernova a good long time ago, and blasted a large bubble (300 ly across) of relatively gas and dust free space, called 'the Local Bubble', and our solar system is well within this bubble. The relationship between that and what is being discussed I do not know, for details haven't been provided even on such things as scale. Do a search on 'Local Bubble' and you will find a great deal of information about this.
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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There would definitely be significant time dilation in close proximity to said black holes, but beyond even a fraction of a light year it would become negligible due to the rate at which gravitational force weakens.
* Q
P.S. If you don't get this note, let me know and I'll write you another.
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.
It's not really a cop out if you can actually give the statistically biasing action. It is a bit of a cop out to just say "specialties make our sentient life possible (or much more probable)" but if you can quantify this, then it would be possible to quantify the experimental bias. The anthropic principle is a lot more rigorous than people give it credit for. Of course rare events are always possible, too.
Capitol Hill region of space. That is one ultra dense region of hot air
Actually, that particular region of the universe consists of dark matter. It's an enormous pile of it, brown in color, steaming and giving off fetid odors that would knock a buzzard off a shit-wagon*. The region is full of it and amazingly, endless numbers of primitive little life-forms actually burrow themselves into it and suck nutrition from it.
* We miss you, George.
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, when Voyager got caught in that planets atmosphere/space-time bubble and time on that planet was accelerating at like almost a week for every second on voyager... and then the civilization finally learned space travel and went up to voyager, and learned about all the time acceleration... Kinda screwed up if this is all true. :P
Just me
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.
As mentioned in the article:
One problem with the void idea, though, is that it negates a principle that has reined in astronomy for more than 450 years: namely, that our place in the universe isn't special. ... "This idea that we live in a void would really be a statement that we live in a special place,"
Hold on a second...
Current thinking is that 74 percent of the universe could be made up of this exotic dark energy, with another 21 percent being dark matter, and normal matter comprising the remaining 5 percent.
So, being part of the 5 percent of "normal" matter isn't living in a "special place"?
It's globules all the way down!
Over-the-top Response Guy! Giving "Over-the-Top Responses" since 1970.
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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I've always preferred the misanthropic principle, myself. "We see the universe the way we do because people are idiots."
God invented whiskey so the Irish would not rule the world.
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.
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.