Do We Live In a Giant Cosmic Bubble? 344
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.'"
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?
Occam's Razor? (Score:2, Insightful)
I'll apply Occam's Razor [wikipedia.org] and ask which is more likely.
Quite frankly I find both solutions rather silly, they sound a little too much like deus ex machina to me. I suspect the truth is still out there and when we understand it will change our view of the universe. It's happened before, it will happen again.
Re:Being special (Score:4, Insightful)
Why is it so hard to believe? Let's say for instance I tell you that there is a one-in-a-million chance that a person will have a particular dream. Every night, 300 million Americans go to sleep. Would you find it hard to believe that at least one person has this dream every night?
And what if you were that one person last night? Would you think you were special? You would, if you were bad at math.
So why is it hard to believe that our planet exists in conditions that have incredibly low odds? The universe is not only more vast than anyone can imagine, it's also been around for over 13 billion years! For all you know, these "special conditions" you complain about could have happened a million times by now.
Re:Being special (Score:4, Insightful)
But what I find hard to believe is that we are in the exact center of such a region.
How exact do you think it has to be when we're talking about cosmic distances? Distances where being in the Milky Way vs Andromeda wouldn't make much difference in how the distant universe looked?
Re:Being special (Score:2, Insightful)
Yes, this is clearly the answer. What we can observe of the universe does not jibe with what we THINK we SHOULD be observing; so, obviously, we are in the middle of an anomaly, outside of which the universe behaves the way we THINK it should behave.
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.
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).
Re:The anthropic cop-out (Score:5, Insightful)
"Average" is Not Normal (Score:3, Insightful)
But the chance of being in a spot that is a perfect representation of the average is rather small. The chances of being in a spot of above-average density and a spot with below-average density may even be greater than being in an average spot. This is of course unless the spot is significantly below or above he average.
It's also possible that intelligence life is more likely to evolve in sparser areas. Dense areas may offer too much chaos for advanced life (multicellular) to take hold. Some speculate that dense space is the best place for life to get started but sparser areas are better for the long-term evolution needed for intelligent life. A dense area of space is more likely to be blasted by a central-galaxy black-hole jet or a supernova magnetically-focused gamma beam; which would fry all the mammals.
Re:The anthropic cop-out (Score:2, Insightful)
Re:Occam's Razor? (Score:3, Insightful)
I'll apply Occam's Razor [wikipedia.org] and ask which is more likely.
Quite frankly I find both solutions rather silly, they sound a little too much like deus ex machina to me. I suspect the truth is still out there and when we understand it will change our view of the universe. It's happened before, it will happen again.
Two thoughts come to mind:
1. Deus ex machina is a term that can be applied to anything which conforms to Clark's Law ("any sufficiently advanced technology is indistinguishable from magic"). Any spacetime/matter phenomenon that can be understood has the possibility of being controlled and therefore to become a technology, therefore Clarke's Law can be applied.
2. "Willam of Ockham had a beard," which is to say he was not an authority in the field and the rule associated with his name fails. It is sufficiently common that data proves a more complex hypothesis true that reality invalidates use of this axiom even in pre-result situations. Acceptance of parsimony (same concept as the razor) without cause is mental laziness as well as the logical error of acceptance of (perceived) authority. Nature doesn't care about how easily our tiny meat computers can process a given data set.
Those said, I may disagree with your supporting statements, but I agree wholeheartedly with your assertion that "the truth is still out there". Call it the first corollary (inclusion of "still") to Mulder's Law.
Re:The anthropic cop-out (Score:3, Insightful)
Since they can't actually give that (whatever it is) as our universe and everything in it is only a single data point, it's a cop out.
No, in fact, it's just the opposite. The anthropic principle is far, far, far less rigorous than our soceity is collectively giving it credit for. It represents an objective low point in the progress of science over the last 300 years. I am not being hyperbolic. Never since the days of Newton, or even before then, have so many "eminent" scientists seriously proposed so much philosophical arguments and circular logic as valid science.
The reality is that fundamental (I say fundamental mind) theoretical physics has made absolutely no progress whatsoever in the last 40 years!! Our theoretical scientific community is collectively demoralized, burned out and beaten. Rather than admit this, they have resorted to fantastic theory after fantastic theory in an effort to maintain their position as the leaders of societies great leap forward.
That the last ~20 years of this period has coincided with the rise of religious and fundamentalist thinking, is no coincidence. Society has sensed that fundamental science has made no progress, and people have collectively turned back to old ideologies, religions and subjective schools of thought. At this point, some scientists have simply stopped trying and have joined them.
I was skeptical of a great deal of modern theories the first time I ever read a modern popular science book. Initially, I was prepared to give the theoretical scientific community the benefit of the doubt on some of its more dubious proposals. But as time has gone by, and line after line has been crossed, I for one have had enough.
The anthropic principle was not, is not and never will be a scientific theory. Is is a pseudo-spiritual argument born from the minds of people raised in an Abrahamic culture, who after countless personal failures have lost confidence in their scientific methods, and who now simply have reverted to the worldview inculcated in them all those years ago. There is far more Genesis than analysis in their arguments.
Re:Occam's Razor? (Score:3, Insightful)
Dark matter and dark energy are as much "hacks" as "gravity" is; i.e. they all are names for phenomena that we observe in the universe except that we have some sort of an explanation for gravity, whereas the former two we have no (at least known to me) current consistent theories that can explain why there is unobserved extra mass in the observable universe and what is causing the observable universe to expand (accelerating the expansion). Note that both of these properties of the universe have been measured (observed).
Re:Just admit you don't know. (Score:2, Insightful)
Case, point: If we used to teach children that "we kinda think the earth is flat but have no evidence" then there is a STRONG likelihood that this notion would have been dispatch a long time ago. Instead, it was publish to the world as fact, and as such, there are still people [wikipedia.org] who think the world is flat [theflatearthsociety.org] and won't accept any evidence to the contrary [wikipedia.org], because that is what they where taught in school.
Re:The anthropic cop-out (Score:3, Insightful)
The only thing the anthropic principle tells us is that we can't use ourselves as a valid data point. It doesn't tell us anything more or less than that.
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.
Re:Bubble? (Score:4, Insightful)
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
Because you are a nerd.
Re:I know I do (Score:1, Insightful)
It's not hilarious. It's fucking stupid.
Re:The anthropic cop-out (Score:3, Insightful)
In summary, just because we observe a universe of nature X doesn't mean our existence depends on X.
You're right of course, and the reason the anthropic principle got trapped in this pretentious and totalitarian implication about what our existence seemingly depends on is, because it got mutilated by "spiritual" pseudo philosophers in an effort to make themselves seem relevant, when in fact those particular questions should have been directed towards biologists in the first place.
But to expand on the problem of logic and religion, because I believe you have hit a broader theme here: religion's job description is to defy logic and scientific understanding. I postulate that for each and every scientific theory conceivable, an unlimited number of unprovable twisted religious explanations can be conjured up. This works basically by defining supernatural influence as whatever areas are poorly understood by the people at the time. Whenever the horizon of scientific understanding is updated, religious people have the option of either rejecting the new findings or updating the nature of god to reflect the new border beyond which there be dragons. And you'll find both things happening in real societies as a reaction to scientific progress all the time.
Re:Being special (Score:2, Insightful)
hehe, Insightful ? Hilarious, I think mods are confused today, THHGTTG is definitely *not* a textbook on cosmology.
Re:Questions for Physicists (Score:3, Insightful)
I don't exactly like the way you formulated the question, but that rings a bell... occam's razor would suggest that if we have to postulate we are in a peculiar place, chances are that our models are flawed to begin with.
"Precession of the perihelion of Mercury" all over again?