Our universe, in a bubble?

David · Oct 8, 2008

OmegaVPrime said: ↑

Not really, there is plenty to discuss on the topic at hand...I mean...if you want at anytime put a post to this thread that relates to it..
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Alright, I think its a very interesting idea even if its kinda far fetched and egotistical to think that we are special. That only "us" live in this void. even so it pretty cool to think that every idea we had about "our" universe is wrong. I believe that everybody is right and wrong when it comes to our universe.

The link to the actual paper:
[0807.1443] Living in a Void: Testing the Copernican Principle with Distant Supernovae

This blog is more intellectually stimulating then that yahoo! new post and i think it details the subject better.

Several of us at New Scientist recently came across an interesting paper by Timothy Clifton and colleagues at the University of Oxford entitled "Living in a Void: Testing the Copernican Principle with distant supernovae".

The paper argues that if we are living in a giant void - that is, if our cosmic neighbourhood is significantly less dense than other parts of the universe, then that could account for the fact that the universe's expansion appears to be accelerating. Astronomers discovered this acceleration in the late 1990s when they found that distant supernovae appear dimmer, and thus farther away, than expected.

Most cosmologists believe that a furtive anti-gravity-like force known as dark energy is to blame.

But no one can explain why the observed value of the dark energy is 120 orders of magnitude smaller than what's predicted from quantum physics. In fact, the level of fine-tuning needed to produce such a specifically small but non-zero cosmological constant is so absurd that the best explanation anyone's come up with is that our universe is merely one of an infinite number of universes.

According to Clifton, the problem may not lie with cosmologists' observations, but with their assumptions - namely, the Copernican Principle, which says we don't occupy a special place in the cosmos, and that the distribution of matter is homogeneous, so any given region of the universe is more or less the same as any other.

If, on the other hand, we live in an especially unusual region of the universe - as in the centre of a giant void - then the local geometry of space-time would be different than expected. Its curvature would affect how light from distant supernovae travels through it. In fact, if the void were big enough - roughly the size of our observable universe - it might account for the supernovae observations that imply acceleration, and do away with the need for dark energy.

Clifton's results are very speculative - there's no hard evidence that suggests we live in a void, nor is the existence of a void that huge very feasible according to the standard model of cosmology. And even if the void theory could account for the supernovae observations, it wouldn't explain supporting evidence for dark energy from the cosmic microwave background, relic radiation from the big bang. Better observations of more supernovae - from, for instance, the proposed SNAP experiment - could help test the theory by gauging how the expansion rate of the universe has changed throughout cosmic history.

Still, right or wrong, Clifton raises an important point. Assumptions like the Copernican Principle, which lie at the bedrock of cosmology, can't be held immune to scrutiny. Scientists shouldn't dismiss ideas just because they might undermine some deeply cherished assumptions.

Nor should they dismiss observations. I encountered such a situation when I was writing a story about the work of physicists Luciano Pietronero and Francesco Sylos Labini at the University of Rome. They argue that 3D maps of the galaxy distribution produced by the Sloan Digital Sky Survey (SDSS) show that the universe is not homogeneous, but fractal. This, too, challenges the Copernican Principle, and as such, most of the cosmologists I spoke to dismissed it outright.

One cosmologist wrote to me in an email: "There is no fractal or inhomogeneous physical model of the universe of any kind. Therefore although there are particular observations that present a challenge to the standard model, there is no sense in which there is a preferred model that predicts or is explained by inhomogeneity . . . So the observations are interesting, but without a physical model to back them up, they are unlikely to have an impact on our thinking about cosmology."

I found this statement rather shocking. Cosmologists are willing to dismiss observations because they don't fit with theory? Isn't science supposed to work the other way round?

Of course, scientists have to work under some theoretical assumptions to get anything done. Working under a standard set of assumptions is necessary for what philosopher and historian of science Thomas Kuhn would call "normal science". But these days, fundamental physics and cosmology can hardly said to be in the "normal" stage - cosmologists don't know what 95% of the universe is made of, they don't know why it's accelerating or whether it is part of an infinite multiverse. I think most would agree that some kind of paradigm shift is inevitable.

But paradigm shifts require the questioning of assumptions. Just look at the shift from Newtonian physics to relativity. A few observational anomalies were in the air - such as the null results of the Michelson-Morley experiment to detect an all-pervading ether in space - but true change didn't come until Einstein sat down and questioned our most basic assumptions about the nature of space and time.

The transition from a paradigm in crisis to a new paradigm is "a reconstruction of the field from new fundamentals, a reconstruction that changes some of the field's most elementary theoretical generalizations as well as many of its paradigm methods and applications", Kuhn wrote in The Structure of Scientific Revolutions.

Kuhn did, however, argue that scientists ought to hold tightly to their paradigms, and not throw them away at the first sign of trouble. "By ensuring that the paradigm will not be too easily surrendered, resistance guarantees that scientists will not be lightly distracted and that the anomalies that lead to paradigm change will penetrate existing knowledge to the core," he wrote.

Still, if cosmologists hold the Copernican Principle to be unquestionable, then science becomes something more akin to religion. Good science requires a willingness to take anomalous observations seriously and to question even our most deeply held assumptions about the world.
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Edit: After reading all the comments left on that blog i found this very well written comment left by Jonathan Seer (Myspace music man at that http://www.myspace.com/callingallmen)

Your last paragraph says it all and not only applies to the topic of your piece, but science in general.

As a big science fan, I've always marvelled at how clearly obvious (to me) concepts seemed invisible to learned scientists.

As hard as it is to believe, as a small child, I assumed that SOME dinosaurs had to be warm-blooded, and SOME had to have feathers.

A good example as to why I thought these things was what I perceived to be the startling resemblence many a drawing of a flying reptile has to a plucked flying bird (as opposed to birds unable to fly) especially a featherless pelican. It looks VERY peradactle-like.

Why I thought do scientists take the naked flying reptile as "accurate" based on their knowledge considering that few would think a modern flying bird without feathers was an accurate portrayal?

As for the warm-blooded nature of many dinosaurs.

To me I could NOT imagine how such large animals would be able to warm up sufficiently during daylight hours like modern reptiles do. I had watched and observed them as a kid, and the notion of something the size of a bus with far less surface area warming up like that was just absurd.

Nothing else made sense to my young mind. Yet at that time in the 60s/70s the overwhelming opinion was they were like reptiles.

Later I learned it wasn't that the establishment was so blind, but rather they had long ago put in a special place certain assumptions about the nature of dinosaurs.

These assumptions over time became as you said more a faith-based belief rather than scientifically based theory.

By the time I developed my fascination with dinos as a child, the "belief" was clearly full of holes, yet because it had become a "faith-based" sort of scientific theory, learned scientists were blind to it.

The same could be said regarding the "blindness" to the native intelligence and just how overwhelming the # of things we have in common and share with less intelligent animals is vs. a vs. the very very few things if any that are exclusively human without any analogue primitive or otherwise in the animal world.

Yet we can still hear many a scientist claim that we humans are extra-special. Hmmm.

It is truly ironic that the biggest weakness in modern science is its tendency to be blind to when members "assume about a theory" the same way a "religious person believes re: their faith."

When that happens the damage to learning can last decades.

For often hand in hand with that self-deception is the belief that the "facts" support their "faith." when it truth it did/does not.

Any attempt to make them re-examine their "belief" is met with the same extreme skepticism and hostility one would get trying to get a religious person to accept the fallacy of some of their beliefs. Very sad.
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Darkravager · Oct 9, 2008

CdnShockwave said: ↑

QFT.

I really don't see how intelligent design and creationsim can be seperated from religion. They seek to prove that the religious creation story is true. They are inextricably linked.
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Except for the fact that intelligent design doesn't try to prove the Genesis account of creation. Instead, it simply seeks to show that the evolutionary theory perhaps doesn't explain everything. If indeed it doesn't explain everything, then the intelligent designers would say maybe there is room for a god in it. They achieve this through scientific studies, some of which is most certainly "real" science.

Creationism does argue for a literal understanding of the Genesis account of creation.

Before totally writing off a system of thought, it's usually a good idea to learn what it really entails.

Edit: Wow Mechatron. That post you showed pretty much echos something I had said earlier in the thread that was deleated. Pretty insightful.

Beastbot X · Oct 9, 2008

Darkravager said: ↑

Except for the fact that intelligent design doesn't try to prove the Genesis account of creation. Instead, it simply seeks to show that the evolutionary theory perhaps doesn't explain everything. If indeed it doesn't explain everything, then the intelligent designers would say maybe there is room for a god in it. They achieve this through scientific studies, some of which is most certainly "real" science.
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Yeah, some atheists believe in Intelligent Design (OMG!).

Jazzy Zx · Oct 9, 2008

*Pop*
We're all doomed

GW_Freak · Oct 9, 2008

Insane Galvatron said: ↑

Interesting theory. I can't wait to see how it pans out. Being in a bubble that makes things appear farther away than they are could be yet another way to explain seeing stars that are far away if the universe is only 6000 years old as YEC suggest. They may not be all that far away...
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Our universe, in a bubble?

David Here for a good time, not a long time TFW2005 Supporter

Darkravager Zombie Hunter

Beastbot X Old skool. In a lot of ways.

Jazzy Zx Wants too be called Jz :P

GW_Freak Banned

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Our universe, in a bubble?

David Here for a good time, not a long time TFW2005 Supporter

Darkravager Zombie Hunter

Beastbot X Old skool. In a lot of ways.

Jazzy Zx Wants too be called Jz :P

GW_Freak Banned

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