'Normal universe' a special case?

  • Thread starter BernieM
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  • #1
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Main Question or Discussion Point

With all the dark energy and dark matter postulated to exist in the universe, would it be fair to conclude that our 'normal universe full of normal matter and energy' is THE 'special' form of matter and energy? And if so, would such things as quantum entanglement, wormholes, etc., exist? Has anyone considered yet the possibility of dark time or dark space?
 

Answers and Replies

  • #2
Nabeshin
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With all the dark energy and dark matter postulated to exist in the universe, would it be fair to conclude that our 'normal universe full of normal matter and energy' is THE 'special' form of matter and energy?
I suppose that makes sense.

And if so, would such things as quantum entanglement, wormholes, etc., exist? Has anyone considered yet the possibility of dark time or dark space?
This doesn't make as much (or any) sense. Quantum entanglement is an established effect, whereas wormholes are merely a possibility in Einstein's theory, and neither have anything to do with dark matter or energy. The notions of "dark time" and "dark space" don't make any sense either -- what is this even supposed to mean? You should note that although we call them dark matter and dark energy, they are not at all (thought to be) related. Dark matter is simply some yet undiscovered form of collisionless matter which does not interact with electromagnetic radiation (most likely in the form of WIMPs). Dark energy is the name given to the force causing the accelerated expansion of the universe, perhaps the vacuum energy of quantum mechanics. Anyways, the two don't really have anything to do with each other.
 
  • #3
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Sorry for not being clear. What I meant to ask is, that if the matter and energy we observe is a special case then is it also possible that things such as entanglement that we observe are ALSO a special case that only applies to our 'special case' universe.
 
  • #4
Nabeshin
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Ah, I see. The answer is still no. Quantum mechanical effects are practically universal -- there's really no getting around them. The best candidate for dark matter, WIMPs, are hypothesized to be as of yet undiscovered particles (Which would undoubtedly behave quantum mechanically, entanglement and all). Similarly, the best known explanation for (in principle, if not in magnitude) dark energy is the vacuum energy, a quantum mechanical effect.

The real point here is quantum mechanics is a deep deep underlying theory in the universe. It transcends different types of particles and energies. Perhaps I can crystallize this with an analogy... Suppose we live on a planet with only red balls. We observe a peculiar effect -- they always fall down -- gravity. One day our learned astronomers report they have discovered, elsewhere in the universe, some blue balls. Since we believe the principle of gravity to be something fundamental, which applies to all kinds of matter, we would assume that it applies (and rightly so) to the blue balls as well.
 
  • #5
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With all the dark energy and dark matter postulated to exist in the universe, would it be fair to conclude that our 'normal universe full of normal matter and energy' is THE 'special' form of matter and energy? And if so, would such things as quantum entanglement, wormholes, etc., exist? Has anyone considered yet the possibility of dark time or dark space?
ummm... actually even in our universe there is more dark matter/energy/force(fundamental)/ghosts than normal matter/energy/force(fundamental)/ghost
 
  • #6
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What, exactly, is a dark force or a dark/normal ghost?
 
  • #7
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What, exactly, is a dark force or a dark/normal ghost?
Dark force has not been detected but has only been hypothesized. ghosts in physics refer to general ghosts in theoretical physics, which either build or destroy unitary.
 
  • #8
Ken G
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It sounds to me what BernieM is wondering is if we have any reason to expect, a priori, that dark matter or dark energy obey the normal laws of physics as we have discovered them acting on bright matter and regular types of energy. I think that's an interesting question, and one might argue that dark energy is already an example of why we can't assume that. In other words, if dark energy is those blue balls, then what we seem to find is that they don't fall down-- they fall up! (In the sense that dark energy, if a cosmological constant, is essentially an unexpected antigravity effect on very large scales in the universe.)

Now, certainly Nabeshin's "blue balls" are not intended to represent anything at bizarre as dark energy, they are meant for dark matter, which could be just some fairly normal type of matter that just happens to interact only by the weak force and gravity, let's say. Then we might expect its gravitational interactions to be perfectly normal. But why should we really expect that anyway, how do we know just how different "dark matter" should be?

I think the answer to that is we have no idea, but we start by assuming the minimum deviation from what we know, and see how far it gets us. So far, we have made progress with dark matter by assuming its gravity, and response to gravity, are normal. I would say that is a perfect example of looking for our lost keys at night under the streetlight, not because we expect to have lost our keys near a streetlight, but simply because we know they will be easier to find if they are in fact there.
 
  • #9
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It sounds to me what BernieM is wondering is if we have any reason to expect, a priori, that dark matter or dark energy obey the normal laws of physics as we have discovered them acting on bright matter and regular types of energy. I think that's an interesting question, and one might argue that dark energy is already an example of why we can't assume that. In other words, if dark energy is those blue balls, then what we seem to find is that they don't fall down-- they fall up! (In the sense that dark energy, if a cosmological constant, is essentially an unexpected antigravity effect on very large scales in the universe.)
Thank you KenG for putting my question so succinctly. That is what I meant exactly. More than that however I am wondering if the dark matter/energy universe is the 'real' universe and our 'observable universe' and it's laws are a special case and condition created by that. That the 'normal laws of physics' are those that govern dark matter and dark energy and we are the anomalous quantity.
 
  • #10
Ken G
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If that turned out to be true, it would bring up some very fundamental questions about what "normal physics" is. You are no doubt taking the perspective that "normal physics" is predominantly what determines what happens in the universe, moreso than what happens to us, but I would say that physics is very much an interaction of human intelligence with its environment, so "normal physics" would always be the things that happen to us (or else we'd have to call quantum physics normal, and classical physics weird!). But the question is certainly an insightful one, and I believe is very much what Bohr meant when he said words to the effect that "there is no quantum realm", meaning essentially that we are indeed the oddballs in a universe where our most basic modes of thought create a kind of fiction about most of the processes going on around us, particularly at the microscopic level, or maybe even, as you speculate, at the astronomical level too. Ironically, those levels are also where physics is most accurate-- it is the physics of our own bodies and lives that we have little predictive power about!
 
  • #11
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If that turned out to be true, it would bring up some very fundamental questions about what "normal physics" is. You are no doubt taking the perspective that "normal physics" is predominantly what determines what happens in the universe, moreso than what happens to us, but I would say that physics is very much an interaction of human intelligence with its environment, so "normal physics" would always be the things that happen to us (or else we'd have to call quantum physics normal, and classical physics weird!). But the question is certainly an insightful one, and I believe is very much what Bohr meant when he said words to the effect that "there is no quantum realm", meaning essentially that we are indeed the oddballs in a universe where our most basic modes of thought create a kind of fiction about most of the processes going on around us, particularly at the microscopic level, or maybe even, as you speculate, at the astronomical level too. Ironically, those levels are also where physics is most accurate-- it is the physics of our own bodies and lives that we have little predictive power about!
Well not everything is perceivable to us humans since our reference frame is always limited to one dimension(limitation).Just as the way Einstein predicted in his theory of Special Relativity.If we ever get to relativistic speeds we might experience such abnormal behavior.Even if we are to believe that the dark matter is the real universe(I think labeling it as a universe is being too simplistic ).I believe it's too early to come up with such statements for starters we need to know what it's made up of.
 
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  • #12
Ken G
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Agreed, we are in a state of speculation at this point. I hope I live to see a more complete resolution in the next few decades.
 

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