Dark Energy and the Cyclic Universe?

In summary: Otherwise, I don't see a point in pursuing this any further.In summary, the conversation discusses the possibility of a cyclic universe and the role of dark energy in preventing a Big Crunch. It also explores the idea that the universe began with a massive quantum fluctuation and why we have not seen another one. There are several theories proposed, including the existence of a suppression field in the universe and how it could affect the occurrence of quantum fluctuations. However, these are all speculative and not supported by scientific evidence. The conversation ends with a reminder to stay within the rules of the forum and to provide reputable sources for any further discussions.
  • #1
bbbl67
212
21
Now two points here. (1) Most Cyclic Universe theories I've heard require the universe to reverse course and fall back into a Big Crunch to recycle again. Now that Dark Energy has been discovered, the chances of a Big Crunch have gone away. (2) Some theories suggest that the universe started with a massive quantum fluctuation, the kind of which we have never seen since.

So my question would be why have we not seen another Big Bang level quantum fluctuation again? My assumption is that the presence of having the current universe here right now is itself the reason why such massive fluctuations have not reoccurred. Perhaps the structured universe itself suppresses the biggest fluctuations?

So, what I'm thinking is that once Dark Energy clears out the present universe, leaves behind mainly empty voids, then that will clear the way for more massive fluctuations to occur. This may start a brand new universe in all of the emptiness. So the Cyclic universe models would still work, it just won't be with a Big Crunch associated with it too. What do you think?
 
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  • #2
bbbl67 said:
So my question would be why have we not seen another Big Bang level quantum fluctuation again?

There are many possibilities, the most general one is that the idea that the big bang was the result of a quantum fluctuation is an incorrect explanation. There may be an unknown force or an unknown behavior of the existing forces at the scale of the big bang that caused it.

bbbl67 said:
So, what I'm thinking is that once Dark Energy clears out the present universe, leaves behind mainly empty voids, then that will clear the way for more massive fluctuations to occur. This may start a brand new universe in all of the emptiness. So the Cyclic universe models would still work, it just won't be with a Big Crunch associated with it too. What do you think?

I can't see any reason to believe this. Further expansion should lessen the possibility that such a fluctuation would occur, not encourage it as far as I understand.
 
  • #3
Drakkith said:
There are many possibilities, the most general one is that the idea that the big bang was the result of a quantum fluctuation is an incorrect explanation. There may be an unknown force or an unknown behavior of the existing forces at the scale of the big bang that caused it.
Yeah, I completely agree, it's not the only possible theory for why the BB began, but we're only talking hypothetically here. One possible scenario.

I can't see any reason to believe this. Further expansion should lessen the possibility that such a fluctuation would occur, not encourage it as far as I understand.
Well, the reason why we would expect this is because it's been shown that within the volume of an atomic nucleus, the energy of the Strong Force's gluons suppresses quantum fluctuations much larger than virtual quarks from existing. What if a similar suppression field exists throughout the universe as a whole, keeping the quantum vacuum fluctuations in check? Thus we may see virtual electron-positron pairs popup, maybe some Higgs bosons, and quark-antiquark pairs, but nothing much beyond that. So we won't see virtual Saturns popping into existence and annihilating. Well, obviously I don't mean an actual Saturn with rings and stuff, just a particle with the mass of Saturn.
 
  • #4
bbbl67 said:
Well, the reason why we would expect this is because it's been shown that within the volume of an atomic nucleus, the energy of the Strong Force's gluons suppresses quantum fluctuations much larger than virtual quarks from existing.

I'm not sure what you mean by this.

bbbl67 said:
What if a similar suppression field exists throughout the universe as a whole, keeping the quantum vacuum fluctuations in check?

There is no such thing as a "suppression field". I'm not sure what you talking about in the part of your post I quoted above, but whatever "suppression" is occurring is going to happen because of the existing conditions within the nucleus and the existing fundamental interactions. In addition, it would be difficult to extend this principle to the universe as a whole, since there are already huge volumes of space that are devoid of matter beyond a handful of particles per cubic meter. Also, whatever virtual particles are created, they are, in the end, virtual particles only. They don't suddenly turn into real particles. That would violate conservation of energy and probably a few other conservation laws as well. We can't even observe the particle-antiparticle pair creations and annihilation, since they are virtual.

Please keep in mind that we're skirting the edges of PF rules here. Speculation like this is not something we generally allow, since it inevitably leads nowhere. If you can find some reputable published articles discussing what you're proposing then feel free to link them.
 

1. What is dark energy?

Dark energy is a hypothetical form of energy that is believed to make up approximately 68% of the total energy in the universe. It is thought to be responsible for the observed accelerated expansion of the universe.

2. How is dark energy related to the cyclic universe theory?

The cyclic universe theory proposes that the universe undergoes a series of cycles of expansion and contraction. Dark energy is thought to be the driving force behind the accelerated expansion and could potentially play a role in the collapse of the universe in the contraction phase.

3. How is dark energy different from dark matter?

Dark matter and dark energy are two separate concepts in astrophysics. Dark matter is a type of matter that does not emit or interact with electromagnetic radiation, while dark energy is a form of energy that is believed to be responsible for the expansion of the universe.

4. How is dark energy measured and studied?

Dark energy is a difficult concept to study and measure, as it cannot be directly observed. Scientists use various methods, such as measuring the cosmic microwave background radiation, observing the large-scale structure of the universe, and studying the brightness of supernovae, to indirectly study and measure the effects of dark energy.

5. What are the implications of dark energy for the future of the universe?

If dark energy exists and continues to drive the accelerated expansion of the universe, it could have significant implications for the future of the universe. It could potentially lead to a "Big Rip" scenario, where the expansion of the universe becomes so rapid that it tears apart all matter and structures, resulting in the end of the universe.

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