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Q: Why Is There Nothing?


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#18 Dubbelosix

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Posted 22 June 2019 - 08:17 AM

That could only be true if there was an absolute symmetry with gravity including all the other forces, but since the universe is observed to be accelerating (even if it appears to be doing so) then you'd have to argue there is an asymmetry. A true zero energy universe would still have to have all its positive energy cancelled by a negative counterpart, but since the universe is dominated by positive energy particles, this approach seems very unlikely. At least to me.



#19 Dubbelosix

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Posted 22 June 2019 - 08:19 AM

But yes hard to tell... Such negative energy idea's bring us back to the Dirac Sea... then you'd have to explain CPT-violation which is an observed violation of Lorentz symmetry in special relativity.



#20 GAHD

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Posted 22 June 2019 - 08:46 AM

That could only be true if there was an absolute symmetry with gravity including all the other forces, but since the universe is observed to be accelerating (even if it appears to be doing so) then you'd have to argue there is an asymmetry. A true zero energy universe would still have to have all its positive energy cancelled by a negative counterpart, but since the universe is dominated by positive energy particles, this approach seems very unlikely. At least to me.

https://www.symmetry...r-flat-universe

Just have to find a big enough triangle to see if it adds up to 180 degrees (or higher, or lower) to see if the energy balances. That's how you get total energy.

Virtual particles in free space (the fabric itself) would have to contain quite a bit of free energy. Also seems to be the case that that's true.



#21 Dubbelosix

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Posted 22 June 2019 - 09:10 AM

The universe isn't completely flat, in fact expect to find a small curve eventually. The only way a universe could be completely flat, is if it was infinitely large. You can demonstrate this in a very simple way, by using a black hole analogy of the weak equivalence principle.

 

A very small black hole has a very large Gaussian curvature [math]K[/math] and so as a black hole eats matter, not only does the temperature decrease (or tend to zero)

 

[math]T \rightarrow 0[/math]

 

it's curvature also tends to zero

 

[math]K \rightarrow 0[/math]

 

But because of the third law of thermodynamics, a consequence fundamentally of quantum mechanics, a system cannot exist at absolute zero temperature, meaning no matter how large a universe or black hole can get, it's curvature will never go to zero. This is why a universe cannot be completely flat. In fact, most cosmologists expect the universe not to be completely flat.



#22 Dubbelosix

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Posted 22 June 2019 - 09:11 AM

The virtual particles are certainly the reason why an absolute flatness to the universe will never exist and cannot exist from all our known first principles.



#23 GAHD

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Posted 22 June 2019 - 09:23 AM

The virtual particles are certainly the reason why an absolute flatness to the universe will never exist and cannot exist from all our known first principles.

So far though, all the data I've found points towards flat. New data and all, so I still hold my skeptic stick even while I think it looks good. I've said this before and I'll say it again: The universe doesn't have to listen to our logic, we have to listen to it's logic. Nice math is only nice if it comes from and agrees with reality. You've got to be willing to throw out the baby and the bathwater if it turns out both are rancid.



#24 Dubbelosix

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Posted 22 June 2019 - 09:51 AM

This is because our instruments can hardly detect it. I quote Susskind ''so far they are saying it is flat but I am quite certain eventually we will detect a small curve.'' Lisi also appears to believe the universe is not flat. All sources will tell you it is flat, but mainstream is often wrong... in fact I am 99% certain that most scientists don't really understand theoretical physics or how to properly understand it or what the laws strictly say.



#25 Dubbelosix

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Posted 22 June 2019 - 09:53 AM

I will though say again, for a universe to be flat requires it be infinitely large - the cosmological horizon proves to a certain extent that the universe is certainly not infinite in extent, but only time can tell about that as a true fact since we are still gathering information from those distant sources, but relativity has strange consequences that we may not even be able to trust the distant sources because these signals tell us something about the past, not the present sufficiently.



#26 GAHD

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Posted 22 June 2019 - 10:47 AM

I don't think it requires bounding or lack thereof at all to be flat. Flat just indicates perpetual expansion. Only positive curvature necessitates that it have measurable size.

https://arxiv.org/abs/gr-qc/9812046
20 years old paper but the observations since 2015 still tend to support it.

The univers may very well be infinite in a very real way that CMB hides from us. Or it might be finite just past the bounds of what we can observe. It doesn't NEED to listen to our math though, or math needs to listen to it. ;)



#27 Dubbelosix

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Posted 22 June 2019 - 10:57 AM

I don't think it requires bounding or lack thereof at all to be flat. Flat just indicates perpetual expansion.

 

Yes, but the perpetual expansion does not mean the universe is literally flat. Besides, I have explained, from the third law a consequence of quantum mechanics, it can only approach zero, but never reach it as a fundamental limit.



#28 GAHD

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Posted 22 June 2019 - 11:57 AM

Yes, but the perpetual expansion does not mean the universe is literally flat. Besides, I have explained, from the third law a consequence of quantum mechanics, it can only approach zero, but never reach it as a fundamental limit.

It's the inverse of that: Flat indicates perpetual expansion. Carts go after the horse. Perpetual expansion does not require flat, it's can be either flat or negative curvature.(another case where positive and negative are rather poor words to use, but we're stuck with english so...)

Take a look at universal topology. There's easily a half dozen models that fit the evidence, and each has some interesting yet-to-be-done tests. There's also a whole slew of models that were crushed by LIGO and WMAP. This is one of those areas everyone under the publish or perish gun tends to throw a paper into the hat for. It's still an interesting area to look at, I hope you do end up taking some time doing that.

What part of QM are you talking about?



#29 Dubbelosix

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Posted 22 June 2019 - 12:23 PM

The universe is indeed appearing flat because of its expansion, but it can never be perfectly flat unless you entertain the universe is infinite in size, but even if it was, that would indicate no thermodynamic energy in the observable universe.



#30 Dubbelosix

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Posted 22 June 2019 - 12:24 PM

Well, virtual particles are just the sci-pop name for all fields in the ground state, which is known as zero point energy. In such a case, the third law of thermodynamics establishes a very specific rule, in which no system can ever be in an absolute zero temperature state. These are fundamental principles that even apply to the universe at large.


Edited by Dubbelosix, 22 June 2019 - 12:25 PM.


#31 Dubbelosix

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Posted 22 June 2019 - 12:27 PM

This is why the limits have to be preserved: We used  a black hole analogy because it is the very best way to find the same principles for the universe, a black hole only loses its temperature if it could ever an infinite size and by consequence of relativity, it would immediately be flat by consequence. But since these things are illegal in physics as we understand it, the flatness is only apparent to our measuring instruments. It can be argued that the universe has got so large, we may never detect this curve, even though in principle it has to exist.



#32 GAHD

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Posted 22 June 2019 - 12:56 PM

Well, virtual particles are just the sci-pop name for all fields in the ground state, which is known as zero point energy. In such a case, the third law of thermodynamics establishes a very specific rule, in which no system can ever be in an absolute zero temperature state. These are fundamental principles that even apply to the universe at large.

That doesn't appy here, apples vs oranges. Possibly apple vs apple-tree. You're talking about matter. I'm talking about matter and it's container as a whole. I think that's where the impasse is located.
AFAICT "matter can't reach zero temperature (movement energy)" is different than saying "mass-energy - Attraction fields = zero"

 

This is why the limits have to be preserved: We used  a black hole analogy because it is the very best way to find the same principles for the universe, a black hole only loses its temperature if it could ever an infinite size and by consequence of relativity, it would immediately be flat by consequence. But since these things are illegal in physics as we understand it, the flatness is only apparent to our measuring instruments. It can be argued that the universe has got so large, we may never detect this curve, even though in principle it has to exist.

Universal topology. Wiki is the easiest place for me to point you. Flat can be either infinte or finite, topologies can be made for either case and will require other experiments to nail down which apply. THe universe might still laugh at us and point us to stranger ideas in the end. Seriously; go, look, learn. It's interesting stuff.



#33 Dubbelosix

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Posted 22 June 2019 - 01:32 PM

What do you mean it doesn't apply here? You are a quantum system, all classical systems are subject to quantum laws - the universe is not exempt from it either.

 

And no, using the mathematical laws appropriately, the idea of infinity does not even exist - it is not a number but a concept. The universe is finite, not infinite from observation, so I have to object to everything you have said. 



#34 GAHD

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Posted 22 June 2019 - 02:03 PM

What do you mean it doesn't apply here? You are a quantum system, all classical systems are subject to quantum laws - the universe is not exempt from it either.

I already answered this part here:

You're talking about matter. I'm talking about matter and it's container as a whole. I think that's where the impasse is located.
AFAICT "matter can't reach zero temperature (movement energy)" is different than saying "mass-energy - Attraction fields = zero"

Elaborating on it. You're only looking at half the equation as it were. The matter-energy component. That's the part that asymptotically approches zero heat energy. This is a different situation. It's not removing +E it's adding -E. Negative energy is a whole other ballpark than subtraction of positive energy.
This is a classic example of why dimensional analysis is important.

For exaple, as the mass-energy of something increased with speed approaching C, it's -E fields would also proportionately increase as it gained a stronger attractive force.
 

 

 

And no, using the mathematical laws appropriately, the idea of infinity does not even exist - it is not a number but a concept. The universe is finite, not infinite from observation, so I have to object to everything you have said. 

The OBSERVEABLE universe is finite. There's a whole branch of theoretical that goes into the larger universe. Here's an article so I don't have to write 15 pages myself. Some of the wackier models tend to make even log scales nonsensical as far as metrics are concerned... 


Edited by GAHD, 22 June 2019 - 02:17 PM.
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