Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: geordief on 14/12/2019 00:45:14
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Did the first (and only?) gravity field start very soon after the BB?
Was it "kick started" by the Higgs field?
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Gravity is posited to exist before anything else. The earliest meaningful epoch is the Planck epoch, up to 10-43 seconds, where the universe consisted of a 'gravitational singularity', which wasn't specifically gravitational since the four fundamental forces had yet to separate.
In the next 10-36 seconds, gravity separates from the other three forces. This is all before the inflation epoch where expansion takes place oodles faster than it does thereafter.
The Higgs field seems to come after the inflation as the strong force separates and the Higgs field confers mass on the various particles forming.
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Gravity is posited to exist before anything else. The earliest meaningful epoch is the Planck epoch, up to 10-43 seconds, where the universe consisted of a 'gravitational singularity', which wasn't specifically gravitational since the four fundamental forces had yet to separate.
In the next 10-36 seconds, gravity separates from the other three forces. This is all before the inflation epoch where expansion takes place oodles faster than it does thereafter.
The Higgs field seems to come after the inflation as the strong force separates and the Higgs field confers mass on the various particles forming.
So is there any picture of what gravity (that is synonymous with spacetime ,I have been told) would look like without a Higgs field?
Anything else to say about "gravitational singularity"? Is it "singular" in any other sense?
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I don't even have a picture of gravity with a Higgs field.
Sorry, I should have said "rough description" rather than "picture" (but you perhaps knew that and gravity pre Higgs may be entering uncharted waters? Quantum Gravity territory?)
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The earliest meaningful epoch is the Planck epoch, up to 10-43 seconds, where the universe consisted of a 'gravitational singularity'
So, what is a gravitational singularity? Wiki tells us. https://en.wikipedia.org/wiki/Gravitational_singularity.
……[It] is a location in spacetime where the gravitational field of a celestial body is predicted to become infinite”.
“Since such quantities become infinite at the singularity, the laws of normal spacetime break down.
Any discussion as to what might be relevant to some postulated point beyond this, also breaks down if we treat a “singularity” as though it were a physical entity.
https://www.quantamagazine.org/where-gravity-is-weak-and-naked-singularities-are-verboten-20170620/
Singularities…….. seem to always come cloaked in darkness, hiding from view behind the event horizons of black holes.
Now, new theoretical calculations provide a possible explanation for why naked singularities do not exist — in a particular model universe, at least. The findings indicate that a second, newer conjecture about gravity, if it is true, reinforces Penrose’s cosmic censorship conjecture by preventing naked singularities from forming in this model universe.
Hunting for the Loch Ness Monster, and other “cryptids” may be an interesting and possibly valuable pursuit if you are a cryptozoologist. You might even unearth facts that are relevant to real zoology, but the two disciplines should not be confused.
In no way am I equating theoretical physics/cosmology with a pseudoscience. Such, it certainly is not. Undoubtedly, the search for naked singularities, or for the reasons why they might not exist, can lead to interesting and valuable discoveries, and should not be discouraged. However, there does seem to be a very simple answer to the question as to why they are not observed in nature – they don’t exist.
“Singularity”, in the sense of a black hole singularity, is simply a convenient term for a situation in which current theories break down. It might be reasoned that such breakdowns occur, and are real, and that they may refer to physical realities. Manifestly, this is so, but the relevant “breakdown” is not a physical object, in itself.
Infinite gravity = infinite curvature of spacetime. (?)
If, at any point, the curvature of spacetime is finite, then it would require “infinite time” for it to become infinite. Thus, it could never become infinite in temporal reality.
If there existed in the physical cosmos a point at which the curvature of spacetime (locally?) was infinite, how could it be observed? What would infinite curvature look like?
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A singularity is confined in the same way as quarks are confined. That tells us nothing about what is actually beyond an event horizon. Just as we may never observe a naked quark, we may never see beyond an event horizon.
Quarks are inferred from observation. What can we learn from the observations of black holes? Well not much. Only charge, mass and angular momentum. Well isn't that all we have on quarks?
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Which seems to suggest there is a "boundary", appertaining to the current state of our knowledge, beyond which the answer to almost any question would be "Don't know; working on it".
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So, what is a gravitational singularity? Wiki tells us:
……[It] is a location in spacetime where the gravitational field of a celestial body is predicted to become infinite”.
“Since such quantities become infinite at the singularity, the laws of normal spacetime break down.
Laws breaking down yes, but the BB is not a location in spacetime, it is all locations in space (everywhere), so no gradient, tides, event horizons, etc. The BB is not an exploding black hole.
“Singularity”, in the sense of a black hole singularity, is simply a convenient term for a situation in which current theories break down.
I can make one without a black hole. Any continuously accelerating frame forms an event horizon, a singularity of sorts where physics breaks down, and yet is meaningless to anything not accelerating with the frame in question.
It might be reasoned that such breakdowns occur, and are real, and that they may refer to physical realities. Manifestly, this is so, but the relevant “breakdown” is not a physical object, in itself.
Agree. I think my example just above underscores that.
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Laws breaking down yes, but the BB is not a location in spacetime, it is all locations in space (everywhere), so no gradient, tides, event horizons, etc. The BB is not an exploding black hole.
Not sure if you are agreeing with the Wiki quotes, or not. It’s probably that interpretation thing again.
Agree. I think my example just above underscores that.
Now, there’s a response that makes me feel less “isolated” than I do with respect to some of the speculative things I post! :)
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This one is farfetched but interesting.
https://home.cern/news/news/physics/aegis-makes-positronium-antimatter-gravity-experiments