(July 20, 2017 at 10:06 pm)Jehanne Wrote:(July 20, 2017 at 9:53 pm)RoadRunner79 Wrote:
Can you explain those, and show where you start with nothing, which causes something.
You simply can't have it "both ways". Either the Universe is spatially infinite, which means that actual infinities exist (per the above), or, the Universe is finite in spatial extent, which means that there is nothing "outside" of it, which means that it is expanding into nothing. From the following Wikipedia article (which is completely accurate -- verified myself through Griffiths):
Quote:Zero-point energy is fundamentally related to the Heisenberg uncertainty principle.[93] Roughly speaking, the uncertainty principle states that complementary variables (such as a particle's position and momentum, or a field's value and derivative at a point in space) cannot simultaneously be specified precisely by any given quantum state. In particular, there cannot exist a state in which the system simply sits motionless at the bottom of its potential well: for, then, its position and momentum would both be completely determined to arbitrarily great precision. Therefore, instead, the lowest-energy state (the ground state) of the system must have a distribution in position and momentum that satisfies the uncertainty principle−−which implies its energy must be greater than the minimum of the potential well.
https://en.wikipedia.org/wiki/Zero-point_energy
In other words, it is impossible to have a zero-energy state anywhere in the Universe, which means that the question, "Why is there something rather than nothing?" is equivalent to asking, "What color is Saturday?" and then arbitrarily assigning Saturday the color "blue" as opposed to pink, red, orange, or saying that Saturday is "Chevy day," etc., etc.
And, so, "nothing" exists as being "outside" the Universe (if it is finite), or the Universe is spatially infinite, which means that actual infinities exist. You can't have it both ways.
As for virtual particles arising without a cause, they do that because they can, which means that they must. There is nothing that "causes" them; if there was, that would require energy that was greater than the zero-point energy demanded by the Heisenberg uncertainty principle, which means that there would have to be infinite energy everywhere in the Universe to accommodate the infinite regress that you would get if you claimed that virtual particles were "caused".
I find it interesting, that following a conversation so focused on everyone being able to see, we are discussing virtual particles, which to my knowledge no one has detected directly. It's further a bit ironic, that they are inferred as a cause for the effects that are seen, but then some want to stop, and say that this effect doesn't have a cause.
Once we get into this area of science, there are a lot of assumptions being made. Necessarily so, because we are talking about the very small and at this time it is at the limits of what we can detect. Now I'm not saying that it is wrong, to infer the best explanation here, but I get a little leery when assumptions are built on top of each other and treated as dogmatic as they move further beyond their foundation. I don't understand your insinuation, that I am trying to have it both ways. When you invoke the Heisenberg uncertainty principle, and zero point energy, it seems, that you are trying to say that there is something which has momentum and position, and yet call it nothing. I can agree, that if there is something, then it must be moving. When I am looking at an analog signal in a control, if it is not moving, then either my equipment/program has failed, or I don't have enough resolution. So if we have something, it is moving, and has a position. There is a noise, and it cannot be absolute zero. However; can we say that there cannot be absolutely nothing? Was this something prior to, or as a result of the universe? I think these are assumptions, which are difficult to support.
I do agree, that if the universe is spatially infinite, then we do have actual infinity (where you not making an argument against actual infinities a short time ago). There are no dimensions, it has infinite energy, infinite mass, it is non-physical. The other alternative, is that the universe is finite and a physical thing. It has dimensions, an age, it can be expanding, and has limits it can be measured. And if you truly have nothing outside, I don't see where the uncertainty principle and thus zero point energy apply. Even then, you are basing this assumption on a very small sample, surrounded by matter, energy, and a lot of somethings.
In your last point, you say that the zero point energy is insufficient to be a cause for virtual particles (which again, are an inference from an effect themselves). You apply the principle of causality here. However from this, I come to the conclusion, that either our assumptions are incorrect, or that there needs to be something else, which is supplying the necessary energy. There are a lot of different views on virtual particles. To the other extreme, some say that they are just a useful mathematical tool and our not real at all. Others say that the perhaps the word "particle" while somewhat useful in picturing what is happening, leads people to misconceptions.
There are a number of reasons, that I am a bit skeptical when someone says that these virtual particles poof into existence from nothing. I agree, that that there is a problem with an infinite regress, but do not think that you can scientifically determine it the stopping point. I would say that the end of the infinite regress is an uncaused cause, not an uncaused effect. Something which always existed. But this is based on logic and metaphysics, and apart from our knowledge or ability to detect it. On the other hand, if something poofs into existence, then it is an effect, that requires a cause. It requires a reason for it's sudden existence or change which is external to the effect.
It is said that an argument is what convinces reasonable men and a proof is what it takes to convince even an unreasonable man. - Alexander Vilenkin
If I am shown my error, I will be the first to throw my books into the fire. - Martin Luther
If I am shown my error, I will be the first to throw my books into the fire. - Martin Luther