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It's confirmed: Matter is merely vacuum fluctuations

newscientist.com

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Re: It's confirmed: Matter is merely vacuum fluctuations

#21

Post by kurtosis »

nebula wrote: post #10

Is it just me or there is really something amiss with this article? Physicists have now confirmed that the apparently substantial stuff is actually no more than fluctuations in the quantum vacuum. So, if they have NOW confirmed this, why didn't the article cite the work that confirmed this? Also the article didn't mention anything on who confirmed and how. It talks about some computer simulations and concludes: Altho…

Our research group has had experimental papers rejected because they did not agree with first principles simulations. The issue is that at least in quantum chemistry and materials physics, the theory is simple and easy to write down but making quantitative predictions from the theory requires the use of (a) massive computational resources, (b) inspired approximations, or (c) all of the above. (unless it's an "emergent" phenomenon) It's debatable what the relationship between theory, experiment and computation is. I submitted an abstract to an APS conference yesterday and I noticed that you were asked to classify your submission as "theoretical", "experimental", or "computational". I think I agree with the APS in that all three styles are useful and complementary to each other.

Re: It's confirmed: Matter is merely vacuum fluctuations

#23

Post by khafra »

mini_word wrote: post #12
jerf wrote: post #4

Earlier quoted context omitted.

Sometimes I wonder how much of quantum mechanics' notorious difficulty is that it is truly hard to understand, and how much is simply that it is hard to understand in English . People hear "virtual particle" and have no clue what that means and associate it with other "virtual" things. Or, more directly connected to the title of this story, hear that matter is "merely" "vacuum fluctuations", which, thanks in no small…

This pattern is called a Sylogism. Everybody hates sylogisms as it's mostly used to manipulate.

1) Syllogisms are mostly used for manipulation 2) Everyone hates manipulation .`.) Everyone hates syllogisms.

...nope, doesn't work for me.

Re: It's confirmed: Matter is merely vacuum fluctuations

#26

Post by kscaldef »

kiplinger wrote: post #13

Interesting Read. Though I have read that some equatins regarding sub atomic particles were "too difficult to solve" before, I never had read a good explanation why. It will be a sad day when the supercomputers we build to solve these equations gain intelligence and use their knowledge against us. Maybe they'll invent some cool null ray.

> Though I have read that some equatins regarding sub atomic particles were "too difficult to solve" before, I never had read a good explanation why.

Solution to the equations of quantum field theory can be formally expressed using what's called a perturbation expansion. This is similar to using a power series expansion to solve an algebraic or differential equation. In a rough way of looking at things, higher order terms in the expansion correspond to particle interactions with more "stuff" involved. This equivalence is what Feynman diagrams represent.

In the case of electromagnetism, this technique is very effective. The term corresponding to a single photon exchange is 137 times larger than the term corresponding to two photons, and so on. As a result, perturbation theory works very well for these calculations.

However, for nuclear forces in a proton or neutron, all the terms are about the same size. You can't cut off the expansion and get a meaningful estimate. In the Feynman diagram view, this is saying that you can't think of it as just exchanges of small numbers of gluons, rather, you'd need to consider huge number of particles and diagrams of extreme complexity. This is the sense in which the equations are "too difficult to solve". You need to do something totally different from perturbation theory to get a solution. Lattice computations, as described in the article, are the best alternative technique we have available at this point.

Re: It's confirmed: Matter is merely vacuum fluctuations

#27

Post by jerf »

mini_word wrote: post #12
jerf wrote: post #4

Earlier quoted context omitted.

Sometimes I wonder how much of quantum mechanics' notorious difficulty is that it is truly hard to understand, and how much is simply that it is hard to understand in English . People hear "virtual particle" and have no clue what that means and associate it with other "virtual" things. Or, more directly connected to the title of this story, hear that matter is "merely" "vacuum fluctuations", which, thanks in no small…

This pattern is called a Sylogism. Everybody hates sylogisms as it's mostly used to manipulate.

I was getting at something more specific than just a logical fallacy, but specifically the part where you sanctimoniously declare "aHA! It isn't real!" It is true that is a special case of a more general logical fallacy, but I see this specific one pop up a lot, reifying ignorance, then declaring it false as if that actually proves something.

Re: It's confirmed: Matter is merely vacuum fluctuations

#29

Post by mini_word »

khafra wrote: post #23
mini_word wrote: post #12

Earlier quoted context omitted.

This pattern is called a Sylogism. Everybody hates sylogisms as it's mostly used to manipulate.

1) Syllogisms are mostly used for manipulation 2) Everyone hates manipulation .`.) Everyone hates syllogisms. ...nope, doesn't work for me.

Ok you got me ! :)
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