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Author Topic: Did matter and anti-matter meet in the early Universe?  (Read 16828 times)

Offline jeffreyH

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Re: matter/anti matter
« Reply #50 on: 28/01/2015 00:26:25 »

At this point, I'm bowing out. Your main point has basis neither in the physics I learned in graduate school nor in the references you claim support it. I'm at the limits of my ability to recast my explanations in new words that will be any clearer or more helpful than what I've said up to this point.
I agree. I think if John has a new theory outside of the mainstream, he should post it in the New Theories Section. This Section of the forum is dedicated to main stream physics.

This is not an easy branch of physics. It needs a theory backed by mathematics that can then be used to make predictions which can be tested. What worries me about what John says is that he feels that you can neglect certain aspects, in other words not to worry about them. You can't do that otherwise you are not taking everything into consideration.
 

Online Ethos_

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Re: matter/anti matter
« Reply #51 on: 28/01/2015 03:17:07 »


This is not an easy branch of physics. It needs a theory backed by mathematics that can then be used to make predictions which can be tested. What worries me about what John says is that he feels that you can neglect certain aspects, in other words not to worry about them. You can't do that otherwise you are not taking everything into consideration.
Exactly..............You can't operate honestly if you only consider those issues that fit your favorite schemes. Science is about experiment and observation, if those findings don't fit in nicely with your preferred views, the good scientist will simply have to change his outlook. Dismissing a detail here and there just because it doesn't fit your theory is bad science.
 

Offline JohnDuffield

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Re: matter/anti matter
« Reply #52 on: 28/01/2015 12:40:56 »
Followed your first link. Within it was the following sentence which directly contradicts your assertion about what a quark-gluon plasma is.

"Beyond the normal phase of QCD (at extreme temperatures and pressures), quark gluon plasma forms. In such a plasma there are no hadrons; quarks and gluons become free particles." (emphasis added)
That's wrong. It's sloppy popscience reporting. Go and ask elsewhere whether the gluons in ordinary hadrons are virtual and whether electrons melt in a quark-gluon plasma.

Followed your second link. It makes no mention of electrons or positrons, so I don't see how it supports your assertion.
An ion contains electrons! Everything melts!

Protons are believed to be composite particles. Electrons are not believed to be composite particles. The dissolution of protons under high energy conditions does not carry any implications about what happens to electrons.
The dissolution of ions does! There's something like 78 electrons in a gold ion.

At this point, I'm bowing out. Your main point has basis neither in the physics I learned in graduate school
Go and follow up on what I said. Do not think you learned everything there is to learn at graduate school, such that you reject anything that is contrary to what you think you know.

nor in the references you claim support it. I'm at the limits of my ability to recast my explanations in new words that will be any clearer or more helpful than what I've said up to this point.
If you don't believe what I'm telling you, go and ask elsewhere, and do your own research.
 

Offline JohnDuffield

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Re: matter/anti matter
« Reply #53 on: 28/01/2015 12:49:38 »
I still don't think this applies to electrons. They say "everything melts", but "everything" is still just nuclei, no electrons involved. Are there studies where they use only partially ionized nuclei?
Yes, gold ions, lead ions. See this RHIC article. It's written for the general public, but look closely and you can spot stuff like this:

"This liquid matter has been described as nearly “perfect” in the sense that it flows with almost no frictional resistance, or viscosity. Such a “perfect” liquid doesn’t fit with the picture of “free” quarks and gluons physicists had previously used to describe QGP."

It would appear that this soup does allow for the conversion of quarks into antiquarks, as normal matter is melted, and then as it cools there is a distribution of combinations of quarks and antiquarks.
The point to remember is that this "soup" is like pea soup. There are no peas in pea soup. 

The article alludes to study of this distribution. What is known about the distribution?
I don't know offhand. 


We've never seen a free quark. Best not to worry about them.
Why?
Because they're "partons". They're just parts. Have a look at TQFT. 


I agree. I think if John has a new theory outside of the mainstream, he should post it in the New Theories Section. This Section of the forum is dedicated to main stream physics.
I don't have a new theory outside of the mainstream. The QGP isn't like what the popscience articles say. A proton contains no real gluons. We melt heavy ions to create a QGP. It isn't my fault if the simplified reporting doesn't say what happened to the electrons. And nor is it my fault that antimatter is used to label both individual particles and pairs of particles. It isn't some new theory to point out the ambiguity and the mere convention and how positronium is like light hydrogen, and that baryon asymmetry is matched by lepton asymmetry. 
« Last Edit: 28/01/2015 13:04:32 by JohnDuffield »
 

Offline jeffreyH

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Re: Did matter and anti-matter meet in the early Universe?
« Reply #54 on: 28/01/2015 13:48:29 »
Just to be balanced on the topic of virtual gluons.

http://en.wikipedia.org/wiki/Gluon
[Since gluons themselves carry color charge, they participate in strong interactions. These gluon-gluon interactions constrain color fields to string-like objects called "flux tubes", which exert constant force when stretched. Due to this force, quarks are confined within composite particles called hadrons. This effectively limits the range of the strong interaction to 10−15 meters, roughly the size of an atomic nucleus. Beyond a certain distance, the energy of the flux tube binding two quarks increases linearly. At a large enough distance, it becomes energetically more favorable to pull a quark-antiquark pair out of the vacuum rather than increase the length of the flux tube.
Gluons also share this property of being confined within hadrons. One consequence is that gluons are not directly involved in the nuclear forces between hadrons. The force mediators for these are other hadrons called mesons.
Although in the normal phase of QCD single gluons may not travel freely, it is predicted that there exist hadrons that are formed entirely of gluons — called glueballs. There are also conjectures about other exotic hadrons in which real gluons (as opposed to virtual ones found in ordinary hadrons) would be primary constituents. Beyond the normal phase of QCD (at extreme temperatures and pressures), quark gluon plasma forms. In such a plasma there are no hadrons; quarks and gluons become free particles.]
 

Offline chiralSPO

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Re: matter/anti matter
« Reply #55 on: 28/01/2015 15:19:10 »
Followed your second link. It makes no mention of electrons or positrons, so I don't see how it supports your assertion.
An ion contains electrons! Everything melts!

I still don't think this applies to electrons. They say "everything melts", but "everything" is still just nuclei, no electrons involved. Are there studies where they use only partially ionized nuclei?
Yes, gold ions, lead ions. See this RHIC article.

I followed the link, and it also defines the "gold ions" as gold nuclei. An ion is a charged particle, and doesn't necessarily have any electrons. For instance, the H+ ion is just a proton. While most gold ions encountered in chemistry are Au+, or Au3+ (having 78 and 76 electrons, respectively), high energy physics is usually done with just the nuclei (Au79+). It takes several keV to ionize a gold atom completely, but these experiments are usually on the GeV or TeV energy scale, easily stripping all of the electrons away from the nucleus.

I will try to find a publicly-available, non-popsci article on the matter later today, but I am positive (no pun intended) that there were no electrons involved in these studies.
 

Offline chiralSPO

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Re: Did matter and anti-matter meet in the early Universe?
« Reply #56 on: 28/01/2015 19:51:23 »
I haven't found any publicly available articles yet, but I read a good review on quark gluon soups from Nature (Braun-Munzinger and Stachel, 2007). It confirms that only nuclei (fully ionized atoms) are used, and only fairly large nuclei at that (it looks like silicon is the lightest element they got to work). They were unable to get single protons or single electrons to "melt" because you need extrememly high quark density, which is much easier when starting with nuclei that contain several nucleons.

It looks like they needed to impart at least 10 GeV to each nucleus to get them to melt.

Also, with regards to the "pea soup having no peas," according to this review, quark gluon soup is made of quarks and gluons just as much as hadrons are--there are no isolated quarks, they are all interacting, but the interaction is weaker at such high densities, so the phase has liquid properties instead of solid properties. As the soup cools, it re-hadronizes.
 

Online Ethos_

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Re: Did matter and anti-matter meet in the early Universe?
« Reply #57 on: 29/01/2015 00:45:36 »



Also, with regards to the "pea soup having no peas," according to this review, quark gluon soup is made of quarks and gluons just as much as hadrons are--there are no isolated quarks, they are all interacting, but the interaction is weaker at such high densities, so the phase has liquid properties instead of solid properties. As the soup cools, it re-hadronizes.
Instead of "pea soup having no peas" this suggests something more like quicksand. Where Quarks and gluons represent the particles of the sand in a densely packed arrangement similar to how one might view the physical characteristics of a fluid like quicksand.
 

Offline JohnDuffield

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Re: Did matter and anti-matter meet in the early Universe?
« Reply #58 on: 29/01/2015 11:56:31 »
Note this from Jeffrey's quote above:

"...There are also conjectures about other exotic hadrons in which real gluons (as opposed to virtual ones found in ordinary hadrons) would be primary constituents..."

There are no real gluons in a proton. Then when you melt a proton to make a quark-gluon plasma, there are still no real gluons. So a quark-gluon plasma cannot be a mixture of discrete quarks and gluons. It can't be like sand. But imagine you heated some sand in a crucible, such that all the grains melted. I'm saying that a quark-gluon-plasma (QGP) is like melted sand, not sand.

By the way, I stand corrected on the gold ions. See Wikipedia where you can read this:

"As an example, gold nuclei leaving the EBIS have a kinetic energy of 2 MeV per nucleon and have an electric charge Q = +32 (32 of 79 electrons stripped from the gold atom). The particles are then accelerated by the Booster Synchrotron to 100 MeV per nucleon, which injects the projectile now with Q = +77 into the Alternating Gradient Synchrotron (AGS), before they finally reach 8.86 GeV per nucleon and are injected in a Q = +79 state (no electrons left) into the RHIC storage ring..."

However I will insist that if you threw an electron into a QGP, it too would melt.
« Last Edit: 29/01/2015 12:00:48 by JohnDuffield »
 

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Re: Did matter and anti-matter meet in the early Universe?
« Reply #58 on: 29/01/2015 11:56:31 »

 

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