Quarks: What are they?

An interesting report and I note some items here in the article. "Quarks are the ultimate building blocks of visible matter in the universe."..."The strong force that binds quarks inside hadrons is carried by another kind of tiny elementary particle called gluons, which are exchanged between the quarks. To separate individual quarks requires an enormous amount of energy (it's not called the strong force for no reason). This amount of raw energy only existed in nature about 10 billionths of a second to about a millionth of a second after the Big Bang, when the temperature was approximately 3.6 trillion degrees Fahrenheit (2 trillion degrees Celsius(opens in new tab)). During this brief, early period, the baby universe was filled with a form of matter known as a quark–gluon plasma, a particle soup of free-floating quarks and gluons. As the temperature and pressure quickly dropped as the baby universe expanded, the quarks became bound together, forming hadrons that ultimately formed the basis of all visible matter that we see today in the cosmos, from stars and galaxies to planets and people. Although the quark–gluon plasma only existed 13.8 billion years ago in the immediate aftermath of the Big Bang, scientists have successfully recreated it in particle accelerator experiments by smashing two heavy nuclei, such as that of lead, into each other close to the speed of light. The first time that this was achieved was at CERN's Super Proton Synchrotron(opens in new tab) in 2000. As such, studying quark-gluon plasmas in particle accelerator experiments is an important way of better understanding the conditions in the universe in the aftermath of the Big Bang(opens in new tab)."

This earlier article discussed the Periodic Table. https://forums.space.com/threads/atoms-what-are-they-and-how-do-they-build-the-elements.58433/

None of this shows how BB cosmology created the inflaton, dark matter, or dark energy or how the early quark-gluon plasma evolved into the universe we do see today.
 
Nov 19, 2021
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Quarks cannot be removed from a nucleon simply because the amount of energy require to pull one away is in excess of the energy required to create one. So as fast as you pull them away, like a string full of beads, they keep reappearing.
 
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Quarks cannot be removed from a nucleon simply because the amount of energy require to pull one away is in excess of the energy required to create one. So as fast as you pull them away, like a string full of beads, they keep reappearing.
billslugg, does your comment indicate the quark-gluon plasma for the early universe was real in nature as the BB model and this article presents? Is there a problem with particle experiments claiming they can recreate this early universe condition; thus, this becomes evidence for BBT?
 
Nov 19, 2021
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We know from collider experiments what the energies of the quarks are and why free quarks cannot exist in today's environment.
If one extrapolates backward in time, to very high energies then I suppose there could have been a time when the energies were so high that quarks could have been in a free state, but that does not comprise "evidence". It is simply an educated guess.
 
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My post #2 provides a quote from the article and it does not present the quark-gluon soup as an *educated guess* :) It gives the impression that the collider experiments *confirm* BBT here, thus evidence for this early universe condition, apparently in the period 10^-10 s to 10^-6 s after BB and well before the formation of the CMBR. That brief period for the quark-gluon plasma is long after the inflation epoch with the inflaton too.

"Although the quark–gluon plasma only existed 13.8 billion years ago in the immediate aftermath of the Big Bang, scientists have successfully recreated it in particle accelerator experiments by smashing two heavy nuclei, such as that of lead, into each other close to the speed of light."

Comments like this in the space.com report look far more than an extrapolation from the present but looks like experimental confirmation for the BBT, quark-gluon plasma said to exist from where our universe evolved and also people :).
 
This article seems to miss explaining one of its statements.

If a proton is made up of 2 up and 1 down quark, and a neutron is made up of 1 up and 2 down quarks, and an electron is not made of quarks, but is instead another elementary particle, then now do neutron stars compress protons and electrons into neutrons, and how do atoms that beta decay emit an electron while turning one of the neutrons in the nucleus into proton?

One plausible answer is that they are all made of even smaller particles, but that is speculative. See https://www.quora.com/Are-electrons-made-from-quarks where one answer says:

"In the Standard Model of particle physics, quarks are fundamental particles. So no, they do not have smaller constituents.

"It is, however, possible to go one level deeper mathematically, while preserving all the desirable symmetry properties of the quark picture. In the so-called preon model, all the known fermions: leptons like the electron and its neutrino, and quarks, are composite particles made up from different permutations of two preons, one neutral, the other carrying 1/3rd unit of electric charge.

"However, it must be emphasized that this is a purely speculative model with no experimental support whatsoever."
 
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Here is another interesting report showing the quantum universe that existed long before the CMBR appears as light in BBT. Can cosmic inflation be ruled out?, https://phys.org/news/2022-11-cosmic-inflation.html

ref - The Challenge of Ruling Out Inflation via the Primordial Graviton Background, https://iopscience.iop.org/article/10.3847/2041-8213/ac9b0e, 03-Nov-2022. "Abstract Recent debates around the testability of the inflationary paradigm raise the question of how to model-independently discriminate it from competing scenarios..."

My observation. This report shows when the exotic physics for BB model is extrapolated back to Planck time and Planck scale, we have a temperature some 10^32 degrees and cosmic graviton background appears. This is well before the quark-gluon plasma phase of the BB model some 10^-10 to 10^-6 s after BB event. Some interesting quantum insights appear now examining the BB model. So, from Plank time to 10^-6 s after BB, many interesting physics used in the BB model to explain the origin of the universe we see today.
 

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