• Question: what are a quarks and gluons?

    Asked by anon-217089 to Savannah on 17 Jun 2019.
    • Photo: Savannah Clawson

      Savannah Clawson answered on 17 Jun 2019:

      Quarks and gluons are some of the fundamental particles that make up our Universe. More specifically, these are the particles of what we call the “strong force” and they all carry a “colour” charge. You can think of the colour charge in the same way that some particles have an electric charge, they just act through different forces. We have four types of force that we know of: strong, weak, electromagnetic, and gravitational.
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      The particles that we are used to seeing around us are made up of quarks and gluons. For example, the nuclei of the atoms that build everything around us are made from protons and neutrons. These protons and neutrons are themselves made from quarks and gluons. A proton has two “up” quarks and one “down” quark, whereas a neutron has one up quark and two down quarks.
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      Quarks and gluons are just some of the particles that make up our current understanding of particle physics – this is called the “Standard Model”. If you’d like to know more about all of these particles, check out this link https://home.cern/science/physics/standard-model 🙂

Comments

  • Photo: Harrison

    Harrison commented on :

    Savannah gave a great summary, as always! Let me just add a few amazing facts. In energy units, the mass of the proton is 938 million electron-volts (MeV). Although the proton is a very complicated thing, it can be thought of as a thing with two up quarks, one down quark, and many gluons. The gluons have zero mass, while the quarks have mass. You might therefore think that the mass of the proton is simply the sum of the masses of the 2 up quarks + 1 down quark. But, we have determined that the total mass of these quarks is only about 10 MeV! So, where does the 928 MeV come from? The absolutely beautiful thing is that the 928 MeV comes from energy, E, in accordance with Einstein’s famous formula m = E / c^2. That is, 99% of the mass of the proton is due to the energy of motion of the gluons! The 1% of the mass due to the quarks is determined by the Higgs field (at least according to our current understanding). In summary, 99% of the visible mass of the Universe arises from pure energy and 1% from the Higgs field. I would love that it would turn out that our Higgs hypothesis is wrong and that the remaining 1% is also due to energy!