Member 1305
1 entry
16711 views

 RSS
Dave Timmerman (M, 40)
Amsterdam, NL
Immortal since Jan 2, 2008
Uplinks: 0, Generation 2
  • Affiliated
  •  /  
  • Invited
  •  /  
  • Descended
  • Recently commented on
    From Lateralis
    The Soul; part of the...
    From lula_assassina
    Shoot up: God's...
    From rene
    SpaceCollective’s first...
    From jo be
    open forum discussion:...
    From paulteagan
    New years resolution: stop...
    Now playing SpaceCollective
    Where forward thinking terrestrials share ideas and information about the state of the species, their planet and the universe, living the lives of science fiction. Introduction
    Featuring Powers of Ten by Charles and Ray Eames, based on an idea by Kees Boeke.
    The Standard Model that explains what the world is and what holds it together.
    It is a simple and comprehensive theory that explains all the hundreds of
    particles and complex interactions with only:


    • 6 quarks.

    • 6 leptons. The best-known lepton is the electron.

    • Force carrier particles, like the photon.




    All the known matter particles are composites of quarks and leptons,
    and they interact by exchanging force carrier particles.

    ON QUARKS

    Quantum mechanics, quarks... Silly names, but easily remembered and very attractive to the human impulse to fantasize.


    There are six quarks, but physicists usually talk about them in terms of three pairs: up/down, charm/strange, and top/bottom. (Also, for each of these quarks, there is a corresponding antiquark.) Quarks have the unusual characteristic of having a fractional electric charge, unlike the proton and electron, which have integer charges of +1 and -1 respectively. Quarks also carry another type of charge called color charge.

    The naming of quarks began when, in 1964, Murray Gell-Mann and George Zweig suggested that hundreds of the particles known at the time could be explained as combinations of just
    three fundamental particles. Gell-Mann chose the name "quarks," pronounced "kworks," for these three particles, a nonsense word used by James Joyce in the novel Finnegan's Wake:
    "Three quarks for Muster Mark!"

    In order to make their calculations work, the quarks had to be assigned fractional electrical charges of 2/3 and -1/3. Such charges had never been observed before. Quarks are never observed by themselves, and so initially these quarks were regarded as mathematical fiction. Experiments have since convinced physicists that not only do quarks exist, but there are six of them, not three.



    Composite particles made of quarks are called Hadrons.

    Although individual quarks have fractional electrical charges, they combine such that hadrons have a net integer electric charge. Another property of hadrons is that they have no net color charge even though the quarks themselves carry color charge.

    There are two classes of hadrons
    1. Baryons - are any hadron which is made of three quarks (qqq). Protons and neutrons are baryons.
    2. Mesons -contain one quark (q) and one antiquark (q-). The sum of the mass of the independend quarks in a hadron is far less than the mass of the hadron they spawn. The mass is mostly there because of the kinetic and potential energy of the quarks converted to mass (A=mc2).

    ON LEPTONS

    The other type of matter particles are the leptons. There are six leptons, three of which have electrical charge and three of which do not. They appear to be point-like particles without internal structure. The best known lepton is the electron (e-). The other two charged leptons are the muon(m-) and the tau(t-), which are charged like electrons but have a lot more mass.
    The other leptons are the three types of neutrinos (v). They have no electrical charge, very little mass, and they are very hard to find.

    Leptons are divided into three lepton families: the electron and its neutrino, the muon and its neutrino, and the tau and its neutrino.

    ON FUNDAMENTAL FORCES

    There are four fundamental interactions (forces):

    • Gravitation

    • Electromagnetism

    • Weak interaction

    • Strong interaction


    You can think about forces as being analogous to the following situation: Two people are standing on an ice pond. One person moves their arm and is pushed backwards; a moment later the other person grabs at an invisible object and is driven backwards. Even though you cannot see a basketball, you can assume that one person threw a basketball to the other person because you see its effect on the people.

    It turns out that all interactions which affect matter particles are due to an exchange of force carrier particles, a different type of particle altogether. These particles are like basketballs tossed between matter particles (which are like the basketball players). What we normally think of as "forces" are actually the effects of force carrier particles on matter particles.

    One important thing to know about force carriers is that a particular force carrier particle can only be absorbed or produced by a matter particle which is affected by that particular force. For instance, electrons and protons have electric charge, so they can produce and absorb the electromagnetic force carrier, the photon. Neutrinos, on the other hand, have no electric charge, so they cannot absorb or produce photons.

    Check the following pages for more information:
    Wed, Jan 2, 2008  Permanent link

      RSS for this post
      Promote (2)
      
      Add to favorites (1)
    Synapses (1)
     
          Cancel