120 likes | 339 Views
The Quark Theory of Matter. Developed in early 1960s to help explain a proliferation of mysterious subatomic particles found in “atom smashers” [particle accelerators] Further developed up to present day Proton and neutron are no longer “fundamental” particles They are composed of quarks
E N D
The Quark Theory of Matter • Developed in early 1960s to help explain a proliferation of mysterious subatomic particles found in “atom smashers” [particle accelerators] • Further developed up to present day • Proton and neutron are no longer “fundamental” particles • They are composed of quarks • “Free” quarks are not stable, they quickly recombine • Quarks are bound together by “gluons”
Size Scales – a Comparison Virus 10-7 m Molecule 10-9 m Atom 10-10 m Nucleus 10-14 m Proton 10-15 m Electron 10-18 m Quark 10-19 m
The Quarks Name Charge Up (u) +2/3 Down (d) -1/3 Charm (c) +2/3 Strange (s) -1/3 Top (t) +2/3 Bottom (b) -1/3
Proton Neutron d d u u d u • Some particles are composed of 3 quarks (above) • Some particles (mesons, found in cosmic rays) are made of 2 quarks • No single quarks are observed in nature
What we don’t know …. • Why quarks can have “fractional” charge when the electron • (still thought to be “fundamental” has a charge of -1 ? • Whether any of the exotic particles we know about now can account for “dark matter” that we believe is in most galaxies • Whether there really is a graviton … • How to reconcile gravity and quantum/subatomic physics • and lots more besides …stay tuned ….