Aren't there more quarks than up, down, strange and charm?
There are two more: top and bottom, but they are not part of
What are those squiggles on the quark cards?
Those represent gluons, the particles that transmit the strong nuclear
force between quarks. They are shaped like little springs because the nuclear force gets
stronger as the quarks get farther apart, just as if they were connected by little springs.
What do the arrows on the cards mean, and why do they point up for quarks and down for anti-quarks?
The arrows represent the direction the quarks are traveling through space and time.
They point downward on the anti-quark cards because anti-quarks behave as though they were regular quarks traveling
backward through time.
Why aren't there any electrons (or muons, or neutrinos) in this game?
All of those particles belong to a family of particles called leptons.
They are not part of the QCD game becuase they do not carry a color charge, and so do not experience the
strong nuclear force as quarks do.
Can I figure out the mass of the quarks from E=mc2 and using the
energy printed on the cards?
No. The energy printed on the quark cards only tells you how much energy the
quark contributes to the baryons and mesons. And that depends not only on the mass of the quark, but also on
how the quarks move and interact inside the particles.
Why can't you disintegrate a pion?
In nature, pions disintegrate within a few microseconds of being formed. But in
QCD-The Game, players cannot disintegrate them simply because the energy they would score by doing so would be too
great. Pions have energies of only 140 MeV. So by only scoring pion energy when they annihilate, and then adding
only one card to the energy stack, players score an energy that is within about 7% of the true value.
Why don't the up and down quarks count toward my score when I annihilate or disintegrate kaons?
Because the kaon's energy is only 500 MeV.
Why is the the theory called Quantum Chromodynamics?
The word Quantum signifies that particle characteristics may have
only a limited set of values. For example, the electric charge of a quark can be only
times the electron charge. And, of course,
the color charge has only six possible values. Chromo is the greek word for color, and dynamics
refers to the science of motion and energy.
What is that picture on the box supposed to be?
Almost everything we know about sub-atomic particles comes from so-called
"atom smashers" where beams of high-energy particles collide, producing a zoo of other particles. Photos of the
paths taken by these particles as they pass through special recording chambers look a little bit like the picture
on the box.
Where can I learn more about Physics?