A quark’s color can be red, green, or blue. That’s fine. A quark’s flavor is, well… strange. Or charm, up, down, top, or bottom. How did scientists come up with such odd flavors?
Quark flavors don’t even remotely make sense because quarks don’t taste like anything: taste and smell is something molecules (a lot bigger than quarks) do. What scientists call “flavor” of a quark is just a feature of these particles, like electric charge.
During the 60s, physicists knew a whole lot of particles, with no reason or rhyme to them. Until people discovered quarks, small particles that make up larger particles, like protons or neutrons (called hadrons). What type of quarks combine determine what particle forms (a proton? a neutron? a Delta baryon?) Thanks to quarks, people started formulating a nice, clean model that made sense of the particles zoo: the standard model.
For the math to work out well, the model needs six types of quarks: up, down, strange, charm, top, and bottom (the song helps…). Just calling them “type” can be confusing because it’s too generic—and there’s other ways to classify quarks, like color. Luckily, the scientific community decided that one strange, made up word (quark) was enough for a while, and called the types “flavors”.
Color has a similar story: quarks are too small to reflect light and get a color we can see. Unlike flavor, however, quark colors at least make some sense.
As people figured out how quarks form protons and neutrons, they realized that it always takes three quarks, which must be all different in some quantum way. This, physicists thought, resembles how red, green, and blue light combines to form white light. So they called this property “color”, because it takes a “red”, a “blue”, and a “green” quark to make a complete “white” particle.
So quarks have colors and flavors that we cannot see or taste. It seems that, to make sense of the quantum weirdness, we need to anchor ourselves in what we can understand, albeit with strange metaphors.
PhysicalLove 