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Bio Beats. Class is in session.

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Today we go deeper than the atom. Quarks.

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You stopped at the atom: protons, electrons, that's it?

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There's a basement under that basement, so let's get in it.

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Blow an atom up to the size of a stadium:

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the nucleus is a pea and the rest is all vacuum.

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Protons and neutrons, crammed in that pea,

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but they're not the bottom: each one's built out of three.

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Electrons ride solo, no smaller parts found,

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but crack a proton open: three quarks bouncing around.

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Up, up, down, that's a proton,

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up, down, down, that's a neutron,

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three in a room and they can't get out,

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every atom you touch got 'em, no doubt.

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Now check the charges, this is where it gets absurd:

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up is plus two-thirds, and down is minus a third.

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Two ups and a down add up to plus one:

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that's your proton's charge, every proton under the sun.

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One up, two downs, and it cancels to zero:

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that's the neutron, no charge at all, the quiet hero.

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They carry color charge: red, green, blue,

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not real paint, just a name for the charge behind the glue.

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Gluons hold 'em like a rubber band, see:

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the farther you stretch it, the more it costs in energy.

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Pump in enough and the band goes snap,

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the energy makes new quarks, none escape the trap.

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Up, up, down, that's a proton,

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up, down, down, that's a neutron,

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three in a room and they can't get out,

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every atom you touch got 'em, no doubt.

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Six flavors in the family, here's the list:

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up, down, charm, strange, top, bottom, that's it.

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But the stuff you touch? Just the up and the down;

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the heavy ones decay in a flash, they don't hang around.

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Now put a proton on a scale, and get this:

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the three quarks' own mass is just one percent of it.

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The rest is energy of quarks and glue in motion,

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E equals M C squared, mass made out of commotion.

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So most of your weight isn't stuff, it's energy locked tight

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in three quarks in a room that'll never see the light.

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Up, up, down, that's a proton,

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up, down, down, that's a neutron,

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three in a room and they can't get out,

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every atom you touch got 'em, no doubt.

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So the atom had a basement, and now you've been down:

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three quarks, one room, and the glue holds 'em down.

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Class dismissed.