James Fodor

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3,084 appearances 4 recordings 1 series first heard Jun 2026 last heard 30 Aug

James Fodor’s voice in public audio — every appearance, attributed to the second.

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Recordings per month over the last 12 months — 4 in all, peaking in Aug 2026 with 2.

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The Science of Everything Podcast · Episode 163: The Standard Model of Particle Physics · 8 Aug 2026 podcast

They can have five or even theoretically more than that.

But usually they have three and they form the protons and neutrons.

So we'll just talk about it in those terms for simplicity.

Composite particles that are comprised of a quark and an antiquark are called mesons and they have very different properties to um to hadrons and uh they're not stable for a long period of time.

The strong nuclear force is so-called because it's uh quite strong.

So uh the strength is hard to measure because it depends on the distance, but um at the scale of quarks, comparing it to electromagnetism, it's about sixty times stronger.

Uh and that's one of the reasons why the protons uh are held together in the nucleus, because although they're being uh pushed apart by the electromagnetic force, the uh of repulsion of all those positive charges, the force holding them together

The strong nuclear force is stronger, so it uh it overcomes that.

Of course, you know, it depends on the size of the nucleus and how many positive charges you have.

Um, but broadly speaking, the strength of the strong force is one of the things that allows nuclei to be stable.

So, one additional wrinkle to mention at this point, I've talked about quarks in general terms and talked about how they have a color charge.

you know, red, green, and blue, and they need to combine together to give a color neutral composite particle.

But I haven't told you about the different types of quarks.

The quarks that make up protons and neutrons, at least in in most cases, are called up and down quarks.

So there's two types.

Up quarks have a positive fractional charge, so positive two thirds, and down quarks have a negative fractional charge of negative one third.

So that gives uh rise to the difference between protons and neutrons.

If you have one up quark and two down quarks, then those charges cancel out and you have a neutral composite particle.

So that is a neutron.

On the other hand, if you have two up quarks and one down quark, you have a total charge of positive one, and that is a proton.

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