The Strange Charm of Quantum Electrodynamics
Quantum Electrodynamics (QED) is a model in physics that describes the very small.
At very small scales, reality is built up like Lego. Atom nuclei are made of protons and neutrons, which in turn are made of quarks. Imagine 3 small lego bricks – say 2 blues and a red – and join them together to form a larger “proton block.” Or a “neutron block” formed by 2 red and 1 blue. The larger blocks have an individual identity and a combined identity.
Electrons however, are believed to be fundamental (in this analogy they would be small bricks that don’t connect to anything). This analogy doesn’t give an idea of relative size, but can be used to create an image of what is occurring at very small scales.
Physicists are literally creative.
Now, these quarks would obviously be named so that their significance was evident. Obviously. So, the 6 flavours (different types with slightly altered properties) of quarks are called:
Excited…? Well, not so much.
Spin me right round.
Let’s take a real quick detour so I can explain the spin of a particle. Unlike a lot of quantum mechanics, there’s not an everyday comparison – it’s not, for example, a description of how fast the particle spins. It’s an anachronism from when we had a lesser understanding of the universe.
However, it follows some of the mathematical descriptions of angular momentum (like linear momentum, but how the object is spinning), and so the name remains.
You can have spin up or spin down with a magnitude attached – like a vector. While a particle can switch between spin up and down, the magnitude will never change.
Up and Down/Physicists are very literal.
As you might expect, the Up and Down quarks are named because they are intrinsically spin up and spin down – always. (Of course the other quarks have spin up and spin down, but Up and Down were named first).
Up and Down are the only stable quarks; the more massive flavours quickly decay into lighter Up and Down quarks.
Using Legos, the outermost shell of colour would fall off the more massive quarks to reveal red or blue (Up and Down quarks) underneath. How the outside world defines them has changed and their properties change too.
The Strange quark was named third and was first discovered in a Kaon – a particle that exists for a “strangely” long time (that’s against a compatible particle; a Kaon has a mean lifetime of only 10-8 s).
Charm has no real meaning in the physical sense. Most believe it was named on a whim – the math worked like a charm.
The loss of Beauty and Truth.
The Top and Bottom quarks were almost called ‘Truth’ and ‘Beauty,’ but were changed after scientists decided that the name was too ridiculous.The names where finally chosen to be analogous to the Up and Down quarks and kept the ‘T’ and ‘B‘ as reference. It suggests that Physicists can only create very literal names!
The Top quark is the heaviest of the six quarks and would weigh as much as an entire gold atom. For comparison, it takes 2 Up and 1 Down quarks to form just one proton.
They’re real, I swear.
Quarks are never found in isolation due to their unique binding properties, and their attributes have been inferred from the particles they make up.
However, they can be modelled to a high degree of accuracy using QED.
If you are able to observe a solitary quark, please email me. I would love a Nobel Prize.