The craziest #physics things I learned that I can’t get out of my head is Wigner’s Classification. In some sense the way particles can be transformed in spacetime define the different types of particles that can exist.

The mathy way of saying this that “irreducible representations of the poincaré group” directly result in the quantum information we can observe and in some sense, the type of particle.

One piece of information about a particle we can know is something called spin. Spin can be understood as the angular momentum of an individual particle. Different types of particles have different spins. Light has integer spin (bosons) and matter has half integer spin (fermions).

Different spins changes the way particles behave. Integer spin particles can stack up on each other and can occupy the same quantum state (light), have integer spin particles can’t occupy the same state (fermi exclusion principle, fermions, get it?)

So just due to the way these particles infinitesimally transform in spacetime (poincaré group) defines the types of particles that exist. Pretty fuckin wild.