4 years with electrodynamics
April, 12019
May, 12020
it was the fact that integration (eg: ∇ ⋅ E) on volumes/surfaces work so nicely that that cut each other off when you integrate over smaller volumes vs the whole ; i mean like the divergence theorem etc
the whole small set of equations describing everything, the unification etc
August, 12021
the dance of particles and field with their stress energy momentum tensor
Tᵃᵇ = Tᵃᵇem + Tᵃᵇparticles
it’s components include energy-momentum density: stored in and flown by fields and particles
and the conservation laws: ∂ ₐ Tᵃᵇ = 0 (not sure) which is like divergence of this field is 0,
more field theory stuff like why Tᵃᵇ is symmetric etc
action principle describing everything
A = -c ∫ mds + ∫ A ⋅ dx + ∫ F^ab _ab dV
May, 12022
uniqueness theorems, how the field is a differential 2-form and the Maxwell’s equations are really is set of 2 equations
dF =0 *d * F = J
June, 12023
… trying to do gauge theory and stuff eventually… let’s see