Source: cirosantilli/quantum-field-theory-lecture-by-tobias-osborne-2017/lecture-2

= Lecture 2

https://www.youtube.com/watch?v=bTcFOE5vpOA&list=PLDfPUNusx1EpRs-wku83aqYSKfR5fFmfS&index=2

* the advantage of using <Lagrangian mechanics> instead of directly trying to work out the equations of motion is that it is easier to guess the Lagrangian correctly, while still imposing some fundamental constraints
* https://youtu.be/bTcFOE5vpOA?list=PLDfPUNusx1EpRs-wku83aqYSKfR5fFmfS&t=3375
  * <Lagrangian mechanics> is better for <path integral formulation>. But the <mathematics> of that is fuzzy, so not going in that path.
  * <Hamiltonian mechanics> is better for non-<path integral formulation>
* https://youtu.be/bTcFOE5vpOA?list=PLDfPUNusx1EpRs-wku83aqYSKfR5fFmfS&t=3449 Hamiltonian formalism requires finding conjugate pairs, and doing a