I was looking over some lecture videos on YouTube the other day and came across this good one on effective field theory in physics. It's a graduate level course, but the introductory lecture shouldn't be too difficult to follow even if you haven't taken a lot of physics ‒ most of the theories are just mentioned by name. Be warned: it is a genuine physics lecture so it's just a professor with a chalkboard. I thought it might give some insight into my frequent references to effective theory (e.g.