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> My dad used something called variational calculus to solve physics problems. It's beyond my understanding, but I gather it was more useful in the slide rule d
by admissionsguy 5y ago
> My dad used something called variational calculus to solve physics problems. It's beyond my understanding, but I gather it was more useful in the slide rule days
In (theoretical) physics, variational calculus is such a basic tool, it is no more obsolete than trigonometry! It's also quite mind-blowing and beautiful, how a single quantity (the Lagrangian) contains all information needed to derive complete equations of motion for a system, or the correspondence between symmetries and conserved quantities via Noether's theorem.
- immmmmm 5y agoas a former physicist i couldn't agree more. in fact you can construct a lagrangian almost uniquely from the underlying symmetries of the system. it's literally the most used tool in theoretical physics, and it's so powerful and elegant that actually convinced myself to do physics in the first place.
- wyager 5y agoI would argue that it seems quite likely that Lagrangian mechanics is more fundamental, in some sense, than any other classical formulation. The path integral formulation gives you a mathematical trick for understanding how the lagrangian “generates” other physical models (like Newtonian physics) via its effect on action/phase.