- #1

Trying2Learn

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- TL;DR Summary
- Why is it not magic?

I understand the process of the calculus of variations.

I accept that a proper Lagrangian for Dynamics is "Kinetic minus potential" energy.

I understand it is a principle, the same way F=ma is a law (something one cannot prove, but which works)

Still... what do you say to students who say "I get the Calculus of Variations and HP, but it feels like magic."

Do you say "It is because you have been indoctrinated with vectorial dynamics and you have never seen analytical dynamics?"

Even in Feynman's notes, he talks about how he was startled by this and how he reasoned that it was natural and good.

Still... the students say "it seems like magic?"

Without rationalizing why the Lagrangian SHOULD be L = T- V, what would you say to people who say (at first glance) it seems like magic?

I accept that a proper Lagrangian for Dynamics is "Kinetic minus potential" energy.

I understand it is a principle, the same way F=ma is a law (something one cannot prove, but which works)

Still... what do you say to students who say "I get the Calculus of Variations and HP, but it feels like magic."

Do you say "It is because you have been indoctrinated with vectorial dynamics and you have never seen analytical dynamics?"

Even in Feynman's notes, he talks about how he was startled by this and how he reasoned that it was natural and good.

Still... the students say "it seems like magic?"

Without rationalizing why the Lagrangian SHOULD be L = T- V, what would you say to people who say (at first glance) it seems like magic?