3 ms·
You may be interested to know that both Maxwell's and the Einstein Field Equations can be derived by minimizing an action, cf. https://en.wikipedia.org/wiki/Ei
by vhffm 6y ago
You may be interested to know that both Maxwell's and the Einstein Field Equations can be derived by minimizing an action, cf.
https://en.wikipedia.org/wiki/Einstein%E2%80%93Hilbert_action https://en.wikipedia.org/wiki/Einstein%E2%80%93Hilbert_actio...
https://en.wikipedia.org/wiki/Electromagnetic_tensor#Lagrangian_formulation_of_classical_electromagnetism https://en.wikipedia.org/wiki/Electromagnetic_tensor#Lagrang...
Enjoy!
- evanb 6y agoWell, sure, but that only pushes the question back one step further: who told you which action to pick? Why pick R and not R^2, for GR, for example? [ Just to avoid someone spending too much time on an explanation IAAPhysicist; yes I understand effective field theory and the preference for Lagrangians built from relevant/marginal operators. ]
- sideshowb 6y agoCan't you get there by assuming electrical effects propagate at the speed of light as well? And magnetism falls out as a result?