:Yeah, concise to you, a physics major!  But I got here to find out what "action" is so I can understand "Lagrangian".  However, what I got from this is: "action is the integration of the Lagrangian across time", which, being circular, tells me nothing other than that I'm even stupider than I already knew I was.  GIVE EXAMPLES please—even obscure ones, if that's the best you can do for an obscure topic. 

 :Hey, I'm just sayin'...   

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