The discussion revolves around the intuition behind Lagrangians and the concept of action, with a focus on their general applicability beyond classical mechanics, including quantum field theory.
Participants generally agree on the utility of Lagrangians as calculational tools and their connection to variational principles, but there is no consensus on a singular intuitive understanding of the concepts.
Some assumptions about the foundational principles of Lagrangians and action are not explicitly stated, and the discussion does not resolve the nuances of their applications across different fields.
dextercioby said:In a nutshell, they are very handy calculational tools, especially when doing quantum field theory, one of the 2 most successful theories of physics. Intuition is built once you read the proper sources. I'd consider Landau&Lifshits' classical mechanics gem.
Hi, I definitely subscribe this but I would like to add: Lagrangians are nothing else but the formulation and application of a variational principle. It works since nature seems to use the shortest path. It begins from classical mechanics of some particles, is great if you come then to field lagrangians and they are used in classical mechanics and QFT wildely.hideelo said:The title sort of says it all, but I'll clarify a bit. Is there any intuition for what Lagrangians are and what action is. I'm asking in all generality, not just for classical mechanics.
I'll check it outdextercioby said:In a nutshell, they are very handy calculational tools, especially when doing quantum field theory, one of the 2 most successful theories of physics. Intuition is built once you read the proper sources. I'd consider Landau&Lifshits' classical mechanics gem.