Can the Variational Principle Explain the Laws of Nature for Classic Fields?

AI Thread Summary
The discussion centers on the application of the variational principle to classical fields, questioning its validity and underlying motivations. It highlights that the variational principle, which minimizes the action, is effective for both point particles and classical fields, linking it to Newton's laws and the Euler-Lagrange equation. Participants ponder whether this principle is a fundamental law of nature that cannot be derived, similar to Newton's laws, and seek further reading on the topic. The notion that the universe operates in a "lazy" manner is also mentioned, reflecting a personal interpretation of the principle. Overall, the conversation explores the philosophical and theoretical implications of using the variational principle in physics.
Phymath
Messages
183
Reaction score
0
I'm trying to understand why you can get away with using the variational principle on classic fields at all. The variational principle says minimize some value of a function the action. This idea is for point particles and is also motivated by the fact that Newton's laws can be derived via the action principle also be used to prove the validity of the Euler-Lagrange function, and also vice versa Newtons laws can be used to derive the Euler-Lagrange equation for classic particles. So how is it at all possible that variation of a field in a local area gives the correct formulation of the laws of nature, is there any reason this works and any motivations that this should work?

Is this just a law of nature that can not be derived similar to Newtons laws being simply stated and unprovable without experimentation. Any book suggestions would also be useful
 
Physics news on Phys.org
a posteriori justification aint so bad
 
I took the variational principle to simply mean the universe, and everything in it, is as lazy as possible. This is in agreement with my personal experience since I am as lazy as possible as well.
 

Thread 'The Physics of unloading sand from a barge'

I think it's easist first to watch a short vidio clip I find these videos very relaxing to watch .. I got to thinking is this being done in the most efficient way? The sand has to be suspended in the water to move it to the outlet ... The faster the water , the more turbulance and the sand stays suspended, so it seems to me the rule of thumb is the hose be aimed towards the outlet at all times .. Many times the workers hit the sand directly which will greatly reduce the water...
View full post »

Similar threads

I Can the Principle of Least Action Unify Different Branches of Physics?
Replies
5
Views
2K
A Why does the principle of stationary action work?
Replies
3
Views
2K
A Is there a principle of stationary action for QFT?
Replies
8
Views
2K
I Noether's second theorem: two questions
Replies
7
Views
3K
A Boundary conditions in ##\delta I=0## to derive Einstein's equations
Replies
8
Views
1K
A Can position and velocity vary independently in Hamilton's Principle?
Replies
2
Views
1K
Principle of least action as a law?
Replies
19
Views
4K
I How can concentration gradient field come into existence immediately?
Replies
1
Views
3K
I Is there a way in Lagrangian mechanics to incorporate the inertial response from initial momentum when using initial conditions instead of BCs?
Replies
9
Views
917
I Action in Lagrangian Mechanics
Replies
5
Views
2K

Hot Threads

Recent Insights

Back
Top