Symmetry and conservation of momentum

AI Thread Summary
The law of conservation of momentum is consistently upheld and has never been observed to be violated. In quantum mechanics, conservation laws are linked to symmetries, raising the question of whether momentum conservation is a result of existing symmetries or if symmetries arise from the conservation law itself. The discussion suggests that the relationship may be complex, with possibilities including a mutual existence or even the idea that neither condition is strictly necessary. This interplay between symmetry and conservation laws remains a topic of interest in physics. Ultimately, the nature of this relationship invites further exploration and debate.
verdigris
Messages
118
Reaction score
0
The law of conservation of momentum has never been observed to be violated.In quantum mechanics conservation laws relate to symmetries.So is the existence of the law of conservation of momentum
due to the fact that a symmetry exists, or does a symmetry exist because the law of conservation of momentum exists?
 
Physics news on Phys.org
I think the answer is just yes.
 
... or even 'neither'.
 
The rope is tied into the person (the load of 200 pounds) and the rope goes up from the person to a fixed pulley and back down to his hands. He hauls the rope to suspend himself in the air. What is the mechanical advantage of the system? The person will indeed only have to lift half of his body weight (roughly 100 pounds) because he now lessened the load by that same amount. This APPEARS to be a 2:1 because he can hold himself with half the force, but my question is: is that mechanical...
Hello everyone, Consider the problem in which a car is told to travel at 30 km/h for L kilometers and then at 60 km/h for another L kilometers. Next, you are asked to determine the average speed. My question is: although we know that the average speed in this case is the harmonic mean of the two speeds, is it also possible to state that the average speed over this 2L-kilometer stretch can be obtained as a weighted average of the two speeds? Best regards, DaTario
Some physics textbook writer told me that Newton's first law applies only on bodies that feel no interactions at all. He said that if a body is on rest or moves in constant velocity, there is no external force acting on it. But I have heard another form of the law that says the net force acting on a body must be zero. This means there is interactions involved after all. So which one is correct?

Similar threads

Back
Top