Time Symmetry and Matter/Energy Conservation

In summary, Noether's theorem states that every conservation law implies an underlying symmetry. The spatial symmetry is responsible for the conservation of momentum (and angular momentum if you include space anisotropy).
  • #1
Rodney Flores
9
0
I recently posted a question on energy and matter and I got a very good answer to that one so I thought another one wouldn't hurt. I understand that time symmetry is what makes all conservation laws possible as is stated in Noether's theorem. Time symmetry is what explains the conservation of matter and energy and in part also unifies the two. Because time symmetry doesn't change the way it works, and energy and matter do, would the symmetry of space not change as well?
 
Physics news on Phys.org
  • #2
Rodney Flores said:
I recently posted a question on energy and matter and I got a very good answer to that one so I thought another one wouldn't hurt. I understand that time symmetry is what makes all conservation laws possible as is stated in Noether's theorem. Time symmetry is what explains the conservation of matter and energy and in part also unifies the two. Because time symmetry doesn't change the way it works, and energy and matter do, would the symmetry of space not change as well?

Er.. correction. The time symmetry is relevant to NOT ALL conservation laws, only the conservation of energy+mass!

The spatial symmetry is responsible for the conservation laws we see for momentum (and angular momentum if you include space anisotropy).

Noether theorem applies to not just energy conservation. It simply states that in the most general form, every conservation laws implies an underlying symmetry. So each conservation law has its own symmetry principle. You should not use one symmetry principle for all conservation laws that might not be appropriate.

Zz.
 
  • #5
oh no my mistake, I said "time" symmetry and when I really ment "underlying" symmetry, exactly in the sense in which you have stated Zapper (the underlying symmetry of every conservation law). Sorry for the confusion, so there is "spacial symmetry" as you have stated, is it distinct from time symmetry? (Thank you for the sources) :)
 

1. What is time symmetry?

Time symmetry refers to the idea that the laws of physics should remain unchanged regardless of the direction in which time flows. This means that if we were to reverse the direction of time, the same physical processes and interactions should occur in the same way.

2. How does time symmetry relate to matter and energy conservation?

Time symmetry is closely linked to the principle of conservation of matter and energy. This is because if the laws of physics are the same in both directions of time, then energy and matter must be conserved in both directions as well. In other words, the total amount of matter and energy in a closed system should remain constant regardless of the direction of time.

3. What evidence supports the idea of time symmetry and conservation of matter/energy?

One of the key pieces of evidence for time symmetry and conservation of matter and energy comes from the study of fundamental particles and their interactions. These interactions are governed by well-established laws of physics, such as the laws of thermodynamics, which hold true regardless of the direction of time. Additionally, experiments such as the conservation of momentum and energy in particle collisions also support the idea of time symmetry and conservation.

4. Are there any exceptions to time symmetry and conservation of matter/energy?

While time symmetry and conservation of matter and energy are fundamental principles in physics, there are some exceptions to these laws. One example is in the field of quantum mechanics, where certain particles can violate the conservation of energy for brief periods of time. However, these violations are still within the bounds of the uncertainty principle and do not fundamentally challenge the concept of time symmetry and conservation.

5. How does time symmetry and conservation of matter/energy impact our understanding of the universe?

The principles of time symmetry and conservation of matter and energy are crucial in our understanding of the universe and the laws that govern it. These principles allow us to make predictions and calculations about physical systems and to understand the fundamental processes that drive the universe. They also play a key role in theories such as the Big Bang, which rely on the concept of conservation of matter and energy to explain the origins and evolution of the universe.

Similar threads

I Does mass conservation correspond to a pseudo-symmetry?
    • Classical Physics
Replies
6
Views
732
I No symmetries in the Universe at the Big Bang...?
    • Cosmology
Replies
5
Views
1K
I Types of symmetries in Lagrangian mechanics
    • Mechanics
Replies
3
Views
909
Symmetry associated with current conservation
    • Electromagnetism
Replies
6
Views
1K
I Noether's second theorem: two questions
    • Special and General Relativity
Replies
7
Views
1K
I Time reversal symmetry in physics
    • Other Physics Topics
Replies
11
Views
3K
I Could the Lorentz symmetry be theoretically broken in vacuum?
    • Beyond the Standard Models
Replies
3
Views
2K
I Consequences of the absence of global symmetries...?
    • Beyond the Standard Models
Replies
6
Views
1K
I Lagrangian symmetry for the bullet and gun
    • Mechanics
Replies
7
Views
756
Does time translational symmetry imply H'=0 or E'=0?
    • Other Physics Topics
Replies
4
Views
1K

Hot Threads

Recent Insights

Back
Top