Does Time Reversal Symmetry Apply to All Interactions?

AI Thread Summary
Time reversal symmetry suggests that the behavior of particles should remain consistent when time is reversed. In the case of two electrons, they repel each other, and reversing time would show them moving towards one another. However, the concept of antimatter implies that positrons, which are the antimatter counterparts of electrons, could attract each other if viewed as matter moving backward in time. This raises questions about whether time-reversal symmetry applies universally to all interactions, particularly in the context of charge interactions. The discussion highlights the complexities of time reversal in particle physics and its implications for our understanding of fundamental forces.
FizX
Messages
9
Reaction score
0
Ok, so if you have two electrons near one another, they will start to repel one another and separate as time goes on. Now if you reverse time, they will move towards one another. But it is said that antimatter can be viewed as matter going backwards through time. Now if this is true, this would mean that two positrons would attract one another, which contradicts the law that like charges repel. Does the time-reversal not apply to all interactions?
 
Space news on Phys.org
FizX said:
Ok, so if you have two electrons near one another, they will start to repel one another and separate as time goes on. Now if you reverse time, they will move towards one another. But it is said that antimatter can be viewed as matter going backwards through time. Now if this is true, this would mean that two positrons would attract one another, which contradicts the law that like charges repel. Does the time-reversal not apply to all interactions?

Remember that momentum gets reversed as well. Picture the two electrons initially far away and moving toward each other. Then they slow down, stop for an instant, and end up moving away from each other.

Film this, run the film in reverse and you will see exactly the same thing.

Regards,
James Baugh
 
oh yeah! wow i can't believe i forgot about that, thanks alot.
 

Thread 'Illuminating Black Hole Shadows with Dark Matter Annihilation'

Abstract The Event Horizon Telescope (EHT) has significantly advanced our ability to study black holes, achieving unprecedented spatial resolution and revealing horizon-scale structures. Notably, these observations feature a distinctive dark shadow—primarily arising from faint jet emissions—surrounded by a bright photon ring. Anticipated upgrades of the EHT promise substantial improvements in dynamic range, enabling deeper exploration of low-background regions, particularly the inner shadow...
View full post »

Thread 'Matter density right after the decoupling'

https://en.wikipedia.org/wiki/Recombination_(cosmology) Was a matter density right after the decoupling low enough to consider the vacuum as the actual vacuum, and not the medium through which the light propagates with the speed lower than ##({\epsilon_0\mu_0})^{-1/2}##? I'm asking this in context of the calculation of the observable universe radius, where the time integral of the inverse of the scale factor is multiplied by the constant speed of light ##c##.
View full post »

Thread 'If the Universe has a cause, what caused that cause?'

Title: Can something exist without a cause? If the universe has a cause, what caused that cause? Post Content: Many theories suggest that everything must have a cause, but if that's true, then what caused the first cause? Does something need a cause to exist, or is it possible for existence to be uncaused? I’m exploring this from both a scientific and philosophical perspective and would love to hear insights from physics, cosmology, and philosophy. Are there any theories that explain this?
View full post »

Similar threads

I Is the CPT-Symmetric Universe Theory the Key to Solving the Antimatter Mystery?
Replies
1
Views
2K
A Does CPT Symmetry Apply to a Mirror World with Reversed Properties?
Replies
5
Views
2K
I Time reversal symmetry in physics
Replies
11
Views
4K
Time-symmetry in electromagnetism: a simple puzzle
Replies
4
Views
2K
I Time Reversal Symmetry in Classical Physics
Replies
11
Views
3K
I Is Quantum Mechanics Truly Time-Reversal Symmetric?
Replies
5
Views
3K
I Does mass conservation correspond to a pseudo-symmetry?
Replies
6
Views
1K
I Are all processes CPT symmetric like measurement, stimulated emission?
Replies
8
Views
2K
I Could the Lorentz symmetry be theoretically broken in vacuum?
Replies
3
Views
3K
Is there a conflict between CPT symmetry and the 2nd law of thermodynamics?
Replies
1
Views
2K

Hot Threads

Recent Insights

Back
Top