Is time reversible in Quantum Math?

[jimzarry]

In a "Briefer History of Time" Hawking says what everybody else does: that the laws of physics do not indicate a preference for time running forward or backward. He says that the forward direction may be required somehow by the increase of entropy from the highly ordered state of the singularity prior to the Big Bang. That doesn't do it for me as an explanation because the degree of entropy seems like an observation of the state of things rather than a fundamental law.

Going forward, Quantum Mathematics describeRs a particle's velocity/position using a probability wave which collapses when viewed by an observer in the present moment. I think this means that an observer (at the present moment) has created an irreversible change which doesn't seem like it would work in reverse. Like the particle that decayed randomly, triggering a geiger counter click, which released the gas that killed the cat. Since Quantum events are defined by probability waves going forward, do events that have occurred revert to probabilities when time is reversed? In Quantum terms it seems like the future is undefined and the past is solidified. Does Quantum math distinguish between the past and the future?

 

[James Leighe]

That doesn't do it for me as an explanation because the degree of entropy seems like an observation of the state of things rather than a fundamental law.

http://en.wikipedia.org/wiki/Arrow_of_time
That may have some information about why time moves one way and not the other. I don't think there is a very satisfactory answer here :(

Since Quantum events are defined by probability waves going forward, do events that have occurred revert to probabilities when time is reversed?

Yes, but if you knew those events were observed you could plug that in. (there is likely some subtleties here)

In Quantum terms it seems like the future is undefined and the past is solidified

We can't guess what happened in the past any more that we can guess what will happen in the future with QM. (see above)

Does Quantum math distinguish between the past and the future?

I don't know of any time symmetry violations, but I'm not sure.

I'm not so super good at this stuff like some of these guys here, but I took a shot at it.

 

[Entropia]

I can say that the concept of time reversibility in quantum mathematics is a complex and ongoing topic of research. While the laws of physics do not indicate a preference for the direction of time, our current understanding of quantum mechanics does suggest that time reversibility may not be possible.

As the content mentions, the concept of entropy and the increase of disorder in the universe is often used to explain the apparent directionality of time. However, this is still a debated topic and not fully understood. Additionally, the concept of time in quantum mechanics is different from our everyday experience of time, and it is still an active area of research.

In terms of quantum events, they are described by probabilities and can only be observed or measured in the present moment. This means that once an observation is made, the probability wave collapses and the event becomes fixed in time. This does not necessarily mean that time itself is irreversible, but rather that our ability to observe and measure events is limited.

Furthermore, the idea of time reversal in quantum mechanics is closely tied to the concept of causality. In the example given, the decay of a particle leading to the death of a cat is a causal relationship, and it is difficult to imagine this happening in reverse. However, there are theories and experiments that suggest that time-reversed causality may be possible at the quantum level, but this is still a highly debated topic.

In conclusion, the concept of time reversibility in quantum mathematics is a complex and ongoing topic of research. While our current understanding suggests that time may not be reversible at the quantum level, it is important to continue studying and exploring this concept to further our understanding of the universe.