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ejproducts
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I am not a physics student - I am a science fiction writer. But an idea is puzzling me, and I will attempt to convey it. However, I apologise if my terminology or an incorrect understanding of things makes my question unclear.
Firstly, I am under the impression that the laws of physics do not care which way the arrow of time is going - they make sense either way. We set the arrow of time when we use equations, but in theory it would not matter if we set it forwards or backwards. In other words, it is my understanding that there is no basic process that is not the same forwards as backwards.
Secondly, I am under the impression that some quantum processes have an objectively random outcome (sometimes I hear this called a stochastic process). It is not that we do not know enough information about the situation to predict the outcome, but that until the outcome occurs only the probability of the outcome is determined - whether by us or by LaPlace's demon.
It is my understanding therefore that an objectively random process has a state where the next state is not definitively predictable (but has a predictable probability) but the next state, when it occurs, can be known. The example I was given was that in the double-slit experiment in which a detector is placed at one slit, it cannot be determined beforehand through which slit a photon will travel, but afterwards it is known which slit it went through.
If this is the case, is this process the same under time-reversal? And if it is, does that entail that there is a state which can be clearly known one moment, and then the next moment that previous state becomes only known as a probability? That is, if an event with a random outcome has a knowable outcome, can a knowable state become random in respect to future observers?
Thank you for any replies, and I understand if, instead of answering my question, you correct my understanding on any topic raised.
Firstly, I am under the impression that the laws of physics do not care which way the arrow of time is going - they make sense either way. We set the arrow of time when we use equations, but in theory it would not matter if we set it forwards or backwards. In other words, it is my understanding that there is no basic process that is not the same forwards as backwards.
Secondly, I am under the impression that some quantum processes have an objectively random outcome (sometimes I hear this called a stochastic process). It is not that we do not know enough information about the situation to predict the outcome, but that until the outcome occurs only the probability of the outcome is determined - whether by us or by LaPlace's demon.
It is my understanding therefore that an objectively random process has a state where the next state is not definitively predictable (but has a predictable probability) but the next state, when it occurs, can be known. The example I was given was that in the double-slit experiment in which a detector is placed at one slit, it cannot be determined beforehand through which slit a photon will travel, but afterwards it is known which slit it went through.
If this is the case, is this process the same under time-reversal? And if it is, does that entail that there is a state which can be clearly known one moment, and then the next moment that previous state becomes only known as a probability? That is, if an event with a random outcome has a knowable outcome, can a knowable state become random in respect to future observers?
Thank you for any replies, and I understand if, instead of answering my question, you correct my understanding on any topic raised.