Comments on: Determinism is inconsistent with relativity http://blog.bbbeard.com/2010/07/11/determinism-is-inconsistent-with-relativity/ A Peculiar, Yet Refreshing, Blog Sun, 05 Feb 2012 12:37:37 +0000 http://wordpress.org/?v=2.2.1 By: Tom Cohoe http://blog.bbbeard.com/2010/07/11/determinism-is-inconsistent-with-relativity/#comment-2720 Tom Cohoe Mon, 12 Jul 2010 17:27:43 +0000 http://blog.bbbeard.com/2010/07/11/determinism-is-inconsistent-with-relativity/#comment-2720 I would say that your relativistic indeterminism is not the same thing as quantum mechanical indeterminism. The difference is that even though one observer cannot, in principle, determine an event in his future if it will also be influenced by events outside his past light cone, the requirement for consistency means that only one future is possible, even though it is not determinable, because the future event has to be consistent with all of the influences from its past light cone, which includes those events in spacetime not accessible to the predictor at the time of the prediction. Suppose I am aware of event A and predict from it that either event B or event C will happen, but which one will happen is not then determinable by me, because I do not know which of event D of event E (assume they are mutually exclusive), separated from me by a spacelike interval at the time of my prediction, will influence the result. However, the result must be consistent with whichever of event B or event C has happened in its past. Only one result is actually possible. It is predetermined by the state of the universe before event D or E, but it is not determinable by me because my local nature restricts my access to information (here, I discount the function of quantum mechanics and speak a universe which is only relativistic). This is why I would say that a relativistic universe is <i>indeterminable</i> rather than indeterminate. Now there is a requirement for consistency with quantum mechanics as well, in that the result of an observation at A affects the wavefunction of all entangled entities everywhere, so that observations involving them must be consistent with the observation at A. But in this case, knowledge of the state of the entire universe in the past of event A (rather than just locally accessible information) would still not allow a prediction to be made. So I would say that a QM universe is indeterminate, whereas a relativistic universe is indeterminable. I would say that your relativistic indeterminism is not the same thing as quantum mechanical indeterminism. The difference is that even though one observer cannot, in principle, determine an event in his future if it will also be influenced by events outside his past light cone, the requirement for consistency means that only one future is possible, even though it is not determinable, because the future event has to be consistent with all of the influences from its past light cone, which includes those events in spacetime not accessible to the predictor at the time of the prediction.

Suppose I am aware of event A and predict from it that either event B or event C will happen, but which one will happen is not then determinable by me, because I do not know which of event D of event E (assume they are mutually exclusive), separated from me by a spacelike interval at the time of my prediction, will influence the result. However, the result must be consistent with whichever of event B or event C has happened in its past.

Only one result is actually possible. It is predetermined by the state of the universe before event D or E, but it is not determinable by me because my local nature restricts my access to information (here, I discount the function of quantum mechanics and speak a universe which is only relativistic).

This is why I would say that a relativistic universe is indeterminable rather than indeterminate.

Now there is a requirement for consistency with quantum mechanics as well, in that the result of an observation at A affects the wavefunction of all entangled entities everywhere, so that observations involving them must be consistent with the observation at A.

But in this case, knowledge of the state of the entire universe in the past of event A (rather than just locally accessible information) would still not allow a prediction to be made.

So I would say that a QM universe is indeterminate, whereas a relativistic universe is indeterminable.

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