Note that according to both QM and GR you don’t need to know “all causes”, only the initial state on a given spatial hypersurface, in order to be able to do a Cauchy development of that hypersurface, subject to some rather technical and non-restrictive energy conditions. Whether the initial state can be known exactly depends a fair bit on what one wants to calculate (e.g. a full quantum state, or a classical state). In that sense, one can, at least in theory, predict the behavior of a physical object, including a human, to a high degree of accuracy, though of course never 100%, and the remainder is not related to light cones, just to the uncertainty of one’s state, especially the quantum state.
Still, if another human can predict your actions with high accuracy, though not 100%, how much free will do you really have? 0.1%? Would you be happy with that?
You are right, I should use “all initial state on a given spatial hypersurface” instead of “all causes”, but the conclusion is the same: wherever the hypersurface is, no observer is able to know all the initial state on that hypersurface which can affect event A, except when the observer is in the future of A.
The second question, I think that “high accuracy” is only the upper limit of a prediction, which is not that easy to reach. In oder to make high accuracy prediction, you need a large amount of resources for observations and calculations. The amount of resources can be some kind of measurement of my free will. However, if I have access to that resources, I can make myself much more difficult to predict, e.g. some optical or electric camouflage.
Seems like you are in love with your conclusion and are throwing all supporting evidence into it, which works in a court of law, but not when you are trying to construct accurate models.
Thank you for your comment, but it would be appreciated if you could prove my conclusion is wrong (e.g. either observer B1 or B2 is able to know or predict event C)
Note that according to both QM and GR you don’t need to know “all causes”, only the initial state on a given spatial hypersurface, in order to be able to do a Cauchy development of that hypersurface, subject to some rather technical and non-restrictive energy conditions. Whether the initial state can be known exactly depends a fair bit on what one wants to calculate (e.g. a full quantum state, or a classical state). In that sense, one can, at least in theory, predict the behavior of a physical object, including a human, to a high degree of accuracy, though of course never 100%, and the remainder is not related to light cones, just to the uncertainty of one’s state, especially the quantum state.
Still, if another human can predict your actions with high accuracy, though not 100%, how much free will do you really have? 0.1%? Would you be happy with that?
You are right, I should use “all initial state on a given spatial hypersurface” instead of “all causes”, but the conclusion is the same: wherever the hypersurface is, no observer is able to know all the initial state on that hypersurface which can affect event A, except when the observer is in the future of A.
The second question, I think that “high accuracy” is only the upper limit of a prediction, which is not that easy to reach. In oder to make high accuracy prediction, you need a large amount of resources for observations and calculations. The amount of resources can be some kind of measurement of my free will. However, if I have access to that resources, I can make myself much more difficult to predict, e.g. some optical or electric camouflage.
Seems like you are in love with your conclusion and are throwing all supporting evidence into it, which works in a court of law, but not when you are trying to construct accurate models.
Thank you for your comment, but it would be appreciated if you could prove my conclusion is wrong (e.g. either observer B1 or B2 is able to know or predict event C)