hsf@hlexa.UUCP (Henry Friedman) (04/30/85)
It seems that the term "random" is being misused in these discussions about free will. Random is not the same as probabilistic. In the information processing model of behavior, one's behavior is a product of multiple inputs (genetic/instinctual, environmental, the specific sensory stimuli, etc.). If we assume that behavior is absolutely determined, then at any point of "decision" about what action to take, the action is, in principle, 100% probable (to a theoretical observor who knows the initial conditions and causal laws). In a nondeterministic version, behavior at any point is a probability distribution. But saying that some actions are more probable than others is not at all the same as saying that the action is random. Also, whether deterministic or not, behavior is DETERMINATE, or fixed in spacetime (even though we can't predict it prior to its occurrence). There is the further possibility, in the nondeterministic model, that ALL probablilistic decision branches do occur--in different branches of the "many worlds" version of reality. --Henry Friedman
ellis@spar.UUCP (Michael Ellis) (05/02/85)
From Henry Friedman: >In a nondeterministic version, behavior at any point is a probability >distribution. But saying that some actions are more probable than others >is not at all the same as saying that the action is random. I have a few questions here. `Random' is used frequently in many texts on physics and philosophy of science describing quantum events, frequently in the same sentence with `probability'. Could be I'm confused, but I will use them both anyway, since that's all I know. Example: (A) "Photoelectrons are emitted when a surface is illuminated by light "only when its frequency is above a certain threshold. (B) "The time and place at which an individual emission occurs is RANDOM. (C) "The PROBABILITY that an emission will occur within a certain "region is directly proportional to the frequency of the light "employed. (A), (B), and (C) together obviously describe the Photoelectric Effect, first interpreted by Einstein in 1905. Provided your language is able to describe this phenomenon, we have but a vexing though meaningless language discrepency. >Also, whether deterministic or not, behavior is DETERMINATE, or fixed >in spacetime (even though we can't predict it prior to its occurrence). I'd like to understand your definition of `determinate'. By determinate, do you mean that Laplace's omniscient Daemon could have fathered quantum progeny -- Schroedinger's Daemon? If so, let her reflect on, say, (ouch!) that electron that just hit me. How would she sense what I assume now to be an expanding probability wave, later focussed entirely at a random point allowable somewhere within that wave, and perhaps later again as yet another probability wave? Surely not as `waves of probability' of the particle's position, since by our assumption, Schroedinger's Daemon REALLY KNOWS where the electron is. But can the Daemon really do without the wave, and see the electron one specific location? No! Because effects like diffractive interference patterns, tunneling, etc., DEMAND a wave-like nature. OK, then she sees a globby electron smeared all over the place, like a wave. But that won't work either -- sooner or later it must collapse, instantaneously, to a point, far in excess of the speed of light. Besides, that contradicts what you said about probability distribution. Which leaves me uncertain as to what you mean by `determinate'. >There is the further possibility, in the nondeterministic model, that >ALL probablilistic decision branches do occur--in different branches >of the "many worlds" version of reality. OK, but then I'm the random one, since the forks that this me right here branched off into actually finished this ar
hsf@hlexa.UUCP (Henry Friedman) (05/06/85)
Reply to Michael Ellis's questions about "random" and "determinate". My objection to the word "random" was based on the belief that it always means that all possibilities have EQUAL probability--like picking a lottery number from the barrel of all tickets. But I see from the dictionary that the word can also be used for anything described by probabilities (a random process). Therefore my objection, in general, is not necessarily valid. However, it appears that some the users of "random" in the free will discussion do use it improperly in the first sense of equal probabilities--as if all possible choices of behavior in a nondeterministic model must be equally probable. Of course that is not so. Concerning my use of the word "determinite" (fixed or definite in spacetime), the best description of the distinction that I've seen between determinate and deterministic was in the encyclopaedaia Britannica article on Time. But basically the distinction arises from (to quote Rudy Rucker), the "block" model of the universe. That is, that the universe can be thought of as a four-dimensional block existing in a matrix of nothingness (or maybe better, existing in a matrix consisting of a hypertime of only one event). (This is my description, not Rucker's.) In the block model, time has direction but doesn't actually flow: everything (past and future) just IS. The concept of an absolute or special "present" is meaninglesss, except as a purely subjective experience of conscious beings (us). Now, in that block model every event in spacetime is definite, DETERMINATE (though only a hypothetical five-dimensional creature could be aware of all the events). The DETERMINISTIC events are those in spacetime that are causally necessitated by earlier events in time. If determinism is absolute, then every event would also be deterministic. But whatever the level of determinism, every event is fixed or definite in the block, even though it cannot be causally predicted from an earlier knowledge of "initial conditions." It would seem that Schroedinger's wave function applies to one's knowledge of FUTURE nondeterministic (quantum) events with respect to a viewpoint from any given PRESENT. But if one accepts the meaningfulness of the block model, one could say that the future event is definite, even though we cannot know in the present what the future event is. In the many worlds version of the block model (the block would now be a five dimensional block) all possible branches of the wave function would exist.