RE: The Time Deniers and the idea of time as a dimension
Hi Stephen; Once again thanks for your comprehensive reply, Ive got a reply for one bit of it so far: [SPK] 'Does a history include values that can be associated with either of McTaggart's A or B series?' [CP] There is a strong argument to suppose it can be. The B series seems to carry all the information needed to judge truth conditions of reflexive statements such as 'event E is past' (from the A Series). The statement is true so long as it is occurs after event E. A B Series can then at least take a part in our conception of a history. [SPK] Seems is a very big caveat of a word! We have to be careful about the assumptions that we bring to the table. Your statement here seems to be consistent with what I am trying to explain, I do not understand the reason why you do not follow this point! Are you trying to argue for local realism without meaning to? I think im arguing for caution about McTaggart. I am trying really hard to argue for perhaps even more than local realism. I want the moving present, which we can not break free of, to be right at the center of our concept of time. I want the past to not exist, and I want the future to not exist yet. A (3+1) D block universe is comparable to a McTaggart B series. However, B series presuppose time! They are defined as temporal sequences. As events in 'before/after' order. They are derivable only, as far as I can see, by combining McTaggart C series - say real numbers, numbers that have a correspondence with points on an infinate line (which musnt be thought of temporally), with his A series (tensed facts: event e is past). A+C=B. So, A series (tensed facts or temporal token reflexives) are prior to B series (temporally sequenced series) just because they are used in the derivation of B series. McTaggart thinks this because he adopts as a premise the idea that change is necessary to time, and that a B-Series can not account for change only the A series can. The A Series embodies the 'moving present' he thinks, events are ordered as future, present and past. It is by associating this moving present with a C Series that he thinks a B Series can be derived. (note, that according to Kant time and space are a priori intuitions, back drops in which objects and events can sit. Following Kant we neednt really agree with McTaggart about change. imho). However, as he points out, A series are defined in a circular way. An A series event can be future, past AND present. To say that event e is future also present and also past is just contradictory. The obvious complaint to McTaggart at this point in the argument is that event e is not future, past and present all at once. Event e is the future, will become the present and then become the past. Event e is not all those things (here it comes) at the same time! In order to overcome the inherent contradictions in the A-series, an A series has had to be invoked again, a meta A series if you like, and notice that this second invocation is subject to exactly the same criticism as before. We have a Meta e (Me) at which e is future, an Me at which e is present, an Me when e is past. A series now of temporally flowing meta es, each one of which are (at some time!!!) future, present or past. Clearly, the A series is obscuring our concept of time rather than elucidating it, and given the B Series is just (A+C) it can not make any sense either. Again, at this stage the illusory nature of the 'subjective time' is winning the argument. Having discarded the A Series as incoherent, and therefore the B series too because it is derived from the A series, the only thing we have left is the C-Series. Something we may metaphorically illustrate by real numbers, numbers that have a correspondence with points on an infinite line (which mustnt be thought of temporally). Time then does not exist, but is properly concieved of as a dimenstion. Note, that it doesnt follow from incoherence in the idea of a B Series, it follows from 1) regarding change as necessary to time, and 2) the A Series as more fundamental to the others (given it accounts for change). I want 'now' to be the fundamental concept in any theory of time. Not just subjective time, but real objective time. I dont think appeals to token reflexives being more fundamental than before/after, or the necessity of change to time manage to establish the priority of the moving present over bloc universes, or C Lists such as real numbers. Thats why I make an appeal to something more intuitive. The A List as concieved by McTaggart may lead to incoherence, but nevertheless, we are embedded in the present. To meddle with its order is to conjure up paradox. Reality can not be like that. Best Regards; Chris. :) From: Stephen Paul King [EMAIL PROTECTED] To: everything-list@eskimo.com CC: Lee Corbin [EMAIL PROTECTED] Subject: The Time Deniers and the idea of time as a dimension Date: Tue, 12
Re: The Time Deniers and the idea of time as a dimension
Hi Chris, Thank you for a very interesting discussion of McTaggart's ideas, frankly after reading Huw Price's Time's Arrow and Archimedes' Point,, I abandoned any hope of them being useful. My current favorite contender for an model of time is that of a perpetually ongoing computation; the universe is constantly computing what will happen next given some present state. I like this idea because it automatically explains the perception of a flowing present moment. To use an artistic analogy, the universe is a play whose acts are ab libbed as the actors interact with each other and not a book that was written in the beginning. Kindest regards, Stephen - Original Message - From: chris peck [EMAIL PROTECTED] To: [EMAIL PROTECTED] Cc: everything-list@eskimo.com Sent: Tuesday, July 19, 2005 3:05 PM Subject: RE: The Time Deniers and the idea of time as a dimension Hi Stephen; Once again thanks for your comprehensive reply, Ive got a reply for one bit of it so far: snip I think im arguing for caution about McTaggart. I am trying really hard to argue for perhaps even more than local realism. I want the moving present, which we can not break free of, to be right at the center of our concept of time. I want the past to not exist, and I want the future to not exist yet. A (3+1) D block universe is comparable to a McTaggart B series. However, B series presuppose time! They are defined as temporal sequences. As events in 'before/after' order. They are derivable only, as far as I can see, by combining McTaggart C series - say real numbers, numbers that have a correspondence with points on an infinate line (which musnt be thought of temporally), with his A series (tensed facts: event e is past). A+C=B. So, A series (tensed facts or temporal token reflexives) are prior to B series (temporally sequenced series) just because they are used in the derivation of B series. McTaggart thinks this because he adopts as a premise the idea that change is necessary to time, and that a B-Series can not account for change only the A series can. The A Series embodies the 'moving present' he thinks, events are ordered as future, present and past. It is by associating this moving present with a C Series that he thinks a B Series can be derived. (note, that according to Kant time and space are a priori intuitions, back drops in which objects and events can sit. Following Kant we needn’t really agree with McTaggart about change. imho). However, as he points out, A series are defined in a circular way. An A series event can be future, past AND present. To say that event e is future also present and also past is just contradictory. The obvious complaint to McTaggart at this point in the argument is that event e is not future, past and present all at once. Event e is the future, will become the present and then become the past. Event e is not all those things (here it comes) at the same time! In order to overcome the inherent contradictions in the A-series, an A series has had to be invoked again, a meta A series if you like, and notice that this second invocation is subject to exactly the same criticism as before. We have a Meta e (Me) at which e is future, an Me at which e is present, an Me when e is past. A series now of temporally flowing meta es, each one of which are (at some time!!!) future, present or past. Clearly, the A series is obscuring our concept of time rather than elucidating it, and given the B Series is just (A+C) it can not make any sense either. Again, at this stage the illusory nature of the 'subjective time' is winning the argument. Having discarded the A Series as incoherent, and therefore the B series too because it is derived from the A series, the only thing we have left is the C-Series. Something we may metaphorically illustrate by real numbers, numbers that have a correspondence with points on an infinite line (which mustn’t be thought of temporally). Time then does not exist, but is properly concieved of as a dimenstion. Note, that it doesn’t follow from incoherence in the idea of a B Series, it follows from 1) regarding change as necessary to time, and 2) the A Series as more fundamental to the others (given it accounts for change). I want 'now' to be the fundamental concept in any theory of time. Not just subjective time, but real objective time. I don’t think appeals to token reflexives being more fundamental than before/after, or the necessity of change to time manage to establish the priority of the moving present over bloc universes, or C Lists such as real numbers. Thats why I make an appeal to something more intuitive. The A List as concieved by McTaggart may lead to incoherence, but nevertheless, we are embedded in the present. To meddle with its order is to conjure up paradox. Reality can not be like that. Best Regards; Chris. :) From: Stephen Paul King [EMAIL PROTECTED] To:
RE: The Time Deniers and the idea of time as a dimension
chris peck wrote: Thats why I make an appeal to something more intuitive. The A List as concieved by McTaggart may lead to incoherence, but nevertheless, we are embedded in the present. To meddle with its order is to conjure up paradox. Reality can not be like that. But are you just expressing a personal intuition there, or do you think some actual logical paradox arises from the block time concept? Also, do you agree that to define a notion of a single universal present, we must privelege one relativistic reference frame over all others? If so, do you think this reference frame is only metaphysically preferred while agreeing with relativity's claim that no reference frame can be picked out as special by any actual physical experiment, or do you hope for a new theory of physics which actually picks out a physically preferred reference frame? Jesse
RE: The Time Deniers and the idea of time as a dimension
Physicist Max Tegmark has an interesting discussion on the physics of a universe with more than one time dimension at http://space.mit.edu/home/tegmark/dimensions.html , specifically http://space.mit.edu/home/tegmark/dimensions.pdf . In the excerpts below, n is the number of space dimensions and m the number of time dimensions, so when he writes m 1 he means more than one time dimension. Quoting Tegmark: : What would reality appear like to an observer in a manifold with more : than one time-like dimension? Even when m 1, there is no obvious : reason why an observer could not, none the less, perceive time as being : one-dimensional, thereby maintaining the pattern of having thoughts : in a one-dimensional succession that characterizes our own reality : perception. If the observer is a localized object, it will travel along : an essentially one-dimensional (time-like) world line through the (n + : m)-dimensional spacetime manifold. The standard general relativity notion : of its proper time is perfectly well defined, and we would expect this : to be the time that it would measure if it had a clock and that it would : subjectively experience. : : Needless to say, many aspects of the world would none the less appear : quite different. For instance, a re-derivation of relativistic mechanics : for this more general case shows that energy now becomes an m-dimensional : vector rather than a constant, whose direction determines in which : of the many time directions the world line will continue, and in the : non-relativistic limit, this direction is a constant of motion. In : other words, if two non-relativistic observers that are moving in : different time directions happen to meet at a point in spacetime, they : will inevitably drift apart in separate time directions again, unable : to stay together. : : Another interesting difference, which can be shown by an elegant : geometrical argument [10], is that particles become less stable when m : 1 : : In addition to these two differences, one can concoct seemingly strange : occurrences involving backward causation when m 1. None the less, : although such unfamiliar behaviour may appear disturbing, it would seem : unwarranted to assume that it would prevent any form of observer from : existing. After all, we must avoid the fallacy of assuming that the : design of our human bodies is the only one that allows self-awareness : : There is, however, an additional problem for observers when m 1, : which has not been previously emphasized even though the mathematical : results on which it is based are well known. If an observer is to be : able to make any use of its self-awareness and information-processing : abilities, the laws of physics must be such that it can make at least : some predictions. Specifically, within the framework of a field theory, : it should, by measuring various nearby field values, be able to compute : field values at some more distant spacetime points (ones lying along its : future world line being particularly useful) with non-infinite error : bars. If this type of well-posed causality were absent, then not only : would there be no reason for observers to be self-aware, but it would : appear highly unlikely that information processing systems (such as : computers and brains) could exist at all. Tegmark then goes into quite a technical discussion about solving the equations of physics given various ways of specifying initial values, the upshot of which is that if m 1 (i.e. more than one time dimension) observers would not be able to predict the state in the rest of the universe from their observations, which would seem to preclude the existence of observers. I'm not sure I fully understood this argument. However the earlier part is quite instructive in giving us a picture of how a universe could look that had multiple time dimensions. Any one entity would still have a single time line, but different ones might disagree about which direction the future was, and time loops would be possible. Personally I think this is a more serious problem than Tegmark's idea about prediction difficulties, although he seems to gloss over it as mere unfamiliar behavior. Nevertheless I think it is instructive to realize that multiple time dimension universes are a conceptual possibility even if they are unlikely to contain observers like us. Tegmark is implicitly writing within the block universe perspective which is generally adopted by physicists. Translating this into a flow of time view seems quite challenging and suggests that that viewpoint may not be as flexible in terms of deep understanding of the notion of time. Hal Finney
