2

How do philosophers explain discontinuous time? I don't mean how do they account for it, but how do they show what is meant by the term. What is meant by it? Specifically, how do they account for changes in tense?

enter image description here

Mellor, Real Time 2. This is the common sense understanding of A times.

And, supposing that B times are not discontinuous, but A times are, does that mean the present does not end (nor begin)?

This ideas seems to follow quite sensibly from the bold, so I'm just asking if anyone takes this route.

e.g., if a continuous interval is divided by an instant T along it, and that is discontinuous with that interval's end, surely that instant T necessarily belongs to the interval ending at that time T. Any instant belongs to an extended "now" before it, and so does not belong to the beginning of the interval after it.

What is after the present never begins (and likewise what is before the present never ends).

  • sorry if this is a duplicate, esp if closed –  Jan 31 '20 at 14:43
  • I mean, there are physical limits like the Planck second which indicate the minimum time intervals it’s actually possible to experimentally measure... – Joseph Weissman Jan 31 '20 at 14:57
  • i guess @JosephWeissman –  Jan 31 '20 at 14:58
  • 1
    Maybe you could unpack a little further what exactly you're looking exactly for here? (Is there something in specific you're reading or studying that might have made this an important or interesting question? What does a great answer to this look like in your mind??) – Joseph Weissman Jan 31 '20 at 15:17
  • i'm asking someone to unpack it for me @JosephWeissman –  Jan 31 '20 at 15:19
  • Okay!! But whose thoughts exactly would you like unpacked...? What are you reading that's made this important or interesting to you? Is there a particular work or idea that you're studying? What hypotheses have you formed? What has your research uncovered so far? (Demonstration of effort is important...!) – Joseph Weissman Jan 31 '20 at 15:21
  • well i started a book real time, but it's from a train of thought concerning the illusion of the flow of time, from an article on time. @JosephWeissman but i'm not sure that will help the question, rather than acting to puff me up –  Jan 31 '20 at 15:22
  • 2
    "The Planck constant is related to the quantization of light and matter." Ref.1 Its use in the definition of Planck time does not mean that time is discontinuous. Good question though. "Because the Planck time comes from dimensional analysis ... there is no reason to believe that exactly one unit of Planck time has any special physical significance." Ref. 2. – Chris Degnen Jan 31 '20 at 15:23
  • i'm asking them to unpack what is meant by "discontinuous time". it does appear, but it is couched in some prEtty technical language @JosephWeissman –  Jan 31 '20 at 15:26
  • @ChrisDegnen Yes, the Planck length/second don't actually suggest spacetime is inherently discrete or 'quantized'! Rather that the energy requirements to do any fine-grained experimentation at these tiny scales becomes absurd/infinite/etc – Joseph Weissman Jan 31 '20 at 15:29
  • You can read how Planck discovered the discontinuous nature of light here: Planck's Law - "In 1900, Max Planck heuristically derived a formula for the observed spectrum [of black-body radiation] by assuming that a hypothetical electrically charged oscillator in a cavity that contained black-body radiation could only change its energy *in a minimal increment*". – Chris Degnen Jan 31 '20 at 15:35
  • @another_name your modifications make the question much clearer, and your link to an author is a significant improvement. Note your author focused on the behavior of the A and B SEQUENCES, IE he was accepting that two incompatible models were in use, and he was accepting that their collective although incompatible predictions may be of interest. Answering your new question: no, a discrete A-time does not extend for infinity with no start. You are applying the B-time approach to A-time with that question, which is invalid. Discrete A-time means that there are minimum logic state step sizes – Dcleve Feb 02 '20 at 22:54
  • "if a continuous interval is divided by an instant T along it, and that is discontinuous with that interval's end," Standard use of pronouns is that they refer to the most proximate preceding noun for which the pronoun is a valid replacement, which would mean that you are saying that instant of time is discontinuous. But discontinuity is a property of spaces, not particular points in space. – Acccumulation Feb 03 '20 at 01:19
  • The problem here is that when we reify it (make it metaphysically real) time is paradoxical whether it is continuous or quantised. . A good discussion can be found in the writings of Hermann Weyl, notably in his book 'The Continuum'. . –  Feb 03 '20 at 12:36
  • not one point, but two -- one point being discontinuous with the other @Acccumulation –  Feb 03 '20 at 22:17
  • "by an instant T" The word "an" is singular. The word "instant" is singular. – Acccumulation Feb 04 '20 at 00:47
  • but i do say "instant T... with [another instant]" @Acccumulation –  Feb 04 '20 at 01:32

1 Answers1

1

First, one should realize that the nature of time is a poorly understood subject, and there are good reasons to reject each of A time, B time and growing time models. See my answer to this question: The passing of time

Neither A time nor B time is readily discretized to become discontinuous. In A time, there really isn't any time, so it shouldn't be discrete. What would be discretized would be state changes, and what it means to set a minimum state change step size -- does not seem coherent. In B time, time is spacialized, and just integrated with geometry. And geometry is not discrete.

The efforts by physicists to evaluate what would happen if space and time were both discrete, are discussed in these physics SE answers: https://physics.stackexchange.com/questions/33273/is-spacetime-discrete-or-continuous

What they have shown is that so far, the experiments show no discreteness. Plus the Weyl's tile argument applies to both Pythagoras's theorem, and to the concept of momentum -- we would need to rebuilt the basis of classical physics and geometry somehow if the substrate of time and space is discrete. We know that both are only approximations, so this is not a killer argument, but we know how to get to both with continuous time and space, but not discrete, so this is a pragmatic objection to discreteness.

Dcleve
  • 13,610
  • 1
  • 14
  • 54
  • but isn't saying "there isn't really" kinda shorthand to absolving the responsibility of answering a question? –  Jan 31 '20 at 20:04
  • Time models are an effort to match what we have discovered about time. The reason we have three is because they are each insufficient -- IE refuted or broken in some cases. Applying those models to a circumstance that violates a core presupposition -- will break them more profoundly. Using a model in an area that you know it does not work -- will not give valid predictions! I showed that your 1, 2A, and 3 don't make sense, because you are misunderstanding A time. 2B is correct in B time and discrete time. 4 is incorrect, discrete time will not reorder B time. 5 is always true of A time. – Dcleve Jan 31 '20 at 21:08
  • But ultimately, the whole series of questions presupposes BOTH B and A time are valid, when they are mutually exclusive. – Dcleve Jan 31 '20 at 21:32
  • are you sure they're mutually exclusive? i believed most philosophers thought not –  Feb 01 '20 at 02:43
  • can we even have the illusion of change without tense? –  Feb 02 '20 at 09:36
  • 1
    A time considers time to be a logic state, and past and future are invented artifacts, while present is the only thing that exists. B time holds that time is a dimension, the past and future exist,and the experience of the present is an illusion. C time is a modificaiton of B, in that it dimensionalizes time, but holds that the past is the part of time which is real, future is invented, and present is -- just a boundary case, while pesentism and its logic model are untrue. These three are incompatible. If you think otherwise, do you have any links? – Dcleve Feb 02 '20 at 18:43
  • surely the "A theory" is incompatible with the "B theory", but not necessarily the "A series" with a "B series". i don't have a reference though, no. how could a A theorist deny that some things are before and after others? –  Feb 02 '20 at 19:08
  • hey. i think i'm just gonna go with the belief that a philosophy of time is completely incoherent. cheers –  Feb 02 '20 at 20:42
  • i mean, there are B times but they are only objective, and there's no other time –  Feb 02 '20 at 20:59
  • 1
    Practical empiricism accepts that sometimes we don't have globally valid models, but that we can have a locally highly useful model. A, B, and C models of time are incompatible, but each is highly useful in understanding some aspect of time, and help us in some usages of time. Our understanding of time is not complete, and using each of these models outside their range of applicability will lead to gross errors. But we still can understand and deal with time under most circumstances, hence our understanding is not "completely incoherent". – Dcleve Feb 02 '20 at 21:51
  • Hello @Dcleve, I wonder if you have an opinion on this paper: The relativity of simultaneity and presentism, by Mario Valente. It largely focusses on the idea of synchronisation in each frame. I note it has been withdawn from Arvix by the author, so I suppose it is probably overlooking something. – Chris Degnen Feb 03 '20 at 11:04
  • @Chris Degnen -- I gave the paper a quick read. I am not a theoretical physicist, nor have I gone through all the logic operations that Special Relativity involves, so I can't give an expert opinion. My first thought was that he does not even deal with non-synchronicity well. If synchronicity is dependent on reference frame, and is only local AND velocity dependent, then one cannot get a global understanding of time, only a local one from his "solution". Also, I think sequence inversion is a worse problem than non-simultaneity, and he does not discuss that at all. – Dcleve Feb 03 '20 at 17:04
  • I also think that General Relativity produces worse problems than Special Relativity does for presentism. I think he would have been better served critiquing "This shows why the price presentism should pay to avoid a contradiction with relativity is an ontological relativization of existence. (Petkov 2009, 130-1)". Petkov is right. But relativity requires rejecting the reality of time, which is also a huge cognitive and scientific negative. We are faced wtih TWO unpleasant options, and attacking one, as Petkov did, does NOT justify the other! – Dcleve Feb 03 '20 at 17:12
  • weird conversation really, but @Dcleve do you suppose that any philosophical conclusions can be drawn from the relative incoherence of A-time? such as the incoherence of the self, or its annihilation? –  Feb 04 '20 at 01:38
  • On the contrary, I consider selfhood, and the state-sequencing that leads to A-time, to be primary data. Our not having good models of time mans the models are wrong, NOT that we should throw out the data! In science and empiricism, data is king, theories are serfs. – Dcleve Feb 04 '20 at 01:44
  • hmm. can we say that -- phenomenologically -- there is always more to time? it's a snazzy caption, anyway –  Feb 04 '20 at 05:34
  • @Dcleve Thanks for the replies. I believe the local understanding provided by Valente's solution satisfies my own question as to whether the Now is universal. However, that means for me the global understanding is a mass of local perspectives. I think I will check out Richard Muller's book 'Now' (from your link). Thanks to you and another_name for excusing this interlude. I'm probably overlooking something. Maybe I'll find it. – Chris Degnen Feb 04 '20 at 09:53