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Just because Planck times are the smallest possible measurement of time intervals doesn't mean that time progresses in discrete Planck time chunks. That's obvio

Just because Planck times are the smallest possible measurement of time intervals doesn't mean that time progresses in discrete Planck time chunks. That's obvious enough, but maybe seems unmeasurable ... and so what difference does it really make? A bigger way to think about it is ... is the a universe like a movie where each still image lasts a Planck-time (or some other smaller chunk)? Is the entire state of the universe encoded in stasis for that instant, and then boom ... it's time for the next "Planck frame". It's really hard to resolve that kind of universal time chunkiness with the ordinary time dilation effects that can be observed at relativistic energies. Whose frame of reference counts? We do know that space-time can be warped ... it's harder to imagine that this kind of warping and curving is discrete. That's one reason why many believe it's a smooth flow.

jrochkind1 8y ago
Yeah, but not just unmeasurable by like a guy with a measuring device, unmeasurable in the sense that it _can't effect anything at all_, right? (if it caused an effect of any sort you could eventually measure or observe in any way... nope). To say that time is "really" continuous under such circumstances seems like a weird philosophical claim.
- whatshisface 8y ago
  Fortunately it's not a philosophical claim - after all even if it was demonstrated experimentally that time moved in frames like a movie, it could still be a movie played on a projector whose reels spun in continuous time. There's no way to know "what it ultimately is," only the most ultimate thing seen so far.
  - jrochkind1 8y ago
    Talking about what might exist that the laws of nature as we currently understand them would prevent us from ever having any evidence whatsoever of... it's def not a scientific claim or inquiry, sounds philosophical to me. If it can't be observed, like it's even theoretically impossible to observe it or have evidence of it, ever... it's not science.
    - TeMPOraL 8y ago
      > If it can't be observed, like it's even theoretically impossible to observe it or have evidence of it, ever... it's not science. More than that. It simply doesn't exist in any meaningful sense and it's a waste of time to even think about it. What cannot be observed in principle has exactly zero impact on the universe. That's pretty much a definiton of "not existing".
      - coldtea 8y ago
        >More than that. It simply doesn't exist in any meaningful sense and it's a waste of time to even think about it. The irony is it's actually a philosophy (a philosophy of science among several in particular) saying the above. It's not anything scientifically observed itself that says that when something can't be measured "it simply doesn't exist in any meaningful sense and it's a waste of time to even think about it".
        8bitsrule 8y ago
        Science is not always aware that it has axioms. Historically, absolute time, absolute space, Euclidean geometry, stuff like that. No place for, say, the qualia which motivate it ... beauty, elegance, the like.
        whatshisface 8y ago
        Euclidian geometry was literally based on axioms from day one.
        coldtea 8y ago
        What the parent means is science doesn't always know it has implicit axioms. And that Euclidean geometry itself is only one possible geometry, but took us several millennia (until e.g. Lobachevsky) to find out -- it was taken as a kind of axiom itself, like absolute time etc.
        TeMPOraL 8y ago
- oarabbus_ 8y ago
  Thank you, you eloquently expressed the point I was trying to make. To say "we know that quantity Y can never be measurable or observable below discrete length X... but also, Y is continuous and can be subdivided below X, just trust us on this one" doesn't sound like science. Philosophical at best.
  - coldtea 8y ago
    Philosophy is not just saying random stuff and "trust us". And inversely, science is not just measuring -- that's the naive positivist (and later Popperian) view of what scientists do. For example: As Thomas Kuhn (1961) argues, scientific theories are usually accepted long before quantitative methods for testing them become available. The reliability of newly introduced measurement methods is typically tested against the predictions of the theory rather than the other way around. In Kuhn’s words, “The road from scientific law to scientific measurement can rarely be traveled in the reverse direction” (1961: 189). For example, Dalton’s Law, which states that the weights of elements in a chemical compound are related to each other in whole-number proportions, initially conflicted with some of the best known measurements of such proportions. It is only by assuming Dalton’s Law that subsequent experimental chemists were able to correct and improve their measurement techniques (1961: 173). https://plato.stanford.edu/entries/measurement-science/#EpiMea https://plato.stanford.edu/entries/measurement-science/#EpiM...
    - jrochkind1 8y ago
      All good points. It's not simple or mechanical, and it's often erroneous, but the realm of science is still the realm of that which can be observed and measured, and refuted or confirmed by observation and measurement. Trying to figure out how to do that is what makes it science. It's possible the Uncertainty Principle is wrong. One can come up with theories that it is wrong. And what sorts of observations might hypothetically observe or refute them. As far as I know, there is no serious science doubting HUP at present. (Which doesn't prove it's right, it's just the current state of things). But simply speculating about what things might exist that current scientific understanding says scientific laws would prevent us from observing or measuring or seeing any effects of whatsoever -- is still not science. It's not that you can't have a scientific theory which current measurements seem to refute and still press for it (your Dalton's law example). It's that you can't have a scientific theory with no even theoretical way to refute or confirm it by observation. That's not a scientific theory.
- coldtea 8y ago
  >To say that time is "really" continuous under such circumstances seems like a weird philosophical claim. Actually what you say is the weird philosophical claim. It's like saying Australia didn't really exist when we couldn't observe it (or see any effects from it reach us). The thing is, to say it could be continuous even if that's not observable might be wrong. But not because it can't be both continuous and not observable: just because it can also be discreet and not observable, and we can't tell which of two it is for sure. Whether we (or any observer imaginable) can observe effects or not, doesn't mean it's not one or the other.
  - oarabbus_ 8y ago
    >It's like saying Australia didn't really exist when we couldn't observe it (or see any effects from it reach us). This is a straw man, and I think you know that. It's more like saying Atlantis doesn't exist, and, well, to the best of our knowledge - it doesn't. I'd be happy to re-evaluate upon receiving evidence that Atlantis may have existed, just as QM physicists should be happy to re-evaluate when sub-Planck-scale phenomena can possibly be observed using a theory which is also consistent with the rest of our observations of the world. Oh and an even better analogy than Atlantis - it's like someone saying Australia didn't really exist when we couldn't observe it, and claiming they would prove it by sailing from Chile to Africa without encountering any large land masses. So no, he's not making any weird philosophical claim at all.
    - coldtea 8y ago
      >This is a straw man, and I think you know that. It's more like saying Atlantis doesn't exist, and, well, to the best of our knowledge - it doesn't. I'd be happy to re-evaluate upon receiving evidence that Atlantis may have existed I don't see much difference. If you're "happy to re-evaluate" (e.g. open to the possibility) then the answer (even re: Atlantis") is "I don't know if it exists", not "doesn't exist".
oarabbus_ 8y ago
>Just because Planck times are the smallest possible measurement of time intervals doesn't mean that time progresses in discrete Planck time chunks. That's obvious enough, but maybe seems unmeasurable ... and so what difference does it really make? Does it mean that time does NOT progress in discrete chunks, or can not? I don't believe so.

jrochkind1 8y ago

Yeah, but not just unmeasurable by like a guy with a measuring device, unmeasurable in the sense that it _can't effect anything at all_, right? (if it caused an effect of any sort you could eventually measure or observe in any way... nope). To say that time is "really" continuous under such circumstances seems like a weird philosophical claim.

whatshisface 8y ago
Fortunately it's not a philosophical claim - after all even if it was demonstrated experimentally that time moved in frames like a movie, it could still be a movie played on a projector whose reels spun in continuous time. There's no way to know "what it ultimately is," only the most ultimate thing seen so far.
- jrochkind1 8y ago
  Talking about what might exist that the laws of nature as we currently understand them would prevent us from ever having any evidence whatsoever of... it's def not a scientific claim or inquiry, sounds philosophical to me. If it can't be observed, like it's even theoretically impossible to observe it or have evidence of it, ever... it's not science.
  - TeMPOraL 8y ago
    > If it can't be observed, like it's even theoretically impossible to observe it or have evidence of it, ever... it's not science. More than that. It simply doesn't exist in any meaningful sense and it's a waste of time to even think about it. What cannot be observed in principle has exactly zero impact on the universe. That's pretty much a definiton of "not existing".
    - coldtea 8y ago
      >More than that. It simply doesn't exist in any meaningful sense and it's a waste of time to even think about it. The irony is it's actually a philosophy (a philosophy of science among several in particular) saying the above. It's not anything scientifically observed itself that says that when something can't be measured "it simply doesn't exist in any meaningful sense and it's a waste of time to even think about it".
      - 8bitsrule 8y ago
        Science is not always aware that it has axioms. Historically, absolute time, absolute space, Euclidean geometry, stuff like that. No place for, say, the qualia which motivate it ... beauty, elegance, the like.
        whatshisface 8y ago
        Euclidian geometry was literally based on axioms from day one.
        coldtea 8y ago
        What the parent means is science doesn't always know it has implicit axioms. And that Euclidean geometry itself is only one possible geometry, but took us several millennia (until e.g. Lobachevsky) to find out -- it was taken as a kind of axiom itself, like absolute time etc.
      - TeMPOraL 8y ago
oarabbus_ 8y ago
Thank you, you eloquently expressed the point I was trying to make. To say "we know that quantity Y can never be measurable or observable below discrete length X... but also, Y is continuous and can be subdivided below X, just trust us on this one" doesn't sound like science. Philosophical at best.
- coldtea 8y ago
  Philosophy is not just saying random stuff and "trust us". And inversely, science is not just measuring -- that's the naive positivist (and later Popperian) view of what scientists do. For example: As Thomas Kuhn (1961) argues, scientific theories are usually accepted long before quantitative methods for testing them become available. The reliability of newly introduced measurement methods is typically tested against the predictions of the theory rather than the other way around. In Kuhn’s words, “The road from scientific law to scientific measurement can rarely be traveled in the reverse direction” (1961: 189). For example, Dalton’s Law, which states that the weights of elements in a chemical compound are related to each other in whole-number proportions, initially conflicted with some of the best known measurements of such proportions. It is only by assuming Dalton’s Law that subsequent experimental chemists were able to correct and improve their measurement techniques (1961: 173). https://plato.stanford.edu/entries/measurement-science/#EpiMea https://plato.stanford.edu/entries/measurement-science/#EpiM...
  - jrochkind1 8y ago
    All good points. It's not simple or mechanical, and it's often erroneous, but the realm of science is still the realm of that which can be observed and measured, and refuted or confirmed by observation and measurement. Trying to figure out how to do that is what makes it science. It's possible the Uncertainty Principle is wrong. One can come up with theories that it is wrong. And what sorts of observations might hypothetically observe or refute them. As far as I know, there is no serious science doubting HUP at present. (Which doesn't prove it's right, it's just the current state of things). But simply speculating about what things might exist that current scientific understanding says scientific laws would prevent us from observing or measuring or seeing any effects of whatsoever -- is still not science. It's not that you can't have a scientific theory which current measurements seem to refute and still press for it (your Dalton's law example). It's that you can't have a scientific theory with no even theoretical way to refute or confirm it by observation. That's not a scientific theory.
coldtea 8y ago
>To say that time is "really" continuous under such circumstances seems like a weird philosophical claim. Actually what you say is the weird philosophical claim. It's like saying Australia didn't really exist when we couldn't observe it (or see any effects from it reach us). The thing is, to say it could be continuous even if that's not observable might be wrong. But not because it can't be both continuous and not observable: just because it can also be discreet and not observable, and we can't tell which of two it is for sure. Whether we (or any observer imaginable) can observe effects or not, doesn't mean it's not one or the other.
- oarabbus_ 8y ago
  >It's like saying Australia didn't really exist when we couldn't observe it (or see any effects from it reach us). This is a straw man, and I think you know that. It's more like saying Atlantis doesn't exist, and, well, to the best of our knowledge - it doesn't. I'd be happy to re-evaluate upon receiving evidence that Atlantis may have existed, just as QM physicists should be happy to re-evaluate when sub-Planck-scale phenomena can possibly be observed using a theory which is also consistent with the rest of our observations of the world. Oh and an even better analogy than Atlantis - it's like someone saying Australia didn't really exist when we couldn't observe it, and claiming they would prove it by sailing from Chile to Africa without encountering any large land masses. So no, he's not making any weird philosophical claim at all.
  - coldtea 8y ago
    >This is a straw man, and I think you know that. It's more like saying Atlantis doesn't exist, and, well, to the best of our knowledge - it doesn't. I'd be happy to re-evaluate upon receiving evidence that Atlantis may have existed I don't see much difference. If you're "happy to re-evaluate" (e.g. open to the possibility) then the answer (even re: Atlantis") is "I don't know if it exists", not "doesn't exist".

oarabbus_ 8y ago

>Just because Planck times are the smallest possible measurement of time intervals doesn't mean that time progresses in discrete Planck time chunks. That's obvious enough, but maybe seems unmeasurable ... and so what difference does it really make? Does it mean that time does NOT progress in discrete chunks, or can not? I don't believe so.