• Questioning the Foundations Essay Contest (2012)

  • There May Be a False Assumption in the Minkowskian Geometry That Led to Block Time, Which Disagrees With Quantum Theory on Whether the Future Already Exists - A Short Look Through the Clues About Tim

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  • Post #6

David Morin further claims that the gravitational redshift Pound and Rebka measured was due to gravitational time dilation:

http://student.fizika.org/~jsisko/Knjige/Klasicna%20Mehanika/David%20Morin/CH13.PDF

David Morin (p. 4): "This GR time-dilation effect was first measured at Harvard by Pound and Rebka in 1960. They sent gamma rays up a 20m tower and measured the redshift (that is, the decrease in frequency) at the top. This was a notable feat indeed, considering that they were able to measure a frequency shift of gh/c^2 (which is only a few parts in 10^15) to within 1% accuracy."

On the other hand, Banesh Hoffmann suggests that the gravitational redshift "arises from what befalls light signals as they traverse space and time in the presence of gravitation":

http://www.amazon.com/Relativity-Its-Roots-Banesh-Hoffmann/dp/0486406768

Banesh Hoffmann: "In an accelerated sky laboratory, and therefore also in the corresponding earth laboratory, the frequence of arrival of light pulses is lower than the ticking rate of the upper clocks even though all the clocks go at the same rate. (...) As a result the experimenter at the ceiling of the sky laboratory will see with his own eyes that the floor clock is going at a slower rate than the ceiling clock - even though, as I have stressed, both are going at the same rate. (...) The gravitational red shift does not arise from changes in the intrinsic rates of clocks. It arises from what befalls light signals as they traverse space and time in the presence of gravitation."

Who is right - Morin or Hoffmann? Both of them?

Pentcho Valev pvalev@yahoo.com

That's an interesting question. There are two main interpretations for the gravitational redshift. Relativists tend to prefer the version where you can take time out of the picture, because we don't understand it. So they often say that photons climbing out a grav field have their energy sapped by the climb, and try to explain the effect purely in terms of gravity affecting light. But this doesn't fit all the facts.

Clifford Will, in his excellent book about the tests of GR, 'Was Einstein right', asks the key question - if a signal is emitted at one height and received at another (a la Pound-Rebka), does the wavelength change steadily on the way, or is it emitted at a different starting wavelength, and then keep that wavelength? He says there's no way to know, and that it doesn't matter anyway. He says we can only work with observables. That point of view is understandable. But he then mentions that there is a way to find out which is true, but we can only find out indirectly. He then mentions an elapsed time experiment, with two clocks at different heights.

This shows that the starting wavelength is different at different heights, it doesn't change en route, and that of the two interpretations, the one with the time rate included is the accurate one. And yet physics students are very often taught the other version. Morin is right. I hope this helps.

But I should say that there's some ambiguity surrounding this, and it's less cut and dried than I've made it seem when summarising it.

Jonathan

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  • Post #8

Dear Kerr,

I'm interested in your essay. I hope you read my essay http://fqxi.org/community/forum/topic/1272 . I discussed your topic in a comprehensive sense, and I solved all the contradictions between quantum and relativity depending on the latest experimental result. My latest paper http://vixra.org/abs/1208.0018 solved the contradiction regarded to GR and quantum field theory.

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    • Post #9

    Jonathan,

    I've been offering up a very basic solution to these problems, but it hasn't garnered much attention. To quote the abstract of my own essay;

    "Time is experienced as a series of events and with its philosophy of measurement as reality, physics treats time as a measurement from one event to the next. I argue that time is the changing configuration of the extant, turning future potentialities into current events and replacing them. It is not the present moving from past to future, but action turning future into past. While this may seem a fairly basic observation, it means time is an effect of action, similar to temperature, not the basis for it. This would mean the geometry of spacetime is correlation of measurements, not causation of actions."

    The reason time flows at different rates is simply because it is an effect of action. Speed of the level of activity, ie. temperature and the rate of change increases. The one twin ages faster because the increased level of atomic activity yields an increased metabolic rate.

    As for one event happening in the past of one frame and future of another, that is just a signaling issue. Both the observer frames are in the future of the frame of the actual event.

    As for the multiworlds issue, the future is probabilistic and it is the actual collapse of probabilities that yields actualities. Time emerges from the process of stuff actually happening. Prior to a race, there may be ten winners, but after it, only one. The fate of the cat is determined by events.

    Admittedly much of the essay is devoted to the psychology of understanding, since I've been raising this issue for years, to little notice and much argument, so the issue has taken on psychological issues. It also delves into some of the consequences for other physics assumptions, such as the nature of space, but that's a broader issue.

    (It's been my experience that it is wise to copy posts before sending them, as about one third seem to not go through. Such as this one, which I did copy, thankfully.)

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      • Post #10

      Jonathan,

      Although I disagree with your conclusion that "the starting wavelength is different at different heights", I am impressed with the clarity with which you present the problem.

      In my view, light falls in a gravitational well just as ordinary material objects do, that is, its speed increases in accordance with the Newtonian equation:

      c' = c(1 gh/c^2)

      where h is the distance between the emitter and the receiver/observer. There is no gravitational time dilation. The starting wavelength is the same at different heights and does not change on the way.

      Best regards, Pentcho

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      • Post #11

      Hi Jonathan,

      You concluded "block time and the accompanying picture must be false". You correctly realized that the block-time view is rooted in an observer-dependent perspective considering "the same event in the past for one observer but in the future for an other one".

      Eckard

      Dear Jonathan Kerr,

      I enjoyed your essay on time. It's quite surprising that only in the 21st century are large numbers of physicists addressing this problem, that is, questioning the reality of relativity's block time. Your analogy about the car repair may be the best explanation one can come up with. Only in the last few years have I rejected block time. I assume that before that I just accepted it unquestioned as "implied by relativity", but without dwelling on it or its consequences.

      Your arguments are excellent and convincing. You seem cautious, almost hesitant to come to your conclusion. Perhaps because you haven't nailed down exactly the faulty step. I think you've come close. You've certainly demonstrated that "remote NOWs" are an ill-defined and unmeasured (almost certainly unmeasurable, even undefinable?) concept. If you haven't already, I suggest you read Daryl Janzen's essay and Israel Perez's essay. Their view of "cosmic time" within the context of relativity seems relevant.

      Good luck in the contest,

      Edwin Eugene Klingman

        Hello John, thanks for your post.

        I looked at this kind of view of time in 2002, when Paul Davies mentioned something like that in an article in Scientific American. He says:

        "For example, an electron hitting an atom may bounce off

        in one of many directions, and it is normally impossible to

        predict in advance what the outcome in any given case will

        be. Quantum indeterminism implies that for a particular

        quantum state there are many (possibly infinite) alternative

        futures or potential realities. Quantum mechanics supplies the

        relative probabilities for each observable outcome, although

        it won't say which potential future is destined for reality.

        But when a human observer makes a measurement, one

        and only one result is obtained; for example, the rebounding

        electron will be found moving in a certain direction. In the act

        of measurement, a single, specific reality gets projected out

        from a vast array of possibilities. Within the observer's mind,

        the possible makes a transition to the actual, the open future

        to the fixed past--which is precisely what we mean by the flux

        of time."

        I'd say this apparent similarity asks as many questions as it answers, but it's interesting. It would be hard to get it make testable predicitons, and it doesn't seem to address time dilation.

        To me, 'the speed of the level of activity' can't explain time dilation. With grav time dilation, it might, if it could explain why there's less and less activity as you approach the mass.

        But with motion time dilation, we seem to have elements of illusion and elements of reality all mixed up together. When two people pass each other on the street, each sees the other slowed down in time, but it's impossible for each to have slower metabolism than the other. So this bit looks like an illusion. But in asymmetrical situations, such as the twins paradox, you get permanent age differences. This shows what a strange conundrum it really is.

        Anyway, I can't do much online for a day or two as I have to get on a plane tomorrow, but will be back when the jetlagged clocks have worn off. Best wishes,

        Jonathan

        Hello Eugene,

        thank you very much. I'm cautious partly because that's the correct approach when criticising established physics. There are too many people who dismiss long standing ideas with a wave of the hand, and that often shows a failure to look into them properly.

        I'll read your essay, and the ones relating to cosmic time that you mention, thanks. Best wishes,

        Jonathan

        Hello Azzam,

        thanks for your post, I'll read your essay. Best wishes,

        Jonathan

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        • Post #16

        Jonathan,

        The reason for gravitational and velocity based time dilation is because since nothing can exceed C, as the motion of electrons within atomic structure is close to C, when the frame of this structure is accelerated/gravitationally attracted, the electrons slow down, so the combination of internal action and external velocity doesn't exceed C. So the rate of change within the atom is slower, thus reduced clock rate. This also causes length distortion, since the shape of the atoms are shortened in the direction of motion.

        If we used the concept of temperature expansively, this slowing of activity within the atomic structure of the moving frame is comparable to its reduced rate of change.

        This then goes back to the nature of space, because without the dimensional addition of time, it reverts back to an(infinite) equilibrium state, rather than some form of geometric fluid. Consider centrifugal force: What is the basis of the "straight line," other than an underlaying equilibrium? External references wouldn't cause this effect of spin. It would be this element of space against which the speed of light is constant.

        As for predictions, I don't see it as a matter of theory, but observation: Does the earth travel the fourth dimension from yesterday to tomorrow, or does tomorrow become yesterday because the earth rotates? I, with the help of thousands of years of cosmological observation, see the later. The former seems highly speculative.

        As for passing observers, that goes to blue-shifting of action and therefore clock rates shortened.

        We could as logically use ideal gas laws to formulate a "volumetemperature," as we use C to correlate distance to duration and come up with "spacetime," but with temperature, we don't confuse the needle with the scale. Duration always occurs within the context of the present, not external to it. What exists, the "present" is the "scale," not the events, which are highly subjective points of reference.

        Thank you, yes, sorry - there's clearly more to your view than my initial picture of it. Will look some more I have time, rushing to get on a plane tomorrow.

        Best wishes, Jonathan

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        • Post #18

        Dear Doctor Kerr,

        As a layman, I found your splendid readable essay actually compellingly understandable. In my essay Sequence Consequence, I have taken a position diametrically opposite to the Minkowski spacetime one by insisting that one real Universe could only be existing once here and now. You state: "The readings on clocks and the motion of light at short range might give the impression of general simultaneity links across space. But long range simultaneity might be more hypothetical, and not real in any active way." There is a problem here in that all supposedly separable scientifically fabricated phenomena are automatically corrupted by the insertion of measuring identical unit standardization. Science is a religion that uses numbers.

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        • Post #19

        Jonathan,

        Thank you very much.

        Dear Jonathan,

        Yes, I appreciated why you were cautious, that was not a criticism. As you note in response, so many critics go 'full speed ahead, damn the torpedos' that it was both unusual and refreshing to find caution in overthrowing a century old accepted paradigm.

        I am pleased that you will read my essay. Unlike the nature of time (perhaps the final mystery) the nature of the wave function may be succumbing to measurements and even, to some degree, to logical analysis. Just as the implications of block time lead to many hard-to-accept conclusions about secondary issues, the concept of 'superposition and collapse' have led to hard-to-swallow implications, as I note on one of the more recent comments on my thread; 'down the rabbit hole'.

        Edwin Eugene Klingman

        Dear Jonathan Kerr

        Nature of time differs as the paradigm of universe we assume changes, in that the emergence of discrete time in accordance with plank time varies. In virtue of this, I think, Minkowski space is expressional only in lambda-CDM cosmology, in that the observer is 0-D; and not with paradigms that have premise of cyclic time.

        With best wishes

        Jayakar

          Thanks Pentcho,

          I should mention that what I thought you asked me was about how to interpret GR. Both Morin and Hoffman were also talking about that, their disagreement was simply about how GR should be interpreted. It's very often a matter of taste, but in my view motion through time is sometimes rather edited out of the interpretation, where it can be without compromising GR, perhaps because block time leads to the idea that motion through time doesn't exist.

          But if you think GR is or may be wrong, then reading their work may not help - it might only help in trying to understand GR better. If you want to go outside GR, then it might be more relevant to look simply at the experimental evidence, and other ideas that have been put forward. I hope this helps, best wishes,

          Jonathan

          10 days later

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          • Post #23

          Dear Jonathan,

          As your essay demonstrates the question of time is undoubtedly a major stumbling block when trying to simplify and unify the theories of physics. What if time is not a dimension at all, but is imposed on physics by us, sentient beings with memory who saw the world around us change, and needed a book-keeping method to label the different states of this world? A timeless universe works quite well from the point of view of physics if all changes are local linear and causal as in some models like mine. It is only when we try to measure things that relativity enters the picture, but SR is not the only possible relativity!

          For example let Lorentz transformations regulate the length of measuring rods, not of space itself (as in SR) nor time itself contract, just clocks slow down. It can be argued that Einstein did no service to physics by declaring the speed of light constant. This made measurement absolute, but the universe became relative. More sensibly let the speed of light have a maximum but be otherwise variable (measurement is relative) while the universe is absolute - ie a universal 'now' can be imagined. Einstein himself said that a variable speed of light is required in GR.

          A timeless universe seems feasible in Beautiful Universe Theory , and was discussed in my fqxi essay Fix Physics! - I will be happy if you have a look at these qualitative and speculative papers.

          With best wishes,

          Vladimir

          Hello Vladimir,

          Good to read your essay, and there's a lot that I agree with there. Also entertaining and funny, the architecture analogy, and relevant as well.

          As you say, we need a paradigm shift, with new fundamental principles, from which we rebuild. But how to see which starting point? I can show a few pointers, and that it has to be entirely new.

          There are around ten different ways of seeing current physics, and the difference between them is often simply the order in which we put things. This concept is fundamental, while this concept is emergent, and further up the food chain. The speed of light is constant, and we adjust everything to that. Or the speed of light is variable, and we put something else underneath it. These alternatives are often equivalent, and we have a puzzle that can be rejigged into various different arrangements, but none necessarily leads to real progress.

          It's easy to say let's cut through the Gordian knot, if we can't decide which of the loose bits of string coming out of it should be worked from. But I say if you look carefully, there are clues as to what the starting point should be, and they should lead (to make a truly mixed metaphor) towards a new set of concepts that will be like a sword to cut through the whole knot.

          The deepest cracks in our present picture are the very places where the best clues are to be found about what the real picture should look like. Time is the deepest crack in our picture. Things really don't match up there. This crack has been papered over until recently, but now we're having to look right into it instead, because of quantum gravity.

          You say time isn't real, and that only the 'now' exists. Most people who say time isn't real say the opposite - that the 'now' doesn't exist. Block time, which comes unavoidably out of Minkowski's geometry, has led many to think time doesn't exist in the sense that motion through time doesn't exist. Instead, they think every 'now' moment exists at once, and they all sit there alongside each other in a block. That's the standard GR view, in as far as there is one. It isn't talked about a lot, as you need at least one unexplained illusion to make it work.

          But the differences in time rate in different places look very real, and are not addressed in either of these views. I've studied the idea of an illusion, it doesn't work, for several reasons. I say that motion through time has to be real, and in my essay I've shown that one of our two pictures of time has to be ruled out, as they can't co-exist.

          What I'm saying to you is that if you try ruling out block time, and say that the rules about simultaneity at a distance are slightly different from what we think (which is very possible as we don't understand time, but have depended on assumptions about time in Minkowski's geometry), then you get a picture of a dynamic universe, in which motion through time is real.

          So in the deduced picture motion through time is somehow real, and to me this view has been arrived at via a very logical sequence of reasoning, as in my essay - you can test every step on the way. And in this picture time seems to run at different rates in different places, so that should be the starting point, and to me it seems much more likely to lead somewhere than other starting points that lead off from here...

          Hope this is of interest, best wishes, Jonathan

            PS I didn't say that time is or isn't a dimension. I'm just looking at the clues and drawing conclusions, trying to limit the possibilities.