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Time is continuous

The September Astronomy issue reports what may be a cosmological bombshell. Time is continuous. It is not quantized. There is no such thing as an ‘instant’ of time, only a continuim. This makes the paper I discussed a few weeks ago look even more interesting than it did then.

The test is quite an elegant one. Light waves from a distant source exhibit fringes called an Airy disk. This is a set of rings around a central bright point with an appearance much like a Fresnel lens.

If we assume time is discrete, there are definable instants a quantum or Planck time interval apart. The speed of light in a vacuum becomes slightly fuzzy rather than exact. Photons that leave a source at the ‘same’ time would go out of phase by a small amount as they travel because some would travel slightly faster than others.

The theoretically proposed smallest time interval (the Planck time) is incredibly short. Phase slippage could not possibly be detected unless the light had travelled for an almost unimagineably long time: such as from a very distant galaxy. If time is quantized, the slippage in the phases should fuzz out the Airy disks of such distant objects.

Astronomers found sharp Airy disks. QED: time is not quantized. The work has already been replicated and seems fairly solid.

I await the theoretical fallout with great interest.

20 comments to Time is continuous

  • JSAllison

    well batpucky, there goes the whole ‘fall between the bits’ thing, another subgenre shot in the butt by reality…

  • Why exactly would this be so?

    More specifically, why would the speed of light in a vacuum become fuzzy rather than exact, if time is discrete?

  • Rob Read

    This paper just says that time isn’t discretely quantised. If the time dimension where a very small circular (or even moebius) topography then that could still allow a cellular automaton style progression to the universe. So no need to abandon “between the bits” yet.

    This topology has some advantages

    1/ There is just a now (as observed) i.e. The universe times itself = the next “instance” of the universe. Mmm Where have I seen that square the state to obtain reality before?

    2/ You can travel either direction in “time” as most theories say is possible, you just get back to the same place.

    3/ All particles could travel space at the same one speed. Particles rotate into the time dimension as they “slow down” and rotate out as they accelerate.

  • See Slashdot article for a one-line summary of the paper.

    By George, think he’s right!

  • Mike Peck

    If the basis for this report is this paper, it’s already generated some controversy and rebuttals; for example here and here.

    This looks like a repeat of last year’s “speed of gravity” controversy to me.

    I should add I don’t actually understand this stuff. Well, I know what an Airy disk is and have some knowledge of classical diffraction theory.

  • Michael

    I’m a little out of my level here (OK, A lot!) but….
    Isn’t time, by definition, an abstraction? Hasn’t it always been an almost arbitrary system for measuring the duration of “existance”? If time could be quantized [able to be broken down into discrete and measurable (quantifiable) pieces] wouldn’t that mean, really, that something existed, then didn’t, then did, then didn’t, etc.
    Matter is quantifable: here’s an electron and here’s a muon; they wiegh this and that. But time?I do think I see where you’re going with this though. Hiesenbergs’ Uncertainty Principle, one of the foundations of Quantum Theory, apparently DOES NOT apply to time. According to Einstien, time is variable. However, we can now at least say that it’s variability is predictable, since the Uncertainty Principle does not apply. That seems like a pretty fundamental and important discovery to me.

  • Jeff

    Honest to God, I don’t understand how any of you get this stuff. I simply cannot grasp it. At all.

    I mean, I’m glad somebody does — it probably means cool gadgets or some other benefit for me down the road. But I just can’t even begin to wrap my brain around it. “Continuum”? “Quantized”? “Relativity”? I swear, sometimes I think people are just making this stuff up and hoping nobody calls ’em on it.

  • Fred Boness

    Is the universe analog or digital?

  • Michael Hiteshew

    Is the universe analog or digital?

    I guess that depends on how you define universe, or more precisely, which parts you’re talking about. Both matter and energy appear to have quantum properties. In some way, you could then say they’re digital. They can be counted precisely: here’s one photon, here’s the second, etc. Here’s one particle of matter, here’s another. They also appear to have minimum sizes or energy levels (Plank numbers).
    Time, according to this recent finding, doesn’t have quantum properties. As Dale said, it’s continuous. Therefore, it’s a purely analog thing. I’m not a physicist, so this is just my understanding based on some limited reading about Quantum Theory. Still, all this makes me glad I bought an analog watch!! 😉 A good question at a cocktail party: “Since time is a continuum, why are you wearing a digital watch?” Guaranteed response: “What the hell are you talking about?” Ok, maybe ya better not.

  • Michael Lonie

    “If we assume time is discrete, there are definable instants a quantum or Planck time interval apart. The speed of light in a vacuum becomes slightly fuzzy rather than exact. Photons that leave a source at the ‘same’ time would go out of phase by a small amount as they travel because some would travel slightly faster than others.”

    Photons traveling through a vacuum do not change their speeds, according to Relativity theory, but change their frequencies instead. That might well account for no smearing of the Airy disk from a very distant point source of light. Certainly Special Relativity is a well established theory.

    Zeno’;s paradox was answered mathematically by the devlopment of the idea of limits. That seems adequate to most thinkers.

  • Doug Collins

    If I might make a slight modification of your explanation:

    I would change “They can be counted precisely: here’s one photon, here’s the second, etc. ”


    “They can be counted : about here is one photon, approximately here is the second, etc.”

    Once a quantum wave function is collapsed into an observation, (or you see it in one universe if you are a parallel universe kind of guy), its position or velocity can only be specified to a limited degree of accuracy. One point that is only infrequently made in discriptions of Quantum Mechanics, (almost all of which seem to have a neurotic fascination with the idea that the world is random and unknowable), is that if one discribes the world only in terms of the wave function, it is in fact not random and is exact.

    Which leads me to wonder if reality is actually the wave function universe, with our universe of matter and energy only a matter of our random perceptions.

  • Dave Farrell

    In the multiverse (approximately), all versions of time must exist.

  • Michael Hiteshew


    First, thank you clearing up my ‘fuzzy’ description. I was tryng to avoid coming off like Stephen Hawking when I’m really just regurgitating what I’ve read. Now let see if I can follow what you’re saying:

    You wrote:
    Once a quantum wave function is collapsed into an observation…its position or velocity can only be specified to a limited degree of accuracy.

    This is the Uncertainty Principle. Ok, I’m still with you…

    You then wrote:
    …if one discribes the world only in terms of the wave function, it is in fact not random and is exact.

    By ‘function’ here, I asssume you’re referring to a mathematical function. By this, are you asserting that the mathematics are perfectly consistent and repeatable – in a statistical sort of way? For example: We can predict with high probability that the electron should be in this region during this time interval. Which leads me to wonder if reality is actually the wave function universe, with our universe of matter and energy only a matter of our random perceptions.

    If reality was the “wave function universe’, couldn’t we just use statistical sampling in place of elections? I’m sure some Democrats in Florida wish we could have in 2000. 😀 My point is that statistical probability is not the same as reality; it only predicts the most likely reality.

    There’s a fascinating display in the Maryland Science Center. Imagine a flat piece of plywood, 3 meters square mounted on a wall. A sheet of plexigalss is mounted parallel to it by hundreds of wooden dowels. The dowels are in rows, each dowel equally spaced from its nieghbor, forming a sort of grid, only with each row offset from the row above and below. There is just enough space for ping-pong balls to move behind the plexiglass. Painted on the plexiglass is a giant bell curve. Every few minutes hundreds of ping-pong balls are dropped from the top, bounce randomly through the offset grids of dowels and then, amazingly, fill the bottom of the display in the shape of the painted bell curve. My point? They never seem to fill EXACTLY the same way. There are always slight, random deviations from the curve.

  • Doug Collins

    First, let me admit that, like you, I am regurgitatging what I have read – and also like you – trying to make some sense of it. Lately I have been reading a lot about consciousness which appears to require more than just a very powerful neural computer to explain. There may be a quantum mechanical mechanism in some of the synapses which could supply the missing ingredient for our ‘awareness’.

    If this is the case, a problem which has been finessed for the last 70 years – the change or ‘collapse’ of the wave function to a discrete reality when a conscious observer observes it -may become a more unavoidable matter for the theory.

    By wave function I mean the Schroedinger quantum wave function. It can be described by a mathematical function, but it is itself a real thing. (This is like the ancient Platonic question of the difference between an earthly imperfect thing such as the Pentagon building, and a heavenly perfect essence such as a five sided geometric polygon. Which is ‘real’?) As I -no doubt imperfectly- understand it, various types of Schroedinger waves, described by the mathematical wave function, are all there is to the world until and unless some consciousness observes them, at which point they degenerate to statistically determined bits of matter or energy. They are not necessarily probability functions. Shroedinger himself did not see them that way. To him they were just waves. Max Born suggested the probability interpretation as a way of understanding them.

    The randomness lies in the change from wave to particle, which in turn may depend on the phenomena of conciousness. While the particle’s position and velocity are statistical, the wave which determines their probability is not. And so far as I can see, it is just as real as the particle. I was about to add that it was more real, because it is there whether we observe it or not, when I realized that it wouldn’t be ‘there’ if we observed it. There would be a particle somewere instead. So, in a way, matter and energy are ‘in our heads’ and the waves are outside of us. If you have to choose one or the other as reality, which is it to be? The wave, or some equivalent thing must exist outside of us, because for most of us, our internal perceptions of reality mostly coincide. I will run into a wall at about the same place in space and time that you would. Thus something outside of us is making our subjective perceptions similar.

    To use your interesting Maryland example, the reality is also the apparatus of plexiglas, dowels and plywood, which within its limits is exact and not statistical, as well as any particular arrangement of ping pong balls which is statistically determined according to a mathematical function physically represented by the apparatus.

    To take your election example seriously, (which I doubt was your intention), if you could scale quantum mechanics up from the microscopic realm and if you could come up with a workable quantum model for the consciousnesses of Florida voters, I suppose you might be able to accurately simulate an election. That would really be an improvement over focus groups and exit polls.

  • jcasadoo

    Could any of you please give the exact reference or any link to the preprint/paper in the September Astronomy issue, at which the comment refers?
    Thank you

  • Dale Amon

    Mike Peck above references the paper and rebuttals.

  • Kem Major

    I like that metaphor of the Florida elections. Reality does follow the laws of probability. Reality (objects we see in day to day life) is nothing more than the average of countless minute dicretes. Mathmatically, the results of quantum mechanics approach the results of classical physics when the size of the system grows large enough so that the relative values of smaller variables of the wave function drop out of the equation by either approaching zero, infinity or one. The frame of reference changes. The Florida issue points out the flaw of attempting to extract meaningful data in the range of the discrete in a large system. The frame of reference changes from discrete (small election) to statisical probability (large election). The uncertainty principle is systemic. There is an inherent probability of a vote not being counted in any voting system, the probability is rather low. Even computers suffer from this natural flux. In small elections it is possible to have the actual error be zero. However the error propagates when the number of voters and stations increase. The problem is systemic. The larger the number of votes, the closer that probability of a real error occuring approaches one. In the case of the Florida election, the difference in the number of votes cast was in the range of random statistical error. No voting system can be absolutely perfect, error will always enter the equation.

    When it comes to time, QED (quantum electrodynamics) treats time and space as having lower limits. Special Relativity treats timespace as a 4 dimensional fabric. Its impossible to talk about time without the consideration of space. According to Gauge Theory (one of the newest spin-offs of QED), Timespace is quantized, but only in a relativistic sense. Timespace becomes quantized within the boudaries of our frame of reference. It is our limitations as active observers that forces timespace to be quanitized, not the other way around. Its confusing, but it makes sense if you think about it.

    We are severely limited in our ability to observe sub atomic events. We can only observe visible side-effects and extrapolate theory. Chromodynamics was hatched on 2% substance and 98% mathematical theory. It is a highly structured system of logical relations with a few swirly cloud chamber pictures to back it up.

    Frame of reference is the key to understanding this whole issue of quantum mechanics. Planck time is the smallest increment of time that we can derive meaningful information from. Below that point, other dimensions (variables deriving from unobservable small interactions between sub quantum particles) start to emerge having relativistic effects on measurements of space and time. This is evolution of ever smaller sub-systems in equations is due to the inherent fractal nature of the universe. (drop some acid and insert psychodellic Mandlebrot image here) The Planck 4-dimensional timespace unit is the lower limit to our frame of reference. Virtural building block of our universe. It essentially defines a single point in our real universe. This point, to my understanding is an infinate universe within itself. Some hypothesize that that every planck spacetime unit, even in vacuum, is a singularity or a shower of virtual particles. It is a impossible to see events in this timeframe as it is for us to observe interstellar events that occur on the scale of billions of years or stellar systems that spread beyond our hyperspacial frame of reference (Hubble constant).

    Right now the biggest problem is a theory that works seamlessly from the infinately large systems (think galaxy clusters) to the infitessmally small (think neutrino)

    In the future, physicists may develope a working gauge invarient version of QED that allows for a single theory to comprehenibly describe the interactions and functions that drive the universe.

    Google “QED” “Gauge Theory” “Fractals” and “String Theory” if you are interested in more info on the guts of current theory.

  • dan

    time is the pattern of the external and internal energy wavelengths colliding and dividing into each other which we (the internal) perceive as a quantifiable reality.
    we have control over our own patterns, if we learn to recognize external ones, we can adjust our wavelengths to divide into outer ones more frequently,similar to octaves in music.They’re are only 11 notes and as soon as you go past the eleventh you hit the same note,its higher ,but the same note.Its because it is exactly half the wavelength.
    If we could do that we could time travel.
    extremely far fetched but maybe

  • Caine

    Could it be possible that were wasting our time by making names and rules and games and saying this happens because of this and so on just because we got bored of living on a earth that was once paradise so we ask questions to something that already has an answer…that is the answer so by doing so we build doubt and fear (unknown) into our everyday lives creating hell on earth kinda like im giving you this info for the same reasons you do? Did i just chase my tail? 😛