I think the essential problem with time is that since we experience reality as flashes of perception, then we think of time as the point of the present moving, or "flowing" from past to future. Which physics codifies as measures of duration and then correlates with measures of distance, using the speed of light, to postulate spacetime as foundational dimensional extension.

Yet a more efficient explanation is that it is action turning future to past. As in tomorrow becomes yesterday, because the earth turns. Which makes time more like temperature, than space. With time, we measure frequency of events, while with temperature, we measure the cumulative energy of frequencies and amplitudes of events.

So physically there is only the present, with past and future as configurations that longer exist, or haven't been manifested.

Different clocks can run at different rates, because they are separate actions. All things being equal, a faster clock/frequency, is using more energy. Sort of like an animal with faster metabolism ages quicker than one with a slower rate, yet remain in the same present. Which goes to the twin paradox.

That different observer will observe events in different order is no more consequential than seeing the moon as it was a moment ago, simultaneous with seeing stars as they were years ago. It is the energy which is being conserved, i.e. always in the present, not the information it manifests and records.

It is this first law of thermodynamics which essentially creates time and gives it direction. The earth turns one direction, not both. Duration is just the state of the present, as the energy creating events changes form. What is measured is the frequency of change.

One could use ideal gas laws to correlate measures of temperature and volume, but as temperature is only foundational to our emotions, bodily functions and environment, not the sequence of perceptions of our rational thought process, we can presume to be somewhat more objective about how it emerges, so we don't assume volume and temperature are the same.

There is the vacuum, as space and fluctuation as the basis of both temperature and change/time.

Time flows from potential, to actual, to residual. Future, to present, to past.

Consider it somewhat analogous of our view of the sun, moving across the sky, from east to west, but which is caused by the earth turning wast to east.

Regards,

John Merryman

I'm an amateur, but the idea that the universe evolves and that past, present and future are not all present at the same time in a spacetime box is indeed very appealing. From my layperson's thinking, I like Short's idea of

"...the universe is made of tiny discrete bits of time and space: basically pixelated, like a computer screen, that ticks forwards in time..."

although, I'd change it slightly to "the universe is made of tiny discrete bits of space" and also change it to changes in the shape and maybe position of these bits relative to one another is what time is.

Said another way, time is not fundamental. It's just a function of physical things happening (e.g., physical change) to these discrete bits. If there were absolutely no physical change in any of these bits, there would be no time. This explains why time is moving irreversibly from past to future: because things keep happening (bits keep changing in shape and possibly position). To go from future to past, there would have to be a reduction in the number of things, or events, that have already happened in the universe. This doesn't occur. Even if the events of a process look like they're happening in reverse, like if a broken cup spontaneously reassembles, this doesn't mean that time is going backwards; it just means that additional physical events have happened that reassemble the cup and that happen to look like the previous events. But because physical change is still happening as the cup is reassembled, and the number of events is still increasing, time is still moving forward.

I think this also has some connection to why different observers may see events as happening in different orders. If the bits are changing shape and position in different ways or speeds at each observer's location, then this could affect the rate at which they perceive time as moving forward.

Anyways, that's this amateur's thinking. Thanks for listening.

    • [deleted]

    Tony Short "is making the pitch to reawaken the older, more intuitive picture in which the universe evolves as time passes."

    Thermodynamics expressed an intuitive picture of the passing of time by dissipation of kinetic energy into heat. Thermodynamics originally defined this in terms of entropy, a function of heat and temperature. Physics was quick to reinterpret heat and temperature statistically, and to redefine entropy as a measure of our uncertainty of a system's actual physical state. Thus, physics made irreversible time a subjective property based on the information that we have on a system. This followed from the definition of physical state in the absence of thermal noise, i.e. at absolute zero. However, absolute zero is unattainable, even in principle. This assumption underlies the difficulties physics has with the arrow of time and with a quantum interpretation of physical reality.

    Dissipative dynamics provides an alternate conceptual framework. Dissipative dynamics defines the physical state with respect to a reference in the system's actual surroundings at its ambient temperature. For the universe as a whole, this is the temperature of the cosmic background radiation at 2.7K. A perfect observer is in equilibrium with the ambient surroundings, but the ambient surroundings and perfect description are objective and independent of any particular observer. A positive ambient temperature provides a simple explanation for the pixilation of configuration space.

    By defining entropy with respect to the ambient reference, entropy is objectively defined. This immediately reveals two paths toward higher entropy and toward the future: by the dissipation of kinetic energy to ambient heat (the thermodynamic arrow of time) and by the decline in ambient temperature, e.g. by cosmic expansion. The latter leads to a refinement of configuration space and to the creation and actualization of new possibilities. This defines an arrow of actualization. Dissipative dynamics also accommodates a third arrow of time, an arrow of emerging complexity for dissipative systems that are open to stationary sources of energy.

    • [deleted]

    Well timed this is hmmmm.

    Now that the essay contest rating phase is complete and the hurried up to wait period of panel judging has commenced, its probably safe to address the conundrum of time in commenting on a topic nobody that has been attending fqxi will bother to look at. Especially given that 'posts in this topic' listing is not being displayed on the margin. In that vein, the essay topic of fundamentality was dominated by an apparent ambivalence to what time might actually be.

    What was most striking was that there seemed little recognition that time in most essayists mind was something that operated at an undisclosed rate, whether neo-classic, relativistic, or quantum. The arguments then proceeded to lay out the respective rationale as a proof of preference. Perhaps that is the real P ratio.

    It is apparent if one looks at the Block Universe, that it too instinctively assumes an undisclosed and fixed operational rate. So everything can happen all at once and any direction in time is also in an opposite direction. Einstein had actually taken umbrage at interpretations which alleged that he had seen length contraction as being something physically real, though perhaps he should have taken heed. His revelation that time stopped at light velocity must surely have kindled a elation of insight, but is perhaps the greatest stumbling block to many whom then reject relativistic arguments from the logical question of how it is physically possible to measure that velocity if time has stopped in relation to light. The sun has been up all day.

    So advancing theoretical conjecture such as discrete spacetime is not heretical to any but the purist. But neither should the quantum mechanical minded take comfort. The analytical nature of SR looks only to invariance of measurement from one reference towards some other at a uniform rate of change of distance between the two. It is not definitively physical of what actually happens to either electrodynamic body at velocity. That is for this generation to discover.

    Physics assumes that (what they represent as) change of number associated with a fundamental variable just occurs, but physics has no rationale for why change of number should ever occur.

    Clearly, time is not a force that changes numbers: on the contrary, time seemingly arises from change of number. Seemingly, time is somehow fundamental, but not base-level fundamental.

    Forget abstract ideas of "causality" and "change", let's look at the nitty-gritty: Shouldn't physics first examine what (they represent as) "numbers" could be, and what "change of number" could be, before going on to look at the issue of what "time" could be? And could they please do this without invoking Platonic realms to cover all the gaping holes in their theories?

      P.S.

      1. Do the "fundamental forces" cause "number change" or does "number change" cause the "fundamental forces"? You can't tell until you get a handle on what "numbers" are.

      2. Mass-Energy equivalence seems to show that Energy exists at the same level as Mass. Energy is not a self-sufficient, causal entity: Energy is no more a cause of change of number than Mass is a cause of change of number.

      Dear FQXi.org Members

      The earth had a real visible surface for millions of years before any physicists ever appeared on that real visible surface, arrogantly offering their preposterous complex finite guesswork about invisible influences.

      Obviously, Nature must have devised the only reality obtainable.

      The real Universe consists only of one real single unified VISIBLE infinite surface eternally occurring in one single infinite dimension that am always illuminated by finite non-surface light.

      Joe Fisher, ORCID ID 0000-0003-3988-8687. Unaffiliated

      • [deleted]

      "One reason I don't like spacetime is that the whole thing has to leap into being at some point"

      Give up that meaningless, undefined word "being". Just put it over the side, along with materialism and physicalism. These are empty concepts, just dead weight; as we like to say today, "not even wrong".

      • [deleted]

      I think the right answer has to be some kind of mixture of the A theory of time (time flowing) and B theory (Einstein). I think the real challenge with A theory is consciousness, as we perceive flow and cannot choose to go back in time. We can choose to go between B theory times. I also think the hard problem of consciousness (how mental states appear from physical states) is intimately tied into time. I think the hard problem is actually caused by what time really is (e.g. consciousness exists through time, but we just cant see it with our evolutionary construction, and if we could we could instantly solve / see the hard problem). Given this evolutionary bias, equiv to not seeing a colour, we need physics to give us something really weird that we can then go 'hey wait a second..this actually is how time works because it's the very solution to how consciousness can possibly be'. In otherwords when we have a breakthrough in time or consciousness I think it will have direct ramifications for other. Hopefully Short can uncover some remarkably odd physics from which a translation can occur.

      Jack

      Website: Philosopher.io

        • [deleted]

        " A theory of time (time flowing) and B theory (Einstein)"

        I think time as an axis of space-time is one thing, and 'experiential' time is something else: an attribute of consciousness. They align in various ways.

        Ref: Natural reality.

        Dear Dr. Short.

        The first sentence in the Technical Abstract of your WHY TIME MIGHT NOT BE AN ILLUSION project funded by FQXi.org reads: "Special relativity lies at the heart of modern physics, and has inspired a fundamental shift in our picture of reality, from a spatial state evolving in time to a static block universe."

        The earth had a real visible surface for millions of years before any physicists ever appeared on that real visible surface, arrogantly offering their preposterous complex finite guesswork about invisible influences.

        The real Universe consists only of one real single unified VISIBLE infinite surface eternally occurring in one single infinite dimension that am always mostly illuminated by finite non-surface light.

        Joe Fisher, ORCID ID 0000-0003-3988-8687. Unaffiliated

        Jim h

        What is fundamental to science is the observer and his need to know. Physics studies our experience of the universe. But the universe is not a show made of "experiences". It is made of "stuff". To think that the universe awaits our gaze in order to happen is once more sitting ourselves at the center of the universe...

        Unlike our experience of the universe, the "stuff" of the universe requires a beginning and a causally driven state of existence and evolution. When we remove the observer (appearance/experience), all that is left is existence. The universe exists and happens. Understanding the universe consists in finding the logical boundaries that allow its existence and evolution.

        In my essay, I suggest that while we can't pop "being" from "nothing" (rule of non-contradiction), we may find "happening" (dynamics) somewhere between nothing and being. The built-in "causality" in this "monistic" dynamic system is a higher probability of existence toward a more logical state of affair. And this (ontological) higher probability of existence of a particle in a place is matching or correlates with our probability of finding it there.

        So, "being" in our universe is impossible. Instead we got "happening", and the rules are about "where" it happens.

        Marcel,

        Time is easy once you see it. The mechanism and pressure that regulate the pace of "time" is the same throughout the universe. A water clock on the Nile and and one on the Mississippi drip along only slightly untrue due to elevation and temperature. A quartz watch. An atomic standard clock. They all, at the bottom level, rely on the structure and pressure of the Universe. Every atom, every photon. Everywhere in the Universe all is uniformly paced by a common structure under uniform pressure; only slightly disturbed here and there by concentrations of mass and energy.

        Marcel,

        Your first 2 paragraphs are a good summary of the materialist position with which I disagree.

        To me the heart of the matter is that you can assign no attributes whatsoever to the "stuff" of which the universe is "made" - it's not even a concept, just a word. Similarly, the word "exist" has no articulable meaning other than "is experienced".

        More to the point of the original article: if I say the block universe "has to leap into being at some point" I've already assumed a meta-time outside of spacetime, and I'm talking about the need for time to have a beginning at a point within that meta-time. But let experiential time be an attribute of consciousness, and the perceived need goes away.

        Jim,

        "Similarly, the word "exist" has no articulable meaning other than "is experienced"."

        Semantic, vocabulary?

        What do you call the "state" the universe was in during the past 13.8 billion years before we showed up to "experience" it?

        I call it "existence". What do you call it?

        Thanks,

        Marcel,

        Tomorrow becomes yesterday because the earth turns. Any "flow," in this existential present, is future to past. Probable to actual to residual. Every action is its own clock, its own frequency. All in the same state of presence.

        Including each and every mind. Flashes of consciousness.

        Marcel,

        What "state" is a photo in before it's detected? QM says it has no definite state - no specific position or velocity. So did it 'exist'? We feel like something was there - a wave function, a matrix of possibilities. But I don't think we're justified in saying the photon "existed" before it was observed.

        I like the quote from Renato Renner in this article: "You have to give up something you took for granted, something that's almost hard-coded in

        our brains." And I think what we have to give up is physicalism. And not because it's "wrong" but because it's ultimately meaningless.

        I think this is an informative post and it is very useful and knowledgeable. I really enjoyed reading this post. big fan, thank you!

        - roll the ball

        Physicists, mathematicians and philosophers do like their Platonic realms, abstract mathematical constructs and non-physical "mind"s, don't they! :-) While these things are possible, they're very hard or impossible to prove and seem to be the same as religious faith is to others.

        Jim,

        "QM says it has no definite state..."

        The meaning of "state" in QM is different, and refers both to the state of our knowledge as well as to the quantum state due to our interaction required to acquire this knowledge. A measurement applies a constraint on the wave functions that forces its temporary quantization. (A constraint introduces a boundary on the normal distribution of the parameter being measured, clipping the infinity tails on each sides, creating a box within which the wave function appears with specific modes i.e. quantized)

        But here, we have atoms, stars and galaxies...

        What do you call the "state" the universe was in during the past 13.8 billion years before we showed up to "experience" it?

        Thanks,

        Marcel,