Real-Time Physics

There is a far simpler, and more physically-motivated, paradigm for understanding nature than is provided by loop quantum gravity, supersymmetry or string/brane theory.

In terms of pure geometry, nature's geometry is full conformal geometry (no absolute lengths; relativity of scale). However, when matter and dynamical laws are included, the full conformal symmetry is "broken" and restricted to discrete conformal invariance. Space-time and gravitation are fully consistent with General Relativity (actually, GR+EM) at all cosmological Scales, but the strength of the coupling between matter and space-time geometry varies in a discrete self-similar manner.

This results in a discrete self-similar structure and dynamics for nature, as is observed.

This alternative paradigm (Discrete Scale Relativity) has been available for decades:

http://www3.amherst.edu/~rloldershaw

RLO

Look in the references below for a description of the reasons why time is absolutely essential in order to accomplish unification of physics. The posted discussions and reports references in the essays are also relevant.

http://www.fqxi.org/community/forum/topic/942

http://www.fqxi.org/community/forum/topic/499

"Chronodiegetics is the branch of science fictional science focusing on the physical and metaphysical properties of time given a finite and bounded diegesis. It is currently the best theory of the nature and function of time within a narrative space." (Charles Yu, How to live safely in a science fictional universe)

If it doesn't work out with the CMB data, just write a book about it ;-)

In an Expanding Universe QM are local, with Iime paramiters hard to observe, thus the "local" field of vision, observation, being un-real.

For a Universe that is contracting Relativity becaomes non local, with all the paramiters of time being unchanged, also "un-real".

If QM and Relativity are theories based on the Universe's "state" ie expansion or contraction, both can be reversed into opposite scenarios, with equal paramiters slotted as is now.

One would therefore think, or imagine that Time is really a separate and fundamental Universe quantity?..with the state of Universe condition having no baring at all?

I'd like to propose a new rule for FQXi articles which talk about the topic of time: nobody gets to talk about whether time exists or not or about whether time travel is possible or not until after he/she has defined what he/she means by the word "time." Is this such an outrageous suggestion? Apparently it is, because this typically is not done in the many learned discussions about these topics, here as well as elsewhere.

I have offered what I believe is a useful definition of the word time. My definition may be found in an essay titled 'Time: Illusion and Reality: An unconventional but constructive look at the fundamental nature of time.' This essay, which is dated June 2008, may be found here. If a person were to Google the phrase 'fundamental nature of time' this essay might be discovered among the first few hits.

I believe that this essay could be, at least, a useful starting point for discussion by others who might like to offer their own definitions of the word time. Should it be surprising that our discussions about time often seem to go in circles or into cul-de-sacs (or culs-de-sac if you prefer) when we've not clearly defined what it is that we're talking about?

Hello J.C.N. Smith,

We have conversed in the past and you gave me some good advice. I just wanted to invite you to read my essay from the third essay contest. It was probably better suited for the first contest, which I unfortunately missed, but I was somewhat able to make my ideas fit the topic. If you would like, you could leave any questions or comments on my forum. It's good to hear from you.

Best Regards,

Dan

P.S. I have explicitly defined time (twice) in my essay. :-)

Julian Barbour is pretty much into the notion that time does not exist. This is based largely on the Wheeler DeWitt equation HΨ[g] = 0, which is a quantum version of the Hamiltonian constraint in ADM relativity.

I could well enough imagine presenting how time exists, but space does not. We could presume there is some one dimensional space, a line or curve, and there is a fibration on that space by a three dimensional space. This internal space is a symmetry of the dynamics of this one dimensional parameterized space we label as time. This then connects to relativity when we consider the metric line element

ds^2 = -c^2dt^2 g_{ij}dx^idx^j,

where mixed time-space metric components are not included. We have here two notions of time. The first is the proper time τ = s/c, which is the invariant of relativity. The other time is a coordinate time t, which is not an invariant.

The obvious question to ask is whether ds is real. We can multiply it by mc^2 and define an action according to the extremal principle of the proper interval

S = mc∫ds,

which appears real in some sense. It has units of action, or angular momentum, which is a measurable quantity. Yet there is something a bit troublesome about all of this. How does the observer on this world line actually measure this interval? A clock is employed which must have some system of oscillations, such as a spring. Yet this is measuring the invariant interval according to something carried on that world line that deviates from the world line. Hence some sort of nongeodesic motion is being used to define or measure an interval along a geodesic path. Of course I am thinking primarily of a mechanical clock, but an atomic one still appears to hold for an EM field must be applied to knock electrons in the Ce atoms.

This Lagrangian is measured according to something which is not invariant. So we might then consider that action as dS = pdq - Hdt. Now we have some Hamiltonian, which might include a part for the dynamics of the clock. Hamiltonians must be specified on some Cauchy surface of data with a coordinate time direction. Yet this has gotten us into some funny issue, for to define an invariant interval it appears that we need a coordinate defined clock.

So far we have some identification of Hdt, or the square of this, with the c^2dt^2 in the interval above. We then have that the bare action term \int pdq is identified with mc*sqrt{g_{ij}dx^idx^j}. So we have a bare action given by our fibration, but we also have some constraint, where H acts as a Lagrange multiplier. So we then have our one dimensional curve defined in a spacetime, where the space is the space of fibration and the Lagrange multiplier determines the symmetry of that fibration which is the Lorentz group.

Now to make things curious, we could imagine this picture as dual in some ways to the picture where time does not exist, but space does. The duality might then have a noncommutative coordinate geometric content in quantum gravity.

Cheers LC

Does time really exist? The real question is in the question itself. If clarified, it leads to two questions:

1) does time exists as an experience? Sure it does. As such it is part of our everyday experience, physical and metal) as well as a fundamental part of physics a.k.a. the study of how the universe as we experience things.

2) Does time really exist outside our experience, physical or mental. This question is right into ontology. If we say yes, we have to give it the status of `substance` and study it as such and using tools and method for such study. If we say no, we still have to prove there is no such substance, still, using the same tools and methods.

The answer is always in a well understood and defined question. The rest is the usual humanity hurdle....So much of it.

Marcel,

What we perceive as "the flow of time" is nothing more and nothing less than the evolution of the physical universe (an evolution which apparently is governed by rules that we strive to understand and which we refer to as the laws of physics). We refer to various observed configurations of the universe as being various "particular times."

For example, the *only* difference between the particular time which we refer to as being a million years ago (i.e., the particular time when the Earth had made a million fewer revolutions around the sun) and the particular time which we refer to as "today" lies in the arrangement of the various parts of the universe relative to one another at each of these two particular times.

jcns

JCN,

So basically it's. an effect of motion and it's not the present which moves along a theoretical narrative dimension, but that the configuration of this present is constantly changing, thus the events come and go, from being future potential to residue of past configurations.

Essentially it is similar to temperature, which is also quite real, if one were to touch a hot stove, or investigate a damaged nuclear power plant. time is the change and configuration and rate of change, as temperature is level of activity.

John,

Yes, you've basically got the idea I'm attempting to convey.

We begin to run into complications, however, when we introduce the notion of "rate of change." This concept requires us to introduce some sort of clock. The way this typically is done is to look at the changing configuration of some subset of the universe, a clockwork mechanism involving a pendulum or an oscillating cesium atom, for example. We then define the change we observe in this clock as being our "time standard," and we compare changes in other parts of the universe with the changes in the part of the universe we've chosen to use as our clock.

If we have chosen our clock wisely we will find that it is a useful tool; changes we observe in our clock can be correlated in predictable ways with changes in the non-clock parts of the universe. In essence, our clock affords us an economical shorthand with which to convey information about changes in the configuration of the larger, non-clock portions of the universe.

It is important to recognize, however, that there is nothing magical about our clock. No matter how wisely it was chosen, our clock is still just a subset of an evolving universe. In the final analysis, the clock that ultimately matters most is the universe itself.

As the universe evolves, its configuration changes; various portions of the universe are displaced relative to other portions. As sentient beings we are able to observe this evolution. We refer to it as the flow of time. The various evolving configurations we observe equate to what we call particular times. A change from one particular time to another requires a change in the configuration of the universe, which in turn requires a displacement of some portion of the universe relative to some other portion. Thus, measuring a change from one particular time to another ultimately involves measuring a displacement of one sort or another.

This is why questions such as "Is time real or is time an illusion?" are not helpful. The answer to this sort of question depends on how one chooses to define time. Time is what it is; it involves changing configurations of the universe. We observe that the configuration of the universe does indeed change; it evolves. Therefore, in that sense the flow of time is indeed real, but in another sense, the sense of time being something separate and distinct from evolving configurations of the universe, it is an illusion.

jcns

John, JCN

You both consider the "time" that is the scale of changes or the X axis of any graph representing spontaneous events; object falling, nail rusting etc. This representation is accepted because we trust (implicitely) that we can`t rush time and that time itself is spontaneous. Every clock is based on a spontaneous process. A clock indicates 1) the PRESENCE of time passing and 2) that it does so at a certain RATE 3) it INTEGRATES its passage under the name "duration". (I agree with JCN; There are many concepts associated with "time" and if none is specified, it effectively means nothing (specific).)

Because all our clocks are based on the rate of a spontaneous process, we could say that the local rate of passage of time, as indicated by a clock, is a measure of the local rate of evolution of spontaneous processes. As such, the passage of time is not a silent witness, just conveniently provided for our graphs, but actually the principle cause for spontaneous processes to happen at a certain rate.

The clock indicates time passing only/only because time makes it works. If time stopped, the clock would stop. Still think the passage of time is not real???

Marcel,

The following is quoted from the thread on my essay in the first essay contest on the nature of time.

"Time is a measurement system that actually measures duration elapsing. It`s measurement baseline is the duration that elapses while the planet rotates.

Duration elapsing, is an accurate description of reality. Time passing, is a description of the illusion that people normally hold of reality."

John, JCN,

...and by that I mean that the process of the passage of time and its local rate are real (ontologically). Everythings else we derive from relation with it, like perception, before after, duration, measurements are all relative and subject to relativity. This is the (my) answer to the question.

Marcel,

Jim,

The illusion "thing" is a common mistake. In our reality, the passage of time is real because we have no choice about its perception. This absence of choice is a sign of "truth" and so it is in real in our reality (which includes physics). So, in our reality it is NOT an illusion. If you consider the universe outside the realm of our everyday perception, the "moment" in time, as a plane or volume made of points all at the same moment (no time between them) does not exist.( It would mean instantaneous communication is possible between any two points! )

To call the passage of time an illusion is to take a concept from one realm and apply it indiscriminately onto another one, where it does not belong.

Marcel,

JCN,

A large part of the problem is our mental functioning needs to integrate all the various aspects of reality into a larger whole, in order to integrate our sense of identity, both individually and collectively. A very good example is the calendar. Months no longer correlate to cycles of the moon because we add 2 or 3 days to most of them, in order to match the solar cycle of the year. Otherwise it would make it much more difficult to calculate when holidays would fall and the constant juggling would make them less meaningful. Similarly the year is not exactly 365 days long, so we add a leap day every four years, as well as the occasional leap minutes and seconds. In a way, it's like comparing cesium atoms and pendulums to find some universal measure of time. The reality is just a bunch of things moving around, many with very regular periods.

Marcel,

It is a question as to whether time emerges from the motion, or there is this dimension that keeps everything from happening at once. The question though, is what are the physical attributes of this dimension? Do the past and future exist out there somewhere on that fourth dimension and it's just our subjective perspective which makes this particular moment seem consequential? Or is there only physical existence and as things move about, it changes the configuration, such that past and future do not exist, because the very same energy which would manifest them, is currently manifesting its current configuration?

Does time exist without motion? Just waiting there for some quantum fluctuation to occur, in order to give it duration? Or does the fluctuation define itself by the terms of both duration and level of disturbance, ie. the scalar measure we call temperature? Wouldn't it be equally logical to assume there must be some scale against which we measure the energy generated, or do we only have other actions against which to measure it?

We do have absolute zero, the absence of any activity and it does seem, as we look out across the universe, that there are only definite levels of energy and temperature before the collected heat radiates away and things just can't get any hotter. So could there be a universal thermal scale which regulates how hot things can get, or is it a completely physical function of the properties of mass, as to how hot they can get before the heat simply burns itself away?

Same for time. Is there some universal duration or dimension of time, or is it just a bunch of energy, coalescing into mass and radiating back out again and its only these processes playing themselves out that creates the effect of time?

As I keep pointing out, when we think of time as going past to future, it does seem like a spatial dimension, along which we move from one event to the next. On the other hand, if we consider ourselves as occupants of the present and it's alot of things moving around and changing the scenery, it seems much more like thermal activity, like molecules of water moving around in a jar. There are no past or future copies of that jar strung along a fourth dimension, like pages in a book, because the same water is still there, just in a different configuration. It is the different configurations which come into being and then are replaced, thus moving from being the future to being the past. The earth doesn't need a fourth dimension to get from yesterday to tomorrow, because tomorrow becomes yesterday as a consequence of the rotation of the earth. It is not the present that moves, but the events.

Time is not an illusion. It is an effect. The question boils down to whether it is foundational to motion, or an effect of it.

The following is cut and pasted from my essay, 'Time: Illusion and Reality,' for which I provided a link in a previous post:

"It is important . . . to recognize and, insofar as possible, to 'internalize' the notion that the configuration of the universe does not change as a result of time advancing; rather, time changes (as we say, 'advances') because the configuration of the universe changes. The importance of grasping this subtle, admittedly perhaps counterintuitive, distinction can hardly be overstated in terms of furthering our understanding of time. Failure fully to comprehend and appreciate it has led, I believe, to many unfortunate intellectual detours and cul-de-sacs over the course of history. The evolution of the physical universe is what we perceive as the flow of time."

If the configuration of the universe did not change there would be no flow of time.

jcns

The following is quoted from the thread on Amrit Srecko Sorli`s essay in the second essay contest, date entered on September 10th, 2,009.

"Events do have duration. We have duration and motion in our timeless universe. In our conscious experience of duration, we assume time is passing.

We move at a surface speed in excess of 1,600 kilometers per hour. The constant physical changes that this planetary motion creates, supports the illusion of time passing. Our clocks are in concert, since we use this same motion as the measurement baseline for our time keeping systems.

For most intent and purpose, time exists on a rotating planet for it`s conscious inhabitants. Had we evolved on the moon, it would be easier to see that time passing is an illusion, that it`s really a case of duration elapsing, that there is no such thing or force as time, in reality."