Q&A with Paul Davies: What is Time?

"The flow of time is an illusion...The reason that it is an illusion is when you stop to think, what does it even mean that time is flowing?"

"Time of course exists. We measure it with clocks. Clocks don't measure the flow of time, they measure intervals of time. Of course there are intervals of time between different events, that's what clocks measure."

Time according to Davies is what clocks measure, which are intervals of time. Time is therefore intervals of time, or time is time, which is circular. We often define time as being time in lots of complex recursions, which of course are all circular but certainly true. It really is not that useful to say that time is time, though.

Of course, time is an axiom and therefore is really not like any other single thing. However, time as an axiom can be defined by the other axioms of the universe. In fact, time is defined as both an interval and as an integration of those intervals, which is an action. The key is to not use time to define time.

Rather, define an interval as matter. The mass of a grain of sand in an hourglass, for example, represents a moment of time as matter. The accumulation of those grains represents the integration grains in time, which is the action of that clock. Thus, time is formally defined as the differential of action with matter, the accumulation of matter divided by the matter of a moment.

It is very useful to define time as the differential of action with matter. Not only is that dimensionally correct, it is actually a universal definition of a clock. The atomic clock is formally set to record 9,192,631,770 or nine billion cycles of the cesium 133 atom hyperfine resonance per second. Each moment of the atomic clock then represents a very small energy equivalent matter of 1.1e-41 kg. This is a matter moment and the accumulation of these moments as matter over one year amount to about the action of three hundred hydrogen atoms.

Now, that is finally defining time without using time!

Having made this point way too many times before, it almost seems futile to keep making it, but the actual physics makes much more sense if we think of it, not as some 'flow' from past events to future ones, but the process by which events go from being in the future to being in the past. Ask yourself, does the earth 'flow,' from yesterday to tomorrow, or does tomorrow become yesterday because the earth rotates?

As Davies points out, "When we observe the world, what we see is an apparently consistent and smooth narrative, but actually the brain is just being bombarded with sense data from different senses and puts all this together."

The "apparently consistent and smooth narrative" is that personal neurological perception of a sequence of events, ie. prior to subsequent. It, that 'flow,' is the narrative , past to future perception, not the constant rearranging of 'data' by which those events are being created and dissolved! The events are flowing through our perception, future to past, not us flowing from past to future, because we only exist in what is physically real and it doesn't move along any metaphysical dimension. Duration doesn't exist as an external 'dimension' to the 'point of the present,' but is the condition of what is present between particular events.

If we understand time in this sense, it is no more mysterious than temperature, as a basic effect of action, ie. change. Keep in mind that temperature is every bit as foundational to reality as change/time. From elemental background radiation to the process of entropy, where energy seeks that thermal median.

Different clocks run at different rates because they are distinct actions. Reality doesn't branch out into multiworlds because it is the collapse of possibilities that yields actualities.

Now I can understand why those firmly wedding to certain physical theories, such as anything depending on a physically real spacetime(not just correlations of measures of duration and distance), may not wish to consider this point, but those less wedded to orthodoxy might want to think it through, just out of curiosity's sake.

Regards,

John M

Actually, I am with you up until temperature...where you said,

"Temperature is every bit as foundational to reality as change/time."

Time is an axiom, but temperature is not an axiom and you seem to imply that temperature is axiomatic or foundational. Dimensionally, time is the differential of action with matter. Temperature is a property of matter, since dimensionally, temperature is the average kinetic energy of a large number of highly interacting particles or objects. Since energy is equivalent to matter, temperature is then a kind of matter and matter is the axiom, not temperature.

Whether spacetime has a prehistory fundamentally, how it emerges does not mean it is not real and that there exists a direct association with energy and thence, matter. I think it time to revisit the 'holy writ' of conservation laws and restrict the general application to the 'closed system' as meaning a discrete volume of energy existing as a field which can include a continuum of density variation precipitating (a) relative rest mass. Cosmologically, Hoyle deserves another look, and it is just as reasonable to conjecture energy as being a profoundly transit manifestation of continual recreation of the stress between the curvilinear and rectilinear geometrically when any tri-vector of space changes and so also projects a uni-vector (tensor) of time. Operationally the modern deficits observed in cosmology beg a 'continual creation' rationale. Count me among the uncommitted to the standard model. jrc

Stephen,

Think of them as frequency and amplitude. The point is that if you can explain time as an aspect of action, then it's not an axiom. While we think of temperature as an average measure, on mass scales, temperature is the state to which energy reaches equilibrium, given more energetic particles give energy to less energetic ones, until the equilibrium state is reached. On the other hand, we think of time as more foundational than it is because our thought processes are sequential. Think how important the effect of temperature is to our metabolic functions. If you go to the most elemental state of energy, say the cosmic background radiation, or vacuum fluctuation, it would be described thermally, not temporally. It would only be when you began to isolate particular frequencies that any temporal measure could be ascribed to it.

I realize there is a lot of mental friction to seeing time and temperature on the same basis, but ask yourself, if that isn't due to mental processes being temporally based, whether narrative, or cause and effect logic. Temporal sequence is not actually causal. For instance, one day doesn't cause the next, nor does one wave cause the next. The sun shining on a rotating planet and wind across the water, vibrations, etc. are causal. It is the direct transfer of energy, not temporal sequence.

Regards,

John M

"...temperature is the state to which energy reaches equilibrium."

Temperature is a property of matter. If you heat something up, it gains mass. That is not only how we think about heat and temperature, that is actually what happens when something heats up. An object does not have to be at equilibrium to have a temperature and an object can be at one temperature and still be far from its energy equilibrium.

"If you go to the most elemental state of energy, say the cosmic background radiation, it would be described thermally, not temporally."

The most elemental state of energy is likewise described as matter, and also not as time.

"Temporal sequence is not causal...The sun shining is causal..."

It is true that time is not causal, action is. It is just not clear what that has to do with temperature. All action is in essence changes in energy of one kind or another or equivalently as changes in matter of one kind or another.

An axiom like time can only be defined in terms of all the other axioms, like the differential of action with matter is time. Time is not like just action and time is not like just matter. That doesn't mean that its not an axiom...that is the very definition of an axiom, that they define each other.

Stephen,

"All action is in essence changes in energy"

So wouldn't both amount of energy and frequency of change be measures/aspects of action?

The difference between time, as in frequency and temperature, as in amplitude, is that we tend to think of time in terms of the particular and temperature in terms of the aggregate. We try measuring time in terms of particular changes, such as frequency of a cesium atom, yet the cumulative effect of change is a lot of such rates and the problem is we assume there must be some universal clock/rate of change, but the only universal rate is cumulative.

With temperature, we instead focus on the cumulative, but it is based on the energy levels of lots of different particles/waves. Yes, they don't have to be in equilibrium to have a temperature, anymore than all the clocks and frequencies have to be synchronized to effect change. I'm only using that to point out the similarities. When we talk about something like the background radiation and say it's 2.7k, that is its temperature, but it's also a measure of the amplitude of the waves of radiation.

Regards,

John M

Einstein not even mentioned? Hmm... Lee Smolin is more courageous:

"Was Einstein wrong? At least in his understanding of time, Smolin argues, the great theorist of relativity was dead wrong. What is worse, by firmly enshrining his error in scientific orthodoxy, Einstein trapped his successors in insoluble dilemmas..."

Philip Ball: "Einstein's theory of special relativity not only destroyed any notion of absolute time but made time equivalent to a dimension in space: the future is already out there waiting for us; we just can't see it until we get there. This view is a logical and metaphysical dead end, says Smolin."

Pentcho Valev

I think the first thing we need to do to really get to the heart of the fundamental nature of reality is to separate clearly the notion of what I call "operational time", which is what clocks measure, and actual *fundamental time*, which clocks cannot measure because they and the physical processes they are calibrated by can only occur *in* time.

For instance, the term "arrow of time" which is commomly framed in the context of thermodynamics or as Paul says the "asymmetry of time" has nothing to do directly with time, otherwise you get the absudity of time occuring in time!!

I think of time as purely a dimension in the same sense as space in that it is perfectly symmetric and notions of direction only emerge in the physical processes of objects in time as well as space, ie there are no directions of space only directions *in* space, the same applies with time.

Greater insights into the apparent time reversal symmetry violations in weak interactions might be gained if we approach it purely in relational terms using only the physical variables involved in the process themselves and not framing it in terms of varying "time" (operational only) intervals.

On the question fundamental or emergent? I there may be some sort of pre-space and/or pre-time, all I would say is the a timelike dimension must be a-priori to anything else that requires dynamics because without it *nothing* can happen. Wheeler said " time is what prevents everything from happening at once" (in the context of a GR "block universe" presumably). I would put it this way " time is what allows anything to happen at all"!

Roy,

There is very much a mental space of time all around us, memories, books, information, paths, virtually every perception is based on some continuity of events, but where is this dimension physically? Do the past and future physically exist and how, given the energy which manifested prior events was in a constant dynamic process of change to even make it physically real? If all those electrons and atoms and molecules and people were not moving about, then could they even exist? So since they are not in those prior moments, but are in the now moment, what is there to make those other moments real? What is more real; The event, or the present? Relativity treats the present as an illusion in order to say all events are eternally real, but it would seem from so much of the evidence around us, that it is only what is present which is real and it is constantly creating and dissolving those ephemeral circumstances, of which we all have spatially different perceptions and even orders.

Regards,

John M

Main page of blog is broken since you put that line there. Will this fix?

Nope. One more should fix. Someone can delete these two posts.

Steve,

I'm not sure how action time and event time are truly distinct. You relate Roy's fundamental time with your proper time, but while Roy's fundamental time seems much more a static background, your proper time seems a bit more in the foreground, with a universal pulse. Which seems a bit like Newton's absolute flow.

To try putting this in the context of my argument against a universal time; If there are multiverses, would they each have their own pulse and if so, is there some even deeper pulse, for which the pulses of the separate universes are a form of action time, on the universal scale? If there is no overall proper time for the multiverses and they truly do represent their own clocks, than why would a proper time be necessary on our scale? Why wouldn't each pulse be its own clock and the only universal time be a composite of all the pulses occurring in the present?

I keep arguing that it is only our sense of the passage of time from past to future which makes the dimension of time necessary. You need that dimension for sequence to occur, but if you see it as simply a dynamic process, there is no need for that larger dimension. There is not 'an absurdity of time occurring in time,' because time is only occurring in the present/that which physically exists.

It is these events which are coming and going, future to past, not the present moving from past to future. The present does not move in any time dimension!!!!!!! The effect of time is created in the present. Just like temperature. Think of them as tangential. Frequency and amplitude.

Then what determines the asymmetry of time is the inertia of this action creating it.

Regards,

John M

"I'm not sure how action time and event time are truly distinct. You relate Roy's fundamental time with your proper time, but while Roy's fundamental time seems much more a static background, your proper time seems a bit more in the foreground, with a universal pulse. Which seems a bit like Newton's absolute flow."

Event time is the time of our commoving frame of reference, and so yes, it is a little like Newton's flow. Roughly speaking, that is like the absolute motion that we have against the CMB, about 550 km/s or so. Action time has to do with the actions of common experience. We experience motions on the order of maybe 0.001 km/s or so, which are roughly five or six orders of magnitude different. That means that the norms of time are fairly close to proper time, but we can measure action time or atomic time very precisely, albeit relative to other atomic actions. We therefore confuse time reversibility or time stoppage as a result of this time differential with the overall time norm.

"If there are multiverses, would they each have their own pulse and if so, is there some even deeper pulse, for which the pulses of the separate universes are a form of action time, on the universal scale?"

My job ends at the edge of the box and proper time is still inside of the box. Beyond the box, anything goes with multiverses that are outside of our universe.

"There is not 'an absurdity of time occurring in time,' because time is only occurring in the present/that which physically exists."

Time is an axiom, but it is not the only axiom. The other axioms of matter and action have similar circularities or absurdities. Matter, after all, is the stuff that the universe is made of, and what is that stuff? Matter. Action is how stuff gets done, and how does stuff get done? By action. These absurdities or circularities are simply what occurs when you try to define an axiom as like something else. An axiom can only be defined as combinations of other axioms, which is then a reflection of the symmetry and self-consistent closure of the universe.

"The effect of time is created in the present. Just like temperature. Think of them as tangential. Frequency and amplitude."

Temperature is certainly a product of time, and so it should be possible to back fit time using temperature as an axiom like Rosseli has proposed. My feeling is that this simply will result in very complex differential equations for action and matter and a tensor algebra that will make GR look like kindergarten. But, I could be wrong...

Steve,

"Roughly speaking, that is like the absolute motion that we have against the CMB, about 550 km/s or so. Action time has to do with the actions of common experience. We experience motions on the order of maybe 0.001 km/s or so, which are roughly five or six orders of magnitude different."

We use measures of actions as time. Whether it is our local frame through the CMB, or a car driving down a road, what is happening is a classic physical process, without even any quantum uncertainty. Say it is the car driving between mile markers; There is a constant physical process of pumping cylinders, turning tires, wind resistance, etc. We compare this to an electronic or mechanical clock, which also is a regular physical process, all of which is physically occurring in this state called the present. The event of passing the initial marker has 'faded into the past,' ie. physically dissolved as the patterns change, as the physical occurrence of passing the succeeding marker occurs. So what has happened is the occurrence of a sequence of events, within a larger physical dynamic, in which many non-linear thermal factors have come into play; atomic, molecular, chemical, atmospheric, of propulsion, resistance, substance, etc. If any of those factors had been markedly different, then the rate of change in this situation would have been different. It is not that time and temperature are the same thing, anymore than frequency and amplitude are the same thing, yet they are complimentary features of the process. Amplitude doesn't determine frequency, nor the opposite, but in real world conditions, they can affect one another.

As I ask Roy, where does that dimension of 'time' actually physically exist, if our only evidence of the past is its physical record in the present and the only proof of a future is a projection of the current state? I have no problem with accepting axioms, but if they seem to be explained by other axioms, it would seem they are not a first order. Is the color blue an axiom, even if the light and space required to create it are axioms?

Regards,

John M

"It is not that time and temperature are the same thing, anymore than frequency and amplitude are the same thing, yet they are complimentary features of the process."

You can back fit temperature into a time. The question is whether this will be useful or not and my feeling is that temperature as time will be very complex. Since what we have now is already very complex and internally inconsistent, it is hard to see how temperature as time will improve that situation.

"...I have no problem with accepting axioms, but if they seem to be explained by other axioms, it would seem they are not a first order."

You are correct and I have been a little sloppy in my wordage. The symmetry of three is just such a powerful allure that it really almost demands a presence. The three axioms are really matter, time, and the action equation, but matter, time, and quantum action complete the universe so nicely. Any two of these axioms determines the third as emergent from the other two as long as the action equation is really the third axiom.

I like keeping the three as axioms, a trimal, since even though only two are really axiomatic, you can choose which two according to the problem that you want to solve as long as the action equation remains the third axiom. This is what I call a trimal tautology, but I am still searching for better words.

"We try measuring time in terms of particular changes, such as frequency of a cesium atom, yet the cumulative effect of change is a lot of such rates and the problem is we assume there must be some universal clock/rate of change, but the only universal rate is cumulative."

Perhaps a definition of time is in order. With the trimal of matter, time, and action, the differential of action by matter defines time without using time to define time. Therefore, time has both an action and a matter, once again, time is kind of two dimensional.

In terms of a clock, each moment of the cesium clock is 1/9,192,631,770th of a second and is equivalent to matter moment of 1.1e-41 kg, which is the matter equivalent of one photon of the Cs-133 hyperfine line. Then, we accumulate those moments as matter and that is the action of that clock. Thus we can hold the past action of any clock as matter in our hand or in our memory. The quotient of that action and the moment of matter provides time as a count of moments.

This serves to define time and to define the nature of clocks. What we assume is that there is a time as an axiom and that we can measure its passage.

Steve,

It's not a matter of fitting time into temperature. Would you try and squeeze frequency into amplitude? As Einstein said, simple as possible, but no simpler. (or something to that effect)

The problem is our logical thought processes are based on temporal sequence, so it takes some looking into the mental mirror to think of it as the changing configuration turning future into past. My experience with trying to explain this, is the more educated someone is, the more it grinds their gears. A cardiologist friend of mine told me I was hurting her head when I pointed this out, while a teenager responded, 'Well, duh.' Keep in mind we still live in a reality where the sun rises and sets, but we can also think of it as the world turning.

I also see the tripartite relationship as foundational and as you describe it; The two fundamental sides defining a larger/complex whole. Eastern philosophy/religion is largely based on that with the yin and yang comprising a larger whole. The Christian trinity as another obvious example and, I suspect, grew out of the nature of time; That God the Father represented the past order, God the Son to represent the present state and when things didn't pan out as they planned, God the Holy Ghost as hope for the future. I was first seriously puzzling over the nature of time, back in the early nineties, when Complexity theory started to emerge from Chaos theory and it did seem to correspond to the issues with time. With order as the past, chaos as the future and complexity as the present, that line between order and chaos. I would though, use 'energy' as a replacement for chaos and information goes in the order category. This goes to my entry in the essay contest.

Energy tends to seem chaotic because it is complimentary to order. When something is very ordered, it is not dynamically changing and so its constituent energy is very stable and addition of more energy is limited. So excess energy is destabilizing to order. Now think of this in terms of the past, which is logically ordered and unchanging, the present, which is the conflict state between prior order attempting to define the energetic state and then the future, which is wherever the energy flows, since it must manifest the physical reality, even if it destroys prior order. So we have those two directions of time; The order coalescing out of the present and receding into the past, while the energy is constantly moving onto succeeding configurations.

Another point I'd make is this leaves space in its own category. It seems there has been an effort over the generations to dismiss it as nothing more than an abstraction, since it lacks any physical aspect to grasp. I think that eventually we will have to accept space as far more of an elemental axiom than just about anything else. Even the speed of light as C is measured in the vacuum of space. Math dismisses it as three dimensional, but three dimensions are a coordinate system. Unless you specify the actual set of coordinates, space is infinitely dimensional, since any set of coordinates can be used to define the same space. For example, the Israelis and Palestinians use different coordinates, growing out of different temporal narratives, to define the same space.

It is argued in math that an infinite number of dimensionless points make a line, but that's flawed. Even an infinity multiplied by zero is still zero, so you would have to give those points some dimension, ie. space, in order for them to add up to anything. One only has to go out on a cloudless night to appreciate the enormity of space and no matter if it is filled with waves of energy and matter, all vibrating at their different amplitudes and frequencies, creating the effects of temperature and time, it is still the frame of all frames.

Obviously this then gets into issues of cosmology and since I'm already arguing against 'the fabric of spacetime' being physically real, the notion of an expanding universe becomes problematic. For instance, in order for this expansion to actually be relativistic, the speed of light would have to increase as space expands, in order for it to remain constant. Otherwise it's not expanding space, but simply increasing distance in stable space, as measured by the speed of light. Yet that would refute the premise of explaining expansion, since it would not appear to expand, if the speed of light increased.

Then there is the fact that overall space appears flat, as gravity and expansion balance out. This must mean those galactic 'space sinks' are not just inert points of reference in an expanding universe, but effectively contracting that which expands inbetween them at an equal rate. This suggests much more of a convection cycle of expanding radiation and contracting mass. Two sides defining a larger whole

I will leave it at that, since it has probably started to grind a few gears.

Regards,

John M

The Earth`s rotational motion is the fundamental physical mechanism responsible for maintaining our confusion over the nature of time.

Our rotational surface motion is approximately 1600 kilometers per hour at the equator. We live on a gigantic merry-go-round. We are physically immersed in this constant motionary milieu, at the same time, as we use this same motion, to measure duration elapsing.

We use the constant period of duration of our planet`s rotational motion, as the measurement baseline for our time keeping system. Duration elapsing is what our clocks measure. Duration elapsing is what we consciously experience.