[demalk (OP)]

How time emerges from quantum entanglement:

https://arxiv.org/abs/1310.4691

How quantum entanglement = informational bits

http://www.flownet.com/ron/QM.pdf

[Colin2B]

The question here however is not whether time is meaningful, but whether it is fundamental.

A viewpoint. One fundamental aspect of physics is measurement. If we look at the dimensions required to define all other measurements we find that length, mass and time are fundamental measurements, so in that respect I would say time is fundamental.
I would also say that spacetime is a very fundamental concept.

So what is fundamental? Well, the photon seems pretty fundamental to me. It has no mass, its speed equals the maximum speed of causality, it interacts sub-atomically as well as macroscopically and we need it by definition to observe anything. Seems like a great starting point. If we can figure out how a photon experiences the world, perhaps we can get a step closer to what the world really is like fundamentally.

Here you are using a different definition of fundamental. The photon is not a dimension or a measurement, so in that way is not comparable to time or space.
I agree that understanding the photon is important to understanding much of our universe, but is it more fundamental that say quarks?

So what does the universe look like from the perspective of a photon? How is its perspective different from ours? Well, according to special relativity a photon doesn't experience time. If you would travel at the speed of light, everything would seem to happen at once.

I don’t think this is what relativity actually says.
As an object travels closer to the speed of light the distance between its current position and destination shrinks, so it takes less time to travel that distance. In the extreme (approaching c) the distance between the points tends towards zero, but can we say that those points are no longer evolving and changing over time? Only the distance has shrunk, not the time, at best we can say that the photon ‘sees’ its destination at only one snapshot in time.
Certainly relativity raises interesting questions about our perception of time and simultaneity and our understanding of the photon plays a part in that, but in GR it often makes little sense to separate spacetime into its individual components.

Turns out, yes, we can. In the quantum eraser experiment we are affecting the behaviour of photons in hindsight. After the photon has already travelled through the slit(s), and has already been absorbed by one of the atoms in the screen, we are able to modify its past behaviour.

There is a growing body of thought that this way of looking at the experiment is mistaken and comes from our trying to place classical view onto atomic scale objects eg the photon take a single path through the slits. That in reality when we try to measure/detect something we determine or affect its nature, eg wave or particle, by the way we conduct the measurement and has to do with the indeterminacy Alan mentioned.

Isn't it obvious that the concepts  'time' and 'random' mean nothing to these photons?

No, I don’t think it is.

If time and future and random are emerging phenomena carrying meaning only to that which has mass

Over the past few years an increasing number of experiments have started to investigate the wave/particle nature of atoms and molecules. Have a look at this one from 2015 which indicates that helium atoms can also display delayed choice behaviour. Note the comment near the end which picks up the evolving view of wave/particle behaviour.
http://physicsworld.com/cws/article/news/2015/may/26/do-atoms-going-through-a-double-slit-know-if-they-are-being-observed

[alancalverd]

Let's have a critical look at the quantum eraser.

I set up a double-slit experiment and record a single photon interfering with itself. Really? An interference pattern is dispersed in space and is recorded by photons transferring energy to, in the classical case, photographic film. Now one photon only has enough energy to blacken one silver halide crystal,i.e. to form a point image. If I claim to have dispersed the photon across several crystals and to have blackened them all, I have created energy from nowhere. Either the most fundamental law of physics is bunk, or the photon has not "interfered with itself" and the interpretation of the experiment is wrong.

Now create an interference pattern, record it on film, present it to a king, and be rewarded for your efforts with a hundred concubines. Father a thousand sons. Then erase the interference pattern. What happens to your heirs and successors?

[Colin2B]

Let's have a critical look at the quantum eraser.
....
....

Sorry alancalverd, apparently we can’t nominate 2 best answers per topic but this deserves another.

[jeffreyH]

Let's have a critical look at the quantum eraser.
....
....

Sorry alancalverd, apparently we can’t nominate 2 best answers per topic but this deserves another.

My sentiments exactly.

[yor_on]

I would like to address the question "Is 'time' fundamental?" once more.

In quantum mechanics time is a necessity, in General Relativity not so.
Have a read.

https://en.m.wikipedia.org/wiki/Problem_of_time

And as I said, in Relativity it depends on what you think is more correct. A generalized 'universe' or a 'local universe'. Einstein saw it as a 'whole universe', then 'time' becomes a 'global variable' definable from your local wristwatch, as well as relative motion and mass. If you treat it locally though, it's no longer a variable, instead it becomes a constant 'time evolution', just as thought in quantum mechanics.
=

What one have to see here is that using your wristwatch as some golden standard stops making sense as soon as you accept the idea of time being a chimera. It actually includes that wristwatch you're using too, if so.

Do you die?

[puppypower]

One source of confusion about time is we don't measure time in a way that parallels the nature of time. Time moves in one direction, to the future. However, we measure time using clocks that are based on a cycling phenomena. Clocks do not measure time in a way that parallels the observed behavior of time. It is like measuring the weight of an elephant with a meter stick. I suppose if we artificially define a convention and everyone plays along this may seem correct.

Cyclic clocks measure waves, which is more appropriate to energy, which is composed of a time plus a distance parameter; frequency and wavelength. One parameter is assumed by the other. We conceptually use something with the parameters of space-time, to measure time, leading to conceptual confusion. We take this tradition for granted. 

A concept, already in use, that better parallels the working nature of time is entropy. Like time, entropy spontaneously moves in one direction; increases, according to the second law. Time moves forward. This is a better conceptual fit than an energy/wave clock.

A possible measuring tool, which simulates time, would be the dead fish clock. With the dead fish clock, we start with a fresh fish from the market and place it on the counter. When it starts to stink, this is a basic unit of entropy time. Just as time cannot spontaneously reverse and repeat itself every twelve hours, like a wave based clock, the dead fish clock can only go to the future and cannot un-stink itself and start as fresh fish. This is where we need to begin so we can conceptualize the question of time being fundamental.

What is interesting about the dead fish clock is the rate of measured time propagation will be dependent on hot and cold. The fish will last much longer when refrigerated, than at room temperature. The time dilation; time until it stinks, will be energy dependent. This makes sense since entropy needs energy to increase.

If we start with a dust cloud, in space, and let it collapse into a star, space-time will contract. We go from higher gravitational energy potential to lower gravitational energy potential. Time slows because the dead fish clock becomes refrigerated due to less energy potential. If we want the stink time to speed up, all need at add energy much as expanding against gravity.

One of the earliest entropy clocks was the hour glass, where the sands of time, flowed. This entropy clock was not spontaneously cyclic, but needs a human to make it cycle. This led to need for labor saving wave/energy clocks. The sands of time continued to have an entropy connection, since the sand is shuffled, each time it is turned, never to perfectly repeat like a wave clock. Eventually, even that was taken away when we started to measure time as though it was space-time; wave.

[alancalverd]

Alas, you have missed a crucial point. The hourglass is a "before and after" phenomenon. So is gestation. By experiment we discover that there are always 24 hourglasses (and 2 tides) between sunrises, 28 sunrises between moonrises, and 9 moonrises between conception and birth. Thus there is something common between several singular phenomena and several cyclic phenomena. Hence time (that elusive commonality) is fundamental to natural processes.

[Bogie_smiles]

Time is something that can be talked about endlessly .

But there are some experiments that have been done that show that the rate of time passing, as measured by two identical clocks in relative motion, will be different, relative to the acceleration profile of the individual clocks; the result is time dilation between the two clocks.

If so, is it true that science attributes the difference in time dilation to the difference in the relative acceleration of the two clocks?

If the experiment was performed again, using a different acceleration profile by different pilots, and with a different resulting amount of time dilation, can the difference between the two experiments be attributed to the different acceleration decisions made by the two pilots?

[Colin2B]

Time slows because the dead fish clock becomes refrigerated due to less energy potential.

As Alancalverd says, you are missing the crucial points here. Time does not slow when the fish is refrigerated, it is the chemical reactions that slow. This is very different from time dilation.

is it true that science attributes the difference in time dilation to the difference in the relative acceleration of the two clocks?

Both relative constant speed or relative acceleration will result in time dilation when one observer measures the other.

If the experiment was performed again, using a different acceleration profile by different pilots, and with a different resulting amount of time dilation, can the difference between the two experiments be attributed to the different acceleration

If the relative speed or acceleration differs between two scenarios then the degree of time dilation will also differ.

[jeffreyH]

In an inertial frame of reference there is no way of knowing the difference between stationary and moving. It can be inferred from external observations but never proved. Also there is no way of determining if acceleration is positive or negative. So that whether or not your speed is increasing or decreasing is also unknown. Again it can be inferred from external observation but is always relative.

[puppypower]

Quote from: puppypower on Yesterday at 12:14:35
Time slows because the dead fish clock becomes refrigerated due to less energy potential.
As Alancalverd says, you are missing the crucial points here. Time does not slow when the fish is refrigerated, it is the chemical reactions that slow. This is very different from time dilation.

I was using the dead fish clock as the measuring tool. I am using an entropy clock. I am not using an energy/wave clock, to measure the dead fish clock, since that will return me to the conceptual inconsistency of using a 2-D wave tool to measure 1-D time.  That will lead to conceptual problems, which will make time hard to define in terms of a fundamental phenomena. If you use a meter stick to measure the weigh of the elephant there is a conceptual disconnect even if made useful; spring.

Relative to the hour glass clock; entropy clock, say we made a tunnel from the surface to the core of the earth. If we moved the hour glass down the tunnel, time will slow as the sands of time, slow. This entropy clocks slows because the gravitational potential energy will decrease as we move toward the core. Again, I am using an entropy clock as the time piece, since it acts in a way that parallels the propagation of time; time moves one way, and not as a repeating wave, like energy.

With the hour glass and dead fish clock, both clocks go one way and do not repeat. In the case of the hour glass, this can be made to repeat but we need to add human interaction to flip the clock. This can also be done mechanically with a machine. However, left to its own device both entropy clocks go through one cycle and then end. We will need to place a new fish to start the clock, again. The entropy clock is quantized, with gaps between the each fresh fish, or the next cycle of the hour glass. We can never flip the hour glass ,perfectly without a slight gap between cycles. The old time concept of reincarnation, uses the human body as the entropy clock. This entropy clock has to become a new state for the next cycle. They sensed the quantum nature of time based on entropy clocks.

There is a conceptual connection between entropy clock time and the more traditional wave clock time, because entropy needs energy to increase. That which impacts space-time and wave clocks, will also impact the entropy clocks. The problem with entropy clocks is there is no consistency between cycles, so one may ask how would that be useful for measuring time. The answer depends on whether a time or space-time convention is more important for measuring time.

[Bogie_smiles]

The question that I was going for in my post, and that comes up in the context of the discussion on Demalt’s thread, is about whether the decisions made by the two pilots are the explanation for the different outcomes, or are the pilots simply automatons, mindlessly carrying out predetermined actions somehow imposed on their minds without their willful participation?


A believer in determinism says that though the pilots believe they control the rate of acceleration, they actually don’t; all human actions are predetermined by a set of invariant natural laws, and outside of the control of any human intervention.

On the other hand, if there is freewill, the pilots have control of the acceleration decisions, because the pilots are making decisions on their own, on the fly, in real time, without the influence of determinism.

It is a matter of if there is, or is not a case for determinism, based on the fact that all natural laws are invariant. I accept that all the natural laws are invariant, but that different sets of those invariant laws can come into play, governed by the circumstances. I can see how the human mind can intercede to affect the circumstances, and thus to determine the particular set of invariant natural laws that come into play at the time of some physical event.

For example, I can think about moving my arm, or not moving my arm, without moving my arm, i.e., independent of the different set of invariant nature laws that would come into play if I do or do not move my arm. The fly is buzzing around and I am thinking of swatting it. I decide to swat it in real time. I swat it and the fly dies. If I decide not to swat it, the fly lives. My decision takes place before the action of swatting, but causes the act of swatting, and so I have affected the various mix or set of invariant natural laws that come into play at the time of the physical event of swatting or not swatting.

[Colin2B]

I was using the dead fish clock as the measuring tool.

The point you are missing is that your clock does not measure time dilation. For that to be true you would observe that all clocks at that location would slow, be they chemical, mechanical or atomic, and they would slow by the same amount.

I am using an entropy clock. I am not using an energy/wave clock, to measure the dead fish clock, since that will return me to the conceptual inconsistency of using a 2-D wave tool to measure 1-D time.  That will lead to conceptual problems, which will make time hard to define in terms of a fundamental phenomena.

There is no conceptual inconsistency. You are confusing the difference between a phenomena and the methods used to measure it.
Putting aside why you think a wave is a 2D tool - which it isn’t in the measurement of time - time measurement is a case of using a series of regularly occurring events to measure the time displacement between 2 other events, see previous post by Alancalverd. With an atomic clock we use the count (1D) of peaks, with a mechanical clock we use degrees (1D), etc. However, there is no reason why we should not use a 3D event eg volume of burnt candle wax, or volume of dripping water. Techniques like these are common eg using degrees to measure volts or amps. None of these present any conceptual problem.

If you use a meter stick to measure the weigh of the elephant there is a conceptual disconnect even if made useful; spring.

No disconnect whatsoever. Either use the stick as the arm of a balance to compare against a standard weight or measure the displacement of a (3D) spring. Again, no conceptual disconnect, except in your mind.

[Bill S]

#36.

You have some gems in your cabinet, Alan.  I particularly like the raindrop/fog illustration.  It appeals to my simplicity of thought.

[guest4091]

puppypower #46;

Time moves in one direction, to the future. However, we measure time using clocks that are based on a cycling phenomena. Clocks do not measure time in a way that parallels the observed behavior of time.

What is 'the observed behavior of time'?
Time doesn't move and it doesn't flow. There is a mental influence. The mind processes perception sequentially. The memory of the previous perception when compared to the current perception lends itself to an  interpretation of a continuous process, especially if the mind cannot detect any differences due to limited resolution. This is similar to the mind interpreting a fast sequence of still photos on a screen as 'motion pictures'.
A repeating cycle is just a convenient method of time keeping. Though the clock starts over at midnite, the day count has increased by one. Time doesn't cycle, it accumulates.
We are currently at 2017 yrs. from the year 1 ce.
When describing events of interest, we correlate them to standard clock events, which provides an ordered record for future use.
_________________________________
If the time of an event is assigned after perception of the event, and perception is always after the event occurs, how does time determine what happened?

[Bill S]

Time doesn't move and it doesn't flow ………Time doesn't cycle, it accumulates.

I’m not arguing with your basic thoughts on time, but I wonder how time would “accumulate” if it didn’t “flow”.

[alancalverd]

A step is not a road. We measure distance by counting the number of steps it takes to get from A to B. We measure the diameter of a shotgun barrel by the weight of a lead ball that just fits it. We measure the kinetic energy of a hydrogen bomb by the mass of TNT that would make the same size hole in the ground.

Quantities and units are not the same thing.

The requirement of a unit is that it should be adequately reproducible. We have no reason to believe that a hyperfine transition of a cesium atom is any different here and now from what it was there and then, so it gives us a useful unit of time.

[guest4091]

I’m not arguing with your basic thoughts on time, but I wonder how time would “accumulate” if it didn’t “flow”.

I pointed to the movies, and the 'moving' images on your computer screen, to show the mind supplies the 'flow'. Events continue to happen, and people continue to perceive them. Our 'now' is the few milliseconds our brain requires to analyze and store the sensory input. 
People waking from a coma do not have any memory of the elapsed time, nor do people with impaired brain functions.(the mind connection)
Time is a human convention for monitoring an amount of activity,
The latest standard is x number of wavelengths of light, a distance, as it has been throughout history.

[demalk (OP)]

Thank you Colin!

A viewpoint. One fundamental aspect of physics is measurement. If we look at the dimensions required to define all other measurements we find that length, mass and time are fundamental measurements, so in that respect I would say time is fundamental.

Agreed, time is a fundamental aspect of measurement and therefore fundamental to our science of physics. However, I am interested in the foundations of reality, not those of the sciences. More about this later.

I would also say that spacetime is a very fundamental concept.

Again, fundamental to science, but not necessarily to reality. The idea of an underlying informational reality seems to be gaining traction among an increasingly credible scientific audience (Erik Verlinde, Leonard Susskind, Max Tegmark to name a few). We should at least entertain the possibility that such a thing might be true, and when we do, we cannot do without reconsidering everything we thought to be fundamental. And yes, that should include the photon as well. More about that later.

Here you are using a different definition of fundamental. The photon is not a dimension or a measurement, so in that way is not comparable to time or space.

This is the definition I intended all along. Fundamental to reality, not science, measurement, observation or anything else. The fact that the photon is not comparable to anything else, is my point exactly. It is the only thing that actually experiences the world objectively.

I agree that understanding the photon is important to understanding much of our universe, but is it more fundamental that say quarks?

Complexity arises from simplicity. Therefore the deeper into reality you peer, the simpler things should become. The incredibly complex structure of the human psyche for example arises from much simpler processes of neurobiology, which emerge from yet simpler processes of chemistry, etc. Get to the periodic table and you're left with 118 (for now) items to describe all of matter. And when we get all the way down to quarks; all of psychology, all of biology, all of chemistry and all of nuclear physics is reduced to six flavours of one and the same particle. Now, we haven't been able to peer any deeper than the quark so from a scientific point of view there is no other option but to assume that this it is the most fundamental particle. And perhaps it will turn out that yes, when it comes to matter, the quark is indeed the most fundamental thing we'll ever find. But...does that also mean it is just as fundamental to reality as the photon? Let's see.

Photons do not interact with the Higgs mechanism. However, high-energy photons can be converted into fermions which do. Quarks are fermions. So once the photon has converted into something with mass, that which it has become is less fundamental in its nature. It has jumped up a level of interactional and existential complexity, from where it is then able to give emergence to atomic nuclei, electrons, all the 118 atoms we know of, all of chemistry, biology and ultimately what we call 'consciousness'. But for any of that to arise, photon-like energy had to be infused with the Higgs field so to say, before it could materialise. IF we define fundamentalness as the deepest level of simplicity that underlies everything else, for now the photon seems to be far ahead of the quark.

Over the past few years an increasing number of experiments have started to investigate the wave/particle nature of atoms and molecules. Have a look at this one from 2015 which indicates that helium atoms can also display delayed choice behaviour. Note the comment near the end which picks up the evolving view of wave/particle behaviour.
http://physicsworld.com/cws/article/news/2015/may/26/do-atoms-going-through-a-double-slit-know-if-they-are-being-observed

Thanks so much, will look into that right now