Questions about time

[Farsight]

The document by "Amrit" was quite obviously written by Farsight.

It wasn't. Amrit wrote it but English isn't his first language so I polished it for him. We think along the same lines. For example in this report there's a quote from him saying "with clocks we measure the numerical order of material change, i.e., motion in space.”

...In order to purse this fantasy

It's no fantasy. Time travel is the fantasy. The flow of time is the fantasy.

...about clocks only responding to motion one has to have some means of saying what counts as the same amount of motion and this requires that we have some idea of what counts as the same interval of time and what counts as the same interval of space.

We define the second and the metre using the motion of light. I've been through all that, see post #63 and wikipedia re the second and the metre.

If someone can show how to do even the simplest of physics applications without these notions, then they might be able to begin to present this wild hypothesis with some degree of plausibility.

I did, in post #140. There's no time in the derivation of the Lorentz factor, just the simplest of geometry. Pythagoras' theorem. But you won't listen because you're a sneering naysayer who thinks he knows it all but actually knows **** all. Instead you come out with dismissive cracks like wild hypothesis and you accuse me of being Amrit Srecko Sorli. I'm not.

 

[Farsight]

Perhaps it is because I have more of a background in theoretical physics and mathematics... but what you describe can be difficult to discuss without defining some of the key terms... sometimes English is too flexible.

You just have to learn to take the evidence at face value.

So if I 'look' at a clock that has stopped, motionless, does that mean there is no 'motion'?

Not in the clock at the macroscopic level. But you can see it, so light is moving from the clock to your eyes, and you can think about what you can see, so electrochemical signals are moving in your brain.

What 'change' is there that we are measuring that denotes motion.

Gradual change in spatial position.

If I look at a pen on a table, look away, look back, and the pen is not there, what does that say about motion?

It says that whilst you were moving your eyes and then looking at something else the pen also moved.

I am not being deliberatly annoyning, I am trying to question the fundamental notions we have and making them ultra clear.

No problem, you're not being annoying. It's all ultra clear anyway provided you just home in on what's actually happening.

More worryingly for me, I have to think about what that means conceptually for the mathematical framework that we will use to describe this...

The maths doesn't change a bit. You still have your t, but you associate it with what you can see and what clocks really do rather than some unseen mystical flowing thing.

What I mean is that just talking in everyday layman's terms no more puts motion on the pedestal than time...in fact for the layman motion and time cannot be teased apart...

You don't need to tease them apart, you just flip them over. It's a trivial change from you need time to have motion to you need motion to have time. You show the layman some science-fiction movie where the hero has pressed the button that stops time. It's now a freeze-frame world with some artistic drops of water or something, only the hero is conceniently unaffected. You ask the layman to look at what he can see, and tell you what's really stopped. The layman won't have any problem giving you the answer: motion.

 

[marplots]

It wasn't. Amrit wrote it but English isn't his first language so I polished it for him. We think along the same lines. For example in this report there's a quote from him saying "with clocks we measure the numerical order of material change, i.e., motion in space.”

Isn't the "order" in that where time comes in? If you could drop the ordering part, "before and after," I think you could make progress.

 

[edd]

So if I posit two systems that progress through the same states you say they must do so at the same rate?

 

[Kwalish Kid]

We define the second and the metre using the motion of light. I've been through all that, see post #63 and wikipedia re the second and the metre.

These definitions of units do not have much bearing on the use of time in physics. You have admitted that you have not actually done and cannot do physics problems, so it is not really surprising that you cannot understand the way physics is done. In order to use these definitions that you have given, one has to already have some idea of what it means for two series of events to share or not the same duration or two begin or end at the same time or at different times.

I did, in post #140. There's no time in the derivation of the Lorentz factor, just the simplest of geometry. Pythagoras' theorem. But you won't listen because you're a sneering naysayer who thinks he knows it all but actually knows **** all. Instead you come out with dismissive cracks like wild hypothesis and you accuse me of being Amrit Srecko Sorli. I'm not.

Why do you make such obvious lies? There is no application given in that post. You have admitted that you cannot actually do physics problems, so why fantasize that you have produced an application? Why fantasize that you have anything to say about physics at all?

 

[Farsight]

Is the argument circular?

No.

Does motion mean the object is in a different position at a different time?

Yes. And you record that different time using something else that features motion: a clock. The clock as a whole isn't gradually changing its spatial position, but its moving parts are.

How do we define motion?

Gradual change in spatial position, the rate of which is calibrated against the motion of light. Or you define it as that thing you can see. What you don't do is define it in terms of something you can't see.

I can accept there is a change in spatial coordinates but how exactly did that change occur?

I don't know what to say other than the object moves.

Are we allowing an arbitrary change in coordinates? Can I say that if A is the point (3,2) that if I now decide A is the point (3,4) I have induced motion? or measured motion?

I don't think so. If the object abruptly changes position that doesn't sound like motion. It has to be a gradual change in position such that the object moves through (3,3) and other intervening points.

Do we have to have two spatial "pictures" to compare?

I imagine so, but maybe it's better to think of a whole series of pictures. Something like a movie.

How do we 'look' at those two pictures side by side to find any change?

When it's two pictures you use a blink comparator. If it's a whole stream of pictures, I'm not sure. Our brains are actually very good at detecting motion, maybe there's some kind of real-time blink comparator in our visual cortex.

 

[Farsight]

Isn't the "order" in that where time comes in?

Maybe. If an object moves from A to C there's an order in there because it moves from A to B then A to C.

If you could drop the ordering part, "before and after," I think you could make progress.

I don't think you can drop the ordering part. If instead of moving from A to C the object moves from location 1 to location 9, there's an order to the motion in that it goes from 1 to 2 to 3 to 4 etc, like 123456789. It moves from 1 to 2 before it moves from 2 to 3 and it moves from 3 to 4 after it moves from 2 to 3. Dropping the order sounds like scrambling things up, and too extreme. All we're really talking about is drawing a pie chart with three equal slices labelled space time and motion, then turning it round so that motion's at the top. It's only a minor change. That IMHO is all you need to do to make progress.

 

[marplots]

So if I posit two systems that progress through the same states you say they must do so at the same rate?

Could you say that another way? I don't understand what you are getting at.

 

[Farsight]

Nor do I. A chemical reaction can proceed at some rate, usually the rate is higher if you warm it. In similar vein a moving object can pass through locations A then B then C at some rate. It might move slow, or it might move fast.

 

[marplots]

Maybe. If an object moves from A to C there's an order in there because it moves from A to B then A to C.

I don't think you can drop the ordering part. If instead of moving from A to C the object moves from location 1 to location 9, there's an order to the motion in that it goes from 1 to 2 to 3 to 4 etc, like 123456789. It moves from 1 to 2 before it moves from 2 to 3 and it moves from 3 to 4 after it moves from 2 to 3. Dropping the order sounds like scrambling things up, and too extreme. All we're really talking about is drawing a pie chart with three equal slices labelled space time and motion, then turning it round so that motion's at the top. It's only a minor change. That IMHO is all you need to do to make progress.

There are other approaches though. You could, for instance, come up with a cyclical process that visits identical states. This would constrain time in the same way that 6:00 today is the same (from the clock's perspective) as 6:00 tomorrow.

Another approach would be to use something that happens without a cause. I'm thinking radioactive decay. While statistically you can put time in there, for an individual particle that will/might/might not decay, causality it broken and you can claim time isn't relevant. (When I reread that, it sounds pretty wooish, but I had some idea going in so I'll leave it.)

You could also localize time to a system that has motion but only a set of finite states. So, for example, you have a bottle filled with a gas that can only reach a finite number of combinations, always returning to a previous "time" when measured only relative to the inside of the container.

Which brings up the question, "Is there time in a bottle?"

My instincts tell me there ought to be time independent functions in physics, but I'm only a layperson, so I can't pull any out to flaunt.

 

[edd]

Ok Farsight's talk of a gradual change is already screwed by the frequently mentioned muon clock - a clock made of unmoving parts with no internal structure as understood by physics.

Now if as I supposed earlier Farsight had accepted that argument and was prepared to accept clocks working on discrete states I had another argument lined up, but as he isn't accepting it I don't have any reason to proceed. His point of view is to me obviously wrong.

 

[RobDegraves]

I have yet to see any actual thesis from either Farsight or Farsight Jr., on how time dilation affects every single possible physical system, from cells to atoms, including every possible measurement system in exactly the way that time dilation says it should but without involving time. To be honest, I have yet to see any actual physics from either, just a lot of assertions and general statements. Do either of them have any background in real physics? I can certainly see why none of this has ever been introduced in an actual physics setting.

 

[Perpetual Student]

It was a great leap forward for physics when Δx/Δt was developed as a precise way to define motion. Consequently, Aristotelian notions of motion were replaced in our scientific thinking, so that space and time have been treated as fundamental quantities ever since. There has not been one single experiment or rationale to change this way of regarding time and space (other than the development of spacetime) and we continue to regard motion as Δx/Δt.
As has been pointed out by several others here, there is no way to define a unit of motion but we have quite clearly found means for defining units for both space and time, which have been scientifically fruitful. In fact, all of the work of Newton, Maxwell, Einstein, and many others has been based on this notion of time and space.
That is not to say that all the basic concepts of physics, space, time, matter, energy, motion, quanta, etc. have any independent meaning. They are all interrelated and our concepts of them do not allow for us to give them some solipsistic meaning.
Debating whether time or motion is more fundamental is nothing more than an adolescent philosophic indulgence. It is indisputable that physics requires that we endow time with units and treat it as a fundamental notion. If there were some way to do that with motion, let it be demonstrated and let's see all the new science that results from that insight.

 

[keyfeatures]

Is the argument circular?

Does motion mean the object is in a different position at a different time?

How do we define motion?

I can accept there is a change in spatial coordinates but how exactly did that change occur?

Are we allowing an arbitrary change in coordinates?

Can I say that if A is the point (3,2) that if I now decide A is the point (3,4) I have induced motion? or measured motion?

Do we have to have two spatial "pictures" to compare?

How do we 'look' at those two pictures side by side to find any change?

The only way to measure time is to compare motion. E.g. - every time A moves 3 times, B moves once. If B suddenly moves twice every time A moves 3 times we assume either B has speed up or A has slowed down. The only way we can tell which is to have further comparative motion checkers.

 

[Kwalish Kid]

The only way to measure time is to compare motion. E.g. - every time A moves 3 times, B moves once. If B suddenly moves twice every time A moves 3 times we assume either B has speed up or A has slowed down. The only way we can tell which is to have further comparative motion checkers.

Look at your sentences. You cannot describe motion without invoking some sort of time. This is just how it is when we are describing relative motion.

In physics there are also things that are not motion-related that happen according to time. Nuclear decay, for example, happens at times and leads to motion, but it is not itself necessarily motion.

 

[Farsight]

There are other approaches though. You could, for instance, come up with a cyclical process that visits identical states. This would constrain time in the same way that 6:00 today is the same (from the clock's perspective) as 6:00 tomorrow.

Groundhog Day! It was a good film, but it was science fiction/fantasy. In the real world you can't get every single atom and electron and photon and neutrino to go back to where or how it was. And it would have been a really boring film if Bill Murray had been reset like everybody and everything else. Anyway, sure, you can contrive a clock based on some cyclical subatomic process that revisits identical states, but it's still a cyclical process/change/motion.

Another approach would be to use something that happens without a cause. I'm thinking radioactive decay. While statistically you can put time in there, for an individual particle that will/might/might not decay, causality it broken and you can claim time isn't relevant. (When I reread that, it sounds pretty wooish, but I had some idea going in so I'll leave it.)

I think it's better to say the cause is unclear. There's been talk of decay rates showing seasonal variations suggesting that the solar neutrino flux contributes to "unbalancing" the atom so that it shakes itself apart like an unbalanced flywheel. We were talking about something similar re muon decay on another thread, wherein the magnetic dipole moment and the Einstein-de Haas effect suggests that spin is a genuine rotation. The upshot IMHO is that radioactive decay can be likened to a warehouse full of humming machines with an average lifetime. Some of them break down, and you can estimate the time by counting how many are still going.

You could also localize time to a system that has motion but only a set of finite states. So, for example, you have a bottle filled with a gas that can only reach a finite number of combinations, always returning to a previous "time" when measured only relative to the inside of the container.

I suppose you could, if the bottle of gas was all there was. But it sounds a bit of a stretch for the whole universe.

Which brings up the question, "Is there time in a bottle?"

What's actually in the bottle is gas molecules, and they're moving. But if they're moving very fast, I could ask you to pick up that bottle and say Is there heat in a bottle?" When you burn your hand and drop it and it smashes on the floor, you know that the answer is yes. It's similar for time. It's an emergent property of motion, but cumulative rather than an average. Slow molecules, cold gas. Fast molecules, hot gas.

My instincts tell me there ought to be time independent functions in physics, but I'm only a layperson, so I can't pull any out to flaunt.

There are, see for example the time-dependent Schrödinger equation. But I don't think they help much. Look at the gif of the waveforms on the right, and you don't see time flowing, you see things moving. Or not, as the case may be. Only to see something not moving, light has to move to your eye, electrochemical signals have to move around your brain, so you still can't away from motion.

 

[keyfeatures]

Look at your sentences. You cannot describe motion without invoking some sort of time. This is just how it is when we are describing relative motion.

In physics there are also things that are not motion-related that happen according to time. Nuclear decay, for example, happens at times and leads to motion, but it is not itself necessarily motion.

You can't invoke anything in language without invoking time because of the way language is constructed. Once it's been named real, the illusion is complete.

You give one example of (nuclear decay) as if there are many. Can you give another one? I'd also say this is to do with current state of observables rather than reality. Same state giving different outcomes according to nothing but probability doesn't really make sense.

 

[edd]

We were talking about something similar re muon decay on another thread, wherein the magnetic dipole moment and the Einstein-de Haas effect suggests that spin is a genuine rotation. The upshot IMHO is that radioactive decay can be likened to a warehouse full of humming machines with an average lifetime. Some of them break down, and you can estimate the time by counting how many are still going.

If the rate at which muons decay is related to either of those things why do a clock made out of muons and a clock made out of tau leptons run at different rates? Muons and tau leptons have the same charge and spin properties.

Sure they differ in mass, but why then does a clock made in the same way but out of electrons not run at all?

Why does a muon apparently hold no internal state - it's completely unchanging until it decays. If I hand you a muon you have no way to determine how old it is. It could have been sitting there for a tenth of a second being very very lucky and not decaying, and when I give it to you your expectation of its lifetime is still 2.2 microseconds.

Something is going on there that is not governed by the spin, not governed by the magnetic moment and which differs between the generations of leptons, and there is no reason to think it involves movement through space.

I suppose you could, if the bottle of gas was all there was. But it sounds a bit of a stretch for the whole universe.

So now you want to bring the whole universe in - that's a remarkably nonlocal theory of time you have.

I don't see how time can be an 'emergent property of motion' in that way, and I don't see how it can be an emergent property of the even more basic idea of changing states. The ideas of muon and tau clocks essentially are that you can estimate how much time has passed by how much their macrostate of the number of remaining particles has changed, but that macrostate evolves at different rates for the two clocks. It's like noting that the second law of thermodynamics tells you entropy must increase over time, but it doesn't tell you how fast.

And again I don't see that noting that a system that hasn't changed doesn't allow you to estimate the passing of time tells us anything fundamental that we didn't already know - that the laws of physics are invariant under time translation.

 

[Michael C]

The only way to measure time is to compare motion. E.g. - every time A moves 3 times, B moves once. If B suddenly moves twice every time A moves 3 times we assume either B has speed up or A has slowed down. The only way we can tell which is to have further comparative motion checkers.

You're still confusing the thing being measured with the method used to measure it.

By the same logic, I can say that heat or mass are in fact motion. I have a mercury thermometer, where an increase in heat is corresponds to a motion of the mercury in the tube. I also have a thermometer where an increase in heat causes a bimetallic strip to move. The spring on my bathroom scales moves more or less depending on how much mass I place on it.

In each case, we use a specific motion to measure a quantity because we have found out that that this particular motion has a consistent relation to the quantity we wish to measure. We can't use the motion of the mercury in the thermometer to measure time, any more than we can use a pendulum to measure heat. "Motion" is not a fundamental quantity. It simply happens that certain very specific types of motion can be used to measure certain fundamental quantities.

 

[Farsight]

If the rate at which muons decay is related to either of those things why do a clock made out of muons and a clock made out of tau leptons run at different rates? Muons and tau leptons have the same charge and spin properties.

There aren't any muon or tau clocks, but if there were, we'd calibrate them so that they ran at the same rate, taking account of the different lifetimes. It would be like two factories full of humming machines, one where the average lifetime is a day, the other where it's a year. You don't worry about a pendulum clock running at a different rate to a quartz wristwatch, so you shouldn't find this a problem.

Sure they differ in mass, but why then does a clock made in the same way but out of electrons not run at all?

Because electrons are stable.

Why does a muon apparently hold no internal state - it's completely unchanging until it decays. If I hand you a muon you have no way to determine how old it is. It could have been sitting there for a tenth of a second being very very lucky and not decaying, and when I give it to you your expectation of its lifetime is still 2.2 microseconds.

Because the muon is a state. Ditto for an electron. The state changes when you do pair production or annihilation or when decay occurs.

Something is going on there that is not governed by the spin, not governed by the magnetic moment and which differs between the generations of leptons, and there is no reason to think it involves movement through space.

There's plenty of reason. A radiating body loses kinetic energy, electrons and positrons annihilate to photons departing at c, muon decay features nuetrinos departing at c, you can diffract electrons and muons, there's a c in the Dirac equation, the list goes on. Au contraire, there's no reason to think it doesn't. The "must be going faster than light" justification for intrinsic spin is a straw man that disregards the wave-nature of matter.

So now you want to bring the whole universe in - that's a remarkably nonlocal theory of time you have.

I don't, and this goes back to the ancient Greeks. It isn't something I've just made up myself.

I don't see how time can be an 'emergent property of motion' in that way, and I don't see how it can be an emergent property of the even more basic idea of changing states. The ideas of muon and tau clocks essentially are that you can estimate how much time has passed by how much their macrostate of the number of remaining particles has changed, but that macrostate evolves at different rates for the two clocks. It's like noting that the second law of thermodynamics tells you entropy must increase over time, but it doesn't tell you how fast.

There aren't any muon and tau clocks, and if they were the different rates are academic. We don't worry about the different half-lives of different radio-isotopes and say Oh dear, time must be passing at different rates. Besides, time has passed is a figure of speech. You can't see time passing. Whoosh! There it goes. No. Try to get out of the habit of saying things like this. Focus on what yuou can see.

And again I don't see that noting that a system that hasn't changed doesn't allow you to estimate the passing of time tells us anything fundamental that we didn't already know - that the laws of physics are invariant under time translation.

No, but giving priority to motion tells you something you didn't know about gravity and black holes and much else.