Relativity Explained Via Movement, Not Time

[Islam Hassan]

Relativity Explained Via Movement, Not "Time"

There is no clock that will measure time independently of movement. And conversely, nothing ever happens that does not move.

Why then do physicists persist in using the notion of "time" in explaining relativity? It would be so much easier, more intuitive and correct to talk of (relative) movement and not time. Things like "time" stopping when we perceive a massive projectile traveling at the speed of light: "time" is a purely anthropic notion that neither begins nor stops since it has no physical existence in itself. What will stop is *movement* this is intuitively easy to understand since mass tends to infinity at the speed of light and you require infinite energy to make it *move*.

Why are physicists so hooked on "time" when only movement exits. I believe that explanations of physical phenomenon -including relativity- would be so much easier using *movement* instead...

IH

 

[WannabeNewton]

Errr...a clock in your own reference frame will proudly measure time even though you are stationary.

 

[Mentz114]

There is no clock that will measure time independently of movement. And conversely, nothing ever happens that does not move.

Why then do physicists persist in using the notion of "time" in explaining relativity? It would be so much easier, more intuitive and correct to talk of (relative) movement and not time. Things like "time" stopping when we perceive a massive projectile traveling at the speed of light: "time" is a purely anthropic notion that neither begins nor stops since it has no physical existence in itself. What will stop is *movement* this is intuitively easy to understand since mass tends to infinity at the speed of light and you require infinite energy to make it *move*.

Why are physicists so hooked on "time" when only movement exits. I believe that explanations of physical phenomenon -including relativity- would be so much easier using *movement* instead...

IH

How can you define movement without time. This is nonsense, you're kidding, right

 

[Islam Hassan]

Not if you are rigourous it won't. It will measure the relative movement of a mechanical mechanism with respect to the only invariant movement reference there is, namely the movement of a particle whizzing along at the speed of light. Our anthropic sense of "time" can never, ever, ever be measured independently of movement.

IH

 

[Islam Hassan]

Errr...a clock in your own reference frame will proudly measure time even though you are stationary.

Not if you are rigourous it won't. It will measure the relative movement of a mechanical mechanism with respect to the only invariant movement reference there is, namely the movement of a particle whizzing along at the speed of light. Our anthropic sense of "time" can never, ever, ever be measured independently of movement.

IH

 

[Mentz114]

Not if you are rigourous it won't. It will measure the relative movement of a mechanical mechanism with respect to the only invariant movement reference there is, namely the movement of a particle whizzing along at the speed of light. Our anthropic sense of "time" can never, ever, ever be measured independently of movement.

IH

If you're being 'rigorous', I think I'll give it a miss.

 

[Islam Hassan]

How can you define movement without time. This is nonsense, you're kidding, right

You define (relative) movement with respect to a standard, invariant movement benchmark, namely the movement of a particle traveling at the speed of light. Your movement and the particle's movement both exist and can be directly perceived and measured. "Time" in itself can't, it is a human construct has no proper physical existence in itself.

IH

 

[Ryan_m_b]

Not if you are rigourous it won't. It will measure the relative movement of a mechanical mechanism with respect to the only invariant movement reference there is, namely the movement of a particle whizzing along at the speed of light. Our anthropic sense of "time" can never, ever, ever be measured independently of movement.

IH

What do you mean? A clock ticks at the same rate always. This change is helpful in defining discrete units of time.

Movement must occur over time otherwise it is not movement.

 

[DaveC426913]

There is no clock that will measure time independently of movement. And conversely, nothing ever happens that does not move.

Your premise is flawed. Your second statement does not follow from your first. Clocks are human inventions. We make them move so that we observe change. It does not follow inevitably that time cannot occur without movement.

"time" is a purely anthropic notion that neither begins nor stops since it has no physical existence in itself.

Time existed quite nicely long before we anthropes came along. Lo, it existed for 10 billion years before any kind of life came along.


If you're going to claim "rigor" in logic, you're going to have to form better arguments than this.

 

[Islam Hassan]

Your premise is flawed. Your second statement does not follow from your first. Clocks are human inventions. We make them move so that we observe change. It does not follow inevitably that time cannot occur without movement.

Very interesting; conceptually, I would have thought that if everything in the universe were perfectly static, then you cannot conceive of something called "time". The only thing that could then conceive of "time" is the observer's mind, which would in any case be an extraneous intrusion in a totally static universe.

Do physicists conceive of time in a totally static system, independent of any dynamic observing entity?

IH

 

[kmarinas86]

Very interesting; conceptually, I would have thought that if everything in the universe were perfectly static, then you cannot conceive of something called "time". The only thing that could then conceive of "time" is the observer's mind, which would in any case be an extraneous intrusion in a totally static universe.

Do physicists conceive of time in a totally static system, independent of any dynamic observing entity?

IH

Yes they do.

 

[danR]

But the speed of light is a constant, in all reference frames, that requires two measures: length and time. Same with any movement. v=L/t.

'Time' is a great mystery, but when we talk about 'movement' it has to be used. Sometimes.

 

[Islam Hassan]

Your premise is flawed. Your second statement does not follow from your first. Clocks are human inventions. We make them move so that we observe change. It does not follow inevitably that time cannot occur without movement.


Time existed quite nicely long before we anthropes came along. Lo, it existed for 10 billion years before any kind of life came along.


If you're going to claim "rigor" in logic, you're going to have to form better arguments than this.

How then, when one makes a measure of the speed of an object or particle, can you distinguish *independently* the time component from the movement component? To my mind, movement is directly perceived and measured whereas "time" a ratio deriving from the movement measure vs the movement of an absolute reference, viz a particle moving at the speed of light.

IH

 

[Ryan_m_b]

Very interesting; conceptually, I would have thought that if everything in the universe were perfectly static, then you cannot conceive of something called "time". The only thing that could then conceive of "time" is the observer's mind, which would in any case be an extraneous intrusion in a totally static universe.

Do physicists conceive of time in a totally static system, independent of any dynamic observing entity?

IH

You can't have a totally static system. At the quantum level stuff will still happen. Even in a material that is absolute zero although the atoms might not move electrons still orbit, photons still bounce about etc

To suggest a 100% static system where no subatomic particle moves and things like vacuum fluctuations do not occur is like asking "what do the laws of physics have to say on this idea wherein we ignore the laws of physics?"

 

[DaveC426913]

How then, when one makes a measure of the speed of an object or particle, can you distinguish *independently* the time component from the movement component? To my mind, movement is directly perceived and measured whereas "time" a ratio deriving from the movement measure vs the movement of an absolute reference, viz a particle moving at the speed of light.

IH

Well, you can measure the frequency of a photon and thus derive a pretty good clock from that, yet nothing in the photon could be considered moving.

I am measuring a frequency of approximately 600THz with nothing but my eyes while looking at the greenery in my garden.

 

[danR]

"Time" in itself can't, it is a human construct has no proper physical existence in itself.

IH

I would be making as much sense saying "Length" is a human construct, and has no temporal existence in itself.

 

[DaveC426913]

Well, this is why we live in a 4-dimensional universe. It requires 4 independent coordinates to define any real point in it. If a point has only 3 coordinates, then it is undefined. That includes length (x) and time (t). And while they are independent, they also are interdependent, changing x will change t.

 

[Islam Hassan]

Well, you can measure the frequency of a photon and thus derive a pretty good clock from that, yet nothing in the photon could be considered moving.

I am measuring a frequency of approximately 600THz with nothing but my eyes while looking at the greenery in my garden.

Agreed, and I would add that the operative word in your post is "derive". Our measure of time can only ever be indirect, via phenomena -like frequency- linked to movement. Nothing *in* the photon is moving but its frequency is linked to a dynamic phenomenon, that of its wave-like nature. So we are back to movement...

IH

[I am quite the layman, and may be making a right fool of myself here, but this time thing has been bugging me for a while now...]

 

[danR]

To my mind, movement is directly perceived and measured whereas "time" a ratio deriving from the movement measure vs the movement of an absolute reference, viz a particle moving at the speed of light.

IH

Yes, t is a 'ratio', if you want to say that t=L/v. Then t=Lt/L. I'm not very good at higher math, but I don't think that is going to get me very far.

 

[ZapperZ]

Agreed, and I would add that the operative word in your post is "derive". Our measure of time can only ever be indirect, via phenomena -like frequency- linked to movement. Nothing *in* the photon is moving but its frequency is linked to a dynamic phenomenon, that of its wave-like nature. So we are back to movement...

IH

[I am quite the layman, and may be making a right fool of myself here, but this time thing has been bugging me for a while now...]

But then, everything is 'derived'. So why picked on "time"?

This whole thread is very puzzling. You make use of light speed, etc., yet, each of these things have implicitly assumed a "time" dimension. How do you defined light without having a time implicit in its velocity?

I will also tell you that a "movement" is undefined without an implicit involvement of time. Our measurement of a unit of space depends directly on our ability to define time, via the speed of light. Unless you think you can formulate a different theory of Special Relativity, this involvement of time cannot be separated out.

Zz.

 

[rede96]

Looking at the simple space-time diagrams I've seen, if something moves through space, it sacrifices moving through time. If something travels at the speed of light, it is not moving through time at all.

The speed of light is the same for all frames of reference. So maybe there is the same situation and the other end of the scale. If something has 'zero' movement, it must be moving through time at the maximum rate.

EDIT: So does that imply that there is a universal rate for time that is the same for all observers?

 

[danR]

Nothing *in* the photon is moving but its frequency is linked to a dynamic phenomenon, that of its wave-like nature. So we are back to movement...

IH

[I am quite the layman, and may be making a right fool of myself here, but this time thing has been bugging me for a while now...]

If we're back to movement, we're back to L/t. That little sucker ain't going away any time soon.

You're not making a fool of yourself. Reality is perplexing. Besides, if I want to make a fool of myself, PF is one of the easiest places to do it.

 

[kmarinas86]

"Relativity Explained Via Movement, Not 'Time'"

Relativity mixes distance with time. So, according to relativity, a "movement" represents some combination of displacement through distance and time. More time or more distance means more movement. Less time or less distance means less movement.

Why then do physicists persist in using the notion of "time" in explaining relativity?

[...]

Why are physicists so hooked on "time" when only movement exits.

Because Einstein invented the concept of a space-time continuum instead of a space-frequency continuum.

 

[Islam Hassan]

But then, everything is 'derived'. So why picked on "time"?

This whole thread is very puzzling. You make use of light speed, etc., yet, each of these things have implicitly assumed a "time" dimension. How do you defined light without having a time implicit in its velocity?

I will also tell you that a "movement" is undefined without an implicit involvement of time. Our measurement of a unit of space depends directly on our ability to define time, via the speed of light. Unless you think you can formulate a different theory of Special Relativity, this involvement of time cannot be separated out.

Zz.

This is all getting very confusing very quickly...regarding defining movement without an implicit involvement of time however, how about this: when my car has traveled X meters, i measure the distance traveled by a ray of light which was emitted as the car started to move. My car would then have traveled an equivalent Y meters of light. This is how I would think of doing it since light is my absolute displacement reference.

IH

 

[my_wan]

I actually have to support Hassan to a degree. I would qualify it more as an event sequence but to say it has some absolute reality outside of the event sequence used to measure it smacks of Newtonian physics to me. It is this artificialness as an independent variable that gets us in trouble with common notions of simultaneity.

 

[danR]

This is all getting very confusing very quickly...regarding defining movement without an implicit involvement of time however, how about this: when my car has traveled X meters, i measure the distance traveled by a ray of light which was emitted as the car started to move. My car would then have traveled an equivalent Y meters of light. This is how I would think of doing it since light is my absolute displacement reference.

IH

I think this is going in the right direction. This scenario necessarily involves temporal markers 'when', 'has (travelled)', 'was', 'then' etc, and the notions of signals and 'simultaneity'. If you follow through long enough, you will have to deal with time. Einstein also had to wrestle with such things and the whole thing was inextricably entangled in time. At least that's an impression I recall when I went through his little book on SP years ago.

 

[danR]

I actually have to support Hassan to a degree. I would qualify it more as an event sequence but to say it has some absolute reality outside of the event sequence used to measure it smacks of Newtonian physics to me. It is this artificialness as an independent variable that gets us in trouble with common notions of simultaneity.

Time is mysterious, but not artificial. It was Einstein's insight that length and time are bound inextricably in a cosmic ying-yang: specifically the L/t 'c', and that that value is a constant, either by measure, or by axiom.

length and time both are relative to this fixed value, still a very counterintuitive notion.

 

[atyy]

Agreed, and I would add that the operative word in your post is "derive". Our measure of time can only ever be indirect, via phenomena -like frequency- linked to movement. Nothing *in* the photon is moving but its frequency is linked to a dynamic phenomenon, that of its wave-like nature. So we are back to movement...

IH

[I am quite the layman, and may be making a right fool of myself here, but this time thing has been bugging me for a while now...]

This is possible in special relativity. The speed of light (movement) is defined to be fundamental and exact, while the second is defined as an integer number of periods of a certain vibration (movement). (I seem to have used "movement" in 2 different ways there!)

http://physics.nist.gov/cgi-bin/cuu/Value?c
http://www.bipm.org/en/si/si_brochure/chapter2/2-1/second.html

You can also look at Woodhouse's notes http://people.maths.ox.ac.uk/nwoodh/sr/index.html , p12, where he says we don't know what a thing is unless we specify how we measure it. He proposes to accept vibrations (movement) of an atom as fundamental, and from there define a clock (time).

Another line of thinking that seems related to your intuition is given by Barbour in http://arxiv.org/abs/0903.3489 .

Generally, there are many notions of "time" in physics - coordinate time, proper time, cosmological time, second law time etc. So a proper discussion usually needs to specify which "time" one is talking about. Although I have agreed with you to some extent that time is most easily defined if we have vibrations, it is actually not necessary. In Newtonian physics, time is defined so as to make Newton's second law (movement!) true.

 

[danR]

This is possible in special relativity. The speed of light (movement) is defined to be fundamental and exact, while the second is defined as an integer number of periods of a certain vibration.

http://physics.nist.gov/cgi-bin/cuu/Value?c
http://www.bipm.org/en/si/si_brochure/chapter2/2-1/second.html

Another line of thinking that seems related to your intuition is given by Barbour in http://arxiv.org/abs/0903.3489 .

The link is using time, in m s^-1. That's an L/t relationship. Also 'period' entails time.

 

[pervect]

The quantum-mechanical transitions that occur in an atomic clock are only vaguely related to any physical "movement" or motion.

So, I don't think the case for making movement "more fundamental" than time is very good at all when analyzed properly.

Physics actually does a pretty good job of separating time into at least two very different but useful notions which are (IMO) commonly confused and conflated by the non-physicist.

Proper time is the time measured by a clock. In the language of physics, its an interval of time, similar to the way the meter is an interval of space. Proper time is what you measure with a clock. It is well defined, the SI unit of time is a specified transition of a certain quantum-mechanical transition of a particular isotope of cesium, and it doesn't "slow down" or "stop" in any meaningful sense.


Coordinate time is the assignment of a time coordinate to events for bookeeping purposes. Physics recognizes that this assignment is more or less arbitrary. It's the laypeople here who often get the most confused (in my opinion, anyway).

Coordinate time leads to the notion of comparing distant clocks, to create an "instant of time", a "now". This notion is more or less subjective as physics recognizes (though it seems to be a problem often to get the lay audience to come to the same realization.) It's a totally different notion of time than the notion of proper time.

Coordinate time, also leads to the concept of time "slowing down", when one measures the actual proper time that elapses with a clock given a particular choice of coordinate systems. In my opinion, the popularizations that think of time as slowing down miss the point. Time always passes at 1 second per second - it's the coordinate system that changes, not anything related to the rate at which time "happens".

Since the coordinates are a purely human invention, and furthermore a matter of convention -one is free to chose to use different coordinate systems - it's somewhat illogical to give them such priority. But many people do anyway.

So, in conclusion, I think time is here to stay, and is a much better basis that "movement" to describe physics. However, it is useful to break the notion of time down into separate issues, the notion of proper time, which one measures with a clock, and which is independent of the observer, and the notion of coordinate time, which is a convention that is observer-dependent.

 

[my_wan]

Time is mysterious, but not artificial. It was Einstein's insight that length and time are bound inextricably in a cosmic ying-yang: specifically the L/t 'c', and that that value is a constant, either by measure, or by axiom.

length and time both are relative to this fixed value, still a very counterintuitive notion.

Time is only intrinsic to the degree that the sequence of events at a given point cannot involve the exact same event happening both before and after a reference event. Yet it becomes undefined relative to a separable point, hence both really simultaneous and really not simultaneous at the same time if time is given an independent status. Hence a violation of the principle of contradiction. Same thing happens when consider you how long now is relative to another observer. Two observers at 86% C are correct in saying that their now is twice as big as the others now.

If I claimed to have a light switch that stopped time in the Universe for a day, what would be the physical consequence if the claim was true? Zilch, nothing. It would have no empirical consequence whatsoever. Not even the day it was supposed to be turned off is real, since there is no events to define a day. How the information defined in a physical event set can vary in relation to one another to allow relativistic time dilation is trivial to outline. How such time dilation can somehow manipulate time defined as an independent variable seems to require a magic wand. Do you need an outline of a mechanistic analogy of the relation between space and time (not a claim of how it 'really' is)?

 

[ZapperZ]

This is all getting very confusing very quickly...regarding defining movement without an implicit involvement of time however, how about this: when my car has traveled X meters, i measure the distance traveled by a ray of light which was emitted as the car started to move. My car would then have traveled an equivalent Y meters of light. This is how I would think of doing it since light is my absolute displacement reference.

IH

That light would have traveled a distance in a particle time! It doesn't do that instantaneously! There is a time component here!

Zz.

 

[my_wan]

Pervect pretty much nailed it. The second notion of time (not proper time) in my opinion is merely the consequence of requirement to impose causal constraints on the order of such events. Hence it is a bookkeeping or symmetry that appears sort of like a background time. But is is just a causal constraint, not some absolute that runs independently from the proper time.

 

[danR]

Time is only intrinsic to the degree that the sequence of events at a given point cannot involve the exact same event happening both before and after a reference event. ...

If I claimed to have a light switch that stopped time in the Universe for a day, what would be the physical consequence if the claim was true? Zilch, nothing. It would have no empirical consequence whatsoever. ...Do you need an outline of a mechanistic analogy of the relation between space and time (not a claim of how it 'really' is)?

The way you use time-markers tells me that 'time' is a very real psychological/linguistic entity. The way physicists use 'time' likewise indicates they regard it as not only real, but in the formalism of 4-space description, entirely interchangeable with 'space'. And Einstein necessarily needed time in his analysis of simultaneity: things either happen at the same 'time', or they do not. 'Events' are informally time entities, not space or movement entities. One could almost consider an 'event' a motionless scalar thing.

 

[danR]

Pervect pretty much nailed it. The second notion of time (not proper time) in my opinion is merely the consequence of requirement to impose causal constraints on the order of such events. Hence it is a bookkeeping or symmetry that appears sort of like a background time. But is is just a causal constraint, not some absolute that runs independently from the proper time.

The thing is the thesis of this post: Relativity explained via Movement, not "Time". In fact, we could re-write the title:

'Relativity Explained by L/t, not "t".'

Well enough. I don't think that's too far from what Einstein said, the L/t in question being c, which is a constant in all observers' frames of reference. Sorta QED, no?