So we have problems with clocks measureing time ?

[mattcom]

what? a clock is something that measures time, like anything else, even the clock work of a solar system. but that solar system IS moving very fast through space, around the center of the galaxy. and how fast is that galaxy moving? are we all moving through space at an amazing speed? how does that effect the rate of clocks? or the rate of a solar system clock? sorry, i may be on a differnt level of understanding than you scientists. what exactly are u talkin bout?

 

[n0n]

what is all this frame talk? frame this frame that, whatever I haven't had time to read the rest of the posts just the last few, so if this has been said before sorry. I think time is fluid, like water & air going from hot to cold

that the fluid(time) uses a scale like absolute 0 temp. only absolute 0 temp. would be the speed of light or 299792458 meter/sec. and any range above absolute 0 temp. would be effected by time much like absolute 0 temp. is effected by heat. For time is infinite distance and is why Einstine declared Space and Time to be the same thing. Thier for time shouldn't be based on frame but on a relitiveness to light.

unit-time to travel (on 2D of Distance)@ speed=(distance/(speed/C))/Distance
C = 299792458 m/s

this then shows the ability to observe separate time continuums. I am on a rocket going the speed of light, it will take 1 time unit for me to get any distance, but say I were traveling 5,000,000,000meters . you would see 16.6782047seconds (or depending on the distance any amount of time).
Based on our rotation around the earth(1609344m/s) and sun(107826048m/s), and say my rocket were in space starting at (0m/s), you would only feel 2.7394470 unit-time. within my 1. note: if the distance were the same as the speed of light but the speed were different the classic t = d/s would work. so the slower you go over a larger area means more unit-time's. but at c always just 1 unit-time, even if its 1000million m away or even greater.

this is usefull in gyro's, for they can tell any movement changes and time relative to the objects initial starting point and speed. the accuracy of the clock would then be dependent on the accuracy of the labled initinal starting point and speed. a chip could calculate the difference and reset itsslef to keep perfect time without a hitch. for as long as the gyro's would keep going

some say that light goes can go faster then the speed of light, gravity waves move at the speed of light too so thierfor gravitational speed increase in relation to light is not increasive only decreasive.

 

[4newton]

what? a clock is something that measures time, like anything else, even the clock work of a solar system. but that solar system IS moving very fast through space, around the center of the galaxy. and how fast is that galaxy moving? are we all moving through space at an amazing speed? how does that effect the rate of clocks? or the rate of a solar system clock? sorry, i may be on a differnt level of understanding than you scientists. what exactly are u talkin bout?

In the spatial dimension you are only able to move in one direction and at only one speed at a time. Your speed and direction are the vector sum of all the forces that act on an object, you, in this case, are the object. Your current direction and rate are as you state. The result of all the actions you list and more. If however you move out into space and you pick a direction and apply a force that will cancel all of the motion you will come to a point of rest or steady state.

Clocks tick at a rate that is dependent on how fast they are moving. Clocks that move faster tick slower and as clocks move in the spatial dimension at a rate that approaches the speed of light the tick of the clock approaches zero.

The question is what is the maximum rate that a clock can tick? In theory this would be when your motion in space is zero. You would then be at a point of zero motion, or zero velocity. That point then would be the zero reference frame for clocks. No clock can run faster because you can not go slower then zero velocity. The experiment that I proposed is to find the point of zero velocity.

 

[Prometheus]

If however you move out into space and you pick a direction and apply a force that will cancel all of the motion you will come to a point of rest or steady state.

Are you suggesting that it is possible to come to a point of rest with respect to the entire universe?

The question is what is the maximum rate that a clock can tick? In theory this would be when your motion in space is zero. You would then be at a point of zero motion, or zero velocity. That point then would be the zero reference frame for clocks. No clock can run faster because you can not go slower then zero velocity. The experiment that I proposed is to find the point of zero velocity.

Zero velocity is absolutely meaningless, unless you are of the opinion that all non-accelerating velocities are at zero velocity, in which case it is relatively meaningless (pun intended).

I do not understand how you can consider it possible for an object to be at complete rest with respect the the entire universe, which will never be at rest with respect to the object. Perhaps you might elucidate this.

 

[n0n]

I think that this has been said before but, their is no such thing as no movement in space. for one, time, speed, and distance are all referances to things on earth. and in space only inirtia exists so any direction at any speed could still be considered not moving at all. time is erronious in that aspect but using constants and relitive referance points, we can figure it out. in a designated distance if you don't speed then time= inf->. but if you do speed then its all relitive. so 1 Distance = infinite time (0 movement in relation to bass object), infinite distance = 1 time (speed of light).

 

[russ_watters]

I think we have a starting point.
The main point is that we now agree that the rate of clocks is bi-directional. If a clock ( L ) that has been moving with a velocity in a spatial dimension and has a spatial velocity that is less than clock ( M ) and clock ( H ) and clock ( M ) has been moving at a velocity that is less than clock ( H ) then, clock ( H ) will run the slowest and clock ( L ) will run the fastest and by agreement, clock ( M ) is in the exact middle and has a rate to that effect.
If we bring all three clocks together, after a set time period, without changing the conditions of clock ( M ) then, clock ( L ) will have accumulated the most time and clock ( H ) will have accumulated the least time.

Do we still agree?

Yep. Still there.

Direct measurement is the key word. At that time no one had measured the change of clocks or rigid objects with velocity.

Quite right. Time dilation was predicted mathematically based on the observation that the speed of light is constant. But are you saying that he shouldn't have suggested it because it hadn't yet been observed? That isn't now, nor ever has been the way science works. Ptolmey's epicycles were such a mathematical model. They matched the observations of known motions because they were designed to - but they had no real predictive value (ie they could only tell you what you already knew about the motion of the planets). Making predictions isn't just a requirement of the scientific method, its the whole reason science exists.

 

[russ_watters]

what? a clock is something that measures time, like anything else, even the clock work of a solar system. but that solar system IS moving very fast through space, around the center of the galaxy. and how fast is that galaxy moving? are we all moving through space at an amazing speed? how does that effect the rate of clocks? or the rate of a solar system clock? sorry, i may be on a differnt level of understanding than you scientists. what exactly are u talkin bout?

I don't know how new this idea is to you, mattcom, so this may come as a shock: the rate of the passage of time is not constant. It varies with speed and gravity.

what is all this frame talk? frame this frame that, whatever I haven't had time to read the rest of the posts just the last few, so if this has been said before sorry.

All physical measurments require a well-defined frame of reference for them to have any meaning. Voltage is measured with respect to a ground, temperature on a scale tied to the behavior of water. Speed is measured with respect to an arbitrary stationary observer.

It may be that this seems so basic to you that you've never even thought about it. If so, fine - its been a part of science since the very beginning, but still (clearly) some people have issues with the concept.

Are you suggesting that it is possible to come to a point of rest with respect to the entire universe?

Yes, that is what is being incorrectly suggested.

 

[brodix]

Well, Dr. Dick should be back soon. Are we discussing measuring time, or what is time?

As my point seems to have been lost in the shuffle, I may as well repeat it;

All physical measurments require a well-defined frame of reference for them to have any meaning. Voltage is measured with respect to a ground, temperature on a scale tied to the behavior of water. Speed is measured with respect to an arbitrary stationary observer.

It may be that this seems so basic to you that you've never even thought about it. If so, fine - its been a part of science since the very beginning, but still (clearly) some people have issues with the concept.

That frame of reference is relative and since time is a measure of motion, it is effectively going in the opposite direction. While the unit of time goes from beginning to end, the process(the frame of reference) is going on to the next unit, toward beginnings, leaving ends.

 

[4newton]

It has been agreed that:
If a clock moves from reference frame ( H ) to reference frame ( M ) the clock will have an increase in rate, the clock will tick faster. Like wise a clock that moves from ( M ) to ( L ) will again increase in rate.
Therefore if the rate of a clock is relative only from frame to frame then the process may continue without limit and the clock rate will increase without limit. You have but two choices. A point where velocity may be absolute zero or time rate without limits.
This of course also applies to meter rods. Your meter rod would increase to infinity.
Do we still agree?

 

[4newton]

All physical measurements require a well-defined frame of reference for them to have any meaning. Voltage is measured with respect to a ground.

this is correct. Your voltage may decrease until it reaches zero the same as you reference. The two points then have the same number of electrons or no electrons. Both are valid for the measurement.
Are you suggesting that every place in the universe must have electrons?

 

[russ_watters]

It has been agreed that:
If a clock moves from reference frame ( H ) to reference frame ( M ) the clock will have an increase in rate, the clock will tick faster. Like wise a clock that moves from ( M ) to ( L ) will again increase in rate.

You said nothing in your last post about a clock moving into a different reference frame. All you had were 3 clocks in 3 frames moving at 3 speeds. But if you accelerate H's clock to M's speed, its tick rate will slow down relative to a stationary observer.

Therefore if the rate of a clock is relative only from frame to frame then the process may continue without limit and the clock rate will increase without limit.

Except for the caveat that no clock can stop due to time dilation because no clock can go the speed of light, there is no limit to how different the readings of two identical clocks can be.

You have but two choices. A point where velocity may be absolute zero or time rate without limits.

Since nowhere in any of this has the word "absoute" appeared, it doesn't belong there either. In fact, it directly contradicts everything we were just agreeing on: if everything is relative (except C), then how can anything be absolute?

Maybe I should have forced you to specify after you first brought up the speeds of M, L, and H: speed relative to what? A stationary observer is, of course, the answer, but that's still not good enough: is that an absolutely or relatively stationary observer? If you say absolutely, then you are assuming that speed is absolute, not demonstrating it.

In any case, if you jump into a spaceship and accelerate to just under the speed of light, you will return to Earth to find an almost infinite amount of time passed on earth: Your clock was going almost infinitely slower than an identical clock on Earth and the clock on Earth was going almost infinitely faster than yours. That's a time rate without limits.

This of course also applies to meter rods. Your meter rod would increase to infinity.

In actuality, if you are measuring its length with a clock and a speedometer, it can either increase to infinity or decrease to zero.

this is correct. Your voltage may decrease until it reaches zero the same as you reference. The two points then have the same number of electrons or no electrons. Both are valid for the measurement.
Are you suggesting that every place in the universe must have electrons?

This may have been a bad example because there can be an absolute ground (and an absolute zero temperature, for that matter). The point was that in a circuit, voltage is measured between any two points in the circuit.

Sorry, but this is so self-evident for low-speed applications that I'm having trouble giving a good analogy. I use them just because it seems like you are overcomplicating this and confusing yourself. How about this: are you on board with the idea that two people can play ping-pong on a moving train as long as the train never accelerates?

Also, I'm a little disturbed by how you ignored the presentation I posted. Did you read it? If so, you saw how specifically it refuted your position, right? How do you reconcile that? The way I see it, that gives you a pretty clear choice: you can choose to accept that your position is wrong or you can choose to accept that your position is right and the entire physics community is wrong. Doesn't seem like a difficult choice to me (but it does require admitting you're wrong - which is difficult for many people).

 

[4newton]

But if you accelerate H's clock to M's speed, its tick rate will slow down relative to a stationary observer.

Again let's cover one point at a time.

First. In my example H is moving at a velocity faster than M and the tick rate should be faster.
Second. Are you saying that acceleration has something to do with the clock rate?

 

[Chronos]

There is a simple way to resolve this issue. Propose an experiment that results in observations that do not agree with GR. As Einstein said, 'it only takes one to prove me wrong'.

 

[Chronos]

Footnote: The reason some of us are so 'dogmatic' about GR, is because it has passed, with flying colors, every test devised to prove it wrong. Nobody said it was perfect, just that is more so than any alternative explanation offered to date. Perhaps someday we will scoff Einstein in the same way we scoff at Newton. But, today is not the day.

 

[brodix]

Chronos,
If space is ultimately flat, wouldn't that imply an absolute from which expansion and gravitational collapse are just fluctuations?

 

[DrChinese]

Footnote: The reason some of us are so 'dogmatic' about GR, is because it has passed, with flying colors, every test devised to prove it wrong. Nobody said it was perfect, just that is more so than any alternative explanation offered to date. Perhaps someday we will scoff Einstein in the same way we scoff at Newton. But, today is not the day.

Who is scoffing at Newton? Einstein's improvements to theory do not lessen Newton's role in any way. Theory is not reality. Theory is a useful model of some realm of reality. So hooray for Newton, and Einstein, and anyone who can improve on GR!

 

[russ_watters]

First. In my example H is moving at a velocity faster than M and the tick rate should be faster.

If H is moving faster, its tick rate is slower.

Second. Are you saying that acceleration has something to do with the the clock rate?

Absolutely: acceleration is how you start moving.

Again, this is experimental fact: that's what happens to GPS satellites when you put them in orbit. And the the clock rate doesn't depend on the orbital inclination - as it should if what you propose is true.

What you have here is a convoluted "Twins Paradox." Are you familiar with that? The way you solve the paradox is through SR and accelerating one clock to meet the other in the other's frame.

Again, did you read the presentation I linked?

 

[russ_watters]

Who is scoffing at Newton? Einstein's improvements to theory do not lessen Newton's role in any way. Theory is not reality. Theory is a useful model of some realm of reality. So hooray for Newton, and Einstein, and anyone who can improve on GR!

Indeed - in many ways Newton did more than Einstein. No math to describe your theory? No problem - invent a new branch of math!

 

[brodix]

I've made two very basic points in this discussion. One, that as a measure of specific motion, time effectively travels in both directions, with the frame of reference moving opposite the specific.
Two, that not only is space an absolute, but is the basis of the abstraction known as absolute.
I am quite sure that had any potential flaws in this logic occurred to anyone, they would have expressed it.
I realize that most people naturally tend to ignore things which do not fit their assumptions, but this is one of the least curious groups I've ever butted into.
No, I am not an expert in math and science, just a long time observer, but sometimes the perspective of a little distance can be useful. Beliefs should always be subject to scepticism, or the conversation becomes irrelevant.
I also pointed out that geometry never got around to incorporating the zero and from this arises the presumption that space is a function of topology, rather then the basis of it. Also, points, lines and planes cannot have a zero dimension, only less than Planck scale, because any multiple of zero is zero.
Some of this is mine. Some of it is others. Open source logic.

 

[Chronos]

At risk of sounding repetitive, there are no 'absolutes'. There is no absolute space, time, mass, or energy. If you truly think about it, this is obvious and indisputable. GR is correct, both physically and metaphysically. The speed of light is the closest thing to a reliable reference standard known. Find one with more predictive power and you will make history.

 

[russ_watters]

At risk of sounding repetitive, there are no 'absolutes'.

Indeed, we've said it so many times, I'm starting to wonder how they keep missing it.

 

[JoeWade]

even if you found an absolute, whatever we witness in OUR frame is RELATIVE to that absolute...

 

[brodix]

Chronos,

You are not addressing my specific point. If all curvature balances out and space is ultimately flat, would this suggest an ultimate state of equilibrium, with expansion and contraction as fluctuations from the mean? While it cannot be reached, absolute zero is a legitimate point of reference with regards to temperature. If you have eliminated all such motion, there is no time, so this state doesn't therefore have any ability to fluctuate and so cannot be said to curve, so what remains, other than empty space? As I've pointed out, geometry has never considered the implications of zero, otherwise it wouldn't attempt to say points, lines and planes have a zero dimension. So what would zero in geometry be? It isn't a point. Empty space is the only logical answer that I can see.
So I've given three reasons why space is the essence of absolute. All methods of determining space as relative involve the proposition that it is a function of measuring properties relative to it, yet these properties must exist in an equilibrium; Matter/anti-matter. Expansion and contraction. As I've pointed out with time, given that it is a measure of relative motion, then the frame of reference is necessarily in motion as well. So what is the state from which these properties all fluctuate?
I have reached these suppositions out of a desire to make sense of the reality I find myself in. If I am in fact wrong, I would certainly like to find it out, but given the extent to which people tend to take assumptions as fact and build religions around them, a blanket assertion does not qualify are a logical rebuttal.

 

[Chronos]

Chronos,

You are not addressing my specific point. If all curvature balances out and space is ultimately flat, would this suggest an ultimate state of equilibrium, with expansion and contraction as fluctuations from the mean?

What specific point are you talking about?

While it cannot be reached, absolute zero is a legitimate point of reference with regards to temperature. If you have eliminated all such motion, there is no time, so this state doesn't therefore have any ability to fluctuate and so cannot be said to curve, so what remains, other than empty space?

Absolute zero cannot be reached. You answered your own question.

As I've pointed out, geometry has never considered the implications of zero, otherwise it wouldn't attempt to say points, lines and planes have a zero dimension. So what would zero in geometry be? It isn't a point. Empty space is the only logical answer that I can see.

Geometry is a coordinate system. Zero in geometry is the center of the coordinate system [x,y,z = 0], How hard is that to figure out?

So I've given three reasons why space is the essence of absolute. All methods of determining space as relative involve the proposition that it is a function of measuring properties relative to it, yet these properties must exist in an equilibrium; Matter/anti-matter. Expansion and contraction. As I've pointed out with time, given that it is a measure of relative motion, then the frame of reference is necessarily in motion as well. So what is the state from which these properties all fluctuate??

You have given three reasons that don't make sense. Your conclusions, therefore, are suspect.

I have reached these suppositions out of a desire to make sense of the reality I find myself in. If I am in fact wrong, I would certainly like to find it out, but given the extent to which people tend to take assumptions as fact and build religions around them, a blanket assertion does not qualify are a logical rebuttal.

Not religion and no one is making blanket assertions, so far as I can see. As scientists, we routinely exclude assertions that are not affirmed by observation

 

[russ_watters]

I have reached these suppositions out of a desire to make sense of the reality I find myself in. If I am in fact wrong, I would certainly like to find it out, but given the extent to which people tend to take assumptions as fact and build religions around them, a blanket assertion does not qualify are a logical rebuttal.

You misunderstand the nature of your conundrum: YOU are the one making the assumption that needs to be substantiated here, not us. Since the laws of the universe work fine without assuming an absolute reference frame, it is unreasonable to assume one exists.

 

[brodix]

Chronos,

What specific point are you talking about?

If all curvature balances out and space is ultimately flat, would this suggest an ultimate state of equilibrium, with expansion and contraction as fluctuations from the mean?

Absolute zero cannot be reached. You answered your own question.

Maybe you could define your understanding of "absolute"

Geometry is a coordinate system. Zero in geometry is the center of the coordinate system [x,y,z = 0], How hard is that to figure out?

The center of the coordinate system is a point and a point is one. AS in two points define a line, three, not on the same line, define a plane(and a circle).
Consider; Three dimensions define volume, but space doesn't have a particular coordinate system, so any number of random coordinate systems can be used to define the same space. As all points are potentially the center of the universe, order requires a particular point of reference, so any particular coordinate system is a unit, a frame of reference. So your point that x,y,z=0 is only relevant if said coordinate system doesn't exist. As you quoted, "Absolute zero cannot be reached." If there are any subjective points on that coordinate system, then x,y,z, is simply the initial point of reference and does exist and so cannot be an absolute.

So what is zero in geometry, other then the empty space?

You have given three reasons that don't make sense. Your conclusions, therefore, are suspect.

As I've had similar conversations on various forums, with a wide range of comprehension, I do know that these ideas possesses some degree of sense. I suppose I'm asking for too much here.

russ,

You misunderstand the nature of your conundrum: YOU are the one making the assumption that needs to be substantiated here, not us. Since the laws of the universe work fine without assuming an absolute reference frame, it is unreasonable to assume one exists.

Of course! A universe in which ninety-six percent is invisible to everything but the math. Thank your lucky stars you're not accountants, or the IRS would be all over you.

The only alternative to Big Bang Theory that I recall was tired light. This doesn't even make sense to begin with. If light is encountering friction, proceeding waves/photons would encounter more then succeeding ones, so the wave length would be shortened. What about energized light; That decreasing amplitude is transferred to expanded frequency, like cracking a whip?
As gravity causes space to collapse and as gravitational processes are shedding temendous amounts of radiation, wouldn't this radiation cause space to expand? As in;

http://www.economist.com/science/displayStory.cfm?story_id=2404626

If space does expand, but the universe, already being infinite, doesn't, wouldn't this result in more pressure on existing gravitational systems, thus causing the effect currently assigned dark matter?
As light from distant sources is clearly magnified by the lensing effect of intervening galaxies, wouldn't this result in a blueshift effect that would reduce the overall redshift and that given the distribution of galaxies, the light of distant sources is going to pass through proportionally more residual gravity fields than closer sources, it would seem that the result would be that the closer sources have a greater average redshift, thus creating the immpression that the rate of expansion is increasing... I think I've probably hit a few mental roadblocks, so I'd leave it at that...

regards,

brodix

 

[russ_watters]

Of course! A universe in which ninety-six percent is invisible to everything but the math. Thank your lucky stars you're not accountants, or the IRS would be all over you.

Are you talking about dark matter? That has nothing at all to do with this thread.

The only alternative to Big Bang Theory that I recall was tired light.

This also has nothing to do with this thread...nor does the rest of your post.

The nonexistence of a universal reference frame is the inevitable conclusion of a boatload of experiments - not the least of which was the Michelson-Morley experiment.

 

[brodix]

Russ,

The nonexistence of a universal reference frame is the inevitable conclusion of a boatload of experiments - not the least of which was the Michelson-Morley experiment.

Yes. There is no universal reference frame. Order is a function of perspective, which is relative. Every point is effectively the center of the universe, the x,y,z. So space is effectively infinitely dimensional. When we try to order it, we assign it a specific reference frame. But the map isn't the territory.
As I've pointed out; In that there are effectively two directions of time within the context of what exists, ie. is present, the past is what is ordered and the future is the random energy that is necessary for order to continue. The order/definition that is the past motivates the energy that ensures the future, while the energy of the future motivates the order of the past. (This is essentially complexity theory, with the present as the complex phase transition between order and chaos. Top down order of the set. Bottom up growth of the process.)
Back to space; The reference frame is order. As such it is a closed system and subject to entropy, ie. in and of itself, it loses energy. Therefore it must have an input of raw energy to continue. This energy is necessarily chaotic. (As I'm sure this description probably seems to you.)
So, yes, there is no universal frame of reference, but the absolute isn't a frame of reference, it is the neutral state, around which matter collapses and energy expands.
Space.

See if you can dig down just a little on this. The see no evil, hear no evil, speak no evil routine gets boring.

 

[Doctordick]

Most of you have completely missed the point!

Well, I am back. I quickly read through the thread. It seems to contain a lot of posts having little to do with my original statement. I find a lot of posts concerned with the definition of time, but no post that made any serious attempt to define what the poster meant by the term. A couple gave a rather superficial definition: those generally contained the term "rate" which clearly requires a definition of time and thus cannot be used in a serious definition of time.

I found (and of course this decision is made with limited knowledge) only two posters with seemingly rational positions and am very sorry to find them arguing with one another. That would be 4Newton and russ_waters. Russ seems to have a better education but 4Newton seems to be more ready to think for himself. Russ, I think you should be more tolerant of his mistaken perceptions and seriously consider your responses to him.

Russ, I am afraid you have been a little sloppy in your criticisms (or corrections) of 4Newton's comments. Yes, his interpretations are a bit askew of the standard but he is not as far from understanding as the others on this thread. Plus that, he has an open mind to issues you deem settled and beyond question.

First I would like to comment on your rather cavil explanation of the relationship between special and general relativity.

Einstein proposed SR because of a known difficulty in reconciling the observation that C is constant with Newtonian physics. GR came about because of inaccuracies in Newtonian predictions about the orbits of planets.

The theory of relativity existed before Einstein; however, it was not called a theory because everyone thought it was correct. As far as I know, it was first proposed by Galileo but the consequences were thoroughly implemented by Newton. The issue is the fact that all of physics must be independent of your personal frame of reference. From Newton's perspective, Euclidian geometry was the only rational geometry to use. As a direct consequence, the conversion from one frame of reference to another (presuming the x-axis is parallel to the velocity vector) was accomplished via t'=t, x'=x+vt, y'=y and z'=z: where the origins of the two were in the same place when t=0.

It is, in fact, the presumption of most that Newton's assumption was absolutely correct which leads to the problems most have with modern analysis of relativity. But let us leave that issue for the moment. What is important here is that Newton's relativity is entirely general and much useful physics flows from that fact. Newton defined an "inertial frame" as the frame where $\vec{F}=m\vec{a}$ is a valid expression. Of great importance is the fact that accelerated reference frames (frames which are not "inertial") are as useful as inertial frame so long as the consequences of that acceleration are taken into account.

In particular, rotation leads to effects which are very significant. Centrifugal and coriolis forces are direct consequences of using rotating coordinate systems. The major problem with "special" relativity is the fact that it only provides the relationship between reference frames in the total absence of acceleration. That is, it fact, why it is called "special" relativity!

A complete theory must be entirely "general". That is why a "theory of general relativity" was required! Without a "general" theory, we are in as much trouble as we were without the "special" theory. The fact that gravitation could be explained as a consequence of "general" relativity was more of an overwhelming support of Einstein's theory than a necessity of it.

You misunderstand the nature of your conundrum: YOU are the one making the assumption that needs to be substantiated here, not us. Since the laws of the universe work fine without assuming an absolute reference frame, it is unreasonable to assume one exists.

With regard to this issue, you are being a little provincial to say the least. It would be better if you were to say," Since most of the laws of the universe work fine without assuming an absolute reference frame, it is unreasonable to assume one is required to explain most phenomena. With regard to your "generalization", I would like to bring to your attention the following:

In 1989 the (COsmic Background Explorer) mission was launched. One of its missions was to measure the temperature of the universe accurately. COBE found that the temperature of the universe is 2.725 K. This temperature agrees remarkably well with that predicted by the Big Bang theory.

But COBE scientists didn't stop there. They noticed that the universe looked a little cooler in one direction, and a little warmer in the other direction. This is called the dipole variation and is caused by the Doppler effect of our solar system's motion relative to the cosmic background radiation, enabling the COBE scientists to measure the speed of the solar system: 371 km/sec.

Check out http://lambda.gsfc.nasa.gov/product/cobe/

Thus it seems that a valid explanation of the Universe does indeed include a natural unique coordinate system. What I would say is that "special relativity" (the idea that ignorance of distant events is not detrimental to our study of physics) is a very valuable tool for setting up constraints on what is to be expected but is certainly not a "proof" that all physics must be frame independent. In fact we have direct evidence (given above) that all physics is not frame independent.

Have fun -- Dick

 

[Chronos]

Well, I am back. I quickly read through the thread. It seems to contain a lot of posts having little to do with my original statement. I find a lot of posts concerned with the definition of time, but no post that made any serious attempt to define what the poster meant by the term. A couple gave a rather superficial definition: those generally contained the term "rate" which clearly requires a definition of time and thus cannot be used in a serious definition of time.

How do you define 'rate'? All definitions I am aware of include the variable 'time'. Please explain how a 'serious discussion of time' excludes time.

I found (and of course this decision is made with limited knowledge) only two posters with seemingly rational positions and am very sorry to find them arguing with one another. That would be 4Newton and russ_waters. Russ seems to have a better education but 4Newton seems to be more ready to think for himself. Russ, I think you should be more tolerant of his mistaken perceptions and seriously consider your responses to him.

He did.

Russ, I am afraid you have been a little sloppy in your criticisms (or corrections) of 4Newton's comments. Yes, his interpretations are a bit askew of the standard but he is not as far from understanding as the others on this thread. Plus that, he has an open mind to issues you deem settled and beyond question.

Because 4Newton was wrong. The issue is settled until new evidence is introduced to refute it. The 'best proven' explanation must be preferred over the 'best unproven' explanation.

First I would like to comment on your rather cavil explanation of the relationship between special and general relativity.
The theory of relativity existed before Einstein; however, it was not called a theory because everyone thought it was correct. As far as I know, it was first proposed by Galileo but the consequences were thoroughly implemented by Newton. The issue is the fact that all of physics must be independent of your personal frame of reference. From Newton's perspective, Euclidian geometry was the only rational geometry to use. As a direct consequence, the conversion from one frame of reference to another (presuming the x-axis is parallel to the velocity vector) was accomplished via t'=t, x'=x+vt, y'=y and z'=z: where the origins of the two were in the same place when t=0.

It is, in fact, the presumption of most that Newton's assumption was absolutely correct which leads to the problems most have with modern analysis of relativity. But let us leave that issue for the moment. What is important here is that Newton's relativity is entirely general and much useful physics flows from that fact. Newton defined an "inertial frame" as the frame where $\vec{F}=m\vec{a}$ is a valid expression. Of great importance is the fact that accelerated reference frames (frames which are not "inertial") are as useful as inertial frame so long as the consequences of that acceleration are taken into account.

That makes no sense. There is no 'modern analysis of relativity' that disagrees with conventional relativity.

In particular, rotation leads to effects which are very significant. Centrifugal and coriolis forces are direct consequences of using rotating coordinate systems. The major problem with "special" relativity is the fact that it only provides the relationship between reference frames in the total absence of acceleration. That is, it fact, why it is called "special" relativity!

Agreed, SR does not include gravity.

A complete theory must be entirely "general". That is why a "theory of general relativity" was required! Without a "general" theory, we are in as much trouble as we were without the "special" theory. The fact that gravitation could be explained as a consequence of "general" relativity was more of an overwhelming support of Einstein's theory than a necessity of it.
With regard to this issue, you are being a little provincial to say the least. It would be better if you were to say," Since most of the laws of the universe work fine without assuming an absolute reference frame, it is unreasonable to assume one is required to explain most phenomena. With regard to your "generalization", I would like to bring to your attention the following:

Check out http://lambda.gsfc.nasa.gov/product/cobe/

Thus it seems that a valid explanation of the Universe does indeed include a natural unique coordinate system. What I would say is that "special relativity" (the idea that ignorance of distant events is not detrimental to our study of physics) is a very valuable tool for setting up constraints on what is to be expected but is certainly not a "proof" that all physics must be frame independent. In fact we have direct evidence (given above) that all physics is not frame independent.

There is no evidence a 'natural unique coordinate system' exists. There is, however, enormous evidence it does not exist.

 

[russ_watters]

With regard to this issue, you are being a little provincial to say the least. It would be better if you were to say," Since most of the laws of the universe work fine without assuming an absolute reference frame, it is unreasonable to assume one is required to explain most phenomena. With regard to your "generalization", I would like to bring to your attention the following:

The CMB does indeed allow us to measure a speed with respect to it - however, that speed is not needed to make any of the calculations 4Newton was proposing. Therefore, its not a universal reference frame.

 

[Doctordick]

Sir Chronos, your responses show little if any thought.

How do you define 'rate'? All definitions I am aware of include the variable 'time'. Please explain how a 'serious discussion of time' excludes time.

We cannot have a serious discussion of anything without first defining what it is we are talking about. The issue of this thread is a concise and well thought out definition of "time". One of the first issues of definition itself is that the word being defined is not to be used in the definition. A definition which includes the word "rate" requires a definition of "rate" before it is useable. Since "rate" is generally defined as the ratio between change in something and the change in time, the concept presumes time is defined and thus is not a valid concept within the definition of time.

He did.

I would say he is still missing some subtle issues!

Because 4Newton was wrong. The issue is settled until new evidence is introduced to refute it. The 'best proven' explanation must be preferred over the 'best unproven' explanation.

It appears to me that you have a lot of confidence in what has and what has not been proven. I think it would benefit you to take a little trouble to think about these things.

That makes no sense. There is no 'modern analysis of relativity' that disagrees with conventional relativity.

Now I would contend that is a rather extreme statement. They certainly disagree as to the proper equations to be used to transform from one coordinate system to another. You should be more careful in your pronouncements.

Agreed, SR does not include gravity.

Neither did Newtonian relativity! What is much more significant is that SR does not include a rule for transforming between accelerating coordinate systems which Newtonian relativity does. It was Einstein's attempts to generalize his theory (an absolute necessity by the way) which lead to the gravitational results. If you look at the fundamental deduction of general relativity, you will find discussion of direct transformations from a coordinate system attached to an accelerating elevator. Problems in measurement arose there which did not allow a simple generalization thus Einstien's result was not unique. A very interesting problem which has received little really serious attention.

There is no evidence a 'natural unique coordinate system' exists. There is, however, enormous evidence it does not exist.

Now here you are fighting a losing battle as "natural unique coordinate systems" are use all the time on a day to day basis in physics. In fact, lots of different "natural unique coordinate systems" are used. For example, the rest frame of the laboratory in which an experiment is done; or a coordinate system which makes the one way speed of light the same in all directions.

The central issue of relativity is that all these coordinate systems are equally valid. In almost every case, each and every experiment suggests it's own "natural unique coordinate system". It is the fact that the "laws of physics" must be the same in all of these coordinate systems which allows us to determine the required transformation equations between those various coordinate systems.

And finally, to Russ, I still say you are being a bit provincial with your comments. I think it would be worth your while to step back once and look at the fundamental nature of the problems which confront us.

The CMB does indeed allow us to measure a speed with respect to it - however, that speed is not needed to make any of the calculations 4Newton was proposing. Therefore, its not a universal reference frame.

I would expect a mentor to take a little more care with his comments. What you say cannot possibly be rationally defended as logical.
You are saying that because "that speed is not needed to make any of the calculations 4Newton was proposing", it is not a universal reference frame.

You seem not to understand the principle of relativity. The principal or relativity is that all reference frames capable of indicating the information associated with any given experiment are fully useable. If one adds to that the fact that the laws of physics are particularly simple in a specific frame (think of Newton's inertial frame), then all one needs is the specific transformation from the particular simple frame to a frame of reference of interest and one knows what happens in that frame of interest. Einstein's General Relativistic frame is just such a "simple" frame, quite analogous to Newton's inertial frame; however, the required transformations to the frames of interest are not quite as simple as Newton's but they can nonetheless be done.

That fact is used over and over again throughout physics. There are a number of unique frames used all the time. For example, the GPS system is a coordinate system tied to time as measured by a clock in Colorado and is by that fact, a very unique coordinate system. Since it is always possible to set up a specific coordinate system tied to a specific clock the term "universal" could be attached to the concept.

There is another rather unique coordinate system used quite often in a lot of experiments. That would be a coordinate system tied to center of mass of the universe (in this case, read "universe" to be a reference to the collection of entities which are significant to the experiment of interest and may range from no more than the components of a single nucleus to a nuclear accelerator, the solar system, the galaxy or everything including the cosmic background). Call such a coordinate system a CoM system. Certainly the CoM system is unique and it is also quite universal. One can very reasonably suggest that relativity should require the laws of physics to be the same in every CoM system conceivable.

In fact, that is essentially exactly what the COBE scientists did when they documented the solar systems velocity through the universe at 371 km/sec.

But all this is outside the discussion on this thread which is "what is the definition of time?"

Have fun -- Dick

 

[brodix]

The CMB does indeed allow us to measure a speed with respect to it - however, that speed is not needed to make any of the calculations 4Newton was proposing. Therefore, its not a universal reference frame.

Yes, it's not stable. It is expanding.

 

[brodix]

Dr. Dick,

What is the definition of time?

 

[russ_watters]

You seem not to understand the principle of relativity. The principal or relativity is that all reference frames capable of indicating the information associated with any given experiment are fully useable.

I understand that perfectly fine.

There are a number of unique frames used all the time. For example, the GPS system is a coordinate system tied to time as measured by a clock in Colorado and is by that fact, a very unique coordinate system. Since it is always possible to set up a specific coordinate system tied to a specific clock the term "universal" could be attached to the concept.

The problem is you misunderstand the word "universal" in this context. The preferred reference frame of GPS is clock in Colorado, but that doesn't make it The universal reference frame. They could use a reference clock located on the moon if they wanted too and the system would still work. The universal reference frame is the frame in which all experiments must be done to get correct results. In 4Newton's experiment, for example, only velocities measured against this frame would give "correct" time dilation readings. The M&M experiment works the same way. The logic is sound, but the evidence says this frame doesn't exist: and Relativity (and yes, I did mention that the concept is common to Einstein and Newton) postulates it based on the evidence.