Room-temperature superconductivity?

[Teahive]

It is not circular at all. This is only one possible experiment: If you get the same result within two inertial reference frames for any experiment (as you will), it proves that the laws of physics are the same within the two inertial reference frames, which in turn DEMANDS that any apparatus you use to measure time must give the same result within BOTH inertial reference frames. As MUST be the case according to Einstein's first postulate.

Yes, the laws of physics within each inertial reference frame are identical. Which means that, when you count "9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom" (assuming it is stationary), you will also see any good stationary clock mechanism increase its second counter by one. So the rate at which different physical processes occur relative to each other is the same within all inertial reference frames.

This does not imply the need for a global "time rate".


Consider a simple computer, consisting of a CPU, some memory, and a quartz crystal generating a clock signal. On every rising edge of the clock signal, the CPU executes one instruction. The contents of CPU registers and memory, but not the clock signal, define the state of the system. What's interesting is that, without access to any external clock, the software running on the CPU cannot measure the rate at which the clock crystal is oscillating. Whether it's 1 Hz or 1 GHz to an external observer, the software will run exactly the same sequence of state transitions. You could even have someone operate the clock signal manually, sometimes rapidly triggering cycles, sometimes stopping the signal for a long time. For the software it makes no difference whatsoever, it simply cannot determine the "clock rate".

The propagation of electromagnetic waves, i.e. c, is like the clock signal, and the CPU is like a clock, a brain, or the world we perceive. In fact you could use this computer to run a physical simulation. To this simulated world, the "clock rate" would be a meaningless concept.

[johanfprins]

Johan,

It is difficult to know how I could make the point you are missing

You are the one who is missing the point

The laws of physics do not require a universal global time.

It does require that identical clocks within two different inertial reference frames MUST keep time at the same identical rate.

All they say is that local time in a given frame is consistent with decay rates, etc etc.

What "local" time? This is a nonsensical concept.

You extend this to saying that therefore "clocks keep the same time". Well, it could be true if you define this is local terms, but not if you imply global equivalence.

Why not?

Why do you think laws of physics being identical in different frames requires a global measure of time?

Since this is obviously the correct and simplest explanation (Occam's razor) which does not lead to paranormal metaphysical, Voodoo conclusions that one twin will age faster than another twin when the twins move with a speed v RELATIVE to one another.

Wel I am now first going to give my attention to my family whose members are not so stupid that they will conclude that in a symmetrical situation one twin will age faster than the other twin.

See you later alligator.

[johanfprins]

Let us try and cut through all the BS tomclarke and teahive is posting:

Let me ask a simple question. If you have two inertial reference frames Kp and K, moving with a speed v relative to one another and within each reference frame there is a meter-stick at rest: Do these two meter-sticks have the SAME lengh within their respective reference frames Kp and K? Yes they have or No they have not?

[tomclarke]

Let us try and cut through all the BS tomclarke and teahive is posting:

Let me ask a simple question. If you have two inertial reference frames Kp and K, moving with a speed v relative to one another and within each reference frame there is a meter-stick at rest: Do these two meter-sticks have the SAME lengh within their respective reference frames Kp and K? Yes they have or No they have not?

Since you make the question relative to the frame, the answer is yes - tautologically so.

[tomclarke]

Johan,

It is difficult to know how I could make the point you are missing

You are the one who is missing the point

The laws of physics do not require a universal global time.

It does require that identical clocks within two different inertial reference frames MUST keep time at the same identical rate.

All they say is that local time in a given frame is consistent with decay rates, etc etc.

What "local" time? This is a nonsensical concept.

You extend this to saying that therefore "clocks keep the same time". Well, it could be true if you define this is local terms, but not if you imply global equivalence.

Why not?

because there is no physical way to compare times between two frames, except via light beams which leads to different answers depending on which frame you take as stationary. hence the concept of "keeping the same time" in different frames is not well defined.

Why do you think laws of physics being identical in different frames requires a global measure of time?

Since this is obviously the correct and simplest explanation (Occam's razor) which does not lead to paranormal metaphysical, Voodoo conclusions that one twin will age faster than another twin when the twins move with a speed v RELATIVE to one another.

Johan, you are here either being willfully stupid, or deliberately ignoring half of the thread above. In the symmetrical situation the two twins age identically. It is only in an asymetric situation that time difference is observed. You have consistently ignored this fact, because you refuse to consider the possibility that time is relative and only local time well defined.

Wel I am now first going to give my attention to my family whose members are not so stupid that they will conclude that in a symmetrical situation one twin will age faster than the other twin.

See above.

[Teahive]

Let me ask a simple question. If you have two inertial reference frames Kp and K, moving with a speed v relative to one another and within each reference frame there is a meter-stick at rest: Do these two meter-sticks have the SAME lengh within their respective reference frames Kp and K? Yes they have or No they have not?

As tomclarke wrote, one meter is tautologically one meter. Which happens to be ~30.66332 times the wavelength of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom.

However, that is a caesium 133 atom at rest. The measured wavelength of that very same radiation changes depending on the relative velocity between emitter and observer.

[tomclarke]

Obviously, you can do this by instantaneously stopping the two reference frames from moving further relative to one another. If the clocks within the two reference frames are synchronised to show the same time within each reference frame respectively, and if, before stopping the relative motion a clock within K has been synchronised with a clock within Kp, and then the clocks within K were all synchronised with the clock that is synchronised with a clock within Kp, and the clocks within Kp were then all synchronised with the clock within Kp that is now synccronised with all the clocks within K, then on stopping the motion one will find that all the clocks within K AND Kp will show exactly the same time. If not, then Einstein's first postulate on which he based his Special Theory of Relativity will be null and void.

I never answered this, from a while back. It is an intelligence test: can you spot the implicit assumption that frame-independent global time exists?

You see, the clocks can be set as stated. But K clocks and Kp clocks will not read the same value at all spatial locations. That is because the 4D space directions of time in K & Kp are not parallel.

Furthermore, the idea of "stopping movement at a given time" is frame-dependent. Do we use K time, or Kp time to determine when to stop? They are not the same.

Before Johan misunderstands this, saying that K & Kp time are different does not mean "clocks keep a different rate" in K & Kp. Further the time axes (for K & Kp) are symmetric between K & Kp. But contours of equitime in K and Kp have different angles in the t-x plane where
t is K time, and x is the K frame unit space vector in the direction in which Kp is moving relative to K. Thus in K changing the K x coordinate has no effect on (K) time. In Kp, changing the K x coordinate does change (Kp) time.

Of course Einstein's postulate, which relates local physical laws to local time, is not broken by the lack of absolute time.

PS - it took me a little while to work this out - it is so easy to be suckered by statements which contain implicit use of absolute time!

[charliem]

I'm starting to think that those involved in this discussion are not answering each other arguments.

A little question to both parties.

Ender and Peter Wiggin are brothers. Peter stays on Earth while Ender makes multiple trips between solar systems at near-light speed.

After some years Ender stops in the planet Lusitania. This planet is on our galaxy so its movement relative to Earth is at much slower speed than light.

Statement: When Ender stops his travels Peter have already died of old age, as can be seen in broadcasts from Earth.

My question is: Is this statement possible or absurd?

[tomclarke]

I'm starting to think that those involved in this discussion are not answering each other arguments.

A little question to both parties.

Ender and Peter Wiggin are brothers. Peter stays on Earth while Ender makes multiple trips between solar systems at near-light speed.

After some years Ender stops in the planet Lusitania. This planet is on our galaxy so its movement relative to Earth is at much slower speed than light.

Statement: When Ender stops his travels Peter have already died of old age, as can be seen in broadcasts from Earth.

My question is: Is this statement possible or absurd?

I think perhaps you were not reading earlier when we had a detailed discussion of twins paradox. I have answered every point Johan has made, and , indeed, attempted to explain to him precisely where he goes wrong. As has teahive.

In this case - the "classic" twins paradox, the two twins are not symmetrical. One has a repeatedly "bent" worldline, the other has a straight worldline.

It is indeed true that the "bent" line will have less proper time (because of time dilation) when they meet up again than the straight line.

In your example they do not meet, but remain in (nearly) the same frame spartially separated. This now gets more complex. Each will of course see images of the other delayed by light time. If there is no (or negligible) relative velocity they can still synchronise clocks by one sending a light beam which is immediately returned, with clock time info, by the other (the "relfector").

The sender must synchronise the average of send and receive times to equal the "reflector" clock time transmitted back. If they do this, they will see notice the time dilation. Otherwise, on top of the time dilation difference both will see the other as older than them by the light time separation.

Why do bent lines have time dilation?

This is the opposite of Euclidean space, where bent lines are invariably longer than straight ones. But the maximally bent line - a light ray travelling back & forth between two mirrors, would have zero proper time, or infinite time dilation, so you can see why this is. The counterintuitive stuff comes from the fact that the Minkowski metric is not positive definite - light-rays mark lines of zero length.

To address Johan's oft repeated reply (he believes the two twins always have same age):
(1) In the symmetrical case of constant velocity, the two twin ages cannot be compared, because they get further and further away from each other.

(2) If they both voyaged away at near speed of light and returned, time dilation would be equal & cancel out (assuming they both had same velocity differential out and in).

(3) The difference in time between "bent" worldline and straight is NOT the acceleration. This can take an arbitrarily small time, in principle. It is the fact that the outward and inward journey are at different velocities. Whatever frame you use to measure, such a "bent" path through spacetime will have smaller absolute length (absolute length = elapsed local time) than a straight one between the same two endpoints.

Technically: spacelike paths have positive length, timelike paths have negative length. Using a different frame to view the paths will alter things, but spacelike will always stay spacelike, timelike will always stay timelike. Light rays travel along geodesics - lines of zero distance, and mark the boundary between spacelike & timelike.

PS - if the voyaging twin moved with constant velocity relative to the other, and then stopped relative to him, the voyaging twin would still be younger.

That is because ages are being measured after synchronisation in the frame of the stationary twin. If we used clocks synchronised in the moving frame (which we in principle could) the stationary twin would be younger.

Obviously, because of the spatial separation, we cannot directly compare ages, so the comparison (via synchronised clocks) will always depend on the frame it is made in.

[johanfprins]

I'm starting to think that those involved in this discussion are not answering each other arguments.

Ah! A breath of fresh air after being inundated by the paranormal metaphysics that tomclarke and teahive want to believe at all cost and against all logic.

A little question to both parties.

Ender and Peter Wiggin are brothers. Peter stays on Earth while Ender makes multiple trips between solar systems at near-light speed.

After some years Ender stops in the planet Lusitania. This planet is on our galaxy so its movement relative to Earth is at much slower speed than light.

Statement: When Ender stops his travels Peter have already died of old age, as can be seen in broadcasts from Earth.

This is where you go wrong. If you apply the Lorentz transformation correctly you will find that at this point in time they are both alive.

My question is: Is this statement possible or absurd?

In terms of the Special Theory of Relativity it is absurd. Unless Ender has spent a lot of time near a black hole, there should be very little difference between the ages of the twins. If, for example, Ender stayed within gravity free space while travelling, he will in fact be older than Peter who stayed behind within earth's gravity field. If both Ender and Peter were all the time within gravity free space, they will be exactly the same age as determined by the synchronised clocks they are each carrying.

Only a gravity field affects the rates of clocks at different positions within space, and, although one can equate gravity with acceleration, the slow-down in the clock-rate has nothing to do with acceleration. The reason why time slows down is that both light and matter are solely wave-fields (NO PARTICLES INVOLVED: Thank you Schroedinger!). When a light wave interacts with matter the speed of light slows down: For example, when a light-wave enters a glass block its speed slows down and for this reason refraction occurs.

The bending of starlight around the sun is also solely caused by the slowing down of light speed within matter and within matter’s surrounding gravity field. Since the fourth dimension can be written as -ict, a smaller c mandates a decrease in the rate of time. In fact, it is possible stop light-speed and thus stop time within matter: Lene Hau demonstrated this on a macro-scale by stopping a light pulse within a Bose-Einstein Condensate at low temperature. But, in fact, this also happens, and is happening all the time, at much higher temperatures: For example, when an orbital electron around a nucleus absorbs a photon-wave: In this case the light wave stops within the electron wave and thus adds mass energy to this wave.

That time stops within the electron wave is inherent in Schroedinger waves, since, as we have all known for more than 80 years, the intensity of a stationary Schroedinger wave is time independent. A free-electron wave which is stationary within its own inertial reference frame is in effect a mini “black hole” surrounded by a spherical “event horizon”. Outside this “horizon” the wave has tails which decay exponentially to infinity. In text books on quantum mechanics these tails are incorrectly called “tunnelling tails”. They represent the curvature in space-time around the mass of the wave.

In contrast, it is one of the postulates of the Special Theory of Relativity that light speed is the same at each and every point within each and every inertial reference frame. Thus, in this case, the time rate cannot actually slow down at any point as it does within a gravity field. The “time-dilation” and “length-contraction” effects derived from the Theory of Special Relativity can thus not be used, as Einstein has done, to justify the need for a curvilinear four-space in order to model gravity.
Einstein reached the correct conclusion but for the wrong reasons.

If his reasons were correct, then also in the case of gravity, light speed should have remained the same value at every point within our universe. Einstein was forced to abandon this principle in his so-called “General Theory of Relativity”. He never explained how this abandonment can be extrapolated from the Special Theory of Relativity, but only mentioned it in passing that you must abandon the second postulate of the Special theory of Relativity. This to me is proof that Einstein’s Theory of Gravity has nothing to do with any relativistic effect at all.

Now let us look at tomclarke’s tautology:

Let us try and cut through all the BS tomclarke and teahive is posting:

Let me ask a simple question. If you have two inertial reference frames Kp and K, moving with a speed v relative to one another and within each reference frame there is a meter-stick at rest: Do these two meter-sticks have the SAME lengh within their respective reference frames Kp and K? Yes they have or No they have not?

Since you make the question relative to the frame, the answer is yes - tautologically so.

Now, in order to eliminate any time changes owing to gravity, let us place Ender and Peter into their own spaceships which are at first floating side by side in free space (no gravity field). They both have a meter stick of the finest material which they find are exactly the same length within a femtometer. They also both have perfect clocks which they synchronise before Ender accelerates away exploring space without ever entering a gravitational field. As soon as Ender reaches his top speed (near the speed of light) relative to Peter, he switches on his radio and broadcast a verbal message to Peter. When Peter receives the message he hears a very low frequency rumble. He rewinds his recorder and after experimenting he finds that when he increases the speed with which he plays back the message, Ender’s voice improves, and at a suitable disc-speed Ender's message can be heard clear as a bell.

Fortunately, Ender and Peter can also correspond by e-mail. Peter sends Ender an e-mail telling him of the slow down in his voice and asking him if he is playing a joke. Ender sends an e-mail back and asks Peter to now broadcast a verbal message to him. Ender now finds in turn that he has to speed up Peter’s message to understand it and e-mail this information to Peter. Since they are twins and know that they will not play tricks on each other they finally agreed that not one of them is slowing the verbal messages down before sending them. But what can then be the cause of this slow down?

So they decided to compare their clock rates: Each one of them will send a light pulse from one end of their respective meter sticks to the other and measure the time interval, and then exchange the measured time intervals by e-mail to compare. Since the meter stick with Ender is 1 meter, and the speed of light is c, Ender measures a time interval (delta)tp=(1/c). Similarly Peter’s meter stick is 1 meter long, and even though he and Ender is moving with a high speed relative to one another, the speed of light within Peter’s reference frame is still c (the same as in Ender’s reference frame): And so the time interval measured by Peter is (delta)t=(1/c); which is exactly the same as Ender has measured. Thus although their voices become retarded when they broadcast, their respective clocks keep exactly the same time; as demanded by the constancy of the speed of light (Einstein's second postulate).

But how do you explain the slow down in the voice broadcasts? Well let us consider Ender and Peter passing each other with the relative speed v and both of them shoot off a flare perpendicular to the direction of the speed. Both Ender and Peter will see their own flares moving perpendicularly to the direction of motion of the other ship: i.e. in both reference frames the position of each flare does not change along the x-axis. But if they look at each other’s flares they will each see motion along their x-axis.

If they are stupid they will conclude that the other flare is actually also moving along the x-axis relative to the spaceship from which it has been launched. But being non-dogmatic thinkers they realise that this is not the case. That to really establish the true path relative to the spaceship from which the flare has been launched, they must use the Lorentz transformation to get the correct path.

Exactly the same happens with the time coordinate: The voice broadcasts becomes slowed down as if the time on the other space ship is slower; but to really know what is happening on the other spaceship, you must use the Lorentz transformation and then you will find that the time on the other spaceship has NOT slowed down at all. Since the clocks with the two twins keep exactly the same time, they must remain exactly be the same age at every instant in time as measured on either one of the clocks; no matter how far apart they are or with what speed they are moving relative to one another.

Thus, as far as the Special Theory of Relativity is concerned, time is everywhere the same: All clocks, no matter where they are or with what speeds they move relative to one another, keep time at exactly the same rate.

I hope this helps.

[tomclarke]

Johan,

I have some sympathy with your wish that the universe were not spooky, as it is, and had a conceptually simple idea of global time.

If you were a more sophisticated (or at least more enthusiastic) mathematician you would however appreciate the Minkowski space math, which is very simple and beautiful.

I'm glad you have stopped arguing there is inconsistency in the Minkowski space physics, which others accept.

Earlier in this thread, if you will care to read, there was a long discussion on whether time dilation, as I claim happens, and you say does not, is experimentally proven.

There have been a number of experiments which explicitly measure it.

More telling, the GPS clock rate corrections routinely make use time dilation as calculated by SR, and denied by you. This is in addition to the gravitational rate correction. For satellites at different heights the two effects vary in opposite fashion, so they can't be confused.

I'll stop trying to explain why theoretically you are wrong, and rest on the conclusive experimental evidence.

If you don't accept this you have less grip on reality than I like to maintain,

Best wishes, Tom

PS - if anyone on this thread feels I need to answer Johan's post point by point I will, but I think we have each clearly stated our position: just that his non-standard theory of physics does not fit the observations.

[GIThruster]

PS - if anyone on this thread feels I need to answer Johan's post point by point I will, but I think we have each clearly stated our position: just that his non-standard theory of physics does not fit the observations.

Personally, I have to wonder where you got the patience to last this long.

[johanfprins]

Johan,

I have some sympathy with your wish that the universe were not spooky, as it is, and had a conceptually simple idea of global time.

If you were a more sophisticated (or at least more enthusiastic) mathematician you would however appreciate the Minkowski space math, which is very simple and beautiful.

I'm glad you have stopped arguing there is inconsistency in the Minkowski space physics, which others accept.

Earlier in this thread, if you will care to read, there was a long discussion on whether time dilation, as I claim happens, and you say does not, is experimentally proven.

There have been a number of experiments which explicitly measure it.

More telling, the GPS clock rate corrections routinely make use time dilation as calculated by SR, and denied by you. This is in addition to the gravitational rate correction. For satellites at different heights the two effects vary in opposite fashion, so they can't be confused.

I'll stop trying to explain why theoretically you are wrong, and rest on the conclusive experimental evidence.

If you don't accept this you have less grip on reality than I like to maintain,

Best wishes, Tom

PS - if anyone on this thread feels I need to answer Johan's post point by point I will, but I think we have each clearly stated our position: just that his non-standard theory of physics does not fit the observations.

You are avoiding logic and distorting the truth Tom. You yourself have claimed that the ages will be determined by which twin returns to which twin. Thus, you must agree that if the twins just keep on moving without turning around, they must age at the same rate since their clocks keep time at the same rate.

Obviously when you correct a GPS sattelite, you must correct for time dilation since you have to correct for the clock on the satellite as observed from earth. This does not prove that the clock on the satellite is actually keeping time at a slower rate than a clock on earth. And please do not come to me with the flying clock experiments which mix time change caused by gravity with time dilation when viewing a clock from another inertial refrence frame. There has not yet been a single experiment done where one of two clocks have been sent on a trip, WITHOUT having any change in gravity, and was then returned and compared. Only such an experiment will determine whether you or I am the fool. I am sure it will not be me.

So let us leave it to a REAL defining experiment! That is the grown-up thing to do when two scientists disagree. When it comes to the mathematics of Minkowski Space (if you want to call this mathematical concoction a "space") you are an infantile amateur compared to me. So stop telling me that there is a space-time path through Minkowski Space. You only have the latter within a gravitational field and this has nothing to do with Special Relativity.

Regards,
Johan

[tomclarke]

Johan,

I have some sympathy with your wish that the universe were not spooky, as it is, and had a conceptually simple idea of global time.

If you were a more sophisticated (or at least more enthusiastic) mathematician you would however appreciate the Minkowski space math, which is very simple and beautiful.

I'm glad you have stopped arguing there is inconsistency in the Minkowski space physics, which others accept.

Earlier in this thread, if you will care to read, there was a long discussion on whether time dilation, as I claim happens, and you say does not, is experimentally proven.

There have been a number of experiments which explicitly measure it.

More telling, the GPS clock rate corrections routinely make use time dilation as calculated by SR, and denied by you. This is in addition to the gravitational rate correction. For satellites at different heights the two effects vary in opposite fashion, so they can't be confused.

I'll stop trying to explain why theoretically you are wrong, and rest on the conclusive experimental evidence.

If you don't accept this you have less grip on reality than I like to maintain,

Best wishes, Tom

PS - if anyone on this thread feels I need to answer Johan's post point by point I will, but I think we have each clearly stated our position: just that his non-standard theory of physics does not fit the observations.

You are avoiding logic and distorting the truth Tom. You yourself have claimed that the ages will be determined by which twin returns to which twin.

This is a loose statement, but yes, if the twins meet up again relative ages depend on their previous movements.

Thus, you must agree that if the twins just keep on moving without turning around, they must age at the same rate since their clocks keep time at the same rate.

I thought you were criticising my logic? I have not claimed any statement about relative ages in the case that they keep on moving. Nor have I agreed that their clocks "keep the same time". As I am sure you know from previous posts.

Johan, do you know what logic is?

Obviously when you correct a GPS sattelite, you must correct for time dilation since you have to correct for the clock on the satellite as observed from earth. This does not prove that the clock on the satellite is actually keeping time at a slower rate than a clock on earth.

Please refer to the earlier posts on this thread from somone who knows about GPS satellites.

The rate of the clock is set differently. Since the satellite is never more than a few light-seconds from earth after enough time this different rate will lead to a time discrepancy that is larger than the time of light from the satellite to earth. Therefore the time "kept by the clock" is demonstrably different from that bof an earth clock independent of relativistic measurement issues.

And please do not come to me with the flying clock experiments which mix time change caused by gravity with time dilation when viewing a clock from another inertial refrence frame. There has not yet been a single experiment done where one of two clocks have been sent on a trip, WITHOUT having any change in gravity, and was then returned and compared.

the flying clock experiments, like the GPS sats, correct for gravity. In fact the clocks have controls flying at same height the opposite way round the earth. Gravity thus cancels.

Only such an experiment will determine whether you or I am the fool. I am sure it will not be me.

I think your certainty will be undented Johan, since the experiments which have been done, and have definitive results, are ignored by you.

So let us leave it to a REAL defining experiment! That is the grown-up thing to do when two scientists disagree.

Johan, scientists do not dismiss valid experimental evidence, so you disqualify yourself. Not, of course, taht I claim myself to be a scientist.

When it comes to the mathematics of Minkowski Space (if you want to call this mathematical concoction a "space") you are an infantile amateur compared to me.

That may of course be true, but I have to say on the evidence of this thread you have no understanding of the math. Specifically you do not understand what is time under a Minkowski metric.

So stop telling me that there is a space-time path through Minkowski Space. You only have the latter within a gravitational field and this has nothing to do with Special Relativity.

Minkowski space can exist just fine with no gravitational field. Indeed ideal MS, perfectly flat, models a universe with no gravitation.

Johan, you appear to be making false statements here. Why?

[charliem]

You are avoiding logic and distorting the truth Tom. You yourself have claimed that the ages will be determined by which twin returns to which twin.

This is a loose statement, but yes, if the twins meet up again relative ages depend on there previous movements.

Tom, if I recall correctly you say that Johan's defend the existence of an universal time, and that that doesn't exist.

Doesn't your interpretation implies the existence of privileged FOR?

If so, how is that different to the existence of an universal time?


P.D. Sorry if I repeat questions already answered. This thread is too long and I have not read all of it.