Strange Claims About Relativistic Time Split From A Alternative Theories Thread

[xinhangshen]

So the aether (whatever the hell it's suppose to be) moves in exactly the way it needs to to make it seem like there is no aether and this is "direct evidence of its existence"? :)

 

Dude you're hilarious. Deluded, clueless and not worth anyone's time. I'm done.

You should never be here!

[Moronium]

If you ask me, Anssi is far and away the most knowledgeable and wisest poster in this thread.  

 

There is (or at least can be) a huge difference between saying:

 

1. The speed of light is measured to be constant in all inertial frames, and...

 

2. The speed of light IS constant in all inertial frames.

 

Proposition 1 has been well documented, empirically.

 

But that alone can in no way prove or even necessarily imply proposition 2.  Einstein himself made it clear that the proposition that the speed of light actually IS (as a matter of ontological fact) constant in all inertial frames was NOT proven by him and, indeed, could not be proven.  This was simply a fundamental postulate which he said he subscribed to as a matter of voluntary choice, not one required by the empirical evidence, he said.

Edited April 9, 2018 by Moronium

[Moronium]

It's best to go back to the beginning to understand the difference, I think.

 

1.  Since we (thought we) knew the earth was rotating and orbiting the sun, Michelson-Morley (MM) assumed we could measure this motion.  But we couldn't, so what now?

 

2.  Lorentz and others came up with an ad hoc hypothesis that that clocks slowed down and lengths shortened with increased speed. The exact equations formulated comprise the Lorentz Transformation (LT), which SR also uses.  This explains why we measure the speed of light to be the same when it "really" isn't.  Lorentz, Poincare, et al, posited a theory of relative motion which employed a preferred frame of reference and was therefore based on the assumption of absolute (not relative) simultaneity.  Such theories are sometimes called "AST's" (Absolute Simultaneity theories).

 

Such theories are just as viable as SR, and are still used today.  The GPS, for example, does not use SR as it's theoretical basis.  It can't.  It uses absolute simultaneity (with the ECI serving as the preferred frame and with all times times and speeds of moving objects measured with respect to the (non-rotating) "master clock" located at the ECI).

 

3. SR, as such, has never been proven empirically, notwithstanding many who claim the contrary.  What has been empirically confirmed is the accuracy of the LT.  The formula is the same for both types of theories, but the meaning of v (velocity) is different.   The "v" in an AST is absolute, in SR the "v" is relative.

 

To reiterate, the point is this:  The speed of light can be epistemologically (i.e., meaured to be) the same in all inertial frames even if it isn't "really" (ontologically) the same.

Edited April 14, 2018 by Moronium

[Moronium]

To reiterate, the point is this:  The speed of light can be epistemologically (i.e., meaured to be) the same in all inertial frames even if it isn't "really" (ontologically) the same.

 

 

A quick, easy example of this can be seen, without the red-herrings generated by different frames, if we stay in the same frame.

 

Assume that A has an extremely accurate yardstick that is exactly 36" long while B has one that looks perfectly calibrated, but which is in fact shorter (say 35").

 

If A measures a football field he will find it to be 100 yards long, end to end.

 

If B measures it, he will conclude that it is MORE than 100 yards long.

 

But it's the same football field and it's actual length does not change every time a yardstick of a different length is used by somebody to measure it. The measurements are different, that's all.  The field remains constant.

 

It's the same thing (but in reverse) according to Lorentz's theory.  There the measurement (of the speed of light) is always the same, but ONLY BECAUSE distorted instruments are being used in different frames.  If every frame had the same clocks and rods (no shinkage) then each would measure the speed of light to be different.

Edited April 9, 2018 by Moronium

[Moronium]

.It's the same thing (but in reverse) according to Lorentz's theory.  There the measurement (of the speed of light) is always the same, but ONLY BECAUSE distorted instruments are being used in different frames.  If every frame had the same clocks and rods (no shinkage) then each would measure the speed of light to be different.

 

The use of the LT actually creates some theoretical problems for SR.  The LT was designed to explain how the speed of light could be measured to be constant when it really wasn't (the explanation was that clocks and rods of different durations/lengths were being used in different frames).

 

But if the speed of light REALLY IS constant in all frames, and if we also MEASURE it to be the same, then we must be using the same standards for all frames.  If you measure a speed to be what it "really is," then you obviously have used correctly calibrated instruments to do so.  Otherwise you would have gotten an "incorrect" measurement.

 

So there is no call for transformations in that case.  Yet SR uses "corrections" for clocks (which relativists want to call "time') and rods (which they want to call "space").

 

 

SR should have no need or use for "corrections" to instruments which make accurate measurements of the "true" speed to begin with.

 

See the problem?

Edited April 9, 2018 by Moronium

[A-wal]

If you ask me, Anssi is far and away the most knowledgeable and wisest poster in this thread.  

 

There is (or at least can be) a huge difference between saying:

 

1. The speed of light is measured to be constant in all inertial frames, and...

 

2. The speed of light IS constant in all inertial frames.

 

Proposition 1 has been well documented, empirically.

 

But that alone can in no way prove or even necessarily imply proposition 2.  Einstein himself made it clear that the proposition that the speed of light actually IS (as a matter of ontological fact) constant in all inertial frames was NOT proven by him and, indeed, could not be proven.  This was simply a fundamental postulate which he said he subscribed to as a matter of voluntary choice, not one required by the empirical evidence, he said.

It's best to go back to the beginning to understand the difference, I think.

 

1.  Since we (thought we) knew the earth was rotating and orbiting the sun, Michelson-Morley (MM) assumed we could measure this motion.  But we couldn't, so what now?

 

2.  Lorentz and others came up with an ad hoc hypothesis that that clocks slowed down and lengths shortened with increased speed. The exact equations formulated comprise the Lorentz Transformation (LT), which SR also uses.  This explains why we measure the speed of light to be the same when it "really" isn't.  Lorentz, Poincare, et al, posited a theory of relative motion which employed a preferred frame of reference and was therefore based on the assumption of absolute (not relative) simultaneity.  Such theories are sometimes called "AST;s" (Absolute Simultaneity theories).

 

Such theories are just as viable as SR, and are still used today.  The GPS, for example, does not use SR as it's theoretical basis.  It can't.  It uses absolute simultaneity (with the ECI serving as the preferred frame and with all times times and speeds of moving objects measured with respect to the (non-rotating) "master clock" located at the ECI).

 

3. SR, as such, has never been proven empirically, notwithstanding many who claim the contrary.  What has been empirically confirmed is the accuracy of the LT.  The formula is the same for both types of theories, but the meaning of v (velocity) is different.   The "v" in an AST is absolute, in SR the "v" is relative.

 

To reiterate, the point is this:  The speed of light can be epistemologically (i.e., meaured to be) the same in all inertial frames even if it isn't "really" (ontologically) the same.

Here at least you seem to understand how the consistency of the speed of light is linked to length contraction and time dilation. Yes, if the speed of light weren't constant then it would be possible for time dilation and length contraction not to occur when comparing different frames of reference.

 

A quick, easy example of this can be seen, without the red-herrings generated by different frames, if we stay in the same frame.

 

Assume that A has an extremely accurate yardstick that is exactly 36" long while B has one that looks perfectly calibrated, but which is in fact shorter (say 35").

 

If A measures a football field he will find it to be 100 yards long, end to end.

 

If B measures it, he will conclude that it is MORE than 100 yards long.

 

But it's the same football field and it's actual length does not change every time a yardstick of a different length is used by somebody to measure it. The measurements are different, that's all.  The field remains constant.

 

It's the same thing (but in reverse) according to Lorentz's theory.  There the measurement (of the speed of light) is always the same, but ONLY BECAUSE distorted instruments are being used in different frames.  If every frame had the same clocks and rods (no shinkage) then each would measure the speed of light to be different.

Obviously if no clocks dilated and no rods contracted then observers in different frames of reference would measure different speeds of light, but that's not what happens in reality. In the real universe the speed of light is independent of the motion of the light emitter.

 

The use of the LT actually creates some theoretical problems for SR.  The LT was designed to explain how the speed of light could be measured to be constant when it really wasn't (the explanation was that clocks and rods of different durations/lengths were being used in different frames).

 

But if the speed of light REALLY IS constant in all frames, and if we also MEASURE it to be the same, then we must be using the same standards for all frames.  If you measure a speed to be what it "really is," then you obviously have used correctly calibrated instruments to do so.  Otherwise you would have gotten an "incorrect" measurement.

 

So there is no call for transformations in that case.  Yet SR uses "corrections" for clocks (which relativists want to call "time') and rods (which they want to call "space").

 

 

SR should have no need or use for "corrections" to instruments which make accurate measurements of the "true" speed to begin with.

 

See the problem?

This makes absolutely no sense! The speed of light is measured to be the same in all inertial frames. So if object B is moving away from object A at say half the speed of light then shines a light at object B, the light will be moving away from object A at the same speed that it passes object B in object B's frame of reference. So the light is passing object B at half the speed of light in object A's frame and at the full speed in object B's frame. The only way that's possible is with length contraction and time dilation, each sees the other as length contracted and time dilated because they're in different frames of reference. There's no contradiction, this is what resolves the apparent contradiction of a constant speed of light.

[Moronium]

A-wal said:  'Obviously if no clocks dilated and no rods contracted then observers in different frames of reference would measure different speeds of light, but that's not what happens in reality. In the real universe the speed of light is independent of the motion of the light emitter."

 

------

 

It's claims like this that lead me to conclude that Anssi, for example, is far more knowledgeable and wise than you are, A-wal.

 

No respectable theorist, including Einstein his own damn self, EVER claimed that the basic postulates of SR were "true in reality."  They are simply unproven postulates which Al himself admitted were freely and voluntarily chosen by him, but NOT dictated by any empirical facts.

 

Your presumption to speak in terms of "the real universe" is extremely naive, sorry.

Edited April 14, 2018 by Moronium

[Moronium]

A-wal, first you say "Obviously if no clocks dilated and no rods contracted then observers in different frames of reference would measure different speeds of light, but that's not what happens in reality," but then you go on to contradict the clear implications of your own claims.

 

Clocks do, in fact, slow down with speed, we agree on that, if that's what you mean by "reality."  Empiircal observations demonstrate this fact.

 

But this just proves what I said, and invalidates your denials.

 

If two observers, moving relative to each other, get the SAME speed measurement using DIFFERENTLY calibrated measurement instruments, then obviously the ACTUAL speed of what they are measuring is NOT (in reality) the same.  The measurement is the same, (therefore) the actual speed being measured is NOT the same.

 

This should be intuitively obvious to anyone with even a rudimentary grasp of logic.  Why do you deny it?

Edited April 14, 2018 by Moronium

[Moronium]

Put one more way:

 

If one guy (A) has a stick which is 36" long, and which he calls a "yard," then he will measure a standard football field to be 100 yards long.

 

If another guy ("B") has a stick which is 18" long, and which he calls a "yard," then he will measure a half-sized (50 yard) football field to be 100 yards long.

 

In that case A and B will get the SAME measurement (100 yards), but ONLY because the are measuring objects of different lengths.

 

On the other hand, if B measures the same standard field that A did, he will say it's 200 yards long.  But he will be wrong, because his yardstick is wrong.

 

The 100 yard-long field has NOT changed when B (incorrectly) measures it.  Likewise, the 50-yard field which he does "measure" to be 100 yards long is NOT somehow magically transformed into the length of a standard field, just because he used a mis-calibrated rod to measure it.

 

But, in effect, that's what SR presumes to postulate.  It attempts to claim that a 50 yard long field IS somehow magically transformed into a 100 yard field, just because that's what B measures it to be with an admittedly distorted instrument.  It's solipsistic nonsense, that's all.

 

Comprende?

Edited April 14, 2018 by Moronium

[A-wal]

A-wal said:  'Obviously if no clocks dilated and no rods contracted then observers in different frames of reference would measure different speeds of light, but that's not what happens in reality. In the real universe the speed of light is independent of the motion of the light emitter."

 

------

 

It's claims like this that lead me to conclude that Anssi, for example, is far more knowledgeable and wise than you are, A-wal.

 

No respectable theorist, including Einstein his own damn self, EVER claimed that the basic postulates of SR were "true in reality."  They are simply unproven postulates which Al himself admitted were freely and voluntarily chosen by him, but NOT dictated by any empirical facts.

Everything in sr follows as a natural and inescapable consequence of the postulate that the speed of light is constant in all inertial frames of reference. Unless that's shown to not be the case sr is an accurate description of reality regardless of whether or not people such as yourself have the capacity to grasp it.

 

Your presumption to speak in terms of "the real universe" is extremely naive, sorry.

There's no need to apologise for your opinion, your opinion is worthless.

 

A-wal, first you say "Obviously if no clocks dilated and no rods contracted then observers in different frames of reference would measure different speeds of light, but that's not what happens in reality," but then you go on to contradict the clear implications of your own claims.

 

Clocks do, in fact, slow down with speed, we agree on that, if that's what you mean by "reality."  Empiircal observations demonstrate this fact.

 

But this just proves what I said, and invalidates your denials.

 

If two observers, moving relative to each other, get the SAME speed measurement using DIFFERENTLY calibrated measurement instruments, then obviously the ACTUAL speed of what they are measuring is NOT (in reality) the same.  The measurement is the same, (therefore) the actual speed being measured is NOT the same.

You've got this backwards. When an observer compares themselves to an observer in a different frame of reference they see that other observer as length contracted and time dilated. Inertial observers always measure light to be moving at the speed of light relative to themselves but measure light to be moving at some other speed relative to any observer that's in motion relative to themselves. This is obvious, if a car is moving away from your car at 20mph and another car overtakes you going 40mph faster than you then it's moving at 40mph relative to you but only at 20mhp relative to the car that's moving away from you at 20mph. So light moves at the same speed (the speed of light) relative to any inertial observer but at a different speed relative to objects that are in motion relative any inertial observer, but objects that are in motion relative to an inertial observer are length contracted and time dilated and if you take that into account and work out what speed those other observers measure for the speed of light they always measure it to be moving at the same velocity relative to themselves from their own perspective.

 

This should be intuitively obvious to anyone with even a rudimentary grasp of logic.  Why do you deny it?

Because it's bullshit.

 

Put one more way:

 

If one guy (A) has a stick which is 36" long, and which he calls a "yard," then he will measure a standard football field to be 100 yards long.

 

If another guy ("B") has a stick which is 18" long, and which he calls a "yard," then he will measure a half-sized (50 yard) football field to be 100 yards long.

 

In that case A and B will get the SAME measurement (100 yards), but ONLY because the are measuring objects of different lengths.

 

On the other hand, if B measures the same standard field that A did, he will say it's 200 yards long.  But he will be wrong, because his yardstick is wrong.

 

The 100 yard-long field has NOT changed when B (incorrectly) measures it.  Likewise, the 50-yard field which he does "measure" to be 100 yards long is NOT somehow magically transformed into the length of a standard field, just because he used a mis-calibrated rod to measure it.

 

But, in effect, that's what SR presumes to postulate.  It attempts to claim that a 50 yard long field IS somehow magically transformed into a 100 yard field, just because that's what B measures it to be with an admittedly distorted instrument.  It's solipsistic nonsense, that's all.

 

Comprende?

You're getting desperate now. Sr describes how rods and clocks that are properly calibrated contract and dilate when viewed from a different frame of reference, as they have to to maintain a constant speed of light in all frames. Using miscalibrated rods or clocks as an example of why you think sr is wrong is a very silly approach.

Edited April 16, 2018 by A-wal

[Moronium]

A-wal, if you were worth responding to I would, but you're not.

 

Every statement, every claim, every comment you make merely presupposes the absolute, PROVEN truth of the very unproven assumptions and postulates which you are purporting to demonstrate.  Circular reasoning is no reasoning at all, I'm afraid.  It's just a method of continuously reiterating your unsupported assertions.  As though loud and repeated playing of your pre-recorded monologue will somehow prove it's "true."  Maybe you should consider taking a course in the philosophy of science sometime, eh?

 

In the meantime, just keep on braying.

Edited April 16, 2018 by Moronium

[A-wal]

A-wal, if you were worth responding to I would, but you're not.

Oh so it's not at all that you don;t have a leg to stand on then? :)

 

Every statement, every claim, every comment you make merely presupposes the absolute, PROVEN truth of the very unproven assumptions and postulates which you are purporting to demonstrate.  Circular reasoning is no reasoning at all, I'm afraid.  It's just a method of continuously reiterating your unsupported assertions.  As though loud and repeated playing of your pre-recorded monologue will somehow prove it's "true."  Maybe you should consider taking a course in the philosophy of science sometime, eh?

 

In the meantime, just keep on braying.

I've explained very clearly why sr says what it does and how you've completely misunderstood it. The onus is not on me to prove to you that sr is a valid description. If the speed of light is constant (it is!) then sr describes how time has to dilate and length has to contract in different inertial frames for light to maintain that constant relative velocity. It's not my problem that you can't understand it. See ya.

[Moronium]

 

 

You've got this backwards. When an observer compares themselves to an observer in a different frame of reference they see that other observer as length contracted and time dilated. Inertial observers always measure light to be moving at the speed of light relative to themselves but measure light to be moving at some other speed relative to any observer that's in motion relative to themselves. 

 

Yes, this is exactly what I said, but which you have previously been denying, so I don't have it "backwards."  The speed of light is not, in actuality, the "same" in each frame, even if each observer measures it to be the same using instruments of different times and lengths.

 

That's what creates the problem for SR.  If SR wants to claim that the speed of light actually IS (ontologically) the same in each frame, then it would have to deny that the measuring instruments used are any different. But it doesn't. Instead it adopts and uses Lorentz's transformation equations (which were developed for use with a theory positing absolute simultaneity).

 

Some theorists do deny that the instruments actually contract/slow down with increased speed, but that doesn't solve the problem, nor is it a position accepted by the mainstream, nor is it consistent with empirical observations, such as the H-K experiment.

 

It is only because, in SR, each observer is required to posit that his frame of reference is "stationary," with the speed of light being isotropic in his, AND ONLY HIS, frame, AND because SR posits a change in measuring instruments aboard moving objects, that  all inertial frames MEASURE c to be the same.   But these conflicting claims (of which there are an infinite number) cannot ALL be true as a matter of observer-independent reality.  It can't be true that, at the same time, EVERY inertial frame is "at rest." 

 

If that were true there would never, ever be any relative motion and there would be no need of any theory of (non-existent) "motion."  We would simply adopt the philosophy of the ancient Parmenides, who claimed that all  perception of motion was an "illusion," because, in reality (he claimed), nothing ever truly moves.

 

Edited April 20, 2018 by Moronium

[Moronium]

If that were true there would never, ever be any relative motion and there would be no need of any theory of (non-existent) "motion."  We would simply adopt the philosophy of the ancient Parmenides, who claimed that all  perception of motion was an "illusion," because, in reality (he claimed), nothing ever truly moves.

 

It is quite easy for anyone to make absurd metaphysical claims, and even to create what may appear to be "irrefutable" arguments to buttress those claims.

 

Parmenides' disciple, Zeno, proposed a number of "paradoxes" to his peers, most of whom were unable to provide irrebuttable counter-arguments.  Though baffled, they still never accepted the notion that nothing ever moves.  

 

Similarly, Bishop Berkeley, carrying radical empiricism to it's extreme, made some excellent points and arguments in favor of his claim that there was no objective reality whatsoever and that all perceptions were created only by subjective minds (solipsism).

 

When Samuel Johnson (a philosopher of dictionary-publishing fame) was asked how Berkeley's arguments could possibly be refuted, he didn't say a word.

 

Instead, he kicked a rock, then said  "I refute it thusly."

 

Einstein and his (at that time) idol, Ernst Mach, were not the first proponents of some metaphysical propositions that conflict with all known human experience.  But no reasonable person has ever been convinced that such positions are "true," no matter how skillfully their proponents argue for the absurd propositions they adopt.

 

Mach was the quintessential proto-positivist.  Like his disciple, Einstein, he declared that, for example, a geocentric and a heliocentric viewpoints were "equally valid."  Even so, he was forced to admit that the "universe is only given once."  In other words, it would be impossible for both views to be "true" in reality.

Edited April 20, 2018 by Moronium

[sluggo]

In his 1905 paper, Einstein questioned the necessity of a special frame for em phenomena. It didn't matter if the coil moved or the magnet moved or both moved. There was still an induced current resulting from any relative motion.

 

Measurement has always been relative to a defined standard. If there are two platforms, the 1st charged to 1000 volts and the second charged to 1010 volts, a voltmeter reading between them indicates 10 volts, the difference. The idea of relative measurements is not new. What is new is the idea that motion can alter perception and measurement.

A light clock will easily demonstrate time dilation as a slowing rate of any process that depends on em interactions. That would also include chemical, thus biological processes. In a sci-fi scenario, if the clock rate slows, so does anaut Alice moving with the clock, and consequently is not aware of any change. 

choices:

1. Alice assumes a pseudo rest frame for most of the trip. (The initial acceleration is short, and the plan is to orbit the destination, take pictures and return). The eta was calculated as t=d/v, per earth charts. The target arrives earlier than the eta. How does Alice reconcile the early arrival, knowing v is correct via a radar check as she left earth orbit, and her clock and biological clock agree? The only factor left is distance d. SR states that a fast moving object (the universe) will experience length contraction.    

2. Alice knows SR states a fast moving object (the clock and self) will experience time dilation.

In both cases, SR provides resolution, so it doesn't matter which state  she chooses.

The interesting point here is this.

A fast moving object cannot alter the dimensions of the universe*, but motion can alter perception, which is reality confined to the mind. In case 1, Alice interprets her own time dilation as length contraction of the outside world.**

* When particle accelerators are wound up, there are never reports of astronomical changes.

** A person on drugs has hallucinations, but they are not visible to anyone else.

 

The propagation speed of light is constant. All experiments verify this to increasing precision to within a fraction of a meter/sec. 

The propagation speed of light is independent of its source. If it wasn't there could be no length contraction or time dilation.

Td and lc work in a complementary manner to preserve the measured  speed of light for all observers in inertial frames.

[Moronium]

Interesting post, Sluggo, but it's not actually clear what you are trying to say or conclude.  Are you responding to any post in particular?

 

I'm not sure if it was in this thread or another, but I have made the point that saying that c is MEASURED (a matter of epistemology) to be the same is NOT the same saying it IS (ontologically) the same.  At one point you say:

 

The propagation speed of light is constant.. 

 

 

  But you end your post by saying:

 

Td and lc work in a complementary manner to preserve the measured  speed of light for all observers in inertial frames

 

 

Are you treating these as the same claim, or different claims?

Edited April 21, 2018 by Moronium

[sluggo]

Moronium #156

It was in response to everything posted in this and related threads.

 

About 12 yrs ago, a visit to a physics forum left me curious as to why Relativity Theory was debated so much after 100 yrs of experimental verification. Presentation and  interpretation was the answer. I'll spare you the verboseness and say, there is a range from, 'the theory is reality', to 'a description in terms of physical phenomena'.

For the inquiring mind, the answer depends on who you ask.

Surprisingly (and maybe not), many of science debates are not about science, but the meaning of terms used, and why I recommend a good dictionary as a primary reference.

 

 

I'm not sure if it was in this thread or another, but I have made the point that saying that c is MEASURED (a matter of epistemology) to be the same is NOT the same saying it IS (ontologically) the same.

 

Observer B is watching observer A move past him at Bt=0, on a parallel course at speed v, and simultaneously emits a light signal in the same direction. B calculates the speed of the signal relative to A as c-v.

Is that what you mean when you say 'real/actual speed'?