Simplified explanation of SR for relativity-denier

[pellis]

Would it be correct, in trying to convince a non-mathematical relativity-denier that Einstein's SR is not wrong, to suggest, simplistically, that "time dilation, e.g. during the relative motion of clocks and trains on tracks, can be viewed as no more than a change of perspective in spacetime"?

When the denier refuses to accept the idea of spacetime, can I move to my second simplified argument to say "What I'm trying to convey is analogous to the way that the classical velocity vector of a train on a track would appear to differ (appear foreshortened or lengthened) when the train is moving, at the same speed, on another track set at an angle to the original track"?

Advice appreciated

 

[phinds]

Arguing with such people is a total waste of time. Fagedaboudit.

 

[PeroK]

Would it be correct, in trying to convince a non-mathematical relativity-denier that Einstein's SR is not wrong, to suggest, simplistically, that "time dilation, e.g. during the relative motion of clocks and trains on tracks, can be viewed as no more than a change of perspective in spacetime"?

When the denier refuses to accept the idea of spacetime, can I move to my second simplified argument to say "What I'm trying to convey is analogous to the way that the classical velocity vector of a train on a track would appear to differ (appear foreshortened or lengthened) when the train is moving, at the same speed, on another track set at an angle to the original track"?

Advice appreciated

No one can be persuaded of anything they don't want to believe. You're almost certainly wasting your time.

 

[Dale]

Your arguments are fine, but doomed to failure anyway. I would give them this link and then walk away:

https://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html

Any alternative theory must explain all of these experiments. Not just Michelson Morley

 

[Vanadium 50]

Arguing with such people is a total waste of time.

Agreed. And arguing with them via proxy is doubly doomed.

 

[pellis]

Thank you all for your eminent and unanimous agreement.

You're very likely right, but I will still try once more.

 

[Mister T]

Thank you all for your eminent and unanimous agreement.

You're very likely right, but I will still try once more.

I would emphasize the practical aspects. Everyday, at hundreds if not thousands of facilities; physicists, engineers, and technicians have to use relativity to get things right. Examples are particle accelerators, engineers designing PET scan devices, the GPS system. None of these things would work right if relativity were not a fact of life.

Do some google searching for Clifford M. Will and his articles. For example: https://philosophynow.org/issues/117/Was_Einstein_Right_by_Clifford_M_Will

Arguments about the details of the theory are unlikely to convince. Many if not most physicists were not convinced that Einstein got it right at the time he developed his theories. It took experimental verification to convince them.

 

[FactChecker]

SR => E=mc^2 => The atom bomb.

 

[jbriggs444]

The Bertozzi experiment is a nice demonstration that the Newtonian formulation for energy is not correct in the limit of high speeds.

 

[pellis]

SR => E=mc^2 => The atom bomb.

True, but my SR-denier won't be convinced by that, or the Bertozzi experiment, because can't quite get his head around the idea that measurements make things look different from different reference frames - he seems to be stuck on the idea that all quantities are always invariant:

According to his way of thinking:
- “Objective science is not the study of different appearances from different frames.” (Forget Lorentz!)
and
- “Nature did not have to wait for SR theory to come along and “construct it from measurements.”" (He can't accept that we organise our observations into theories/models - he wants to cut out that conceptual layer and simply deal with what he thinks can be apprehended directly.

...hence my simple examples for what I regard as a challenge.

He's not completely stupid and can argue his viewpoint fairly consistently, but it's just so at variance with what is manifestly workable (I don't insist on "true" as all knowledge is, in principle, provisional, though most textbook/core-course knowledge has proven extremely reliable for many decades).

Ultimately, he relies on faulty intuition and doesn't seem interested in making the necessary effort to test and revise his intuitions. As a psychologist acquaintance put it, his sense of identity is probably bound up with SR-denial.

 

[Ibix]

he want's to cut out that conceptual layer and simply deal with what he thinks can be apprehended directly.

Ask him to tell you how much he weighs without using any theory. In particular Hooke's Law is necessary to believe the result of a spring balance and the principle of moments to believe the result of a beam balance, so he cannot use either of those.

More generally, how does he know that weight is a thing? Might a spring balance behave differently under red light, or in a room with a copper floor, or... Has he tested all those things? Did he test them all on Tuesday, and at night? If not, but he still believes "weight" is a useful concept (and, even more, that it will still be a useful concept tomorrow), then he has a crude theory of gravity whether he likes it or not.

 

[PeterDonis]

Objective science is not the study of different appearances from different frames

SR agrees with this. SR says that you can express everything in terms of invariants--things that are the same regardless of your choice of frame.

What SR differs from Newtonian physics (which I assume is what your SR denier intuitively thinks is "right") on is what things are invariant. In Newtonian physics, distance and time are invariants and the speed of light is not. In SR, the speed of light and the spacetime interval (which doesn't even exist in Newtonian physics) are invariants and distance and time are not (more precisely, coordinate time is not, and SR, unlike Newtonian physics, distinguishes between coordinate time and proper time, which is the invariant spacetime interval along a clock's worldline).

And of course extensive experiments (already linked to in this thread) have shown that the things SR claims are invariants, are invariants, and the things that Newtonian physics claims are invariants, aren't. So your SR denier is not actually arguing against SR here; he's just ignorant of what experiments have shown us about what actually is invariant in the actual world.

Nature did not have to wait for SR theory to come along and “construct it from measurements.”

I'm not sure what this even means, but if he thinks Nature behaves according to Newtonian physics, he's just wrong. Experiments disprove that claim. Nature behaves according to relativity, not Newtonian physics. That's just the fact. And yes, Nature did not have to wait until humans discovered relativity theory to behave according to relativity. It has always behaved according to relativity. We know that too since we have a model of the universe as a whole based on relativity that makes accurate predictions about things that are the result of events billions of years ago.

 

[PeterDonis]

he wants to cut out that conceptual layer and simply deal with what he thinks can be apprehended directly

That's fine: the fact that the speed of light is invariant can be apprehended directly, in experiments. And that fact is inconsistent with Newtonian physics and consistent with relativity.

Differential aging can also be apprehended directly in experiments (for example, muons confined in magnetic traps and circling around inside them at relativistic speeds have measurably longer lifetimes than muons at rest), and is also inconsistent with Newtonian physics and consistent with relativity.

So if he really wants to do what he says, he should accept relativity because that's what we apprehend directly in experiments to be true.

 

[Dale]

my SR-denier won't be convinced by that

Nor will they be convinced by anything else.

You should take the opposite approach. It is on them to convince you. Send them the list of experiments I linked to earlier. For them to convince you that SR is false it is up to them to make an alternative theory that explains all of those experiments. Not just one or two. Until they can show that their theory quantitatively reproduces all of those, then they have an unconvincing argument.

 

[Frabjous]

Ask him why his GPS app works.
https://www.astronomy.ohio-state.edu/pogge.1/Ast162/Unit5/gps.html

 

[FactChecker]

If he accepts that atom bombs and GPS work, but can't believe SR, then he is like the Flat Earth advocates. He will never admit the truth. Avoid the subject and accept that he will never be a physicist.

 

[pellis]

SR agrees with this. SR says that you can express everything in terms of invariants--things that are the same regardless of your choice of frame.

Maybe I misunderstood the SR-Denier's meaning, and yours, in realtion to "Objective science is not the study of different appearances from different frames"?

While I agree, of course, that "you can express everything in terms of invariants", I thought it would nevertheless be correct that SR relates different appearances from different frames, via the Lorentz transformation, and therefore that "the study of different appearances from different frames" is "Objective science"...?

I'd appreciate being corrected by you, on this point, Peter.

As regards "what he thinks can be apprehended directly", I believe he just wants his everyday view of the world as he sees it to be confirmed.

 

[pellis]

Ask him to tell you how much he weighs without using any theory. In particular Hooke's Law is necessary to believe the result of a spring balance and the principle of moments to believe the result of a beam balance, so he cannot use either of those.

More generally, how does he know that weight is a thing? Might a spring balance behave differently under red light, or in a room with a copper floor, or... Has he tested all those things? Did he test them all on Tuesday, and at night? If not, but he still believes "weight" is a useful concept (and, even more, that it will still be a useful concept tomorrow), then he has a crude theory of gravity whether he likes it or not.

Thanks, but my "Armchair-SR-denier" is not sufficiently engaged to try anything practical.

 

[pellis]

Nor will they be convinced by anything else.

You should take the opposite approach. It is on them to convince you. Send them the list of experiments I linked to earlier. For them to convince you that SR is false it is up to them to make an alternative theory that explains all of those experiments. Not just one or two. Until they can show that their theory quantitatively reproduces all of those, then they have an unconvincing argument.

As mentioned in other replies - he's an armchair-SR-denier who dismisses spacetime as meaningless...

 

[pellis]

Ask him why his GPS app works.
https://www.astronomy.ohio-state.edu/pogge.1/Ast162/Unit5/gps.html

I'll have to try that one on him... Thanks

 

[pellis]

If he accepts that atom bombs and GPS work, but can't believe SR, then he is like the Flat Earth advocates. He will never admit the truth. Avoid the subject and accept that he will never be a physicist.

Indeed.

After any reply PeterDonis might want to give, I'll have to leave it at this point - didn't expect so many helpful replies, but have other responsibilities demanding my attention for next few weeks. Many thanks to you all.

 

[PeterDonis]

SR relates different appearances from different frames, via the Lorentz transformation

Coordinates are not "appearances". They are just mathematical abstractions. The Lorentz transformation relates coordinates in different inertial frames in flat spacetime. If you have a non-inertial frame, or spacetime is curved, the coordinate transformations between different frames will be different (unless you restrict yourself to just local inertial frames).

"Appearances" are measurements made by different observers. Those always correspond to invariants. When people talk of things like "length contraction" or "time dilation", what they actually are talking about (although unfortunately many sources obfuscate this) is not different coordinates in different frames; it's the fact that, for observers in relative motion, measurements of "length" and "time" correspond to different invariants. Spacetime diagrams can often make this much clearer.

As regards "what he thinks can be apprehended directly", I believe he just wants his everyday view of the world as he sees it to be confirmed.

I agree that's probably what he wants, but his everyday view of the world is not something that can be "apprehended directly". Neither is the relativistic view of the world. You have to combine direct observations with theory to get a "view of the world", at least as he's using the term, since what he is calling his "everyday view of the world" contains lots of things that are not direct observations but depend on theoretical claims.

 

[pellis]

SR relates different appearances from different frames, via the Lorentz transformation

You replied: "Coordinates are not "appearances". They are just mathematical abstractions."

Ah! I was using language carelessly. Many thanks for the clarification.

I quite agree, on the 2nd point.

Regards - P

 

[pellis]

FYI, and confirming your earlier scepticism, if interested; this is the final communication from my SR-denier:

"No measuring instrument has ever approached ‘c’… not that it matters to the “thought experimental” theorists of SR theory claiming that ‘c’ is the same as measured from *all* inertial frames of reference.

Some “textbook” theories are wrong. SR theory is one of them. Neither physical objects or distances contract as a function of differences in frames of reference, and time is not an entity/medium passing at different rates in different places or “for” different observers with their variable clocks.

I hope you meant it when you said, “…I give up…”

I’m done… again!"

I give up!

 

[FactChecker]

FYI, and confirming your earlier scepticism, if interested; this is the final communication from my SR-denier:

"No measuring instrument has ever approached ‘c’… not that it matters to the “thought experimental” theorists of SR theory claiming that ‘c’ is the same as measured from *all* inertial frames of reference.

Some “textbook” theories are wrong. SR theory is one of them. Neither physical objects or distances contract as a function of differences in frames of reference, and time is not an entity/medium passing at different rates in different places or “for” different observers with their variable clocks.

I hope you meant it when you said, “…I give up…”

I’m done… again!"

I give up!

He may not understand the logic. It is not necessary to have an instrument traveling near the speed of light. It is only necessary to have an instrument accurate enough and moving fast enough to show that the velocity of the instrument is not summed with c to give its measured speed of light. The Earth orbits the Sun at a speed of 67,000 mph. Our instruments are sensitive enough to detect the effect of that speed if SR was wrong and speeds were additive.

 

[Ibix]

I give up!

There's a reason we just ban them here. Arguing with them is like shooting zombie fish in a barrel. You can't miss, but you can't stop 'em either.

 

[Mister T]

FYI, and confirming your earlier scepticism, if interested; this is the final communication from my SR-denier:

"No measuring instrument has ever approached ‘c’… not that it matters to the “thought experimental” theorists of SR theory claiming that ‘c’ is the same as measured from *all* inertial frames of reference.

You don't need to approach the speed of light. SR works for all speeds. The GPS satellites have measuring instruments aboard them. They are atomic clocks that send and receive signals with each other and with engineers on Earth. If they ignored the effects of SR the GPS wouldn't work right.

These are not thought experiments. They are facts of life. It's the way Nature behaves.

Your friend can deny it. He just won't engage with reality. He prefers to stay in his own head and just use devices that depend on the validity of SR.

 

[PeterDonis]

No measuring instrument has ever approached ‘c’

Relative to what? As is often pointed out in discussions here, everything on Earth, including our measuring instruments, is moving at very close to $c$ relative to cosmic ray particles coming in from space. Our instruments measure exactly what relativity predicts in such cases.

the “thought experimental” theorists of SR theory claiming that ‘c’ is the same as measured from *all* inertial frames of reference

Has he heard of the Michelson-Morley experiment? And more recent versions with better accuracy? The speed of light being invariant was not a "thought experiment"; it was based on actual experiments.

Some “textbook” theories are wrong. SR theory is one of them.

Relativity is not a "textbook" theory. It is confirmed by countless experiments. As has already been mentioned, technologies we all depend on, like GPS, would not work if relativity were not correct.

Neither physical objects or distances contract as a function of differences in frames of reference, and time is not an entity/medium passing at different rates in different places or “for” different observers with their variable clocks.

These claims are experimentally false.

I agree it's not worth your time to pursue this argument further.

 

[Dale]

Our instruments are sensitive enough to detect the effect of that speed if SR was wrong and speeds were additive

Our most sensitive clocks can detect relativistic effects at walking/jogging speeds.

 

[Vanadium 50]

Our most sensitive clocks can detect relativistic effects at walking/jogging speeds.

True, but I don't think they are that portable. Maybe an RV?

 

[Meir Achuz]

He may be right. Since the earth is flat, that could change everything.

 

[Mister T]

True, but I don't think they are that portable. Maybe an RV?

Huhh? You can put an atomic clock on an RV and drive it at walking or jogging speeds. You don't have to be walking or jogging to move at a walking or jogging speed.

 

[ersmith]

Our most sensitive clocks can detect relativistic effects at walking/jogging speeds.

I'm aware of Chou et al observing time dilation at 10 m/s, which is Olympic sprinter speed, but hadn't heard of further improvements. It wouldn't surprise me though, Chou's work was a few years ago.

 

[JLowe]

There's a reason we just ban them here. Arguing with them is like shooting zombie fish in a barrel. You can't miss, but you can't stop 'em either.

To be honest, arguing with them feels a bit like being a bully. Like you're picking on someone smaller than you.

 

[Sagittarius A-Star]

I'm aware of Chou et al observing time dilation at 10 m/s, which is Olympic sprinter speed, but hadn't heard of further improvements. It wouldn't surprise me though, Chou's work was a few years ago.

I found this:

Resolving the gravitational redshift across a millimetre-scale atomic sample
...
Nature volume 602, pages420–424 (2022)
...
Abstract
Einstein’s theory of general relativity states that clocks at different gravitational potentials tick at different rates relative to lab coordinates—an effect known as the gravitational redshift¹. As fundamental probes of space and time, atomic clocks have long served to test this prediction at distance scales from 30 centimetres to thousands of kilometres^2,3,4. Ultimately, clocks will enable the study of the union of general relativity and quantum mechanics once they become sensitive to the finite wavefunction of quantum objects oscillating in curved space-time. Towards this regime, we measure a linear frequency gradient consistent with the gravitational redshift within a single millimetre-scale sample of ultracold strontium. Our result is enabled by improving the fractional frequency measurement uncertainty by more than a factor of 10, now reaching 7.6 × 10⁻²¹. This heralds a new regime of clock operation necessitating intra-sample corrections for gravitational perturbations.

Source:
https://www.nature.com/articles/s41586-021-04349-7

A free version:
https://arxiv.org/abs/2109.12238