I am 99% sure I already posted a blurb about someone who knows far far more than all of us about GPS than all of us combined who is convinced that GPS actually disproves SR.
Additionally you are correct that if the calculations give the right predictions or close enough for most of the things we are concerned with we may observe that while it is incorrect, it is still useful, a bit like a stool with a bad leg, you can still use it a bit till you get a new one. But if you keep using it without getting a new one as soon as possible, you are going to look like an idiot when eventually it will goes wrong.
Even when the correct, or more correct answer is found, the basic rough and ready calculations might not change a lot.
Light is already moving at C and should have no dimension, and yet it does, and if you move faster relative to light, now it’s dimensions to shrink, but wait your velocity to light has not changed it is still C.
Maybe we should say it is C+, or C++ physics/coding cross over joke.
A joke only real nerds get!
Additionally it seems wrong to say that this effect is because of length contraction, it is plainly the Doppler effect, making frequencies higher or lower.
And Doppler is only equivalent to length contraction if length contraction is both not real and only half the picture as Doppler slows frequency and expands apparent length for things receding.
Except no one can even hope to model this without involving different frames of motion disagreeing about if a photon is in a specific location at a specific time.
If 2 sensors were in the same location (segmented, layered, whatever) moving differently you would have one sensor see the photon and the other not.
Only if you can accept that can you have C be constant.
And if that is the case fine, but it also means you could have one sensor change it’s motion to meet the same photon twice, or possibly avoid detecting a photon all together by changing the sensors motion (while being definitively in the path of the photon the whole time).
If you still believe SR after really understanding my arguments, I have a Unicorn farm to sell you! It’s under the Brooklyn Bridge which I’ll include in the deal!
Doppler expands apparent length for things approaching since closer portion is more current than the more delayed rear which reflects the older position.
And contracts apparent length for things receding.
Which is interesting because the frequency is raised by Doppler which would cause us to assume a shorter wavelength.
But there is no paradox because the frequency rise is an illusion, but one that acts quire real, the length expansion/dilation from Doppler can’t be realized.
So Doppler seems to make the wavelength look longer (when it has not yet arrived), but actually makes it shorter when 2 observers are approaching.
Certainly the length contraction/expansion of the Doppler effect is perverse, and very unreal.
For the record in all the posts to this thread and the other thread, no one has seemingly even tried to answer the whole of any thought experiment I have presented.
No one is able to solve the paradox in their own head to attempt a complete non conflicting answer.
No one can, there is no possible resolution.
But please prove me wrong.
Does anyone think they have already solved it and I ignored it? Then please show me up!
Consider a room, 50 m by 50 m, with doors at the north and the south ends. Take a long plank and accelerate it to a relativistic velocity such that it contracts to a length shorter than 50 m.
In the lab frame, I can pass the plank into the room from the north, then shut both doors simultaneously so that the plank fits in the room. I then open both doors and the plank leaves out the south.
From the plank’s point of view, the room has shrunk. The south end of the plank enters partway through the north door. The south door shuts. The south door opens. The south end of the plank exits through the south door. The north end of the plank enters the north door. The north door shuts. The north door opens. The north end of the plank exits through the south door.
No paradox. This was a question on a homework set I took a decade ago. We were asked to resolve this very paradox. The resolution is very clear if you do the math!
I don’t understand why you claim that the math clouds the physics. Using math forces us to state our assumptions up front (and tells us which we need to rethink), and it allows us to get the answers we need without turning to a higher authority. We can even make new maths if the old ones don’t work!
Take away lesson: observers in different inertial frames do not agree on simultaneity. This is what you’re missing in many of your thought experiments – syncing watches is not always possible!
Some of your other thought experiments are only paradoxical if you assume we live in Eulerian 3-space. We don’t.
The problem is that you can’t simultaneously close the doors since it only looks to be simultaneous to you.
SR makes this a very confusing experiment because from your POV you can obviously close the south door before the plank hits it (or leave it closed) and you can obviously close the north door once it is in.
But you can’t close them simultaneously, also it only works for a vanishingly small instant of time from the barns view.
Precisely, because the plank leave the room again though a shut door.
It destroys the door
However if the plank doesn’t exit but orbits around, now your argument fails.
Or if you like, take a hexagon disk which will not quite fit into a cylinder and spin it up, now it can fit according to the stationary cylinder, but it has become an even worse fit form the disks perspective, you put it on and the hexagon fits into the cylinder nicely while it is unable to be put on. That is a paradox.
Do you see how easy it is to find the flaws in the first example and how hard it in in the other?
note:Hexagon to make the length contraction obvious.
All of the arguments for SR like this are from the the one angle SR does sound plausible.
The hexagon can’t be smaller and larger than the cylinder at the same time and once simultaneity issue problem is removed you cannot longer solve it.
You can’t address MY thought experiment, you have to refer to a different one that can be solved.
But thanks for at least ALMOST analysing my experiment.
Strange that it isn’t so obviously solved?
And strange that the version you showed me can be understood without mathematics or knowing precisely how short the plank should be.
I should insist that you prove yours with numbers I can’t check just for symmetry
In your altered version.
You had to because you are unable to solve mine.
Great, did you do the math?
Can you do it now for my example?
Then give me the results, even without the results just that what will be seen results.
Maybe partly because I don’t use the math.
Not that I can’t add, subtract, multiply, divide and square, but I can’t read most most equations to save myself.
That is my cross to bare but I did not need math or numbers to describe you experiment.
Oh, I also don’t trust math because it is very easy to do something with math and without realizing it you have done something that is mathematically sensible but not physically sensible.
Anyway can you really grasp the meaning of the find structure constant?
It’s not even that I don’t think it has a meaning, but it is so abstract it is hard to reconnect it to reality.
I think I may be vaguely understanding ‘alpha’, but I will admit it’s only a vague sense.
And that seems to be a common opinion regarding 7.29735257…
Which of my experiments are significantly effected by non-simultaneity?
The people in the opposite cabins? Because non-simultaneity can only be small over a potentially small distance and at any rate is is unable to account for an ever increasingly larger discrepancy such as time not passing mutually for the opposite cabin.
There are thought experiments that SR can easily explain.
I am not making those arguments, so why not argue mine not others.
Let’s not dance around what this paradox is. This is the well-known ladder paradox (or barn paradox), and its resolution is precisely the fact that simultaneity is relative. I close the doors simultaneously in my reference frame. Yes, in a manner of speaking, this “looks to be simultaneous to [me]”, but this isn’t a problem. It looks simultaneous in one reference frame, and not simultaneous in a different reference frame.
No shit. At any non-zero speed, the plank can only remain in the barn for a finite amount of time. As this speed increases, the time decreases. What’s your point?
OK. This is a different – but also well-known – paradox, the Ehrenfest paradox. I’m going to change your hexagonal disk back to a circular one, since by your own admission its peculiar geometry is to make visualization easier. The radius of your disk doesn’t shrink, because any point along the circumference moves orthogonally to the radial vector. Since the radius doesn’t shrink, your disk can’t fit into a cylinder of smaller radius.
Yes, the circumference gets smaller by a factor of gamma. Since the circumference is no longer 2πR, we conclude that the disk is not in Euclidean space. Acceleration must warp spacetime.
This comment reveals that you don’t really understand what doing the math actually entails, and makes me suspect that you don’t trust mathematics because you refuse to put in the work to understand mathematics. You don’t need to assign a precise length to the plank – just call it L in the rest frame.
The reasons I harp on you to do the mathematics is the following:
– In a sense, the burden of proof is on you to explain why the paradox fails. Special relativity is a mathematical theory built upon a few axioms about the nature of the physical world. Any contradiction must be mathematical, and once you point out what that contradiction is, you should be able to trace it back to which axioms are in conflict, and thus which we need to get rid of or alter.
– To expand on the previous point, no one said math is easy. It takes a lot of time, something that few people have. Since you are the one who wants to overturn relativity, please do so using mathematics or experimentation. Why am I limiting you to those? Because your paradox leads to contradiction due to common sense. Common sense is often wrong, particularly in physical regimes (such as relativistic or quantum ones) where our brains didn’t evolve, and so we must rely on experimentation and mathematics to navigate these domains.
– Everyone is harping on you to do the math because when you do the math, you understand the problem and the paradox. This is why math textbooks are filled with proofs that are “exercises left for the reader”. You understand physical theories best when you solve problems with them. Similarly, you can’t understand how to paint by simply watching someone paint – you have to get your hands dirty and play around. Arguing by thought experiment is fine, but it only enables you to pose questions (which are frequently ill-proposed because your assumptions aren’t explicit). It does not equip you with the machinery to answer those questions.
So? If I showed up at an academic conference on Islam with a dissertation on a new and radical interpretation of the Koran, but I don’t understand a lick of Arabic, who would take me seriously?
I don’t trust thought experiments because it is very easy to do something with language and without realizing it you have done something that is grammatically and semantically sensible but not physically sensible.
I can do the same thing.
I fail to see what this has to do with anything.
A few things about this paradox
How is she moving relative to me if we always remain the same distance from each other?
Even if we were moving past each other, why is this a problem?
Really? Really? Getting up from a stationary position and moving is not notable acceleration?
But it does! If you curve through space, you’re in an accelerated reference frame!
I’m not sure what you’re getting at here. I have a feeling you’re confused about how infinitesimal quantities can be related, but it seems like the crux of your complaints against special relativity can be encapsulated in this quote of yours:
Are you referring obliquely to Selleri’s argument against special relativity? I’m not sure, but you’ve also made mention of walking around turntables and of trains on circular tracks, so I’d advise you to do some reading on the Sagnac effect, as well as on how different synchronization conventions cause Selleri’s paradox to disappear in the limit of an infinite radius (i.e., linear motion).
Really? Really? Getting up from a stationary position and moving is not notable acceleration?
Edit: I should also note that you experience significant acceleration just by staying in your car. You’re spinning around at relativistic speeds! You’re in a non-inertial reference frame!
physics/coding cross over joke.