What Time Dilation ACTUALLY Is In Relativity (Hint: It has nothing to do with time)

Interesting interpretation. It seems though that, if we consider what observers measure, this would give back the usual formalism of special relativity : proper time being measured with the local speed of sound within each clock, the measured speed of sound would be the same in all reference frames. A mathematical formalism based on this would give back the Minkowski metric and the Lorentz transformations, so I feel like it's not that different from the usual interpretation. In my opinion it's actually very close to it – the "air" is a given coordinate system, and the demonstration in the video is perfectly valid in the usual interpretation : we can do special relativity in one single frame of reference, i.e. based only on the perception of time of a single observer. If we want to consider what other observer perceive however, we need to introduce Lorentz transformations in the mathematical formalism. An interesting point : this can be used to show that the speed of light doesn't have to be isotropic in relativity. Just as you showed, even if it were anisotropic we wouldn't detect any physical difference.

So at Mach 1, a clock stops registering time completely . . . .

You've missed a very crucial point on light clocks (which unfortunately is rarely if ever mentioned), namely the fact that their use as time reference is only justified by first accepting the postulate that the speed of light is independent of the observer. When looking at your sound clock, the obvious reaction is that the sound clock just is not a good clock, because it does not correctly measure time when in motion relative to the air. And I can experimentally verify that when moving along with the moving sound clock, by just looking at my wristwatch which does not operate on sound, and noticing that it does not slow down the same way the sound clock does. Now you may say the postulate of constant light speed is a postulate, and we should not accept it without experimental evidence. And you're right in that. So we should look at a clock that does not operate on light, and therefore should not be affected by light speed. So where do we find such a clock? Well, we find it for example in myon decay. That decay is an effect of the weak force, with no electromagnetic involvement. So if relativistic effects are only an effect of the clocks we use, the myon decay should not follow the laws of special relativity, just as my wristwatch doesn't follow the laws of "sound clock relativity", and for the exact same reason: The mechanism does not involve the mechanism that, under this hypothesis, causes the clock to slow down. Now the decay time of moving myons can be and has been measured. And it follows the laws of special relativity. Which you'll have a hard time explaining if you think that relativity is merely an artefact of how we measure time, as opposed of an inherent property of space and time.

As someone doing a PhD in physics I want to say a few things: - Special relativity is not mysterious, it is counterintuitive but well understood. - The twin paradox has been solved for a long time and it is well undersood in the scientific community. Just because some youtubers can’t explain it well it doesn’t mean it’s not solved. - The aether approach to special relativity was disproven by the MM experiment a long time ago. - Special relativity is the foundation for General Relativity and Quantum Field Theory, the two most successful theories in all physics. So any modification of special relativity must figure out how to still predict particle physics, the standard model, black holes, the expansion of the universe, etc. - The similarities between sound and light are well understood by the fact that both satisfy a wave equation and wave equations have Lorentz symmetry, thus transforming according to the gamma factor. But the similarities end there since light is a wave of the electromagnetic field which has been proven to propagate through empty space many times.

But assume that you have an interferometer with two legs, AB and AC, and that it that it gives some interference pattern in frame of reference of the point A. On the margin note that this setup can be thought of as two clocks, one which is rotated in regard to another by 90 degrees. For simplicity assume that c=1, you are in the absolute timeframe (v=0), |AB| = |AC| = dx = 1. Then the two light-beams will meet back at point A at absolute t=2, and observer at A will notice a constructive interference. Then let the interferometer start moving at AB direction with v=0.5. Then the light will reach point C at absolute t=sqrt(4/3)=1.1547..., and by symmetry the whole trip ACA of the light will be finished at absolute t=2*sqrt(4/3)=2.3094... . But the whole trip for ABA will be finished at t=8/3=2.6666..., so now the light-beams won't meet at A, and - for the most frequencies of light that we may use there will be no constructive interference. That is, we would be able to detect if we are at absolute motion or not. I'm not sure, did I just recreate Michelson Morley experiment? Someone may notice that I assumed that |AB|=|AC| which may be problematic because to assume something on length I would have to assume something on time yada yada yada. But I don't think it is a problem, you don't need to know exact lengths of AB and AC. You just do your experiment in one frame of reference(for different light frequencies, just to be safe), notice the interference pattern, then you repeat it at some speeds v and verify the interference pattern again. You can also abstract away the whole interference business if you assume you can detect if two beams arrived simultaneously, not going into details how you can achieve this. By relativity principle the patterns should be always the same, regardless the speed. But from what I understood from the Dialect's video and then calculated it, I arrived with the violation of the relativity principle, and experimental data. And thus - contrary to what was said in the video 13:49 - it would be possible to determine the motion with respect to the ether. I also commented on the other video about different problem I suspect: https://www.youtube.com/watch?v=ff0aofh6urU&lc=UgyqIftixcOVBaUVGid4AaABAg&ab_channel=Dialect I don't see things adding up without at least Lorentz contraction being a real phenomenon, but nor sure if this would be enough. Nevertheless I could be wrong in my calculation so can someone verify? I also created GeoGebra visualization: https://www.geogebra.org/m/rhdp9f6v

I realised I did not see the previous video you put out, and this one makes a lot more sense now. Why is this seemingly discarded as a possibility by most physicists, whereas in QM there is a recognition that different interpretations are all treated as currently indistinguishable possibilities?

Since I started reading about Special Relativity about 14 years ago, I've always been frustrated by my own difficulty in getting to grips with the mathematics involved. But this video (especially the derivation of gamma) has finally added a whole new layer of clarity to the theory for me. Fantastic video, subscribing.

I think you are missing here a crucial part AND it is what happens with the sound/light clock when it is ticking not perpendicular but paralel to the motion of the clock. Then you have simple but different calculation of the time dilatation where you just have 1(1-v^2/c^2) instead of square root of that. In this case you need also the Lorenz contraction to make both time dilatations (perpendicular and paralel) to be the same. In such case you will need an explanation of the Lorenz contraction in the paralel plane) which in my opinion will involve anisotropic change in the electromagnetic field (or in general in all fields) that make this effect! Please let me know if you are interested to discuss it further. I have some nice ideas to share :)

You analyzed what happens when the sound clock is ticking perpendicular to the direction of motion, but what happens when it's ticking parallel? For one tick the time it will take is t = D/(c-v), and for the other it will take t = D/(v+c), for a total of t = 2 D c / (c^2 - v^2). This gives you a "time dilation" factor of 1/(c^2 - v^2), with no square root. Notice, that's very different from the transverse case. It was the difference between parallel and perpendicular ticking that the Michelson-Morely experiment was looking for, and didn't find for light. That's why those papers describe this as a pedagogical tool: the luminiferous aether was ruled out by experiment more than a hundred years ago. Note, also, that for sound the Doppler shift generated when the source is moving is different that what's seen when the observer is moving. No such difference can be found for light, and the relativistic Doppler shift works quite well.

First example smacks of Lorentz ether theory. EDIT: lol at 11:40 welp, my intuition was right. 13:00 You just described time. "[t]his dialation effect isn't just limited to clocks, but rather extends to anything that relies on the information for its functioning." The motion of bodies is what time is. This is a wasted exercise. There is no "uncertainty" at all because your "uncertainty" relies on the assumption of universal time. I had high hopes for this channel. But you've slipped into woo.

Here's the link to my video on inconsistensy of special relativity: https://youtu.be/9CYRV-ewclo

However, as your medium's density and other flow characteristics change, your sound speed changes. So, your calculations are always varying. That's why light is used. Because it is the same for all observers.

Maybe I misunderstand you, but in your theory time dilation would not only depend on your speed, but also on your particular direction of travel. This seems to me to be a big problem. Since the Earth moves through space, it would have to be going through the aether at a particular speed and direction (or aether going through it, depending on your perspective). It also rotates, so any given point on the surface would have to be moving faster or slower through this aether depending on the time of day (half the time it would be moving ‘against the stream’, the other half it would be moving with it). This implies that measured time would for example be going faster in Europe than in Australia for 12 hours, and then catch up again. However, as far as I know we have never observed this. How do you explain that?

This interpretation should be experimentally verifiable i think. Two synchronized clocks. One clock by a photon emitter, one clock by a photon detector. Measure the one way speed of a photon. In other words, do not measure the time it takes to bounce and then return. After taking the first measurement, rotate the apparatus 180 degrees so that the emitter and detector are in reverse of the original layout. Measure again. If the time it takes the photon to travel in one direction is not the same as the the other direction, then the interpretation in this video is right. You could also use this device to create a universal velocimeter. If the one way speeds are the same, either this interpretation is wrong or you are not moving w/r to spacetime. The Michelson-Morley experiment involved bouncing photons. If the relative speed of the photon compared to the device is 1.7c in one direction and then .3c on the return trip, the average is still 1c. This is why the experiment needs to measure the one way speed.

With your "air frame" you seem to have reinvented luminiferous aether. Any signal-bouncing clock moving with respect to air/aether will experience a different time dilation depending on its rotation with respect to the axis of motion. This should be measurable (and in your actual air clocks, it would be). But light shows no such effect, which we have known at least since 1887 (Michelson–Morley). There is no aether.

How do you not have more subscribers? These videos are unbelievable. You are amazing at teaching and the videos are such high quality. Amazing work as always!

09:38 ...or conflate time dilation with the DOPPLER effect. I don't conflate "time dilation" with the DOPPLER effect but rather always explain what it has to do with the symmetry of the DOPPLER effect: If we approach each other at v = βc = 0.6c, each of us will see the other's clock tick faster, but how fast? Turns out, if we consider you and only you at rest and your clock "running normally", I should get your signals compressed by a factor 1/(1 + β) which here is 0.625 and you should get mine compressed by (1 − β) which here is 0.4. If one of us radar - measures the relative speed, it will be (1 − β)/(1 + β) =: 1⁄K² which here is 0.25. Now comes the clue: since the optical DOPPLER effect must be symmetric, you must measure any signal with a certain period (according to my clock) compressed by 0.5 instead of 0.4, so my clock must tick slower by factor 1.25.

Time and space are not attributes of the universe. They are attributes of our knowledge of the universe. -PD Ouspensky

This video could be slightly edited with some even omitted (like the speed of sound in a time dilation video) but your science is very sound, you are articulate, you are intelligent. I didn't mean to be harsh but had to throw in some constructive criticism, otherwise your future is bright and I truly did enjoy your physics video, very well done!

These videos are excellent! Thank you for your hard work in producing them! I've watched them multiple times to pickup all the nuances. I have a few lingering confusions. In the case of the space traveling twin, when their rockes fire, they will experience an acceleration (I know you claim that one cannot feel force but we can measure acceleration and feel acceleration via our haptic sensation in our nervous system). The notion that acceleration is purly coordinative (no absolute motion) and that the space traveling twin is justified is claiming that they never accerleated and that the earth and the earthbound twin accelerates at the turnaround seems to be contradicted by the different experiences of the twins. The symmetry is broken by the fact that the space travling twin will experience the acceleration at the turnaround point but the earth bound twin will not.