What Time Dilation ACTUALLY Is In Relativity (Hint: It has nothing to do with time)
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- čas přidán 16. 05. 2024
- What causes Time Dilation? In the context of special relativity, where different observers disagree on basic facts about space and time, there has never been a clear consensus on this question, even among the experts. But an alternative interpretation known as Dynamical Relativity offers an entirely mechanistic explanation of the phenomenon, devoid of any mind-bending, space-and-time-altering pseudo-mysticism. What is this explanation exactly, and can it lead us to a deeper, more logically coherent understanding of the theory? Join us to find out. Plus, introducing the affordably-priced SoundBot-2000 -- watch out for its adorable critical-thinking alerts!
Thank you for watching, and please consider supporting us on Patreon -- it makes a difference. / dialect_philosophy
An approachable introductory paper on Dynamical Relativity:
arxiv.org/abs/1405.3979v2
Contents:
00:00 - Intro
01:03 - "Hearing" Time
03:11 - Deriving Gamma
05:36 - The Clock Paradox
09:54 - The Twin Paradox
10:56 - Dynamical Relativity
13:40 - It's About Uncertainty, Silly - Věda a technologie
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.
It seems to me like hes saying that since they can be modelled identically whether you use sound or light, then the cause of the resultant phenomenon has to be due to the fact that they are waves of constant speed and "information" in each context propogates at that same speed. So at least if i understand it correctly, (unlikely), he would agree with you.
@@renedekker9806 Well, the issue there is that you are presumably noticing that the sound wave moves faster when moving with the medium than moving against it. But that's is only measurable if you use a signalling system that is not based on sound. If each side of the clock increments a counter at a shared location using sound signalling and not a faster signal like electricity, then the clock ticks consistently despite the difference in the speed of the sound waves. In other words, it is impossible to use a system with solely sound-based signals to determine the anisotropic nature of sound. Only with faster signalling mechanisms are we able to determine it.
So there is no difference with light and sound.
@@renedekker9806 you'd think so, but no. The round trip time for the sound waves going up and down vs forward and back is the same when accounting for length contraction, which happens due to interparticle forces being slowed down by moving near the speed of sound (causality in this thought experiment). Remember that the clocks and robots would have to be made entirely out of sound particles for it all to work (a weird concept, but standing waves actually are perfectly analogous to particles, so just imagine that). So the length contraction actually happens unbeknownst to the sound robots conducting the Michelson-Morley experiment, and they measure no difference in the speed of sound.
Really, the realization that needs to be made is that the speed of light only appears constant because we are measuring it using units that already depend on it. 300 m/s is really just 0.000001c, but c is variable, therefore so are our units of measurement. We don't notice changes in the speed of light because our units of measurement change with the speed of light.
The Michelson-Morley experiment was wrong. It was never going to be possible to measure the aether wind regardless of its potential existence.
@@renedekker9806 There _is_ length contraction for the sound clocks when you allow their entire structure to be composed of sound alone. Imagine standing waves as the sound equivalent of particles (it's theorized that actual particles are already standing waves, so this shouldn't be too strange to you).
When the clock is composed of sound particles, these particles will arrange themselves into material structures like real world atoms and molecules. If the clock then begins to move relative to the medium (the air), the effective distance between particles in the direction of motion will be increased due to the amount of time necessary for sound waves (their only way of interacting) to propagate between the sound particles. As a result, the structure will contract in the direction of motion so that the particles settle into the same effective separation as normal.
The contraction factor is the same as the time dilation factor (from our perspective, as light based beings, no time dilation is occurring, just the sound-based interactions including clock ticks are slowing down. likewise, while we observe the standing sound waves get closer together due to length contraction, the actual space that the sound waves occupy in our atmosphere doesn't contract, just the sound waves occupying that space).
When you do that math, you'll find that the sound clocks tick the same regardless of their orientation to the direction of travel. My math involved a sound clock moving at c * sqrt(2)/2 where c is the speed of sound. When the clock is perpendicular to the direction of travel, the light travels in a zigzag path that is sqrt(2) times longer than a stationary clock, thus, that is the factor by which sound-based time slows down for the clock.
When the clock is parallel to the direction of travel, it is contracted in length by sqrt(2) and thus, the light still takes sqrt(2) times longer than a stationary clock to tick (note that just like in real life with light-based signalling, the sound-based clock cannot measure one way travel time of sound waves and can only measure round-trip time).
So yeah, the sound-based clocks cannot measure their velocity relative to the air, and we cannot measure our velocity relative to the aether.
And yes, if light slows down by a factor of 2, we can't notice because our units of measuring distance and time depend on light. Our light-based clocks slow down by two, lengths contract without us noticing because the particles are still behaving normally in their compressed positions we still measure a meter to be 1/300,000,000th the speed of light despite light being half the length, the meter is also half the length and we don't notice because our eyes and cameras are also affected the same as our measuring sticks.
There is a way to measure the aether, though. Because we have absolute acceleration that we can measure from time dilation in a twin paradox experiment, we can always measure our acceleration relative to the aether, even if we can't measure our velocity (we _could_ actually measure our velocity relative to the aether as well, but only if space is positively curved, which it appears to be flat, so no luck on measuring absolute velocity).
Anyways, once it is understood that time dilation and space contraction in the sound-based world are just illusions caused by the speed of sound altering the functioning of sound-based objects, and real time and space are unaffected by the perspective of sound-based observers, we can extrapolate that our own time dilation and space contraction in our light-based world are just illusions caused by the speed of light altering the functioning of light-based objects, and real time and space are unaffected by the perspective of light-based observers.
A higher being (still 3-dimensional, but whose fundamental forces propagate at speeds much higher than the speed of light) would see all of this, including the aether.
So we can also conclude that spacetime and spacetime curvature are illusions, and that the true reality is that gravity is just regional variations in the speed of light that both deflects normal light waves via refraction and also effects standing waves (aka masses), since those are also still just waves in the aether that can be refracted by gradients in the speed of light.
Light is slower in gravity wells, therefore. Which also explains why clocks high up in gravity wells run faster than those lower down. Light also reaches a speed of zero at the event horizon of a black hole, which also explains why we can't ever observe something fall all the way into a black hole.
@@renedekker9806 But the speed of light is not the same in a vacuum vs air, so you get exactly the same issues if the experiment is conducted with light clocks and align them with the flow of air.
Time and space are not attributes of the universe. They are attributes of our knowledge of the universe. -PD Ouspensky
You can say so, yes. The Relativists try to tell us that time can „vanish“ somehow ( and you will live longer or would reach Sirius within a day) like „space“ ( the „fabric of space“) can change its „geometry“ under the influence of energy (= mass, E = mc^2, this equation not being wrong as such).
This, yes. This is why I don't buy into the whole idea that we live in a 4D Minkowski Space-Time. This is taking a mathematical abstraction (whose mechanical underlying realities are not well defined) and making a flimsy claim about the ontology of the universe from that.
I think it's quite sound to keep viewing things as a 3D+1 universe, where time is not a "dimension" but an effect within the universe that applies to everything static or moving. I'm very much a modified-Newtownian and modified-Galilen-relativity kind of guy.
@@nemvus_ Yep, but that doesn't sell well.
@@KaiseruSoze Exactly. People love to bash Newton for getting things wrong, when thinking of absolute space or time, but the more I learn, the more I realize the so-called revolutionary changes from Galileo/Newton's time to now are... very overhyped "sells" of different ontological interpretations which have the appearance of seeming deeply to tell us something new about our universe, when really the math doesn't prove that.
Everybody trying to figure out what Kant figured out centuries ago.
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.
Im also curious to see how he addresses this. However, for parallel, that's what the Lorentz length CONTRACTION was for.
you beat me to it .....
Explanation: www.mysearch.org.uk/websiteX/html/7%20The%20Michelson%20Interferometer.htm - this addresses the issue with Michelson's results. He was incredibly close.
Just imagine a light clock with 2 sides separated by half a light second (let's call this k) of distance. What happens when such a clock moves parallel to the direction of motion at half the speed of light? According to this clock 1 tick would have been measured after k distance traveled. But if you repeat the experiment with the clock ticking perpendicular to the direction of motion, the clock would tick just after traveling 1/(k^2 * 2), which means you get 2 ticks (and a fraction more for the next tick) on this clock, more than the previous one, traveling at the same speed the same distance.
Y'all still don't understand aether 😂
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.
You might get a phd in physics but I know you don't know the following.
The Michelson Morley experiment IS NOT ABLE to detect an ether, even in the case of ether existance. But I know young academics just propagate half-truths because that is what they have been told and they dont know any better.
The actually observed perihelion shift of Mercury is 41 arcseconds as decribed by Newcomb in his final document (not 43 that GRT predicts after several attempts). The observed perihelion shift of Venus is -7 arcseconds but Einstein predicts +8 arcseconds. He also can't account for perihelion of Mars. The light deflection confirmations are riddled with issues and only a few plates were somewhat in accord with Einstein's theory. Most were not but were discarded. Also the DIRECTION of the light deflection was not in agreement with Einstein. Most talk about magnitude but never about direction. Mr. St. John (Mount Wilson Observatory) regarding gravitational redshift: "Owing to the different and even inconsistent corrections applied to the observed sun-arc displacements, the resulting approximate agreement (Perot, Birge, Grebe & Bachem) with the deduction of the Einstein theory fails to carry conviction."
Also contrary to popular media outlets, GPS does NOT require GRT to fully work. Also most tests that 'proof' relativity in the photonics realm are null results.
the MM experiment was for a stationary aether. If it was in motion like the river model video describes, they wouldn't have detected the aether wind. If the earth goes around the sun at 30 km/s and teminal velocity is only 11.2 km/s there should still be some wind, but if all the aether in the solar system was twisting like a whirlpool, that might not be the case.
If MM looked up, they would have detected a variance. It would be chalked up to gravitational time dilation, but if space is in motion, the equivalence principle is moot. It's a wind.
@@leoncampagna6933 Ether is completely disproven.
@@BW-go3ih I'm going to need a bit more then your word on that. Got the experiment that disproves the river model specifically? It's my understanding aether was deemed unnecessary, so they stopped probing. Bernhard Reimann's view of 1853, which is similar to the river model, was thought to break the laws of thermodynamics. That's the head scratcher, Where does the aether go?
You are lucky then. I have not slept a day in my life thanks to the unbearably loud constant sound the stupid sun makes. I wish sound could not come through empty space.
So at Mach 1, a clock stops registering time completely . . . .
Photons also don't experience time. The instant they are made they also disapear (From their perspective of course)
And what a hell is going on at mach 1,5? Going back to history?
As long as you are an air, the medium in which the Mach number means something, you are still making sound at the speed of sound. Can a pilot hear himself talk at Mach 1? Or does the pilot lose all communication because his voice will not go into the microphone?
The speed of sound is the speed of sound even if you're going faster than the speed of sound and you make a sound you're going to hear the sound that you made. You are right there where you made the sound.
It would only affect somebody on the ground. They would hear the sound at a much later interval. You would have already passed. ... all of a sudden they hear your voice.
So now we have made the example with just sound. Time does the same thing. 😮
He told you it is not related to time,,,,,
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?
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.
In the air-clock example, you can measure the time dilation of the clocks pretty obviously. But the important question to ask yourself is: how are you doing this measuring? You are using light waves, of course. But if information were restricted to traveling only via sound waves, that is, you only had sound waves as tools for measurement, would you still be able to determine whose clock is actually ticking slower? Moreover, you would not find it just as impossible to detect the presence of the air as you would find it impossible to detect the presence of the ether by using solely light waves?
Alas, this doesn't prove that an aether doesn't exist. The theories of Lorenz & Poincare, among others, had objects moving in the aether undergo Lorenz-Fitzgerald contraction, thereby explaining the results of Michelson-Morley. The "v" in the original Lorenz transformations was the speed of the electron with respect to the aether, not the speed with respect to any old internal observer like the "v" in the transformations of Einstein (erroneously still called "Lorenz transformations"). It is precisely the fact that Einstein uses "v" for relative speed between two arbitrary interval observers that leads to the Twin Paradox (contradiction, really). By the way, if the aether doesn't exist, what is "waving"? If space is empty, what is an EM-field? Nothingness has no geometry to curve or move or change in any way. I think that matter is standing waves ON the aether; the aether isn't some separate medium like the air through which little baseballs fly through.
A clock moving with its top to the vector will have pulses like a heartbeat. A clock moving with its side to the vector will have even pulses. But neither would observe time any differently, nor are their rotations affecting the overall rate of time.
By tilting the clocks you could determine the vector of travel relative to stationary, which is impossible with light and spacetime.
@@itzakehrenberg3449 The argument that space is empty therefore EM fields don't exist isn't really an argument. It's equally likely that EM fields could be different from sound waves. And indeed they are, EM fields are mediated by photons. When two electrons repel each other, that's because of photons, which are fundamental particles perfectly capable of traveling through space.
Lorenz's aether theories require accepting that the laws of physics also warp under motion in such the perfect way that the aether isn't observable, at which point it is just a mathematical theory that describes nothing.
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.
For the longest time it frustrated us when people said "the Doppler effect explains time dilation", because the Doppler effect was about receiving light signals from incoming/outgoing bodies and was not symmetrical, like time dilation was. But you are correct, and once we came across dynamical relativity, the reason for people conflating the Doppler effect with time dilation became apparently clear to us, as they both stem from the same underlying cause, which is the source-independent speed of light.
What we dislike about the Ted-Ed twin paradox video is that it states that you'll see time ticking slower for the rocket twin as she travels away, and then her time ticking faster as she return, and that's what they attribute to time dilation. The video gets off on the technicality that this is what you would literally observe with your eyeballs, but of course that's misleading.
We lost you a bit on your math here, and whose value belongs to whom, but it sounds like you're explaining essentially the relativity of simultaneity, which we do plan on tackling next!
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: czcams.com/video/ff0aofh6urU/video.html&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: www.geogebra.org/m/rhdp9f6v
Hey there, it sounds like you are indeed describing the Michelson-Morley experiment. And yes, your conclusion that Lorentz contraction must be a real phenomenon is also correct. Indeed, it was by adopting this dynamical model that we became convinced that length contraction must in fact be physically real, and consequently began seeking an explanation for it. (To be noted, it must also be real in Einstein's theory, but, like time dilation, there is no casual explanation for it.) We'll be putting a video out about it in the springtime -- we guarantee it's going to be quite fascinating...
Any methods we can devise to measure time ultimately depend on the propagation of elecrromagnetic waves (yes, even mechanical clocks). If there's an "absolute time", we cannot observe it. Any clock we can come up with will experience "time dilation".
@@ErikaJonell That doesn't really make sense. Where are "you" in this scenario? An outside observer of the system who is stationary with respect to all three clocks? Are you stationary relative to the two clocks you consider "external"? Are you stationary with respect to the clock in the middle?
Regardless, there's no way adding a third clock would change the fundamental interactions. All of the interactions are symmetric: information about the middle clock travels to the outer clocks, and then information about the outer clocks travels to the middle clock. Any asymmetries would then cancel each other out. In fact, there is no way to prove that light doesn't travel at 2c in one direction and instantly in the opposite.
@@ErikaJonell Look up the michelson morley experiment. They had two clocks moving at different directions relative to the "medium."
This argument in this video is total BS when we consider the question of reference frame. Which reference frame are you measuring from? With respect to some medium? Which medium? What's the proof that it exists? If it exists, there must be some reference frame which is stationary compared to the medium - the medium's own reference frame say.
When u consider the fact that time dilation, length contraction are just effects, the main thing is and always has been the relativity of reference frames, it becomes clear that this video is presenting total nonsense. The space-time interpretation is only a later addition. It wan't even there in the beginning.
Clocks are impossible without time dilation. That's the beauty of it!
Just because your clock that measures something takes 0.2 times as longer for one period to complete doesn't mean that time actually changed its 'duration.' For this to happen would have literal reality and universe breaking consequences
Time dilation is just a convenient were to talk about how we *measure* time; time is absolute; our measurements of time are not; thus, our time measurements are relative
Philosophically, absolute time is a simple given and is more fundamental than science. But how we measure time will always have relative aspects, thus, time dilation
Think about a super strong gravitational field bending all forces in a given frame; this means no matter what clock you use, this gravitational 'field' will cause a complete change in the accelerations of all particles within it; thus, the clock will 'slow down' relative to clocks outside this gravitational field
If time were actually relative, it would cause a feedback loop of infinite double time relativity that would induce a total collapse of all physical reality
Very insightful! But, I think I am missing something.
If the sound clock is at rest (with respect to air) and I am moving at the speed of sound (again, with respect to air), would I 'see' the sound clock 'frozen'? No, right? I would still hear it ticking. Even if we only stuck to sound waves for all communications/experiments, I could still 'hear' the clock ticking, right? But, that's not what we see in experiments with light. Anyone care to help explain?
If you stuck only to sound waves, and you were traveling at the speed of sound, you would never "hear" the clock tick, because the sound wave could never catch up to your ear drums. Similarly, we can extrapolate from that analogy and say that if you travel at the speed of light, you never would "see" the light clock tick (as what happens at the event horizon of a black hole, for instance).
@@dialectphilosophy Thanks for the reply. What if I am moving towards the sound clock, then I would definitely hear it, right?
But, if I am travelling towards a light clock at the speed of light, I still wouldn't 'see' the ticks, right? [I mean, we have other problems for travelling at the speed of light, so it's hard to comprehend this.]
So I can't shake the feeling that the fact that sound travels through a medium, does make a difference.
For example, if we consider the doppler shift, it's different whether the sound clock moves (where the wavelength changes) or I move (where the wavelength stays the same). But, that's not the case with light because there is no fundamental difference.
I have a question. If clock A was moving away from clock B and then got back, it would show less elapsed time, than clock B, which stayed stationary, right? But how do we know which clock was stationary? From clock A point of perspective, clock B was moving away and then got back, and from clock B point of perspective, A was moving away and back. So whose time was "slowed down"?
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.
Dude look up Brain Greene's WSU special relativity video. You're sorted. Thank me later
What If you were to find out general relativity is incomplete. In which that is why it remains a theory... time is not linear.
Love your videos! Could you do a deep dive into how we could conceive of relativistic mass in this framework?
No.
In your uncertainty section at the end, you imply that there is always some uncertainty in time "delta t", and that this will propagate into uncertainty in velocity (and therefore momentum) "delta v", or uncertainty in position "delta x". Are you foreshadowing some kind of quantum physics connection here?
Can you check if it is right. In inertial frame of reference in cartesian coordinate metric tensor is minkovski tesor like ct^2-x^2-y^2-z^2 but in twin paradox if we change coordinate system we should check if metric tensor also changed. But only transformation that preserve minkovski metric is lorentz transformation. And in non inertial frame formula for measuring distance no longer work . And thus their calculation agree. This is symmetric we get minkovski metric thorough experiment and they also can find metric that same way. I also dont know details but discussion will help us. If you want example please say. And I am not sure how we get minkovski tensor?
This was a great video, really gave me a new way of thinking about relativity.
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.
the same????
Can you do a demo where the two sound speaker systems are traveling towards each other, and it's not clear which one is time dilated? From each of their perspectives, the other one has sound waves traveling at an angle. If secretly only one of them is moving, how is it that only one of them has it's clock dilated; especially if there is no absolute ground beneath them to tell us which one is moving and which one is standing still. Shouldn't both have the same dilation, and age the same amount, no matter if an object is moving or standing still for this reason? In other words, we'd never know who's clock was dilated or that it even happened?
@Dialect Yes, but what happens if your cloak is flying up aligned to the direction of the light beam? If there is an Aether drag then you introduce light speed one-way asymmetry. Thus, light would go slower reaching the upper mirror and faster to the same amount when reflected back towards the lower mirror. In this case if you adopt the Aether model the clocks will be not time dilated. But this is not what we observe. In SR time dilation will occur for any direction of constant speed travel. Therefore there is no preferred frame of reference.
Does this not disprove your Aether explanation?
I believe there is a problem with this analogy of sound to light. The speed of sound will be different for the observer watching the sound clock move by him. The speed of light will not be different for the observer watching a light pulse clock move by him. This method of deriving the Time dilation only works for light clocks! It is beautiful!!
This is the only comment that I read that is correct. The speed of light is constant regardless of the frame of reference, but this is not true for sound. So you cannot use "sound clocks" in the way you are trying to do. Why are you trying to re-invent the already established (in many videos) "light clocks"?
@@barryzeeberg3672same thing I always looked for in the comments. the problem with introducing the medium air is, that it acts as a reference for motion, while for the special relativity theory there is no medium (no aether ) and thus no reference for absolute motion.
in the air example, if you are inside the moving vehicle, you could find out that you are moving with respect to the medium, simply by using 3 clocks which are oriented perpendicular to each other, you would find, that they would show different times, while they would not if you were not moving with respect to the air. in the srt this would not be possible, independent of your motion all your clocks would show the same time (see also Michelson Morely experiment)
There's also no mention of the Michelson-Morley experiment, and how the aether drag hypothesis was rejected because stellar aberration is always observed.
@@barryzeeberg3672Couldn't you argue that the speed of sound is the same for all observers but the pitch (Doppler effect) is different. What if we reintroduce the ether for light ?
The problem is with you mixing sight and sound. 'watching the sound clock'.
Did I miss something here? Yes, the same equation for gamma holds for this experiment special relativity, but in this experiment BOTH an observer moving with the clock in the airplane AND one on the ground will BOTH observe the "sound clock" to run slow, because the sound is moving through an absolute medium (the stationary air). But this is not what is observed for light because the speed of light is constant for all observers regardless of their reference frame (the aether does not exist).
A valid question to raise! Indeed, what you are asking is about the relativity of simultaneity, or why do observers see each other's clocks run slow? We will be giving full treatment to this question in the follow-up video (probably coming around October or Nov) but the important questions to ask yourself now is, if both observers see a moving sound-clock run slow, this is because they are doing that "seeing" with light waves. But what would happen if we tried to "see" the clock using only sound waves, i.e. restrict our measurement tools and our speed of information to being sound-wave based?
@@dialectphilosophy Could it be that it would not be possible to tell the one way speed of sound?
@@mikkel715 You are very much on the right track... 😎
@@mikkel715 You can’t know the one way speed of anything because clocks that are apart from eachother cannot be synchronized without delay of the synching signal.
Yes, the replies are correct. Anything you measure involves a round trip.
I very much appreciate the effort (and time 😊) you put into making that video. Thank you so far.
If you still want to improve this one a little bit I'd propose you include the following consideration in the construction of your "sound clock":
If you build that with a very "directional" emitter (speaker) and receiver (microphon) - I think this can be better depicted with a "light clock" operating with a pencil-thick laser beam - will it then
(a) be necessary to adjust the direction into which pulses are sent and from which they are received slightly sideways, the more the faster the apparatus moves, because otherwise the sent pulse would miss the receiver and the clock stops ticking?
or (b) does the apparatus adjust somehow automatically for that, no matter how fast it moves, in its own frame of reference light/sound pulses are sent exactly perpendicular to its direction of motion?
To depict this mentally think of someone standing on moving truck with a pump and a water hose, and a "clock" sending "water pulses" to a bucket also on the truck. Obviously this may or may not need such an angle correction depending on how much influence of air resistance you include. For that reason maybe assume a closed truck.
hi
For the analogy to be fully correct, whatever mechanism you use to focus the sound waves into a narrow beam needs to have the property that it doesn't rely on any information propagating faster than sound. If you do that, you'll find that the beam automatically comes out at the required angle to hit the receiver, whatever speed the clock is moving sideways.
In the case of the water hose, the water in the hose is moving at the same speed as the truck, and will continue to do so after it leaves the nozzle, so it will appear to an observer on the ground to be coming out at an angle.
No
I used to think about this. When I was little I think I used to think about something conceptually similar to the light clocks, how they record time passing at a slower rate when they are moving for purely mechanistic reasons. Then I would think, OK, we may measure time as passing more slowly, but it doesn't mean it's actually passing by more slowly. So I believed everyone still had a universally identical experience of the rate at which time flows. Now what I understand you're saying is that every atomic, molecular, etc process in our bodies is affected just like the clocks, so we really do experience time as flowing more slowly, and we really would age more slowly, so to speak, if in a moving reference frame.
This purely mechanistic interpretation makes it possible for there to still be a universal time as you mentioned later in the video. From my naive perspective it sounds sensible and really tempting because it is so simple and is based on easy to understand mechanistic reasons without invoking the concept of a spacetime fabric and all that.
Nonetheless, if the physicists are not adopting this explanation but rather the more esoteric one about the fabric of spacetime contorting to keep c constant in all reference frames, then there must be some reason. Is it just to retain scientific credibility? Is it just adherence to a mainstream interpretation by default because no interpretation can really be proven and it doesn't matter how they interpret it, as long as they're all using the same theory? Or is there something deeper to this? Those physicists are pretty damn smart and I'd be interested to see what they think. Unless you yourself are a physicist (or a person with very deep training in physics), of course, then I would have more confidence in this perspective.
I would ask why does gravity also affect the perceived flow of time? In general relativity the geometric conceptualization of spacetime appears in even greater force than it does in special relativity. Do mechanistic explanations still suffice? If not, i.e. if GR requires the more mystical interpretation, then I am more inclined to believe in that "mystical" interpretation since a purely mechanistic one in that case wasn't enough.
The most likely reason this interpretation hasn't been adopted (yet) is because it doesn't explicitly account for the symmetry of time dilation/the relativity of simultaneity. That is, relativity asserts that both observers will see each other's clocks moving more slowly, so that "time is relative" and there is no absolute time.
A satisfactory explanation of this symmetry has never yet been given, nor has a satisfactory explanation of length contraction been put forth either. As we will see however in upcoming installments, it's not very difficult to account for these additional phenomena if we investigate the meaning of "measurement" a little more deeply, and ask what it truly means for observers to "see" each other's clocks running slow.
Very excited to see more about it. Of course, I expect to be able someday to explain the michelson-morley experiment in this setting. But of course this may take time to be fully understood.
I think in order to explain the analogue of the Michelson-Morley experiment you'd have to have an analogue of Maxwell's equation for air. Only then you'd have genuine length contraction for any system moving relative to the aether (air), making the different velocities-relative-to-the-aether on the two arms of the interferometer undetectable. (I found Bell's paper "How to teach special relativity" pretty helpful here; see especially pp. 75-6.)
As it stands, I don't think it's quite right to say (as the video does) that absolute rest relative to air is undetectable.
@@Swiffah145 Might you justity why you don't think absolute rest in the air/ether is undetectable?
@@flov74 I think it's because it's just the case of finding the right experiment
@@Swiffah145I was looking for this. This whole basic concept violates the result of the Michaelson-Morley experiment, unless the medium was also in motion around the sun. But if it were in motion around the sun, we should by now have detected differences in the speed of light due to the location of satellites and spaceships. Since we haven't, then this is more an interesting analogy.
That's super easy.
First of all if "length contraction is real" then the M-M experimental shows that the two-way speed of light will be measured as c for any non-accelerating observer in all directions (the result of the M-M experiment).
First off if your visual minded you can look up the "Couder Walking Drop Experiment." The drops and their waves will contract in the direction of travel when they move at velocity V in analogy to length contraction. To first order this matches the length contraction seen in relativity. This isn't a perfect analogy but its close. It only matches to first order because the velocity of the waves in the water are not the maximum velocity of everything. The water isn't a universal medium.
Now if you want a deeper mathematical understanding, you can study the Bell Spaceship Paradox. If two spacecraft have a string tied between them and they both accelerate off in the same direction with the exact same amount of acceleration as measured by their shared initial reference frame then the string breaks. The length of the string and both spacecraft will shorten WRT the original frame. Bell believed the same thing as this video explains. You can work out all possible frames of reference and this will always be true.
Now if this isn't enough you can look at the math below.
The classical wave equation is as follows:
d^2 Psi/dt^2 - c^2 d^2Psi/dx^2 - c^2 d^2Psi/dy^2 - c^2 d^2Psi/dz^2
The above is just a simple classical wave equation and nothing special.
Well, we can have the wave move off as velocity v in direction x. This would relate dt and dx as follows. The below is just telling us that the wave is moving off with change in x over change in t with a value of v. This relates dx and dt together.
dx/dt = v or dx = v dt
If we use this to substitute dx for dt we have.
v^2 d^2 Psi/dx^2 - c^2 d^2Psi/dx^2 - c^2 d^2Psi/dy^2 - c^2 d^2Psi/dz^2
If we then divide everything by c^2 we have:
(v/c)^2 d^2 Psi/dx^2 - 1 d^2Psi/dx^2 - d^2Psi/dy^2 - d^2Psi/dz^2
Multiply by negative 1 and clean it up:
(1 - (v/c)^2) d^2Psi/dx^2 + d^2Psi/dy^2 + d^2Psi/dz^2
If we square root each term, we can see the x term is shorter by (1 - (v/c)^2)^.5 which is EXACTLY the same result as in Relativity.
This means a wave structure of say length D pushed off by velocity v in the x direction will be shorter by (1 - (v/c)^2)^.5 in the direction of motion.
This may sound not very important until you understand that quantum mechanics tell us that EVERTHTING is made out of waves.
Relativistic quantum mechanics has the following wave equation:
d^2 Psi/dt^2 - c^2 d^2Psi/dx^2 - c^2 d^2Psi/dy^2 - c^2 d^2Psi/dz^2 + (m c /hbar)^2 + Psi
The last term doesn't change anything (it's just the "at rest mass term").
Even a bigger "coincidence." "Space time" in special relativity has the following formula.
c^2 t^2 = c^2 s^2 + x^2 + y^2 + z^2
Energy has the following formula:
E^2 = (m c^2)^2 + (px c)^2 + (py c)^2 + (pz c)^2
Now a lot of scientists call the two above "proof that 4D spacetime exists." OR it's just a simple wave equation and it's proof that all stuff in the universe is propagation of waves.
The M-M experiment showed that there should be a difference in the two-way speed of light if BOTH lengths were exactly the same. However, what the math above shows is that wave structures should contract by (1 - (v/c)^2)^.5 in the direction of travel where v is the velocity of the wave structure moving off (a wavepacket and the group velocity) while c is the propagation of the medium (the front velocity). If this happens then the two-way speed of light will be measured to be the same. This contraction is seen in the "Couder Walking Drop Experiments" (which you can Google on CZcams) and is predicted in the above math I did.
All we have to get away from is the idea that "rigid" and unchanging objects exist. A ruler is made up of a huge number of electrons, protons, and neutrons that have forces pushing and pulling on them. The equilibrium of this "push" and "pull" decides the length of all objects. If all fundamental forces and all particles like protons, neutrons, and electrons are part of the same underlying field (or fields with the same underlying "front velocity" or propagation speed). If this is true, then I'd expect and wave structure moving at velocity v in direction x to be contracted by (1 - (v/c)^2)^.5. Now in this universe objects that form wave packets can move at slower than the speed of light (thanks to a process like the Higgs Process) but the underlying fields (when two fields aren't "playing with each other" like the Higgs does to the electron field etc) is ALWAYS the same speed c.
Now this shit gets even more complex (but the whole thing mathematically fits perfectly still) when you assume all the different reference frames and shoot for a general result. It works perfectly but that would take a hell of a lot longer comment to explain (and more time than I have).
All of Special Relativity and General Relativity (down to the event horizon of a black hole and at or below the speed of light) can be interpreted mechanistically. Now no experiment has ever taken anything faster than light and we can't see in below an event horizon of a black hole so differing from what GR and SR say for those is perfectly fine (it's outside of anything we have ever or may ever test).
These ideas make many physicists uneasy because it takes something complex, mystical, and important sounding like 4 dimensional spacetime and makes in mundane and mechanical. Even worse it predicts that there is some rest frame to the universe but because the observer transforms perfectly with everything else when moving at velocity v there is no marker in the universe to tell us where it is. All disproofs of an "aether" require there to be some symmetry breaking. That something doesn't transform like everything else when moving at velocity v. I don't think there are any such "markers."
Most physicists I've met have a pure HATRED for the above ideas because it makes relativity such a mundane theory with something so simple sounding proposed (an absolute rest) that we should be able to see but can't. It also gets rid of a lot of the sci fi cool. After 20 years of discussing with physicists, none of the physicists have said anything to disprove the ideas given. Some respected physicists like John Bell have believed in these "heretical" ideas. Usually, they get the most flak from laypersons that know next to nothing about relativity.
Most fields of study just like most religions have orthodoxy. It's human nature to get mad when someone goes against the orthodoxy.
But in your "toy" universe, the only thing that changes when you move through space is the ticking of your sound clock. Everything else continues to "age" at the usual rate. For example, if you compared your sound clock to your digital watch you would see that they are no longer synchronized. But in Einstein's relativistic universe all natural processes experience time dilation. You age at a slower rate, your digital watch slows down, the vibration of quartz crystals slows down, radioactive decay slows down, etc. (And what happens if you are moving at a speed that exceeds the speed of sound? Does time stand still?)
The sound waves are just an analogy for anything that travels at the speed of light in our universe
That's because matter and matter interactions--such as those that go into your digital watch and all of the atoms that make up your body--are dependent on light wave interactions, not on sound wave interactions. So you're mixing your types of clock ticks, resulting in nonsense.
@dialectphilosophy Hi, at 4:03 why is the velocity of sound along the direction of the diagonal (or hypotenuse) D' the same as the velocity of sound along the transverse (or perpendicular) leg D?
Is that assumed or is it a given?
And if that is the case, on what grounds is such an assumption valid for sound waves in general?
Or is it an empirically verified fact that the velocity of sound is the same in all reference frames?
Hope you can shed some light on this. Thanks.
The speed of sound is the speed of molecules in the air bumping against each other. If a volume of air is transported, the sound within it is transported along. In this case, there is no transporting of molecules of air. All of the molecules are standing still in the atmosphere of the earth.
If the moving clock moves at a constant speed, could it not be used as its own frame of reference. And in that case, wouldn't the sound wave also be moving in that direction?
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?
If you're not familiar with it, look up the michelson morley experiment.
One's relative velocity to the aether isn't observable in this theory, and the results will be consistent with SR. Look up Lorentz Ether Theory.
The earth isn't moving through space, it's stationary.
@@lrn_news9171 If that’s true then the Earth would have to be the only place in the universe that is stationary in relation to aether since practically everything else has relative motion in relation to Earth. That seems insanely unlikely to me.
The reason this works is because it's no different than SR under the hood. In SR, if we assume C is constant, no matter the reference frame, this begets an upper-bound to all speeds measured, and so we can derive gamma between reference frames. In your model, the upper-bound is assumed, and then gamma is derived wrt the medium. The only difference is that SR assumes space-time as a fixed background, whereas this model assumes the medium as the fixed background. In GR, this is common vernacular as gravity waves propagate through space-time as if it were a medium. In QFT it's also common understanding that the speed of light limits the motion of waves in the underlying quantum fields.
In other words, the ether is still not necessary 😎
"wrt"?
@@selfsaboteursounds5273 It seems more like space-time is the aether.
@@Mavrik9000 it's shorthand for "with respect to"
@@Mavrik9000 yeah, but the old idea of the aether was that it could move wrt something else? idk the center of the universe or something. regardless, i personally believe it's naive to think that EM waves can propagate through nothing whatsoever -- intuitively, a wave needs a medium. even in classical EM the fields permeate all space, so I don't know why everyone is stuck thinking light can propagate through pure void. Cosmologist are convinced the void is full of dark matter / dark energy, and quantum theorists are convinced the void is full of quantum foam, so it's really silly imo.
Then again there is some self-resonance to EM waves, as the electro and magnetic components spiral around each other, so it's almost self-propagating, but still, it's very hard to swallow.
Am I right to suggest that this model only works if the width of the clock is much less than the distance travelled in one 'tick'??
If the moving clock was wide enough, the receiver would still receive the incoming wave in the same time as the stationary clock. right??.
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.
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.
It is impossible to measure the one way speed of a photon.
But his clock breaks down much sooner, since in a medium as he describes time dilation isn't isotropic. Maybe he overvulgarized it, but it's not my job to check the original source.
Look up the michelson morley experiment.
@@Ildarioon Well, you can certainly perform these measurements. I'm assuming that no mater how fast you're going, the one way speed in any direction will still be measured as c. That result would differ from how the sound clocks work and rule out this interpretation of GR. Sure you can't know that photons always travel at the same speed in every direction because the physics works out to be the exact same result. But that's the very reason that a hypothetical asymmetric speed of light is not relevant to this experiment... because it will yield the same result as if it were symmetric. This experiment should still be valid.
That doesn't assume the speed of sound is always the same for all observers, moving or at rest relative to something, and the medium (aether) is also unnecessary.
When air density changes and sound waves refract, how similar is it to curved spacetime? Suppose we make the clocks components as light and fluid as air, held together only by complex sound waves.
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.
And a few other thoughts:
1. In the comments there are many people who argue that light propagates with no medium. Has this ever been demonstrated? Does a perfect vacuum exist anywhere in our universe given the bubbling of virtual particles into and out of existance? We seem to now accept the Higg's mechanism gives particles their mass and this involves a Higg's ocean that permiates all of space. Could there be a similarly elusive medium for electromagnetic propagation (aka aether)?
2. In earlier videos on this channel, there are discussions of empty universes (except for, say, two objects participating in the twin paradox experiment). I'm not sure it makes any sense to discuss such scenarios as the universe in which we find ourselves is full of matter and energy and we've never been able to run a single experiment in a universe devoid of all this exogenous matter. So we really have no idea how bodies would behave in such a hypothetical universe, and no way to test hypotheses.
3. It's a detail but no measurement of the one-way speed of light has ever been made. Only round trip measurements. This seems to be a minor point but I'm wondering if the symmetry breaking in the twin paradox is somehow related to the fact that we really don't know for sure that the speed of light is equal in both directions (only that the average speed over a round trip is c.)
excited to see another dialect video!! great work as always
Amazing animation for understanding. Thank you
This is brilliant, please keep making these.
in your video, you measure time by sound waves. Does this mean that if we use different measures such as biological measures (some chemical reactions or heartbeat, metabolism as measurement of time) gives same result; which explain why time dilation has effect on biological process rather than just optical illusion (which is my misunderstanding when I read the book using observing light as measurement for time frame)
You are on the right track of thinking.... to put the pieces of the relativity puzzle together, the one most important and crucial question to ask is: "what happens when we try to measure time/distance with light waves?"
IMHO the answer to all issues is hidden in the methods we use to measure time. We actually are measuring many different quantities - in example showed in the video there waves traveling through distances that are being counted. It's not time though. Same is for every other clock constructed so far. Every instrument is counting some kind of movement (or change of conditions) assuming it is constant enough to be a reference for other physical phenomena.
True, but if you use spacetime algebra, you find that Lorenz boosts are just rotations and time like intervals and paths have well-defined real lengths. Time is meaningful and photon clocks *do* measure it accurately. Of course, this is in SR
Extraordinary animation quality. Bravo. Since I am not a QFT person: is there a possibility, that Quantum Fields act as 'that medium' c in your video is relative to?
Yea we’ve basically gone from “Aether” to “Space-Time” to “Quantum Foam”
@@renedekker9806 Thanks! :)
Yes, indeed, that is extremely likely possibility. As we'll be showing in future videos, this idea of relativity as a wave-theory is directly emergent from the idea of giving ontological weight to the electromagnetic field itself. Stay tuned!
@@dialectphilosophyhow does the particle in a superposition see the world? Is the world in a superposition from its point of view and if so would a collapse of the wave function just be an entanglement between the two. Amazing video i thought also maybe the wave function is the space itself just viewd from inside. I love this video so much so so much love it.
All the quantum fields are like the electromagnetic field -- they exist in their own right without requiring a separate medium.
For some weeks now I have been thinking about this same interpretation of time dilation but from a different angle. What happens at the event horizon of a black hole from the point of view of a particle falling on to it. My intuition is that it's time stops at the event horizon relative to non-dilated cosmological time. In others words the information speed would be zero at event horizon. Since the information speed would be zero then can we conclude that the speed of light would be zero at that point? If so, then can we conclude that the particle would freeze at event horizon as opposed to continuing it's journey to the singularity? I am not a physicist to give this argument the necessary assessment and am struggling to find any references on why this could not be the case in open sources.
The standard view is that you wouldn’t even notice if you crossed the event horizon. No one knows what happens at the singularity though
From the Lorenz invariance, we can recognize time as a bidimensional, Euclidean sub-manifold in which the temporal distance between any two points (events) in the spatiotemporal 5-D manifold is the same as the 3-D spatial, Euclidean distance between the same two events. Here is how and why:
Lorentz transformation (+ + + -):
(δτ)² = (δx)² + (δy)² + (δz)² - (δt)²
which, by moving the t term to the left-hand-side member, gives
(δt)² + (δτ)² = (δx)² + (δy)² + (δz)²
wherein both equation members, the left- and the right-hand-side are easily recognizable as a 2-D temporal, Euclidean and a 3-D spatial, Euclidean differential distance squared, and both are equal as per the Lorenz invariance. If equal when squared, both differential distances are also equal when not squared. If equal when differenced, the temporal and the spatial distance could only differ in a constant, which is zero because it is zero in the case of both events being the same.
So, we shouldn't consider τ, the interval between events, also called proper time, as a distance in a Minkowskian, curved, 4-D spacetime manifold of events (x,y,z,t) but as a second time coordinate in a flat, Euclidean 5-D spacetime manifold of events (x,y,z,t,τ). Our brains never developed a sense of the τ time coordinate, most likely because our ancestors were never exposed to relativistic conditions in which recognizing τ could mean a survival advantage or disadvantage.
But the sound wave analogy is not correct, since the moving observer will be able to measure the velocity of the air relative to him. But not in case of space.
That's why its an analogy
Imagíne you are made of sound waves.
I Love your videos, thanks for these beautiful insights
And please also do a video on Mach's Principle
He has done a video on Mach in the past. It was called "Mach's Bucket" or something.
@@Elrog3 I asked about Mach's Principle
@@renedekker9806 yes that's a great point.
Read Hermann Bondi Joshep Samuel paper on "The Lense-Thirring Effect and Mach’s Principle"
Rotate the clock 90° then move it at the speed of sound in the direction of the upper portion of the clock. Would the signal ever reach the upper portion of the clock to be registered? With the clock essentially stay at zero.
If the (sound/light)-clock is inclined at an angle theta with the direction of motion, then the generalized time dilation factor for the configuration is : 1/(-B*cos(theta) + sqrt(1-B^2*(sin(theta))^2)) , where B = v/c . I see numerically that the geometric average of this factor is 1/sqrt(1-B^2), the usual gamma, which is quite satisfying because it takes away the arbitrariness of the clock being aligned perpendicular to the direction of motion (and even removes the requirement that such a direction exists).
Thanks so so much for your videos dialect. You are offering the absolute best explanations that clear up so many misunderstandings in physics. I'm surprised you don't have more views. I am forwarding your videos to all the physicist I know.
He doesn’t have the views or subscribers because most people aren’t idiots.
@@sharpthingsinspace9721 that truly fascinating that you said that. Is there anything in particular that you feel is incorrect?
@@tnig I’m surprised you know any physicists. There is some much wrong with this video that I don’t even know where to start. Are you pretending to understand the theory of relativity? Does dialect suffer from the Dunning Kruger effect?
@@sharpthingsinspace9721 please tell me one thing that is incorrect about this video or any other videos from Dialect. At least address your main concern
@@tnig doesn’t understand the difference between the speed of light and the speed of sound. He thinks we are being accelerated up. He clearly doesn’t understand the theory of relativity, but he will always have a small cult following of naive and uninformed people.
What about addition of velocities? Why would c be a limit for any particle if there were a static aether? What about the increase of mass?
These will all be tackled in future videos, stay tuned!
Because you are made of sound wave, to take the analogy to its completion.
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.
Thanks for your efforts, It is really a good explanation with animations.
Extrapolating this approach to light can be experimentally confirmed or rejected. If we’re in a moving reference frame with respect to an ether, then the twin paradox age discrepancy will show an asymmetry with respect to which direction the twin travels. ( unless the twins happen to start off in a stationary reference frame with respect to the ether)
But the aether (ether) does not exist .. there is no such thing as "with respect to the aether". This is the whole point of one of the axioms of special relativity: "there are no privileged inertial frames".
@@timhill9039 my comment is meant to demonstrate one way at arriving to your assertion.
there is no way a space medium doesnt exist
@@timhill9039
@@timhill9039it isn't necessary, but it has never been proven that it does not exist, just that you cannot measure your relative motion with respect to it (in a laboratory). In fact, looking at the cosmic background, the side where the signal is blue shifted is where your velocity vector is pointing in the ether
"assuming that if such ether exists the cosmic background looks homogeneous when you are at rest in it"
9:57
In the sound clock world there is no twin paradox because some "absolute" velocity is well-defined as velocity relative to the air.
Did you watch the whole video? It doesn't matter if theres a well defined velocity or not
@@lih3391
I did. And yes, I do recognize that even if there were an aether whos state of motion can be determined, a light clock will still run slow if it moves around and returns, just like the sound clock in air.
However, this is not my point here. The question whether or not there is a well-defined velocity _is_ important for whether or not "time dilation" leads to a paradox (by which I mean an apparent contradiction, not necessarily a real one).
If we cannot interpret the "stationary" one as moving and the "moving" one as stationary, there's no paradox whatsoever.
@@lih3391 I did watch the whole video. Without a absolute frame of reference, this explanation just ceases to exist.
@@lih3391He just referenced all velocities in relation to the stationary air, so yes, it absolutely matters
@@jensphiliphohmann1876 I guess I overlooked that jump in logic, my bad. Its been a while since I looked at the twin paradox, so I forgot what it was about.
If you are curious, a good explanation is done by minutephysics in part 8 of his relativity series.
czcams.com/video/LKjaBPVtvms/video.html
The experimentally verified constant-ness of the speed of light leads you to lorentz boosts and proper time, which minutephysics captures in the mechanical device nicely.
The paradox lies in the linguistics, relativity having been presented as time dilation being the effect of relative velocities.
We should be thinking of lorentz boosts instead of gallilean transforms with extra rules. Since the extra rules are often explained in words, people get confused.
@Dialect So how would you make a diagram explaining perceived gravitational time dilation using your acoustic clocks ?
Gravity is pressure which slows the speed of light and also causes length contraction.
BTW, we can also use air and water to simulate what happens when we cross the event horizon, but it doesn't mean it describes the actual event horizon of a black hole, just provides insight on new scientific instruments for detection and observation. Wave equations are similar after all, but the formers depend on a medium to propagate, while EM waves propagate in vacuum. Unless we discover an underlying medium for wave propagation, describing gravity waves and entanglement on it.
I love this easy to grasp way of looking at it, keep this up!
@@RockBrentwoodCan you explain for a layperson?
Fabulous video. Love the animation.
@Dialect I've done a lot of thinking about this same subject and what I've concluded and what seems like a good summarization of this video is that "We use imperfect clocks" Would that be fair to say?
This is very interesting.
I haven't read the paper you referenced yet but doesn't your model predict the existence of an aether?
If so, how do you explain the results of the Michelson-Morley experiment?
How do you measure the speed of the Earth, or yourself, in this medium?
You cant measure the speed of Earth with light, ether or not, with the Michelson Morley experiment.
Why would anyone introduce unknowable quantities like the aether rather than going with a minimalist ontology?
$$$
I'm sure there's an explanation, but it isn't a rational one. People are irrational creatures and believe all sorts of things for poor reasons.
William of Ockham approves.
For a mathematician, it’s actually not difficult to grasp what the theory of relativity reveals: in order to give a true account of cause and effect, we have to look at Lorentz invariant properties of the system. It’s the same thing we do when looking at invariants under homeomorphisms in topology or linear invariants in linear algebra. *That* is the underlying reality that we have to study, not any particular perspective on it.
If there were an ether through which light would move to make clocks tick, then there should be an inertial reference frame that makes clock tick the fastest. AFAIK that has not been observed, however it should be quite testable. Therefore I have difficulties with the concept.
To truly mease the clock differential you always need a round trip. Otherwise you are measuring via the medium - ie exchange of light for information and all the distortions that causes. So, you theory only has to explain round trip differences.
@@gravitationalvelocity1905 You can place the starting point and destination point far away from each other, synchronise the clocks of the two probes, and then send each one along a different path but with the same acceleration magnitudes (only a shift in the axis of the acceleration, so flying different parabolae that are rotations of each other). If there were an ether akin to air, then would you then not notice less clock ticks on some paths?
@@EightBit72 Impossible to synchronise remote clocks as you must transmit the sync signal via the medium.
You did well in illustrating how sound clocks would be unreliable in measuring time dilation. I agree with your statement that it is not time which is relative but rather our understanding of time which is relative.
Well according to him it's the one who leaves and comes back lives slower no matter what. But that is not true. According to the real experiment done in 1971 in which two airplanes flow eastward and westward separately and then came back earth, the one flow eastward lives slower but the one flow westward lives faster. But according to him both airplanes should live slower then the anyone on earth. It seems the speed is the speed to an absolute media instead of to the observer.😮
Awesome. I was surprised by the analogy by light and sound, seeing the gamma factor appear. Now the next step seems the recall of some "ether" of sorts, but not one where light travels through, but one that "is" light, like sound is a wave in air. I'm eager to know more.
The aether that you are referring to is the permittivity (electrical energy) of space.
@nononononoohno theoretical physics IS nonsensical science and misinterpreting observations and applying that misinterpretation to all of science.
Do you know that the majority of physicists believe that clocks measure actual time? What's next? Are they going to tell us that rulers measure distance? That scales measure weight? Thermometers measure temperature?
It's a sad world we live in when supposedly learned people don't understand elementary physics.
There is hope though. You can at least reason with AI. Get it to understand the errors of its ways. Today's physicists are so egotistical and steadfast in their beliefs that you practically have to throw them off the edge of the earth before they will admit that they are wrong. I pity the fools that follow these religious zealots. If only they had a mind of their own, they wouldn't be so easily brainwashed.
Yes. Sound waves are scalar waves unlike transversal EM waves. Light is an EM wave so it’s nothing like sound. Right? Not quite. What if this ether wasn’t a medium per se, but a scalar wind blowing expanding circular bubbles out from every point of the universe at the speed of light. EM would ride this expanding wave. A photon with energy would vibrate longitudinally traveling with this wave, and would experience no time. “Sound waves are usually considered as simple scalar wave fields that lack any vector properties such as polarization and spin, but our findings show that generic sound wave fields actually have as many degrees of freedom for micromanipulations as optical fields” according to new research.
I still say that time dilation is caused by acceleration but amplified by the amount of time (or distance) you spent accelerating (and also while travelling at normal speed). It's like saying that dropping an apple from a tower, "it's the fall that will smash the apple but also the height". But it's definitely the fall that's the key event there even if the height amplifies it. . I still put a like for amazing job you did at explaining your pov with nice animations.
I agree with the aether interpretation though, it makes sense so much more to accept that spacetime is a real "stuff".
You are correct about the acceleration causing the effect since a non (or uniformly) accelerating body by definition is taking the shortest path between two points in spacetime.
It may make sense to you that there is a medium but that doesn’t make it correct.
You’re just going back to try and reprove the luminiferous aether, which has been thoroughly disproven.
@@graxxor
You are correct about the luminiferous aether, but this is not what I am talking about. The Michelson-Morley disproved the possibility of a fixed, rigid aether. Once Einstein came up with the spacetime solution, he was actually tempted to rename it as a "new aether".
Einstein's colleagues found that the word aether would bring confusion with the original concept, so he abandoned it. Einstein final view was this :
Einstein 1920: "We may say that according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an aether. According to the general theory of relativity space without aether is unthinkable; for in such space there not only would be no propagation of light, but also no possibility of existence for standards of space and time (measuring-rods and clocks), nor therefore any space-time intervals in the physical sense. But this aether may not be thought of as endowed with the quality characteristic of ponderable media, as consisting of parts which may be tracked through time. The idea of motion may not be applied to it."
@@En_theo "this aether may not be thought of as endowed with the quality characteristic of ponderable media" Means that it's not what you think it is.
@@graxxor
I said that spacetime would be a "real stuff", whatever that stuff is. I stand correct and your answer is purposely vague since you don't talk about the reality of it but rather of its properties. Those are two different things. FYI, many physicists are trying to work that out, it's not consider, as YOU THINK, that spacetime has been proven as not "real".
I purposely didn't put the end of Einstein quote, just to make you say what you were clearly going to say : "According to the general theory of relativity space without ether is unthinkable" . I think it's pretty clear. Even without that argument of authority, you should not be so preposterous about your statements.
The Apple doesn't fall when dropped, it's acceleration becomes zero. The ground is constantly accelerating up at 9.8m/s/s, hence the apple is hit by the ground rushing upwards.
One of the things I have always loved about this model is that it's ability to explain things without requiring rules that just are, and instead makes rules an emergent property of something. The speed of light becomes the maximum speed that local space can move, just like the speed of sound is the maximum speed that air can move. So just like air the apparent time or speed seems to change dependent on the motion /density of the space itself even if it seems to always be a constant on a local scale.
It seems to resolve a whole lot of issues that are currently patched together with "dark mater/dark energy" if the space in a rotation galaxy is moving/spinning with the galaxy then you don't have to make up something to explain why the galaxy doesn't fly apart with the relatively small mass/gravity holding it together. The stars in the galaxies don't fly out because the space is also in motion, and as space caries the forces, the stars in that moving space don't experience the expected force that an observer outside of that moving space would expect. This also explains why there are galaxies that are not spinning and do not seem to have any dark matter.
It also allows for some interesting possible explanations of what gravity could be from a sub atomic scale. For example, just like black holes colliding can create ripples in space we call gravity waves, every other thing moving through space would also cause ripples in space, including all those sub atomic particles constantly whipping around at almost light speed. The difference being frequency and scale. This wold mean that the more ripples there were the more distance something that was on the same scale as those ripples would have to travel, creating an emergent property that looks like a smooth curvature of space on a larger scale. So something like electrons orbiting an atom would have to travel further on whichever side of the atom was closest to the source of the electron scaled ripples (since they would still spread out like any wave following the inverse square law) making it the atom as a whole experience a pulling force in the direction of the source of those ripples. From a larger scale the electrons would just seem slower on one side. And basically ever electron would be producing these tiny ripples as they moved through space affecting every other electrons movement and travel distance. this would mean that space was "slower" for electrons where there were more of them close together if you observe things from any scale larger than an electron, but "further" for anything smaller than electrons.
Another interesting concept it allows for is you could imagine matter it's self is an emergent property of the movement of of a super-fluid like space where the smallest subatomic particles are something like a toroidal vortex bubble (kind of like the bubble rings dolphins blow). they would be created if too much energy was ever in a single point in space to move in a linear direction at the speed of light. And as a result of space being like a friction free (super)fluid, they would be very stable and hard to dissipate because the only way to dissipate the energy would be to spread it out. Of course that would also mead that black holes are literally holes in space where the space itself around the black hole had so much energy/inertia that it made an empty area in space like spinning water in a glass can create an empty space in the surface of the water till it slows down. Cool thing about this is that we could potentially make particle analogs in super-fluid liquid helium.
Obviously these are a somewhat crude and simplified slice of what treating space as a fluid or maybe super-fluid allows for, but it still rather neatly eliminates some of the "just accept it" hand waving currently used to explain the things we observe in the universe like dark matter, dark energy or many of the quantum "it's all the possibilities till observed" things that are currently accepted as the only viable answers.
Air can move much faster than the speed of sound. A supersonic jet enginr spews air much faster than the speed of sound.l, actually even faster than it's own speed.
Remember, motion is relative to the perception of the passage of time and the passage of time is an illusion.
Nothing actually moves outside of the perception of the passage of time.
From the perspective of our time dependent perception of The Universe, everything is in motion relative to something else.
From the unobservable perspective of the Time Independent Universe, there is no motion or phenomena. All information embedded within Spacetime are fixed and stationary.
@@thatchinaboi1 BS. Motion is relative to observers. Not passage of time, which I'll claim, even u can't define.
@@aniksamiurrahman6365 How can you separate observation from the perception of the passage of time? 🤦
@@aniksamiurrahman6365 The only BS here is in your own understanding.
Been thinking this since re-watching your older videos on the topic: Isn't there a unique reference frame where the net momentum of all objects is 0? Does that have any significance?
Average or net? 4 vector or only spatial?
We do this with the cmb
@@subjekt5577 If it's zero, shouldn't it be the same for average and net? And I mean spatial. Shouldn't the 4-mometum just be some constant?
I wonder what percent of the commenters who are so sure they understand this stuff better than actual physicists have even a bachelor's degree in physics lmao.
Some, as me, are just trying to pinpoint mistakes in there. But maybe since I don't hold a degree in physics, it's not so easy.
Maybe Sabine or Eugene will make a debunk video soon
The medium needs a constant. What is the medium? Space. Therefore, what is the constant of space. Problem; Density. Just like sound in water vs the air. This way of thinking requires some nuance, for sure.
I enjoyed this critical thought analysis for it's inspiration.
The issue about the twin paradox is about saying the stationary twin is moving relative to the actual moving twin, which in this video does not answer. The paradox becomes "exceeding simple" because the green robot is absolutely the only one considered to be moving
Watch any video on this topic and the experts leave out some question unanswered. I am fed up.
The green robot is absolutely the one moving because it is moving not only relative to the blue bot, but also a medium of air. The twin paradox exists if there is no medium or aether to ascribe "true" (if unknowable) velocity.
Yes, it is resolved. There's no relativity. That's how you resolve all of relativity's problems.
Things like the sagnac effect (ring laser gyros) wouldn't work if relativity was correct in its assumption that there is no preferential reference frame. This makes relativity logically inconsistent and requires the construction of abstract frames of reference and/or the assumption of instantaneous travel of light to resolve various problems.
Light propagates through a medium. I can encounter light long after that object exists to have a frame of reference, this means that it is the underlying medium into which light propagates which serves as the base point of reference. Again, the sagnac effect would not work under relativity without "aether" (if you will) as light must be perceived as traveling the same speed regardless of distance.
It is endlessly comical to me that the central subject of relativity - light - refuses to be treated as an object which can have a frame of reference by said theory.
@@Aim54Delta "There is no relativity"... Stopped reading there. nothing you say after that point could possibly have anything relevant to say.
Y’all are simply ignorant. The twin paradox is unresolvable because it’s contained within SR which is an approximate model. It is solved however in GR, and people who try to solve it in SR have to pull their legs behind their heads to do so.
Likewise light is indeed considered to propagate in a medium in QFT. If you go farther in physics you will see that the previous models are simplifications. In QFT c is the speed of ‘sound’ of the ever present quantum fields.
Not sure if the following is fully correct, but the twin paradox seems to be a special case due to rejoin of the clocks, where some unconsidered effect(s) of relativity could be cancelled.
To be able to check the difference of the elapsed time in the experiment one of the reference frames - also mentioned in the video - has to accelerate and deaccelerate (to change its velocity and direction) and for those periods the RF becomes a non-inertial one, maybe with a different value of c, or similar.
However if the time difference of the clocks is not measured time dilation just remains a mathematical construct like interior of black holes, wave equation of a particle, etc.
Inside an accelerating frame of reference, here on Earth for example, time goes by as "normal" anyway.
Velocity includes direction. You meant speed and direction.
Such a high proportion of muons created in the upper atmosphere make it to ground that the best explaination is that they experience relativistic time dilation. And it's a time dilation independent of acceleration. Now the Twins paradox could be constructed so that there's an arbitarily long period of coasting at relativistic speeds and it still is a paradox if you hold onto the idea of there being no universal rest-frame. Introduce a universal rest-frame, and it's no longer a paradox.
It's energy the one that produces time dilation; the acceleration is an indirect explanation. The general theory of relativity defines this. In the special theory of relativity, the kinetic energy is involved in space contraction & time dilation. I can recommend a recent paper named "A New Interpretation of the Special Theory of Relativity" (DOI: 10.21275/SR23918031232). There is a new explanation about space-time as space-energy, relativistic simultaneity, Ct 4th dimension, etc. Hope you like it, regards
Well done! Thus was my introduction to the sound through a medium analogy for time dilation. Surprisingly intuitive and thought-provoking
Not so well done. Special Relativity provided an answer to the Michelson Morley experiment. The triangle derivation comes from that experiment as the expected result, that was in 1881. Nothing new here. Einstein provided a solution to the difference between the expected results based on classical mechanics and the actual result by providing for a new mechanics. If they can do another video showing the Michelson Morley results that would make it interesting, but as it is, their classical mechanics results predicts incorrectly.
Turn those clocks (and those little robots) sideways and do all those experiments, and there is no time dilation.
Doppler vs Pythagoras
Why does it work with light not with sound then?
You put a lot of effort into it. The only thing that might confuse people in the beginning is that when a clock measures a different time, that is not because of movement but because of a flawed clock. At this stage, not all people are aware that c is independent of the speed of the observer, which is essential for the explanation.
"Light is nothing more than a sound wave in the Aether" - Nikola Tesla
Question:
How does this model account for the dilation of muon decay?
My first guess is that it implies that the time experienced by elementary particles is also mediated, implying that our "elementary" particles have their own internal mechanisms, a la something like string theory. But are there any other possibilities?
@@MarshmallowRadiation Muons produced in laboratory are slower than muons produced from cosmic rays colliding with the atmosphere . Using classical theory , objects that has more energy will need to lose more energy to stop , thus will take a longer time to stop . I think that decay is objects colliding and losing/spreading there energy to more and more matter , I am skeptically about the way they measure these particles , because their detectors require the particles to literally collide with the detector , which the particles could be from the detector .
Atomic clocks that tell time can tick slower travelling near light speeds. That's distinct from a common misconception that suggests the faster motion through space, the slower time _“itself”_ progresses...
Anywhere between the three dimensions of space represented by _x y z_ is our location in reality. What displaces from one location to another, moves. Motion is fundamentally indispensable to factoring the amount of time _(i.e duration)_ of displacement...
If two notions can’t simultaneously be *fundamental* to each other, then time can’t be fundamental to motion when it’s been proven motion is fundamental to factoring time.
I would be interested in having a conversation with you answering the question, "Does or could a gradient of time dilation actually cause the effect we call gravity?" Give any amount of matter, velocity and it therefore has momentum. If that matter passes thru a gradient of time dilation so that the rate of time slows down, wouldn't its velocity increase to maintain the same overall momentum?
This doesn’t really explain the phenomena of time dilation in anyway - it only shows that audiowaves are a bad medium to use for a clock when moving at a high velocity.
The “wow-effect” with time dilation is not that clocks suddenly tick slower, but that life and organisms themselves are slowing down (atleast in reference to someone outside looking at the moving organisms).
The sound wave animation in the clock is a really good way to understand what is happening, instead of just drawing a ray.
Seeing physics more visually is helpful and I bet that a similar approach with the areas of physics that are currently difficult to visualize would actually help scientists to make a breakthrough into the major areas we're stuck at such as unifying gravity with the standard model (quantum gravity). Maybe even with dark matter / energy.
A physics simulator for such visuals and for testing any hypothesis would be good.
If anyone's interested in a visuals simulation or in such a project, let me know.
That does sound interesting. I program as a hobby, making very basic simulations or whatever piques my interest. I'm not very skilled in the graphical sense, though.
@@acebinko1 Also, here's some inspiration for a visuals in a book about astronomy for blind people, it's called Touching The Universe:
Not sure if I agree with this parable. Given that one of the clocks accelerates, it change interial reference frame, hence the obeserver's (clock) also change its view of simultaneity. Its not that time ticks slower when the clock change direction in that instance but that the clock's view of spacetime changes and so it views the other clock as ticking ahead of its own time. You can't apply the timedilation formula on the full trip if one the observers (clocks) change inertial reference frame without considering this fact.
i was already subbed to you and then you come up with this
i gotta say i had a recognition for good channels :P
Nice explanation. Is it just a different way to help understand it (like Copenhagen versus many worlds) , or a new type of physics? I guess if you have something novel here, you should be able to design an experiment that makes a testable prediction that is different than SR/GR. What happens when your experiment exceeds the speed of sound? In your model universe, you could design a clock that is independent of the speed of sound: have you found a phenomenon or particle similarly independent of the speed of light? Could you design a better MM experiment to identify the speed of Ether? Looking forward to new predictions and disproving relativity, please post a video when you do!
Ether is so nineteenth century.
That was good, thank you. Did you know that if what you're saying is correct, then warp drive may be possible? I've spent decades working on this and published many papers. The "insistence for symmetry" as you put it is spot-on. In GR there is no such symmetry in time dilation. If the clock is in the gravity well, time runs slower, and if that observer looks up toward another clock above him, that clock runs faster. It's not symmetrical. The symmetry is what leads to the crazy idea that going faster than light breaks causality and results in time travel. Once you eliminate the symmetry, those are non-issues and obvious impossibilities, but the medium allows us to modify the maximum speed and create a warp drive without violating causality, and no CTCs. FYI: I have the interpretation you are looking for. It's already done, baked, and ready for a fantastic animation like this.
Could you please share your papers?
@@joel.9543 The link will be deleted. Just google that title and it will come up.
That sounds interesting, can you please post a link with a video explaining your views more in detail?
1. Who is Dialect?
2. Dialect is my favorite science YT channel.
3. Now do time dilation in gravity wells.
I may be missing something. With two observers with light clocks moving relative to each other, each will witness the other observer's clock tick more slowly relative to their own. It doesn't matter which observer's perspective you consider. But with these sound clocks, one stationary in the air and one moving relative to the air are fundamentally different, no? The stationary one will view the moving clock as ticking more slowly, because the sound has a longer distance of air to travel through. But would the moving clock likewise view the stationary clock as ticking more slowly? This model seems to say no, the moving clock will view the stationary clock as ticking faster because the pulses of the stationary clock have an objectively shorter distance to travel through the medium than the pulses of the moving clock - breaking the symmetry between observers by introducing this universal reference frame of the aether-medium. Is that really what this model posits? Can this be tested?
It is not that easy: When both clocks move, dhe distance between is changing too. So the time between the "ticks" seen by the other one is distorted. Only when they rejoin, can their times (clock readings) be reliably be compared.
Thank you for your time and effort. In an era of mass media, and with the sensationalism of how far one could stretch theories of reality, it gives me a glimmer of hope to see someone choosing to spread knowledge and understanding, rather than succumbing to the intoxication of approval.
@@Nonononono_Ohno There's your first problem, right there. The speed of light cannot be the same in every frame if time dilation exists, and the entire topic is time dilation. The closer one gets to C the slower causality occurs.
I love this channel so much. Your channel give a new way of interpretation of science and it is also pretty similar to what in my thought.
I have an question. What will happen to the curvature of spacetime that is affect by the massive object that move very close to the speed of light ?
For example, the stellar black hole move at 99.9999% speed of light ? Does it emit any energy because it distort another region of space as it move ?
And does it have something like sonic boom version of gravitational wave ?
What will happen if the black hole move pass the spaceship at far enough distance that spaceship doesn't get eaten by the black hole ?
The merging of black holes generally involves a 'spiraling' motion, allowing them to pick up some awfully fast speeds for extended periods of time. Gravitational waves strong enough to be detected over many light years don't come cheap, the energy locked up in them is enormous (not in a useful fashion, being distributed over as many light years, but just the numbers are impressive).
While an aircraft need not move at supersonic speeds to create supersonic effects, it still entails parts of the aircraft locally moving supersonically relative to the airflow (this phrasing is backwards, you say the airflow is supersonic in one particular region around the aircraft, but in this discussion all clocks dilate relative to the medium, so equivalently the air moves at a constant speed and the aircraft has some parts moving faster than other parts, or something like that...). The analogy now must break down unless we discover new physics that permits superluminal interactions. The black holes can't move or move in part faster than light, so the conditions equivalent to a sonic boom simply do not exist.
The next best thing is the ever-glamorous Cherenkov Radiation, where you cheat by imposing a medium on light. If you move a particle very quickly through a material where light gets slowed down (which is kind of a macroscopic effect, individual photons you might analyze would only ever travel at exactly the speed of light, it's just they get held up bouncing around all the atoms and molecules), then you will find the particle/material glows, perhaps dimly, with a rather blue (distribution tends to involve higher frequencies) hue. A sonic boom has lots of high frequencies because it's an abrupt change to the airflow, though that will be tempered by the fact the "particle" (aircraft) has a large length scale, and the boom travelling from up in the sky down to the ground attenuates relatively quickly, at least compared to light (attenuation of pretty much any wave will reduce higher frequencies more than lower ones, because of some principles about energy and how it dissipates), so sonic booms will have more of a low rumble than Cherenkov Radiation.
Standing on a spaceship in a gravitational wave, you cannot humanly 'experience' [ripped apart maybe, funhouse mirror no] any effects (without some extreme coincidence of the gravitational field, like if it was somehow travelling one way with a distortion aligned in a different direction). The gravitational wave will pass through the ship one side to the other at the speed of light. Have you ever been stood facing away from your bathroom mirror, and turned your head fast enough to see the back of your head before the light bounces back?
I don't know enough about the structural integrity of interstellar (one would hope not to have a black hole near Earth) vessels around strong and dynamic gravitational fields, but I imagine, for what effects are had, the strength will depend on the intensity and the length scale. Longer fluctuations, even if very strong, would be like bobbing in a rolling ocean, with waves so much larger than the ship that there is no difference in effect from one side to the other. Shorter/higher frequency waves (regardless of what type of wave: sound, light, water ripple...) carry more energy for the same amplitude. If your head is more stretched than your toes, you may be having a bad day today.
@@PeterBarnes2 Thank you for answer. So, the sonic boom simply do not exist in that case. Maybe doppler effect exist instead ? In fact, the reason that I ask this question is because I wonder if that the moving object really don't slow down if there is no external force ? The moving object might emit some energy in some form of gravitational wave but since the gravity is very weak. The amount of energy might be too low to detect.
Moreover, in fact, I really doubt if it really impossible to move faster than light or not or it is actually possible but need insanely high energy with the order of magnitude around the cosmological constant level. Since the black hole is massive enough to distort the spacetime, if we give it enough energy, it might be able to somehow move faster than speed of light for a fraction of second by distorting the space around it. Then emit insane amount of energy in form of sonic boom of gravitational wave and back to some speed that is slower than speed of light.
@@uesdtosignin1038 Well, one thing is that you can achieve arbitrarily large Relativistic Momentum:
Momentum is mass times velocity. When one refers to mass, they might mean 'Rest Mass' or 'Relativistic Mass.' These are equal when the mass is not moving relative to you (the observer), yet, while Rest Mass is constant, Relativistic Mass increases by the factor "Gamma" (the same as derived in the video), dependent on the speed relative to the observer. Velocity also acts distorted by this factor Gamma, but being reduced by Speed instead. When Velocity and Relativistic Mass are multiplied, the factors Gamma cancel out, and so the Relativistic Momentum behaves exactly like Newtonian Momentum (that is, momentum when you forget about Special Relativity).
In particular, applying a force for a period of time to any mass will increase its Relativistic Momentum completely linearly, no factors or distortions or anything. The trick is that the mass will not _accelerate_ linearly. Its speed will increase in kind at first, but slowly more and more of the force goes into increasing the Relativistic Mass the object has.
In relation to the video, you can interpret this as the object moving so fast, clocks seem to slow down drastically, which makes it seem like it's harder to accelerate the object, as if it has more mass than it really does.
(You could perhaps interpret this as being a 'drag force' related to gravity, except that it isn't: aerodynamic drag is a force proportional to the square of the velocity, whereas this deviation would have to be a function of the acceleration, instead, because the object doesn't slow down on its own. I suppose it's possible everything in the universe experiences some kind of actual drag, but you have to allow for different frames of reference. The air has an ambient velocity, and drag is related to your speed relative to it. This is why in the video, Dialect says to assume the sound-clock is very aerodynamic, with no drag.)
The kicker is in the fact that all modes of interaction in the universe depend on the same kinds of clocks. You can't just put energy into an object in larger amounts to skirt around it, because the way you even measure what you're putting in, and the way you observe the energy changing the kinetics, depends on these clocks, and the clocks do simply slow down.
The only conceivable way around the issue is to change something else, be more fanciful. This would be warp drives. Unfortunately they have some drawbacks on becoming practical, such as (possibly) using forms of matter or energy that don't exist and probably can't exist, amounts of energy that correspond to the masses of large planets, a complete lack of stability, no way of communicating controls from the ship to the material warping space, and the incineration of everything in front of you when you turn the warp drive off (which, again, can't be done, because you can't communicate the command to do so). There's also the issue that some people are pretty sure such a warp bubble would not accelerate to superluminal speeds, it would only be able to maintain them if they happened to already exist.
Some of these are perhaps easier to solve than others. Why not make a warp tunnel instead of a ship-board "drive"? Everybody loves trains! And Stargate, that show was fun. It'd be like if the Stargates were trains! If it's an externally created field, then you don't need to communicate anything, the people outside handle everything. And, if you're generating this field externally, you don't have to worry about stability, you just stick a PID on it and call it a day! (Actual Stability and Control is more complicated than this, but one can imagine letting people who major in Stability and Control just have at it.) This should also handle the incineration issue (Which happens because you collect all kinds of dust and light and other particles, which get trapped in the front of the 'warp bubble,' which you then turn off, releasing multiple lightyears of accumulated vacuum-of-space; if the field doesn't actually move because it's like the rails under a train, then there's no issue. Probably.).
The amount of energy required is just some engineering problem, no big deal, just throw more money at it! The form of energy required (you need either negative energy or exotic matter, or maybe both) is probably an issue, but smart people disagree on whether there can physically exist solutions. Some people also complain that superluminal speeds are synonymous with backwards time travel, and that this is a big physics no-no. They'd certainly be right, except maybe if there's an alternative interpretation like in the video by Dialect here.
The "some sort of medium" that the second clock moves relative to is "the observer" of both clocks. It is relative to "the observer" that the first clock is stationary and the second is moving. It is just SR. This is the best explanation of SR I have seen.
Your tests were run in an atmosphere with sound.
Run them again in a vacuum and use light.
I'm confused, I feel something is off without being able to point it... So, what about velocity additions and infinite energy required to reach c?
I think it's the implementation of a medium relative to which light travels at c. It should travel at c relative to any observer.
Multiple things wrong with this:
-since the clock ticks depend on the medium, you can change how fast the clocks tick by moving through the medium or changing the medium. However, that is only specific to the sound clocks. If you were to place an atomic clock beside it, the movement through the medium wouldn't show the same type of "time dilation".
-it's easily possible to exceed the speed of sound. In which case your clock doesn't tick at all. There's no reason given as to why you can't exceed the speed of sound in this toy universe, either.
-there's a conflation between observing mediums: the clocks work on soundwaves in a medium (air), but the observer observes the clocks via light (or more generally electromagnetism). So there's an asymmetry present here which is not present in SR/GR.
A great presentation. This is something I have been talking about for nearly 40 years. I know its long been assumed that an ether based system with a privileged , fixed real time coordinate system could never be proven for reasons explained, but what if it could be shown to exist - it would make Special Relativity irrelevant and provide us with a whole new perspective on the Universe. That would be an exciting quest. What we need is an equivalent of 'Bell's theorem' for Relativity.
Question regarding the robots: At 10:15 you state "They will experience time differently depending on that state of motion."
How can "they" (each robot) know the other robot is experiencing time differently at these moments of their own motion in their independent frames? Is this 'knowing' knowable only from any 3rd party observer's removed/outside perspective of each robot's independent experience - but has established a fixed frame of reference - shared with what is deemed the one robot in this fixed frame, i.e. in one of your videos, the observer of the earth/rocket ship and background-fixed stars?
How is it that each robot - as you state - can know it is experiencing time differently from the other robot? Is this not only knowable to an outside observer at the so-called moments/time witnessed by said outside observer? Is not each robot's experience of time unaltered to its self and senses as they move at essentially any velocity? Is not the perceived passage of time in own's own inertial frame essentially not sensed/experienced differently from one's own perceived "before" (or measured by one's own clocks on one's walls) and only possible from a 3rd party's perspective viewing the two robots (while sharing a fixed position with only one)?
Seems the final solution at the end is to establish with what's agreed upon to be a fixed frame of reference - or a "pseudo absolute position in space" - which if I sense where you're going with this - is not arbitrary or pseudo within a fixed aether.
Lastly, it seems you clear up my questions at the end by stating it's not time itself that is relative but merely our knowledge of it - based on the knowledge of observing how information, in the example given, determined the rate of time passed/hair popping out. Pushing toward more videos on information theory, no?
But what if you add another clock to the robots, but this time a mechanical one? If it all comes down to the speed of sound in a medium, then the two clocks wouldn't show the same time after the ride (the moving mechanical clock would keep on ticking at the same paste like the stationary one, as it won't be affected by the movement within the medium).
The problem is chemistry, including transition of force through solid objects is an electromagnetic effect by electrons moving and pushing on electrons - anything involving atoms is built out of things that tick according to the electromagnetic clock.
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 :)
Share them with me. Im actually really interested. I also figured out the flaw with the parallel motion of the clock and i was quite annoyed because i really thought that maybe this interpretation could perfectly explain relativity in a simple manner but i guess science is cruel lol. So how do you think lorentz contraction could work out this flaw
When we define *seconds* as when a device receives a signal (which varies depending upon speeds & mediums said device travels through), the concept of a _second_ becomes meaningless...
Which raises the question… What _is_ time, objectively?
time does exist , just a concept .
@@m.c.4674, concepts that can _describe_ what exists don't themselves, exist.
The sound clock remained me of a sand clock. Thank you this is an excellent video that has assisted me greatly in understanding this concept of time dilation.
It's a high-tech sand clock that doesn't need to be turned upside down when you start your next egg!
So is c just the speed of causality like the speed of info to alow us to register the passege of time?