Is One Way Speed of Light Problem For Special Relativity??? 

Hey Lukas! Your videos continue to impress us - and we want to say it’s extremely refreshing to see someone on RU-vid approach these sort of topics with a rigor and clarity of thought that doesn’t shy away from nuances. Plus, your love and enthusiasm for the topics at hand readily shines through, making your videos an enjoyable viewing experience, even when one may struggle to follow the math 🙃 You tackle the one-way problem quite deftly here, fleshing out numerous details we wish we’d been able to address ourselves, and doing so with an approach that is thoughtful and well-balanced. Indeed, we are very glad you made this video. If we had to make a quibble with it, it would be in your assertion that the one-way-speed-of-light problem is “well known”! We certainly weren’t aware of its implications until recently, and in the past our viewers gave us a lot of flak for saying that the constancy of speed of light was an “axiom”, decrying that it was actually proven fact. To us the issue is perhaps not that the problem is not well-known (Veritasium certainly spot-lighted it) but that most people don’t realize that the entire symmetry of observer’s seeing each other’s clocks/lengths ticking slowing/contracting is a consequence of one-way light speed isotropy, not two-way light speed constancy. (Time dilation and length contraction are NOT a consequence of one-way isotropy however, as they must be retained in some form in either a relativistic framework or an absolutist ether view). Moreover, we are told the basis for rejecting an ether theory is that we cannot empirically detect any such ether. But by that criteria, we would also be forced to reject Special Relativity, because there is no way to empirically detect one-way light speed isotropy. The invariance of the laws of physics meanwhile also follows from one-way light speed isotropy, since we’d have to change up how we express Maxwell’s equations if we abandoned it. (Indeed, one might wonder why we would expect reality to conform to how we wish to most simply express it…) Currently our philosophy stance is that at the end of day, a theory is going to have to posit something that is unobservable. The question then becomes, do we stand to gain anything by once again adopting an absolute (albeit unobservable) simultaneity? We’ll be exploring that topic in upcoming videos. Hope your channel continues to grow and gain exposure, as RU-vid needs more thinkers like you! Additionally, regarding your request for Einstein’s remarks on absolute motion, they can be found in this 1918 work “Dialogue about objections to the theory of relativity” - there’s a link to it in our Einstein Twin Paradox video.

The main benefit of Dialect's view of things is that a variable anisotropy restores sanity to the concept of simultaneity. In my opinion, this is the critical benefit to using variable anisotropy factors. Yes, somebody has to declare a master reference frame (which could be anywhere). There are experiments that suggest there is perhaps such a frame associated with the cosmic microwave background radiation so maybe choose that but, yes, traditional special relativity is not overturned by these ideas and the fact the GPS works so well is the best proof that scientists and engineers understands how to agree on simultaneity, position, and the speed of light.

Thank you for making these videos! I appreciate them a lot.

I was waiting for your reaction to the last dialect video and here it is!! Thanks :)

It always bothers me the "you're a flat earther" argument, that some people like to use against youtubers like dialect. Granted he could be wrong, and if I'm not mistaken, he isn't trying to debunk any well stablish scientific facts but rather try to find answers for the questions that we haven't agreed on.

Perfect job as always!

I view the anisotropy of c the _exact_ same as the ability to chose a convenient reference frame. It is a free parameter we can chose to make the math simpler. Having a particular frame where k=0 significantly increases the math overhead for everyone else and is completely unnecessary. But it can be done. Like you can do simple harmonic motion in rotating cylindrical coordinates if you really want to. It doesn't change the physics, it just makes your life more difficult. Calling it a loophole is like saying inertial forces are a loophole to Newtonian physics. It's an artifact of a choice of coordinates, nothing more.

I have thoroughly enjoyed the debate between you and Dialect. Irrespective of who's right, you guys elevate this debate to a higher level.

Best video on this topic that I have seen in a long long time. Most of these channels shun the use of some simple math, but you don't and that makes all the difference.

Videos from the other channel are basically dedicated at proving there is an aether. The funny thing is that Einstein himself was NOT against the aether. He actually argued that there is a natural equivalent to the aether in the General Relativity which is the background metric (ignoring local massive objects) generated by all the masses in the Universe.

Standing light waves can only exist if the speed is equal in both directions. And standing waves do exist! You can easily demonstrate them with a UHF transmitter. Please stop calling it a postulate, it is an experimental fact that the speed of light is equal in both directions.

Special Relativity is a simple theory of hyperbolic perspective which is also true, and it is amazing that anyone should have any difficulty with it. If we meet a challenge to this theory, then try converting it to a challenge to the theory of elliptical perspective. The Earth is really shaped liked a rugby ball, but our rulers shrink or expand as we rotate them to create the illusion that it is round. Herdthink geographers are conspiring to cover this up.

Isn't Rømer's determination of the speed of light in 1676 using the moons of Jupiter as a clock, a one-way measurement? The speed of light = 1 astronomical unit /11 minutes (not really accurate, but nevertheless a demonstration of isotropic speed of light). If the speed of light were actually anisotropic, it would also play havoc with the orbits of the planets.

Thanks for these videos. I'm not a physicist, it was a field I liked since my school days, your explanations and explanations of reasoning are amazing, and I liked your attempts to try and see if you can attack those theories, and what happens if you do, what are the attack vectors etc. I think physics and science needs more people like you than taking everything as unquestionable gospel. No-one questioned relativity, but you gave really good examples and explanations as to why this is so, you even managed to make complicated math seem simple, all without patronizing your viewers as if they're idiots, Bill Nye style. Had physics had more people with these skills, we might have had more physicists. Thank you and Subscribed. I also have a question. I like relativity, and I quite understand it for a layman, however I'm not really a fan of magic constants or magic properties (like aether in the case of Einstein and your video, or even the widely accepted dark matter etc). When I see one, despite all saying, well this is how it is, internal alarm bells ring in me saying this is wrong. So, you can imagine I kinda have issues with c, the speed of light. First of, I think c as speed of light is a misnomer, as it's not a speed of light at all, but the maximum rate of information propagation. It applies to anything and everything, not just light. It even applies to gravity, which we kinda don't quite understand yet. Then I realized, the force of gravity decays through distance. Electromagnetic forces also decay through distance. Not light it seems. Well, why not? Are there clues out there that light could also decay through distance? Yes. Redshift. But physicists interpreted this as it's not light decaying through distance, it's actually objects moving faster the further away they are. That's silly I think. Why would the universe accelerate outwards? There is no reason for this, not even a big bang is reason enough for this acceleration. If you see it as light decaying through distance though, it explains away the universe accelerated expansion. So I concluded, one can theorize for everything decaying through distance and this could be a fact. Then I was trying to connect the pieces, gravity is affecting the geometry of spacetime, and this also explains its existence but also its decay through distance. What about everything else? Then I stumbled upon a brilliant youtube video, theorizing about the possible geometry of spacetime, what if spacetime was actually hyperbolic? We are unable to detect this in the same way we cannot tell the earth is round if we are at its surface. Although, if spacetime is hyperbolic, it would seem as if objects are accelerating the further away you look. It would explain the decay of everything through distance, including that of light, and most importantly, there would be no c. No real actual limit on the rate of information propagation, it'd actually be instant, this limit c only appears as you account for the geometry of the medium in which information propagates, spacetime. Everything made sense to me after this video. If you would like to reply, I'll see if I can find this video again, and maybe you could make your own video reaction to this video. I'd like to see this. Thanks. PS: Ok, I just realized one more relation, scientists describe gravity as a weak force, while electromagnetism is a strong force. However, the area of effect of gravity is vastly greater than that of electromagnetism, and if you wanna measure them in regards to their area of effect, or rate of decay as I call it, gravity actually has a slow rate of decay compared to electromagnetism, and this would make gravity as a strong force in this regard, and electromagnetism as weak. Is there an actual inverse relation? An inverse relation to the strength of a force vs its rate of decay? Am I onto something or am I seeing things? Tell me I'm about to unify those forces. LOL (or completely disappoint me) PS2: You do the math, I'll share that physics nobel. LOL 😃

You can tell that light travels at the same speed in all directions by observing something like the Cherenkov radiation in water cooled nuclear reactors. If the speed of light were different in a certain direction, it would have an observable effect on the radiation emitted. Also a substance's light refractive index is not dependent on the direction light is moving through the medium. We know this by observation.

What if the two clocks are moved simultaneously in opposite directions at the same speed? Wouldn’t that retain the synchronicity?

Why not take two synchronised clocks next to each other, and move them BOTH in opposite directions to a predetermined distance. They should remain synchronised, and thus able to measure a true c

One of the most insightful and informative video on this topic available for free 🙂

Great Video, I really enjoyed it :-) There is another problem with the video from dialect. The ansiotropic speed of light is limited to a lower limit of c/2. If it would be slower than that, the one way time would exceed the roundtrip time, and we would be able to measure it. Therefore, the idea of assigning different values of k does not work for observers moving faster that c/2 relative to the medium. Let me know what you think about this argument. Thanks again, Mads :-)

I skipped Veritasium video, as I preferred a less click bait approach, thanks! Good presentation

If the measured speed of light actually depended on relative motion you would experience some wierd outcomes. Eg, if a distant object that was being observed suddenly started moving towards the observer, the light would catch up to and pass light emitted earlier and a clock on that object would appear to run backwards.

I really enjoy your videos! I don’t understand the can’t measure the single direction of the speed of light as seems to be done all the time in microwave systems or anywhere where we are sensitve to wavelengths of electromagnetic propagation. Any optics theory just falls apart and I dare say that instrumentation of a particle accelerator would be of little use is particles where changing velocity around a synchrotron.

An anisotropic speed of light would have wider implications for cosmology as you would have to reconcile the hubble constant by a similar factor, giving rise to there being a center of the universe.

The speed of light can be calculated directly from the permeability and permittivity of the vacuum. Both of these values can be measured directly from simple experiment. Neither value is dependent on direction.

I've got a question, couldn't you use a third clock at some distance equally far away to sync the clocks. An example clock 1 is at my location. Clock 2 is 2 light minutes away and clock 3 is 1.5 light minutes away from clock 1 & 2. Clock 3 then sends a signal to both 1& 2 to sync them. 2 could send a signal to 1 as a measurement.

I disagree that 1 way SOL cannot be measured. Astronomers have been doing it since 1919 and just haven't thought of it that way. Angle of gravitational deflection is theta=4GM/c^2r, which can be solved for c, c=(4GM/rxtheta)^.5 So by measuring the deflection angle of starlight during eclipses we are, in fact, measuring the 1-way speed of light!

I'm amazed by these demonstrations and I cannot appreciate enough the great work done here, the first thought that occurred to me had to be the inception of field theory, and the maxwellian derivation of speed of propagation of electromagnetic fields. since a definite wave speed from a wave theory did not suggest a parameter or any sort of anisotropy, the problem of the one way measurement of speed of light did not have to be a kinematical issue, since the wave theory predicts an isotropic value of propagation in all directions, the wave must thus travel by this speed in all moments, so shouldn't this be a wave problem and not a kinematical one, anyway if there's more that I should know regarding the possibilty of emergence of this anisotropy in the motion of light, I'm open to full understanding.

11:05 Remember the Michelson-Morley experiment trying to measure the aether?

The speed of light depends on the amount of gravity in the vicinity. Everyone should already know this. The speed of light isn't constant since the measures of time and distance used to measure speed are not constant. In fact the changes in time and distance exaggerate the differences in the speed of light.

can we anisotropically travel faster than the speed of light? If I can move from point A to point B with infinite speed but to move from point B to A I'd be forced to travel at [c] that would be okay right? no infractions against causality would happen.

I think the perspective shared by Dialect is important, because the way relativity is taught, you can be led to the assumption that constructing a simulation of our universe using absolute space is impossible. That’s at least the impression I got, and caused a lot of confusion as I tried to work through “well what if I tried to get the effects of relativity in absolute space.. what will stop me.. what am I missing?” It’s not common knowledge that you can’t measure the two way speed of light. At least before the Veritasium video. I’ve never seen it covered up to and including a university level physics course. I’m curious to see what point Dialect is working towards. I suspect that working with alternative perspectives of space time could become important to make further progress in our understanding of physics, so I think more of those kinds of perspectives is great.

What if we start with two clocks and they each move in the opposite directions from the starting point? Then the time dilation will be identical

Re: The Light Postulate? At the 'initiation' of light from an emitter? (for example(s): the operation of a flashlight, a 'struck match', a star, whatever?! ) From the 'Planck moment'? How 'instantaneous' is the velocity of light? Does it 'speed up' to its ultimate vacuum frame reference velocity? Or...? Is light always at C, only to be 'deflected' by 'source' acceleration(s) per gravity? I'm sneaking these questions to various youtube threads but your 'enlightenment' (as well those expert others) will do wonders for my ego against certain 'precocious' relatives of mine!

Part of the problem is that the speed of light is not a constant, vut loses approximately 4.6mm/s/year. Shown by the redshift from some of the furthest galaxies. But second, special relativity is wrong also. The frames of reference we are in is affected by the same gravity etc. we are not in separate universes that only contact each other when we come together. The twin paradox exists in the model due to the time assumption.

There's a way to agree on that frame: suppose that the observer are in some fluid and the fluid has some temperature(isotropic )associated with due to the temperature there will be blackbody radiations and the radiations will have same temperature everywhere in the rest frame of the fluid but as soon as you start travelling with some speed there will be an anisotropy in the temperature due to the Doppler effect,

You said in your video that "although there is no reason suppose that the speed of light changes (in a two-way measurement), there's no reason to suppose it would stay the same". Yes, there is. Until a mechanism is proposed, investigated and verified that could even in principle change the speed of light during a two-measurement then there is no reason to live as if there is. Given the physical impossibility of travelling faster than c, there is only one way to have a variable speed of light that none-the-less gives an average of c and that is to ALWAYS travel at c. I have absolutely no problem with the model that takes the two-way value to be the one-way value as no physical contradiction arises as a consequence. (The only time I've ever heard this "assumption" be criticized is by a creationist trying to pick fault with science!)

The GPS system we ALL use is based on the one way speed of light and simple geometry of intersecting spheres.

Could one not synchronise two clocks (and light sensors) in one place and then move each of them in opposite directions by a defined amount? Then one sends two light pulses at the same time, one to each clock, and finally compares the times at which the clocks received the time signals. Why wouldn't this enable a comparison of light speed in two different directions?

Well there is place in space-time called photon sphere near Black Hole. The light shot forward will return to your back. With Michelson-Morley experiment: what if movement of eater is in (let me say it) time direction? Is there analogue of M-M exp. with time crystals? And about the last one(frame of absolut rest): sphere of detectors, laser at center, detection of energy(wawelength, frequency) in each direction. For absolut rest frame they are equal everywhere. No?

I think Dialect’s argument makes more sense than special relativity. With media, it is more reasonable to create a reference frame with media than assuming each observer is the rest media as special relativity assumes. Without media, it is more reasonable to assume the reference frame is the emitter not the observer. Either way isotopic speed of light is better to describe the simultaneity of events happening around us. Einstein assumes nothing travels faster than light thus even if it happens differently at time it is fine since the observer will never know but there is many body reaction that will project the causality to us even if we cannot observe something directly.

Please correct me if I'm wrong, but there seems to be a third way of measuring the one-way speed of light that should eliminate the problems with clock synchronization posed by moving a clock from one location to the other as well as that posed by the possible anisotropy of the speed of light. Wondering why this scenario hasn't been addressed in this video. =================================================================================================================================================

Move both clocks halfway. What position is time dilation calculated relative to? Is there an absolute position and if not how do you know which clock is moving and which not.

when separating the two clocks, to keep them in sync, how about: send a light pulse from A to B every 1 second. At clock B ignore the "time" it "took" to get there, ignore the time between pulses at B, just count the number of pulses. Clock B moving at 99.9% light speed will still "see" the correct # of pulses and can just keep setting it's clock to zero seconds + the number of pulses, this would limit the uncertainty of synchronization at B to the pulse frequency, so to get more accurate, send pulses more frequently. when it's gone far enough and decelerated, can't clock B know when it's returned to rest with respect to clock A by spotting when the inbound pulses are coming at the exact same shape and frequency as pulses generated by it's own time-keeping mechanism?

Why not just stand directly between the points and send a light pule in both directions to synchronize the clocks? Then they're perfectly synced and you can perform the experiment

What if there was somebody equidistance between two clocks? The delay should be the same for each, if they're not at the same time they'll know they're not synchronised.

Does "speed" mean relative to an inertial frame of reference, or does "speed" mean invariant with respect to the frame of reference?

The one way speed of light has been measured and it is c. This was done by transmitting a radio wave from one dipole antenna to another dipole antenna, where both the transmitted signal and the received signal are measure by one oscilloscope (ie. one clock). The orientation of the 2 antennas were pointed in many directions and experiment was repeated many times over months. But the experiment showed something unexpected. It showed that speed of light is instantaneous in the nearfield and reduces to the speed of light about 1 wavelength from the source. Since Relativity assumes light only propagates at speed c, and this has been shown to not be true especially in the nearfield of the source, then Relativity needs to be reanalyzed. Derivation of Relativity using instantaneous nearfield light shows that Relativity reduces to Galilean Relativity, and only in the farfield does it reduce to the speed of light c. This is because as c=infinity, the Relativistic gamma function becomes equal to one, causing the Lorentz transforms to reduce to the Galilean transforms. But using farfield fields yields the Lorentz transforms. But since time and space are real and can not depend on whether nearfield or farfield fields are used (i.e what frequency of light is used), then the effects of Relativity on time and space must be an optical illusion. Time and space are absolute as indicated by Galilean Relativity. When moving objects are observed using farfield electromagnetic fields then time can appear to dilate and space can appear contract, but the effects are not real and can be verified by using nearfield electromagnetic fields which will show time and space have not changed. Since General Relativity is based on Special Relativity, then the effects of General Relativity on time and space must also be an optical illusion. So what is a better theory of gravity if General Relativity is wrong. It is well known that General Relativity reduces to Gravitoelectromaganetism for weak gravitational fields, which is all that we observe. Consequently Gravitoelectromagnetism predicts all known observed gravitational effects. But the difference is that Gravitoelectromagnetism is a field theory, whereas General Relativity is a geometric theory. Gravitoelectromagnetism assumes gravity is modeled by 4 equivalent Maxwell Equations as for Electromagnetism. The equations only differ in the constants used. Gravitoelectromagnetism is field theory of gravity and assumes there are both an Electric and Magnetic components of gravity. Just like for electromagnetic fields, changing magnetic fields create electric fields and visa versa. Gravitoelectromagnetism also assumes time and space are absolute and not flexible as General Relativity predicts. For more information see my short 15 min RU-vid presentation and the paper below it is based on. William D. Walker and Dag Stranneby, New Interpretation of Relativity, 2023. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-sePdJ7vSQvQ.html

You can synchronize clocks by doing this: Have both observers on the same orbit and orbital speeds but at opposite directions. When their distance from each other is nearly zero, they transfer their clock information to each other.

Start with both clocks at a central location, synchronize them, and then move them equal distances at equal velocity in opposite directions to the test distance.

My feeling about this is "Why WOULD the speed be different in the two directions?" There should be no preferred direction - if we allow for those speeds to vary, that is assuming that the universe is not isotropic. Also, I've never considered the "light postulate" necessary. Once you have the first postulate, invariant laws, well, Maxwell's equations are laws, and they predict the speed of light. So by postulate one the speed of light has to be the same for all observers. Finally, who cares? Any dependence of the speed of light on direction can't possibly affect any of our predictions. If it could, we'd have a way to measure it. So the very fact that we have no way of measuring it means that it has no impact on us, so we can ignore the whole business.

I think it might be possible to break relativity by somehow testing reciprocity, if there is an aether or an apsolute reference frame reciprocity would not hold.

Can you sync two clocks together, and then send them off in opposite directions, bit the same distance ?

i think jwt can see the lack of medium light need to clone it self (might need to turn off most filter . ) on tv its like when not enough backlight led are present . In space , it will be like someone removed medium in the region . There should be a lot of those like huge amount

Instead of a single light pulse, can you measure the one way speed of light by sending two pulses of light to the traveling clock with a delay between the pulses?

I recently commented on another video that a synchronized measuring device could be sent to space with a program that continually adjusts the time so it stays in sync with the device on earth. This could be used to measure the speed of light when it's travelling away or toward the earth to see if there's any difference. I can't think of any reason this isn't possible.

the only problem i got ? Newton resistance to change . But it does not seem newton resistance to change is considered with light by academia

Why not do the experiment in short distances so that the effect of dilation is insignificant?

There are several observations that show the speed of light is the same in all directions. There are technologies that work that are based on this assumption and that would not work otherwise! 1. GPS 2. Phased array antennas 3. Standing waves between a microwave source and reflector - this can be used to measure wavelength and calculate C. If the speed was not the same in the two directions sinusoidal standing waves would not form.

light postulate(mine) once generated light does not move but clone it self in a spherical way via all valid medium within reach (most medium move)

question. If light has no motion at all. (humor me lets exclude mathemetic to keep argument sane) what did i just break . Not from academia toy list . But what would stop working properly in creation (non religiously) if i am right . There is no isotropy of anisotropy of speed of light

It is correct the speed of light in each direction is the same regardless of the motion of the object , even if the speed of light is not the same in each direction. It is correct that the observation one obtains by traveling in each direction is the same Lorentz transformations as one gets from applying Einstein’s convention of one constant value for speed of light in all directions. If a star system 5 billion lightyears away if we assume einstein convention , is in a direction the one-way light is getting to us instantly and we can’t measure it , it will align with a clock synchronization on that star system that would be fixed such that we could not distinguish it from isotropic.

One problem to me is special relativity has no ability to describe interactions between objects that is moving close to speed of light or faster than speed of light such as those in the unobservable universe that is leaving us. But they should have the same physics and chemistry as us just we see them freeze in our telescopes. They are not freeze to a observer in between and we can see the middle man moving with responses to those freezing universe.

Doesn't the frequency and the wavelength of the light determine the speed? Am I missing something stupid?

Why are you using deltaT = 10m instead of 10min at 4:23? It evokes a unit of distance instead of time. Very informative video by the way.

Special relativity is always surprising & deep thinking always open new ideas & kind of think for eg measuring speed of light from our perspective we see the light moving from place to other (passing adistance in certain time )... But for the perspective of light itself the light is not moving because the length of the distance between the two places is contracted up to zero & consequently the time taken is also zero... (in reality it's zero because during the speed of light the time is frozen & the clock is not running)..... Also not only the distance between the two points the light will pass were contracted to zero BUT THE WHOLE UNIVERSE IS CONTRACTED TO SIZE ZERO FOR THE PERSPECTIVE OF THE LIGHT (of course moving with C speed)

One condition requires in the MMX to validate a null state is that light speed is isotopic and only isotopic. This supersedes a principle we call - time dilation. Otherwise, if we choose to maintain both are valid, we have a bi-standard in our believes to defend with. How can we fall for the stories of a man only do thought experiments indoor through his entire life. I’m old, but if you are still young don’t follow his foot steps.

I believe the issue extends beyond solely the inability to measure the one-way speed of light. The fundamental issue lies in the fact that the one-way speed of any object is unmeasurable, as all speeds are contingent on the value of the one-way speed of light.

Why not do the experiment in short distances so that the time dilation is insignificant.

I saw this video and Blow my mind , very interesting

But sir, as you've shown, in the one way speed of light with slow transport sync differens very little with the two way speed of light. Whether by the math in @8:39, this difference is proportional to distance. If anisotropy was real, wouldn't this difference have been a good experimental way to detect that? After all, light speed can't differ when we're trying to do slow speed vs light pulse syncronization.

the fact that the one way speed of light hasn't been measured might be an uncontroversial fact, but it's not very well known.

Alain Aspect, the Nobel price of 2022 has the tool to generate an instantaneous transmission of the information with quantum entanglement pairs. Is that tool could be utilized in an experiment setup to mesure C in one direction?

Yea the point that i never taught about is the direction EVERY DIRECTION

Thanks man, great video! 🎉

Is there a way of knowing the isotropy of the speed of light without measuring a one way distance? You only have to compare two speeds and see if they are the same not really know what their values are like in michelson moreley.

It is one frame of reference that is same for everyone: CMB

First postulate: Laws of physics are the same in every INERTIAL frame of reference. Accelerated frames have different laws of motion depending on acceleration.

We can measure one way speed of ligth: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-EtsXgODHMWk.html

Wait a minute. What if you made the light reflect on its return back so it takes many trips?

Your math is wrong. it's (1-1/γ)* S/v for how much time you lose at a speed (rather than how much time the universe gains at your speed relative to you, which you're really only interested in the clock in the moving frame, not the universe's clock)... 1/γ is sqrt( c^2-v^2 ) / c. a slow moving clock over the same distance does lose less time. You calculated it yourself that over 600lightseconds and at 0.000033c(10km/s in lightseconds/second) the clock would only lose a few ms (it's actually 9.9ms). This is much less than the 600 seconds that would be lost going the speed of light) (or 160 seconds at half the speed of light)... BUT - the speed of the solar system through the universe is 370km/s or 0.00123c(according to the red shift of the CMBR); and you would have to wait until a specific time that mars and earth are in a line towards Virgo... otherwise most other direction aren't going to have as much shift. So- the mars clock is say 9ms delayed... the one way it would take light 600+73.8ms or -73.8ms worst case to get here... I don't see the issue. 0.000033c is 1/37 the speed overall, so if it happened to be going inline with Virgo to start the difference to the 9.9ms difference wouldn't be that much. Second your anisotropic factor isn't right either 1) you didn't show what the compliment of k would be... 2) it would be a factor added to or subtracted from V like sqrt(c^2 - (v+/-k)^2)/c (which in the solar system's case is k=0.00123c (best/worst case). which over 600seconds is +/- 0.738 seconds; which makes the 9ms is an insignificant error. (I did forget to contract the length.... 1/γ * S/V * (1-1/γ) = S/γV *( 1- 1/γ) = S/γV - S/γ^2 V = (γS -S)/ γ^2 V -or S/γV - S/γ^2V ; (personal comment 1/γ is so much more useful than γ ... but whatever) The additional difference from length contraction changes the distance only a tiny bit anyway... changing only decimals at 10^-12 seconds); And no - not everyone can claim to be in a stationary frame. Consider 8 rockets passing the earth at the same time, that at that moment do have synchronized clocks, each travelling 0.1c more then the prior. Compute the relative time contraction for rocket 1 to 2 and for 7 to 8. They are all the same 0.1c apart, so they should all experience the same time dilation compared to the one before it... and yet at sqrt( c^2-0.7^2) - sqrt( c^2-0.8^2) is much larger than sqrt( c^2-0.1^2) - sqrt( c^2-0.2^2) (0.994 - 0.979 = 0.015) vs ( 0.714-0.600 = 0.114) . so I don't know the specifics of these experiments that have attempted to measure a difference in speed by the relative speed of the receiver you mentioned at the end... but I'd expect since they are moving significantly slower than 0.00123c - that any small change is imperceivable. (Oh you said transmitter - no light doesn't inherit inertia that way - it would have to be a moving receiver relative to the emitter; and then the distance it's moving would have to be significant. Interferometer experiments also need to factor in Light Aberration; and even with a constant 1 way speed of light one would expect a null result. The last several videos on my channel are about this 1-way constant speed of light in a stationary medium of space (which moves only because of gravity really - as in LIGO detector). Links in descriptions go to docs on github and the demos.... The laws of physics would be the same - but it would mean that a force applied in the direction of motion vs opposite the direction of motion will impart a different velocity... this actually means that there is sort of a friction of space - that a force backwards slows down a fast moving object much more than a force forwards would accelerate it; but we can't go fast enough to make a significant change ... the parker space probe is only half of our speed through the universe at 159km/sec (vs 370km/sec)... and the force difference at 0.001c would be in the order of pico-newtons(maybe fempto - I didn't keep those calculations)... and if measured on a torsion balance would be accelerating masses in opposing directions and end up canceling it out... so the most precise measuring method can't be used... but even then - only if applied in a very specific direction.

This just seems like a no brainer. Like 1+1=2. But you can write a hundred pages proving the obvious. Why would there be any reason for it to be slower in one direction? Sounds kind of silly.

After viewing the dialect videos, the simultaneity, true lenght and true time to me, aren't concepts that we can observe in any "real" frame of reference, not a single one. Thus I have a huge surprise when you say dialect wants to choose a master frame to attain his purposes. From what I understood, the true length and true time and thus the simultaneity, can only be thought, be mentally calculated on paper but they can't even be directly seen. The same way that on the 3D space on earth no one can see true distances or true length, everyone has his point of view and the only thing in common that they all have is that they are all wrong, you can't chose any frame and say this is the "good" frame, because all of them are wrong in some way or another. This might be my biased interpretation of dialect since my education is on geometry, not on physics. I'm looking forward about what he says next.

Expertly analysed. Very well done. And thank you for mentioning Dialect's reference frame "choice" for the one way speed of light. @0:36 The reason why physicists consider this theory to be correct is because experiments of time dilation directly correspond to two, one way speeds equalling 3×10⁸m/s. The very fact it's impossible to measure the one way speed of light is further proof that Einstein’s block universe description of time and space is correct.

One Planck length per Planck second. Always. But gravity is the mayor of the density of the metric.

Can anyone answer this question? What if the one-way speed of light were vastly vastly different in opposite directions. Say it was 1 meter per second in one direction and 600,000,000 m/s in the other. Would it be in any way possible to detect that big of a discrepancy and if so why would it not be possible to detect a much smaller discrepancy?

move both the clocks in opposite directions at the same speed for the same amount of time

Relativity: "There is no aether." Quantum Field: "Am I a joke to you?"

What if you synchronize the clocks midway, and make them travel the same distance with same speed in opposite directions, do the pulse measurement then bring them back midway to compare results. Would this work?

Here is why I see value in Dialect's interpretation, though I can't speak for him. (And while I think his videos are a little overly-dramatic, he doesn't claim he's presenting anything new, at least not so far, just shining a light on existing Dynamical Relativity theories that aren't well known). Basically, special relativity asks me to accept some things about how time and space that make no logical sense at all to me. The speed of light being the same in all reference frames and not varying based on velocity is one, the relativity of simultaneity is another, and of course there is length contraction and time dilation. IAnd when you ask a physicist why any of these things are, they just say something like, "well, that's how the universe works." There isn't a deeper understanding, besides maybe a hand-wavey idea that minkowsky geometry is physically real--which still doesn't really answer anything for me. I just can't make a mental model for any of this in my head. And I have tried SO hard. Even the weirdness of quantum mechanics allows me to make mental models (however strange--or wrong--they may be). But special relativity just seems, physically, like nonsense. Nonsense with *incredibly* accurate predictions, but nonsense nonetheless. Now, obviously, the universe isn't obliged to make sense to me. Maybe it really is nonsense to any kind of human logic, which is what I had accepted for a long time. But if there is an alternate interpretation of special relativity, one that retains all of the math and all of the precise predictions, but that makes intuitive sense to me, that doesn't feel like nonsense, that I can actually *understand* (vs just memorize, as is the case with traditional special relativity) then HECK YEAH I am taking that option. It doesn't matter if it's right or wrong so long as it makes the right predictions, what matters is that it a) helps me make mental models that give me much more accurate intuitions about how relativity works, and b) just makes me feel a lot better about the world I live in. It makes science feel weird, and not fake and made up. (No, I don't think special relativity is fake and made up, but since it has always felt like nonsense, I've never been able to shake an irrational feeling that it's all fake--which, again, isn't the universe's problem, but an alternative interpretation makes *me* feel so much better). Dynamical relativity does this by restoring things that match our intuitions: absolute motion, absolute simultenaity, time that doesn't depend on observer/how fast you're going, a speed of light that obeys sensical physical laws (ie doesn't magically stay at the same speed relative to you no matter what), and an actual honest-to-god intuitive, sensical, easy-to-understand explanation for time dilation and length contraction (he hasn't gotten to length contraction yet, but I've looked into some other dynamical relativity resources to see the length contraction explanation). To me, that is an absolute revelation. It kind of seems to me like in the science world, it's seen as uncool or taboo to be uncomfortable with the weirdness of special relativity and to want the world to make logical, intuitive sense. But I'm not an actual physicist, and I am over the moon with finally having an explanation for the weirdness of special relativity that makes sense to me, and that I can wrap my head around. It's important to add: Even if dynamical relativity is right, everything you say at the end of your video here is true: anyone can claim to be in a rest frame, and no one else can prove them wrong. Because everything we are made of matter governed by the speed of light, everything we do and everything we measure will always look like Minkowski spacetime. Special relativity in Einstein's formulation is still incredibly useful and by far the best mathematical formulation for understanding space and time as we measure and experience them. In this interpretation, length contraction and time dilation *are* real for us since we are made of particles governed by the speed of light, and that is why we have to use special relativity, not newtonian physics, to get the most accurate measurements. Anyway, just my personal thoughts on the matter!

I've been following this series of Dialect for a while, and whether or not this k-factor does mean something or not is not the most interesting part. The most interesting part of his videos is how he talks about how Einstein struggled to reconciliate the fact that all motion is relative apart from acceleration, and that in the end Einstein was closer to accepting that there must be an ether. He brings the receipts, i.e. manuscripts of Einstein's to demonstrate that this was indeed what Einstein thought. However, I'm neither a physicist nor a historian, so I cannot say if he's misrepresenting Einstein's arguments nor if what modern physicists think about absolute acceleration and it's place in relativity.

Here's something about relativity to think about. Supposedly, if you were moving at a velocity close to light speed you would perceive everything outside of your frame as being contracted in your direction of motion. Some people will try to use that idea to explain muons reaching earth before they decay, suggesting that in the muon's frame the atmosphere would be contracted to about 1/10th its normal depth as perceived from the earth frame. Well, everything outside the moving frame being contracted is the same as the moving frame being lengthened, logically. Would a muon being 10x its stationary length make a noticeable difference in how long it took to go through the atmosphere? Obviously not, it's length would still be minuscule. That's the flaw right there, you can't say that one frame contracts without acknowledging that it would be equally valid to say that the other frame lengthens or, to be even more logical, to look at as one frame contracting and the other lengthening by the same percentage. Of course, the real explanation for muons getting through the atmosphere before decaying can be found in the Encyclopedia Britannica. Go search their site for the topic of muons and see if relativity is mentioned anywhere in the page.

I suppose you could measure the one way speed of light at the photon sphere of a black hole

Why do people always use hypothetical experiments that never happened, that all preemptively assume time dilation to say a fixed speed of light must exist. Tell the real repeatable experment that actually happened to prove any of your claims. Not this well if we pretend we did this experiment it would have to follow these rules because said so.

I don't understand. If something is one light year to the left and another is one light year to the left, then they are both one light year from me. Does talking about any other distance measurement even make sense?

Is there an ether… it would be fine for QM… but QFT ?

Hello, just wanted to write out a few things that come to mind when watching these videos and reading their comment sections. I think im pretty safe in assuming that most people watching these youtube physics channels have a great interest in the subject, would consider themselves quite intelligent in their respective fields, but dont necessarily have the mathmatical ability or physical expertise to be solving or even recognizing the holes in modern physics. If we did we wouldn't be frequenting physics channels unless we were looking for lecture ideas. That doesn't make our opinions or efforts in learning the material lesser per se. But it does mean on average we might place more faith in the compacted, simplified youtube versions of physics explanations by our favorite presenters without the context and scrutiny that might be needed to have a full perspective of the topics being discussed. We have to place faith that what were being given on youtube is correct and if there is a deviation from the nuanced interpretation, whether by intent or accident, we dont necessarily have the tools to recognize it. The point of Dialect seems to be to highlight this. They are putting up fairly bold claims and some relatively harsh criticsm for this small slice of the internet. I don't personally agree with every method they've taken but I do agree with the goal: inject scrutiny in this community and allow for mindsets that are less closed off to new interpretations - as should always be the goal in science no matter how absolute the current interpretation appears to be. Whether they've been too inflammatory in this pursuit can certainly be up for debate but lets not forget that they have a long term goal with their video series and they are very notably not done. Debating it now may in retrospect be pointless once we have a full persepctive on their finished content. Either way the deed has been done now and it is up to us the community to determine whether good or bad will come from it. Dialect will play the antagonist for many and the physics channels will hopefully respond with great videos like this and provide greater nuance to the difficult subject matter being discussed. We will all learn more and appreciate more of the intelligent discourse surrounding these topics. And we will hopefully have clarification on misconceptions to this material that we didnt even know we had. Be patient, and maybe even more so be kind. Were going to see a lot of belief speaking before fact in the coming days and how we handle it will determine a lot more about us as science appreciators than the soapbox comment section scientists that say they knew better the whole time. Dialects' shakeup could very well lead to a lot of bad science but even if it is it'll become good science if we harness the opportunity for learning and growth.

Why not move two synchronized clocks from a starting point in opposite directions with the same speed? After some proper time T‘ they stop at the same distance away from the starting point. Voila: you know the distance and you have two synchronized clocks.

L'Hopital was a French mathematician. His name is pronounced loh-pee-TAHL not L-Hospital. Bad mistake.

But aren't we trying to prove time dilation? If we don't know that time dilation occurs until we have proven the theory of relativity but we are already supposing that if we move the clock then there will be time dilation. Isn't this circular?

The speed of light is not fundamental. If one measures the magnetic permeability and the electric permeability of free space in a lab, It is simple to calculate the light speed. There is no directional dependence on these two fundamental physics constants.