How Variable Speed of Light Explains Gravity

[@howardlandman6121]

Einstein wasn't the only one considering VSL. For example, Ishiwara wrote in 1912 that "if the speed of light varies in space and in time, then these variations lead to the appearance precisely there of a gravitational field." [Ishiwara, J., Zür Theorie der Gravitation, Phys. Zeitschrift 15, 1189-1193 (1912), translated by Barbour in Vizgin, Unified Field Theories in the First Third of the 20th Century, Birkhäuser Verlag, Switzerland (1994)]

[@GreylanderTV]

Hi, I have not watched all your videos yet, but variable speed of light is something I have often pondered. Something that seemed pretty obvious to me early on in studying GR, but in part due to a hint given by one of my professors, is that you can reformulate general relativity in terms of a variable speed of light which depends on both space and direction. In essence you exchange the metric tensor, g, with an inverse "speed of light" tensor C given by g = c/C (treat /C as tensor inverse, with c just a scalar constant). Furthermore, we restrict ourselves to coordinate systems in which the metric does not mix space and time. This is always possible because there are 4 degrees of freedom in choice of coordinate system, meaning the metric tensor only has six physically meaningful degrees of freedom. The spatial components of g and C each form a 3 tensor, g3 and C3 respectively. These are the physically meaningful fields for GR. Note that we can interpret g3 as a tensor generalization of "index of refraction": C3=c/g3. You get the speed on light in a particular direction from C3*dx, where dx is a spatial vector. We can rewrite any physical equation in terms of C rather than g. And all experimental predictions of physics remain unchanged. We are simply re-writing and re-interpreting the equations. Et voila! Variable speed of light. Nothing forces us to accept the geometric interpretation. Or we could even allow that g3 and C3 could depend on both "geometric" and "index of refraction" components. Either way the physics does not change. It might be argued that this formulation is less elegant, but I think it dispenses with unnecessary assumptions. It also avoids a great deal of misleading physical intuition that results from playing around with coordinate systems that mix space and time coordinates, something which is physically meaningless. Thoughts?

[@wendlt]

I don't really follow your tensor math, but the premise seems to be that the equation g=c/C underlies your math. This can be rewritten as c/g=C. So is C just a new constant that relates g and c? Seems like a scalar to me but I'm sure you've got a more complex math structure in mind for C. How do you get a tensor by dividing two scalars? Doesn't at least one have to also be a tensor? On looking up tensor in wikipedia a tensor seems to be an array or matrix of values with a transformational law of how to manipulate these values. Does your tensor C represent a geometrical structure which shows how photons move in gravitational fields? I need a more layman's explanation of your ideas which seem very plausible but not exactly clear to one at my level.

[@GreylanderTV]

@@wendlt My g is the "metric tensor" of general relativity, not g the "gravitational constant". A tensor is (somewhat over simplified) a matrix -- one that potentially has a different value at every point in your coordinate space (i.e. "space" (3d) or "space-time" (4d)). The metric tensor, g, can be used specifically to calculate the _invariant interval_ between two events(two points in space-time) -- the _proper distance_ or _proper time_ between two points in your coordinate system. A coordinate system is physically meaningless unless/until you also have a defined metric tensor, g. In other words you need the "metric" (or "measure") in order to relate your coordinate system to physical things you can actually _measure_ . My new thing, C, is also a tensor. "/C" is just the invers of that matrix or tensor, so could also be written as "* C^-1" (times C to the -1 power). So g = c * C^-1 or C = c * g^-1. Basically my whole thing here is swapping the variability of time & distance (which can only be understood relative to a constant speed of light anyway) and makes time & distance fixed as the normal "flat" space we can understand intuitively, and making a "speed of light tensor" that is variable in our boring flat space and time. Where in "classical general relativity" you would calculate intervals using metric tensor g, in my formulation, you would calculate variable speed of light using tensor C. Note that the _physics_ does not change at all. The same experiments would measure the same results. I am quite certain that Einstein was well aware of this interpretation of general relativity, even spoke about it***, but likely preferred the constant c and "geometric interpretation" as he saw it as more "elegant" to note that coordinate in and of themselves are meaningless, which is why he would say that "time" (the time coordinate) and "space" (the 3 space coordinates) are "the same thing"... because they are. They are just arbitrary was of organizing and labelling points in space time. Unfortunately many people (including phsysicists) tend to believe then that "time"(the sequencing of causality) and "space"(causal disconnection) are the same thing, or at least physicists sometimes forget this distinction when explaining things, because mixing up time and space coordinates and showing students or laymen a spacetime diagram where time(causal sequence) goes "sideways" has a great "ooh and ahh" factor (e.g. Scharzchild solution with sideways light cones inside the black hole). Can't track down the quote, but Einstein once said (paraphrasing) that the "geometric interpretation" is unnecessary and the metric tensor is, ultimately, just another field (like the electromagnetic field, etc). Which is an important point that underlies everything I am saying here.

[@koenraad4618]

I assume C is a scalar function, not a tensor function, of space and time coordinates.

[@mathoph26]

Seriously this seems amazing, really like it, do you have the name of the paper? I think it is amazing because I practice only applied physics (this is called engineering ^^), so not GR, QED and shit. During my phd I used to work on magnetic nanoparticles, which have a dielectric optical tensor (because of the magnetic moment) with non diagonnal element leading to Kerr effect, which is equivalent to consider an inverse speed of light^2 tensor inside this particle (the speed is modified by the way). And that remark on the tensorial form of the speed of light + the Dicke formula to take into account gravitationnal field, without involving the so abstract 4D space (which we NEVER use in practical physics), seems really attractive for me !

[@GreylanderTV]

@@mathoph26 Yeah, the analogy to tensor & variable index of refraction in a medium is strong. On thing about c in a medium: the speed of causality(what c really means in today's physics) in a medium remains c even as the effective speed of propagation of electromagnetic waves becomes c/n (or c/N if index of refraction is a tensor). The leading edge of an electromagnetic wave will still propagate at vacuum c, but is exponentially dampened to insignificance. I think courses & textbooks on general relativity could well do with more emphasis on orthotemporal coordinate systems that look as 'normal' as possible, instead of gawking at "time going sideways" inside the black hole in the Schwarzschild coordinates, which is completely meaningless.

[@SuperMagnetizer]

It seems plain to me that just as light is refracted when entering glass or water, so is it also refracted when entering stronger fields of gravity, and for the same reason. The speed of light is reduced in both cases, which has nothing to do with curved spacetime.

[@gamerfortynine]

It doesnt reduce. Its redirected to a path of least resistance, as if it has sentience. Thats why quantum effects drive scientists insane.

[@frun]

GR is a pretty accurate approximation though.

[@ian_b]

Why? What is a field of gravity?

[@frun]

@@ian_b Flow of heat. Find out what Ricci flow is - kzbin.info/www/bejne/nqiydKR3br2qbKM

[@outisnemo8443]

@@frun: Yeah, definitely, bro. Until, you know, it's not, and they have to invent dark matter to explain away why it doesn't work.

[@nealesmith1873]

I've been interested in this for at least 30 years but never saw it discussed before. Very interesting!

[@RFQuantumLab]

Dear Alexander, Around 1911 Einstein proposed to incorporate gravitation into a modified version of special relativity by allowing the speed of light to vary as a scalar from place to place in Euclidean space as a function of the gravitational potential. This "scalar c field" is remarkably similar to a simple refractive medium, in which the speed of light varies as a function of the density. Fermat's principle of least time can then be applied to define the paths of light rays as geodesics in the spacetime manifold. Specifically, Einstein wrote in 1911 that the speed of light at a place with the gravitational potential Δφ would be c'=c0(1+Δφ/c^2), where c0 is the nominal speed of light in the absence of gravity. In geometrical units we define c0 = 1, so Einstein's 1911 formula can be written simply as c' = 1+Δφ. However, this formula for the speed of light - indeed, this whole approach to gravity - turned out to be incorrect. In the general theory of relativity, completed in 1915, the speed of light in a gravitational field cannot generally be represented by a simple scalar field of c values in Euclidean space, due to the intrinsic curvature of spacetime. In terms of some quite natural coordinate systems, the speed of light varies not only from place to place, but also in different directions at any given place (even though the speed of light always has the invariant value c in terms of local free-falling inertial coordinates, consistent with the equivalence principle). For example, near a spherically symmetrical and non-rotating mass, we can define stationary coordinates in which the speed of light is isotropic, but in these coordinates the circumference of a circular orbit of radius r is not equal to 2πr. On the other hand, we can define stationary coordinates in which a circular orbit of radius r does equal 2πr, but in terms of these coordinates the circumferential speed of light differs from the radial speed. The former is given by the same formula as in Einstein’s 1911 paper, but the latter differs from the 1911 formula by a factor of 2 on the “potential” term: c'=c0(1+2Δφ/c^2) or again, c'= 1+2Δφ (In geometrical units).. To explain this in detail, we must first consider how the Schwarzschild metric is derived from the field equations of general relativity. To deduce the implications of the field equations for observable phenomena Einstein originally made use of approximate methods, since no exact solutions were known. These approximate methods were adequate to demonstrate that the field equations lead in the first approximation to Newton's laws, and in the second approximation to a natural explanation for the anomalous precession of Mercury. However, these results can now be directly computed from the exact solution for a spherically symmetric field, found by Karl Schwarzschild in 1916. As Schwarzschild wrote, it's always pleasant to find exact solutions, and the simple spherically symmetrical line element "let's Mr. Einstein's result shine with increased clarity". Thank you,

[@TheMachian]

Hello, thanks for taking the time to write this comment. This is not unknown to me. His initial approach suffered from neglecting wavelenghts. However, the VSL concepts remains viable. All the details are in my book "Einstein's Lost Key". Feel free to contact me (Channel Info) for a pdf.

[@garrythorp8770]

Replacing distance with time at c gives a (newG/massp) about equal to (upqk/totalqk) in p.

[@jimmyzhao2673]

Someone should write a formal paper on this theory and win a *Nobel Prize*

[@pacotaco1246]

They'd have to find evidence of this theory before winning such a prize

[@m.j.r.technologyreveiws1075]

Nice! A mathematical explanation of my perceived thoughts on the matter. Our perception from within our earths and solar systems and galaxies gravitational field is that everything we see farther and farther outside our gravity well is more and more redshifted. Meaning it only looks to us like it’s accelerating away.

[@ZahraLowzley]

What is the difference between a house and a home? If you can perceive this, and willing to think , with your actual thoughts, not the narrative , you get it, everything

[@VirtuelleWeltenMitKhan]

I wonder how big and how old the universe is when it just looks like accelerating away. Is dark energy still needed? Does it fit the "corrected" observation?

[@GamesBond.007]

Afaik the only known cause for light refraction is related to a change in the propagating medium. So in space I think it refracts mostly because of the medium made of plasma gas which surounds the sun, and the galaxies. As soon as it leaves that medium and enters another medium free of plasma it will change its speed and refract. Galactic redshift could also be caused by charged plasma gas (but not only by it), as apparently there is a phenomenon called `plasma redshift`. Light waves loose energy when traveling through charged plasma because it collides with electrons and there is an energy transfer. Since E=hf, a drop in energy is equivalent to a drop in frequency, which causes a redshift effect.

[@hugo-garcia]

Speed of light is not about light is the speed of causality and spee of information. Are you saying information and causality can chance its speed ?

[@axle.student]

Yes, this is already shown as true in different densities of the mediums a photon travels through :)

[@jeromemalenfant6622]

I don't understand how a variable speed of light theory explains the gravitaitonal red shift if only the wavelength but not the frequency of light changes when the light slows down near a massive object. As an analogy, light slows down in water comparted to air, but if you're standing at the bottom of a pool the light coming down to you from a source above the pool does not appear redder. That's because our eyes respond to the frequency of the light, not the wavelength, and the frequency of the light doesn't change as it goes from air to water. Also, I thought that Einstein's first attempt at a theory of gravity, namely a 'variable-speed-of-light' theory, gave the wrong answer for the deflection of light by the Sun; i.e. the same value as Newton's theory, but half of what Einstein's later, complete theory of general relativity predicted. And does a VSL theory explain frame dragging due to a rotating massive object, an effect predicted by GR and confirmed by the Gravity Probe B mission?

[@paul_gradenwitz]

Very interesting consideration. Variable speed of light is what we experience in the increased travel time of light that grazes heavy masses as is tested with the Shapiro delay. But since we have with a variable propagation delay that the speed is different for different directions we have to describe that propagation speed as a tensor. I would love to discuss more about that.

[@atheistaetherist2747]

The SOL does not depend on direction. It is the same in all directions, relative to the aether. But, the aetherwind has a direction (500 km/s south to north throo Earth, about 20 deg off axis, RA 4:30).

[@nickallbritton3796]

@@atheistaetherist2747 what ether? You don't think there's a luminous ether do you?

[@nickallbritton3796]

@@atheistaetherist2747 ?? Are you talking about Demjanov rearrangement because that's chemistry. If you want someone to follow you you need more than 2 words. But anyway the luminous ether doesn't exist unless you can explain over a century of null results in Michelson-Morley repeat experiments.....

[@drbuckley1]

@@atheistaetherist2747 If you replace "aether" with "observer" I might agree with you. Everybody's "proper time" passes at the speed of light; it's our observation of clocks traveling in different directions and relative acceleration that seems "wrong."

[@atheistaetherist2747]

@@drbuckley1 Clocks & processes are affected by length contraction & by the speed of the aetherwind & by the nearness of mass & by the speed of em radiation. Our perception of time (ie our perception of ticking) likewise. Proper time or absolute time is the time measured in the absolute frame, ie where the aetherwind is zero km/s. In other frames measurements of ticking will be or can be different, we have a relativity, but not the silly Einsteinian Special Relativity.

[@Chr15T]

Einstein's general relativity correctly predicted gravitational waves which have since been proven to exist (indirectly, then directly). Gravitational waves cannot be explained simply by a variable speed of light. Obviously, black holes also cannot be explained by VSL since if just the speed of light is varying, the light path will always be reversible. And in recent times, we have made a picture of a black hole. So VSL is at best an approximation to GR for slowly changing and weak gravitational fields.

[@bessokeks4006]

"And in recent times, we have made a picture of a black hole." Yes, and astronomers never have lied

[@Chr15T]

@@bessokeks4006 We also have fantastic indirect and direct proof of the existence of gravitational waves. VSL may be a nice approximation for gravity but -sorry- fails for strong fields where Einstein's GR yields correct predictions. Best by test.

[@_.LZ._]

@@bessokeks4006 average conspiracy theorist

[@bessokeks4006]

@@_.LZ._ Yeah, ans you are the source of truth...

[@_.LZ._]

@@bessokeks4006 Not me, science

[@reframer8250]

Great video! Looking forward to see the next one :)

[@TheMachian]

More to come!

[@Naomi_Boyd]

This is a very complicated video for such a simple concept. There are really only 2 propositions that need to be considered. 1. Light always travels at a constant velocity in a vacuum. 2. Light always measures as having the same velocity in a vacuum regardless of the reference frame of the observer. If gravity dilates time, these propositions are mutually exclusive. They can not both be true.

[@TheMachian]

VSL goes beyond the SR axioms you quote, yes. Give me a simpler version of GR with tensors.

[@florisv559]

Are you in a vacuum when you are near a powerful source of gravity? A vacuum implies absence of matter, right?

[@Naomi_Boyd]

@@TheMachian Help me with the Wheels Down Problem, and I give you what you want.

[@Naomi_Boyd]

@@florisv559 Irrelevant! Whether you think of gravity as the bending of space or the flight of a magical particle which imparts kinetic motion in the opposite direction of its motion, the point is that gravitational fields must reduce the speed of light.

[@JoseSilveira-newhandleforYT]

Thanks Dr. Unzicker!

[@hjs9td]

This dovetails nicely with Rupert Sheldrake's idea that constants we expect in the Universe are not constant.

[@supercobra1746]

Hi! I'm working on a theory and my formulas could be interpreted as yours. I'm talking about sum of m over r. m comes from the quantity of "units of matter" in radius r. Basically, it's volume over radius in the scale of light and that's how you get c squared.

[@discoveringthegardenofeden7882]

Sir, I have a question: From minute 17 onwards it sounds contradictory. Slides seem to indicate that light falling into gravity well increases in speed WHILE on other slides it lowers in speed. Hence, for clarity: For an observer on the surface of the planet: What happens when propagating light from afar falls into our gravity well? How, in that case, does the frequency change? How, in that case, does the wavelength change? In the gravity well if c= times lambda times f, where wavelength now has an increased value (longer) and frequency stays the same, has the light speed effectively increased due to the falling into the gravity well?

[@frun]

Both frequency and wavelength decrease as does the speed.

[@dexter8705]

I would have said increased speed, but the frequency doesn't change much because gravity stretch's the wavelength while simultaneously increasing its speed... Gravity what can I say. It's the same reason the pound rebka experiment was a bust.

[@BlueGiant69202]

The paradox for me is how to reconcile VSL with Maxwell's constant speed of light in a vacuum being the square root of the inverse of the product of two constants (magnetic permeability and electrical permittivity). How does VSL scale down to gamma radiation passing very close to an atom of cesium? Does VSL say anything about optical cloaking with metamaterials?

[@paaao]

You sir, seriously need to investigate Ken Wheeler's theory of magnetism. Put your current beliefs aside, assume what he's saying is true, and begin questioning what "science" currently proposes. It's not extreme. There is a space-time, and there is an anti-space-time. The two are one.

[@McDaniel77]

@@paaao Mathematical concepts like Space, Time, Spacetime, BHs, DE, DM etc. are not real, it's fiction, but it's not science fiction, because religious beliefs, evidence free claims, no physical backgraound at all, makes these assumptions irrational BS. The speed of light is changing in matter due to refraction and maybe other interactions happening. In vaccum it's 1 c, in water it's 0.75 c, in daimond it's 0.4 c.

[@Bobbel888]

That question was my initial entry to `variable speed of light`: What would be permeability and permittivity of the vacuum?

[@marcmillis3867]

@@Bobbel888 magnetic conductivity + dielectric conductivity of the aether ( the "energy carrier". Wave theory in the aether. A gaz at 689 billion atmosphere moving at pi/2 * C Aeolotropic zero volume élasticity collapsible. Acting as a rigid solid. 3 electrodynamic waves. 2 outward. 1 inward. You have 2 pressures perpendicular ( plan XY) to a tension Z (the line of force that " has the tendency to get shorter" (faraday).... Electrodynamic wave theory my friends. Superimposable mass free energy exists. Therefore space is a physical manifold. Einstein is a hoax

[@godsize9]

Over short distances could it be treated as a constant, over large distances as variable. Definitions of large and small required.

[@itzchi]

Great technical video. But you can please explain a little more in layman term why 2 bodies with mass attract each other? Also can VSL explain gravitational waves (if they exists)? 😀 Thanks in advance.

[@earthenscience]

Distinti believes that gravity is ether consumption.

[@pacoes1974]

1. Mass bends stuff including spacetime. 2. Stuff wants to go straight but mass bends the straight line making stuff go round in time and space. 3. Slow things fall toward other things based on their arch of trajectory along their straight line. 4. Mass slows spacetime the closer you are to the mass increasing the bending of the straight lines of objects in the field. 5. the reduction of wavelengths of energy hints at some kind of transfer of energy do to the interaction with this altered field of spacetime (I am assume frequency increases). 6. This hints at some form of resistance. Most likely the slowed spacetime. I kind of see it as a line of cars hitting a city or a town. They are moving along on the interstate with limited resistance and a constant speed. When cars hit the city or town and all its winding roads we get congestion. The larger the populations center the more congestion and the more traffic will slow with an affect on other cars further out from the center of the area. This slowing makes it take more time to get to your destination.

[@rodocar2736]

Pound Rebka experiment just demonstrates that time speed changes in different gravitational potencial levels

[@Drbob369]

No one else is even suggesting anything else but how does the force of gravity come about apart from mathematics? Good work!

[@frun]

No. Gravity comes from a heat transfer.

[@Bit-while_going]

Gravity comes from the centrifugal force of particles flowing around some dense object. The object gets in the way and so the particles have to flow around and when they do their bonds get stretched. Since the effect is a vortex though, we just think of it as a vortex of curved space, but that's a purely mathematical mechanism.

[@Bobbel888]

4:35 finally: r_i seems to be some distance. 5:35 how is ∇c² defined? The true test of a gravity theory is dynamics of a galaxy, where existing theories needed to claim dark energy/matter.

[@eacasanovas]

Hi. There is something that strikes me about your analysis and that is that you don't seem to take into account gravitational time dilation. That is something that must be taken into account whenever we talk about light beams approaching massive bodies. Have you considered that? Thanks

[@GreylanderTV]

I haven't gone in depth on Unzicker's approach to answer for his equations, but I'd say in general if we allow for a variable speed of light, then we can understand that in a region where c is slow, all physical processes are slowed down, which means the passage of time as perceived by an observer (all internal mental and physical processes slowed down) will seem "slow" as compared to their observation of some distant region of space where c is faster. Keep in mind that while c was first conceived as "speed of light in a vacuum" it is actually a constant that governs every known equation of physics.

[@ernestschoenmakers8181]

@@GreylanderTV If light its phase velocity c enters glass or water then they say light slows down but it's the group velocity that's less than its phase velocity but energy must be conserved of the light otherwise how can light pick up speed again when it exits the medium?

[@GreylanderTV]

​@@ernestschoenmakers8181 The best way to understand how energy (an momentum) can be conserved as a wave slows down and speeds up is to start by imagining holding a long rope and shaking one end to make wave that travel down the length of the rope. This is a handy visualization, since you can literally give a rope a single jerk and watch the resulting ripple travel down the length of the rope. With me so far? OK. Now, instead of a norma rope imagine the rope gets gradually thicker along its length. The speed of waves traveling along a rope will depend on the tension and linear mass density. Where the rope gets thicker, the waves are slower. You could also make some parts of the rope wet to increase mass along that part of the rope, or the type of fiber used in the rope may change to something heavier or lighter. So what's going on here? If you snap your end of the rope and watch your ripple travel down this rope, you will see it slow down at the thicker/heaver areas of the rope and you will see it speed up again where the rope gets thinner. The kinetic energy of wave Mv^2. So (oversimplified, but it holds up) as the wave travels through heavier (denser) parts of the rope, M of the moving parts of the ropes is larger, so velocity must be lower. The wave slows down. As the wave reaches lighter(less dense) part of the rope it speeds up again, neither gaining nor losing energy. When we talk about speed of light being variable, it is analogous to saying space itself has properties analogous to the tension & density of the rope that can vary depending on location. When speed of light slows down in a medium like glass or water, the situation is a bit different. Technically the underlying speed of light, does not change. Instead, the apparent slowdown is due to the interaction of light with charged particles in the medium. But the energy is never lost -- it is always there in the combination of light (EM waves) and the jiggling of particles in the medium (mostly electrons).

[@djelalhassan7631]

I am warming up to the Variable Speed of Light explanatory power

[@philoso377]

The equation on page 11:44. Try a substitute c*c for 1/e0/u0. This is a door behind which we can get a deeper understand of g and this universe. Once we open this door it is easy to understand why I declare that g is derived from e0 and u0, and hence Aether. Aether was ruled out from our ignorance. It is not too late to reincarnate it.

[@alexandrekassiantchouk1632]

1) Does it solve Vera Rubin puzzle? 2) Does it debunk Big Bang? 3) If not, read Beyond Cutting Edge with Bob Lazar.

[@thomaskoscica7266]

Regarding Redshift: Presume the wavelength emitted from a particular level in hydrogen atom depends on atomic physics and not on propagation speed of light. By the VSL theory, a photon emitted in the early universe would find itself speeding up as the universe aged due to lowering of the universe's average mass density. If frequency is constant and unchanged for this photon during its existence, then the faster photon would be measured now (wavelength = v/f) as a longer wavelength, or red-shift. Continuing this argument: Because the average mass density of the universe is now lower, the VSL theory predicts that the speed of light now is faster than in the past. Presume again that the wavelength of a photon emitted now in a lab on Earth still depends on atomic physics, thus being the same wavelength as ancient times. Because the speed of light is now faster, the emission frequency we measure (f = v / wavelength), and use as reference, is higher than in the past. In other words, it is not that photons from the far away past have lowered in frequency, but that photons measured in the present for comparison have increased in frequency. Whether VSL theory proves useful or not, it is an interesting thought exercise.

[@TheMachian]

It takes a little time until you get acquainted with the variable scales. It is important to distinguish spatial and temporal variability. Check out the video about the Hubble redshift, there is an overview about the evolution of scales. The system is consistent however.

[@AndrewWutke]

How do you define speed of light. Is that the average round-trip speed? For instantaneous speed you need instantaneous clock synchronisation. The theoretical framework for this is the absolute reference frame and Tangherlini transformations In the absence of gravitation, the speed of light varies in inertial frames moving relatively to the absolute frame yet the round trip average speed of light is constant, and the same as in the absolute frame. You have the same time dilation and length contraction as in Special Relativity minus relative simultaneity paradoxes. If c is set to infinity then you have Galilean transformation. We have a starting point to generalise Newton Mechanics.

[@makeitreality457]

Good summary in the beginning. Variable speed of light (VSL) provides an alternative to viewing General Relativity (GR) spacetime as warped or skewed, in either or both space and time axes. This video demonstrates that formulas can be turned around to make light speed the variable quantity. But the interpretation robs Peter to pay Paul. Consider speed as distance over time. If the speed is variable, either or both space (distance) and time axes. The formulas are saying the same thing in different ways! (Which is exactly what to expect when solving for C). But where does this give us any new insight for harnessing or controlling gravity?

[@johanneshakansson7562]

Thank you for a good video! 16:15 makes me ask: Is light passing over a gravitational well deflected more if polarized vertical vs horizontal?

[@TheMachian]

A good question. I have to think about.

[@GreylanderTV]

@@TheMachian There are crystals which have different index of refraction depending on polarization. Would be interesting if something similar could happen if vacuum could have in essence a variable index of refraction which also depended on polarization.

[@howardlandman6121]

I don't think so. This would show up as deflected images being doubled or smeared in the radial direction, which we don't see.

[@dehilster]

I do not believe in the equivalence principle. The situations are not the same and to say so without a physical model for both light and gravity, it is simply still a thought experiment.

[@TheMachian]

Well, anyway light is deflected by masses...

[@ianp3112]

Belief has nothing to do with it sir! Why not learn the actual topic, explained very easily for the lay person! Check out David Butler on KZbin and his series how far away is it?(astronomy) and how small is it?(physics) Now that's real science that will help you make sense of the world better! Cheers 😽

[@vittoriobeghelli3561]

Great explanation! Thank you!!

[@dexter8705]

You got the video title wrong, it's meant to read how gravity affects the variable speed of light.

[@omvishwakarma3410]

Dr Unzicker I have a request to you please provide links to these papers it would real help people who will possibly do research on these things

[@zyxzevn]

Ron Hatch - Gravity in the light of GPS. 2013 - He also explains with different words, how the speed of light affected by gravity. And that we can see this in the GPS. kzbin.info/www/bejne/eXi9YnqLlK13rbs The main difference I remmeber is that the frequency of received light does not change during the trip, but the frequency is already different at the positions where they came from.

[@JesseKozlowski]

RIP Ron Hatch. I cherished our email correspondence over the years.

[@fabienpaillusson7390]

Very interesting. I may be missing something but I don't understand the distinction made between cases where the frequency remains and cases where it doesn't. Any chance you could clarify? Thank you.

[@TheMachian]

In classical optics, f has to stay the same. There are just gradients of c , but no temporal change. In a universe with changing c instead, the change is equally distributed to f and lambda - that holds for atoms. Not to forget the 3rd case when you consider propagating light in a homohgeneous universe with no spatial gradients of c - then lambda is preserved.

[@vicenterivera188]

Is it possible to perform experiments in order to tell this theory from GR? Does it yield different predictions ?

[@TheMachian]

More will follow. In first place VSL has some explanatory power conventional GR lacks.

[@GreylanderTV]

I'm reaching 12:00 and you note something like an equivalence between "curved space and constant c" and "flat space with variable c". I don't think this is possible unless you generalize c to a tensor C and allow a variable tensor C. Otherwise to get the same physical predictions you still need a metric g, and may at least have a curved space (no need to mix in time). See my longer comment. This is getting very close to my own ideas, and I'm wondering if, as I finish the video, you will be stating something equivalent to my longer comment. [edit: reaching the end, I guess you do not consider the idea of generalizing c to a tensor C. I think it solve all problems with "variable speed of light", and it results in a 1-for-1 equivalence with the standard formulation of GR]

[@kafalonitis]

I find this theory most interesting, but I need to think about it in more detail and properly understand it. Is the Equivalence Principle not needed? I have come to this conclusion but from an entirely different approach as can be found in the "Novel quantitative push gravity/electricity theory poised for verification". I think it is pertinent to explore various alternatives in order to decipher the enigma of gravity. I am wondering if there is some connection between these two theories. All avenues should be considered and explored as there are no sacred tenets to go unchallenged under the prevailing circumstances.

[@lasa18]

Wouldn’t the age of the universe need to be recalculated if the speed of light was varying? I’m kind of intrigued to know what VSL says.

[@TheMachian]

Yes, you can find this in my book, but the order of magnitude is the same.

[@pinchopaxtonsgreatestminds9591]

The misunderstanding of gravity comes from the Cavendish experiment which does not show mass attracted to mass, it shows ab object moving towards another object, and that's all it shows. you can't see the mass, because mass is resistance to movement, and we weigh stuff. You weigh a sponge, and you weigh a smaller sponge, and you are weighing mass, and you put the big sponge in some water by the small sponge, and water floods into the big sponge, and moves the small sponge towards it.. you have a correlation that the big mass moved the smaller mass towards it.. but it wasn't the mass that moved the smaller sponge, it was the holes in the mass. There is a relationship to mass, and holes in mass, and you can make it a 100% relationship by having the centre of a particle as a hole in space. Now the mass is the weight which is the spin inside the hole, and mass moves towards holes in mass, and gravity spins in the hole. The spin is resistance to movement, because when something is spinning it is not going anywhere apart from the local hole, and the holes are what gravity moves towards, not the spins. Therefore mass is not attracted to mass... and that's going to mess you up every time you use m1 m2. Then a black hole does not need any mass, it just needs to be a hole in space. Then you get new ideas about Dark Matter.

[@dabrowsa]

not a physicist, so this may be a stupid question: I thought that length contraction in a gravitational field was only in the direction of the gravitational force, but you seem to assume it is in all directions. Is that what you mean? Also, isn't GR itself a VSL theory? I.e., it implies light is slower in a gravitational field - no?

[@perlindholm4129]

Idea - If information for transformations of energy is dependent on speed of light. You have enough data for that transformation then Sure adapt speed of light so that that perticular energy can only be transformed to gravity and not something else //Per

[@Trizzer89]

There should be an experiment devised to test this variability

[@Mikey-mike]

Good one. I love this vid. Thanks for your work.

[@TheMachian]

Glad you enjoyed it!

[@petarswift5089]

M. Milankovitch also never accepted that the speed of light is constant. I don't know why

[@nulliusinverba4942]

I dont think light is bent by gravity because light speed is still c (special relativity). the fact there is redshifted by an observer is dependant of the relative flow of time under the same gravitational field, in other word time flow slower so the frequency is thus lower, hence stretching the λ (it's just because of the observer time flowing slower.). There is something wrong with this assumption that light is bent by gravity, light is not slowed down. I think Eddington jumped to conclusions, and so are many others about general relativity. But yes, we overlooked this idea..

[@lantonovbg]

c is constant but G is variable, depending on the local mass density

[@philoso377]

Everyone, except Mark and I, took g force as an intrinsic force originate from within all matter of the universe. In contrary, I see g force is an extrinsic force. Alternatively, it is an intrinsic force of vacuum possessed by this universe that also responsible for gyroscopic response. If you seek deeper understanding in gravity don’t look in microcosm inwards or particle physics but in macrocosm outwards into the vacuum which I call Aether.

[@Burevestnik9M730]

We need to think about space itself first and understand space. Does the space move? If it moves, what is it moving against?

[@johnlord8337]

Actually there is no such variable speed of light that explains gravity. The only concept is explaining symptoms of external objects with a gravitational object, and not talking about the actual gravitational object and its outward gravitational field. A large gravitational ojbect contains a (PE) gravitatonal source and its (KE) manifests outward as the gravitational force field (or warping of space-time fabrics). It is other particles as external entities that are nearby or flying by (neturons/neutrinos or photons/photinos) who have no interaction, continue to fly by and eventually escape, or are gravitationally captured. Boson hybrids with portions of electro-gravitics in them can also be affected across the space-time fabric, while a photon with a double EG structure, with a neutron-like neutral force field around it is partially affected, ... and the slower and less energy photinos are gravitationally captured and orbit. A gravitational object of sufficient energy and forces, warps the space-time fabric 360x360 around it, compacting the space-time fabrics into a spatial gravitational force sphere. This is all outward manifestations, and doesn't really tell you what is the actual source of the gravity, but that these are its energies, forces, and properties. One needs to find the actual and pure gravity source, then and only then can one consider making a (G) gravitational constant, which is only found within these EG objects, ... and has multiple gravitational fields across the actual space-time fabric, all of the bosons (except the ES-ES neutrino boson) and the photon/photino. Also leptons (EG electron/electrino and EG positron/positrino and their higher EG muon and EG tau particles would have their own gravitational value. So an entire cosmos, which only admits to 1-6 hydrogen atoms per square meter of space, and then not admit to free bosons, free leptons, and space-time quark fabrics, is sheer BS - and idiocy ... as space (and Dark Universe) holds unlimitted sub-quantum particulate matter, energies, and forces. There is no sheer gravitational constant unless you can get down to the actual graviton, measure it, and then make extrapolations of all higher matter, bosons, space-time fabrics, sub-particulates and higher particles of matter. The best way is to measure and understand the ES and EG models of the leptons and the difference of the neutron boson and the photon boson, and you will be able to measure any QED between the electrino composites (and the graviton core) of an electron, ... or the positrino composites (and its graviton core), ... which then make up the ES-EG and EG-ES boson hybrids and the EG-EG electron photon, then all else will fall rapidly into place.

[@martinsoos]

In this short video, properties of gravity are shown by large objects changing the dynamics of small ones. Such as small objects mostly moving sideways between the large objects and the need for randomization on the computer model along the sides of the screen to keep the large objects from being pulled to the walls. kzbin.info/www/bejne/ap23n42wmNGNbJo If gravity could be found by the use of math, I think simpler minds would have already found it.

[@axle.student]

Thanks for an interesting video presentation. I am not a physicist but my recent investigations have notice some fundamental problems with the geometry and fundamental assumptions used in SR. I did do a lazy thought experiment regarding gravity GR in relation to >cough< time dilation and speed of light and it seamed plausible that regions of mass and the gravitational fields could be considered as a region of higher density. It follows like any wave propagation that its speed would be lower in that medium in the same way that light is slower in a gas or liquid. I noticed references to a radial geometry from the Schwarzschild coordinates and wondered if this has any similarity to radial field lines. I think the radial based geometry is a good starting place for past and forward light geometry in SR but the 2D flat geodesic (polar) coordinates system appears to break the space-time union as well as possibly implying non local causality. I am curious what the base geometry is in VSL (real universe, natural. Not the abstract versions converted to human readable x, y, z + t.)?

[@johnlord8337]

False statement - the velocity of light is slower in a gravitational field. NO ! - photons (gravitational lensing) follow a longer gravity well and fly out, their velocity is NOT slowed down, only the direct pathway is extended. Even considering the compaction of the space-time fabric around a gravitational object, having a higher density, still doesn't stop or slow down photons. Only the indirect and slightly longer diverted pathway of extended distance. All of what is said by Einstein or others about this is BS. Only smaller photinos or other EG particulates and particles fly through the longer distance of the force field and compacted space-time fabric, escaping or otherwise being captured.

[@eytansuchard8640]

The variable speed of light idea is correct in the far observer asymptotic coordinates. By the work of Bondi et. al. (see Super Translations) such a choice of coordinates does have a physical meaning despite the fact that such a choice violates the principle of Relativity. Bondi showed that in the asymptotic limit, SR is not equivalent to GR. Locally, however, a variable speed of light may not be empirically correct. If it is empirically correct then the last version of GR does not correctly describe gravity. It is possible but it needs an empirical corroboration.

[@duncanmountford8426]

How does cosmological VSL change estimates of the age of the universe? What are the observational consequences of VSL that could distinguish it from the conventional (doppler shift) explanation for cosmological red shift?

[@johneonas6628]

Thank you for your video.

[@manuelcastaneda7838]

Why would anyone use reduced Plank constant. Why would use : F= G(M m)÷(r^2) F=(mM)÷(4pi r^2 G ) is proper notation.

[@Dyslexic-Artist-Theory-on-Time]

Could the 1 over c squared represent one photon? We could have a variable speed of light with potential photon energy continuously transforming into kinetic Eₖ=½mv² energy of the electron that has mass. It looks to me that the numbers are representing spherical 4π geometry with the process relative to the spherical surface. That would explain why we see so many numbers squared as in t², c², e², ψ² and velocity v².

[@gamerfortynine]

How many years did it take Hawking to realize if light could be slowed, the black wholes would have eradicated all of existence? We got hawking radiation cause the math cant uphold your assumptions.

[@hpeterh]

However doesnt it stay true, each observer who uses his local measuring instruments will measure the same value for "c". When they are at different gravitational potential this still stays true because their clocks arent synchronous. So far I remember, SRT and ART never states, "c" is the same everywhere, it says "c" is measured the same everywhere in the universe. When there is no absolute clock, then there is no absolute speed measurement. So how could we measure variable speed of light?

[@TheMachian]

Not directly, as you correclty remark. Yet, the deflection is a consequence of VSL

[@curiousmind9287]

Alexander, thank you for this new video! Please never stop exploring. My question is probably silly, but here it is. Is our definition for the word “speed” needs revision? Perhaps it should be something different than distance over time. Maybe it just not broad enough to incorporate whatever it is speed for light?

[@zarinavarina8580]

I'd say speed as distance over time is fine so long as neither distance nor time are recursively defined by the speed of light. But unfortunately, I think that's how distance and time are officially defined right now.

[@tedwalford7615]

Yes! "Speed" relative to WHAT? Is there some fixed/"unmoving"/zero-speed center post of the universe somewhere, relative to which all speeds are measured? Of course not. If two objects are seen to be moving apart at some constant combined velocity, how can you say what is the "speed", or velocity, of each? Assign half to each? Or view one as "nonmoving" and and therefore assign all the velocity to the other? Or vice-versa?

[@GamesBond.007]

Why would light be accelerated or decelerated in a gravitational field if it has no mass ? Only if lumineferous ether exists this would make sense, as the ether would be bend by the gravitational field and the light traveling through it would be bend too as the ether is pulled into the gravitational field. This would make it follow a geodesic like in einsteins GR. But Einstein removed the ether so no.

[@frun]

Wrong, Einstein proved ether.

[@GamesBond.007]

@Dsyelxia in what universe ?

[@frun]

@@GamesBond.007 In 1920 Einstein accepting the ether theory Albert Einstein said: “Recapitulating, we may say that according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an ether. According to the general theory of relativity space without ether 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 …”

[@dexter8705]

​@@GamesBond.007 if by aether you mean space then you would be correct. If not you don't know what gravity is,

[@ingoos]

Hi,everyone. Kindly peer-review / correct my understanding: The age of the universe may NOT actually be 13 something billion years or so. We assume that it is, due to the time that it takes light from the farthest galaxies.... We also assume that the speed of light has always been constant. iirc, from the big bang, space expanded & still continues to expand... -in fact, faster than the speed of light. Anything within expanding space will also be traveling at the same expansion rate (so faster than the speed of light, but at or less than the speed of light, relative to other stars & galaxies...) The point: images to be gathered by the HST /JWST will only reveal what happened well AFTER what we are already seeing... but not anytime BEFORE.

[@linz8291]

Yeep…our universe is not some 13 billion years, if you think about curved space affected time frame. FTL and VSL are exceptional functions to current planetary space expanding.

[@jonbold]

VSL is better than curved spacetime because it is closer to the nuts and bolts truth. Try adding a third mass to Newton's formula!

[@CACBCCCU]

I start tracking with you around 12:26 but then you jump to Dicke and the formula where the weirdness of assuming a real change in lightspeed means a real nonzero change in wavelength is added to the real change in frequency seems to pop out of nothing but overactive mathematical generalism, and I guess it means to you that light is slower in strong gravity? That's backwards. Energy (positive) bends toward mass, that means it temporarily speeds up when it passes close to a mass, like a pendulum swing, except light has no detectable gravity of its own. The fastest neutrino path would bend more than twice as much as a light path would bend. That's if speed has anything to do with it. Best analogy to light bending toward mass due to increased lightspeed is a swimmer being drawn toward land by a *reverse* "riptide-like" flow effect supported by "water depth" (gravity potential) being greatest (most intense) closest to matter instead of the reverse, namely shallowest water depth closer to solid earth.

[@TheMachian]

c=lambda f always holds.... this is all.

[@CACBCCCU]

@@TheMachian Put another way, the wavelength, being a spacing between wave-cycles, is best held constant to constantly track with the constantly flat spacings of Euclid's constantly flat unbent space, leaving all flat space vacuum lightspeed variation as frequency variation, in the absence of any known evidence to the contrary, so no call for delta lambda, just delta f.

[@trescatorce9497]

So what is the speed of light away from any masses? Basically, what is the value of c-naught

[@ready1fire1aim1]

Anyone else find it ironic that the symbol for physics (dot in a circle) is also the symbol for metaphysics, 0D = metaphysical point?

[@richardchapman1592]

Wanting to question the maths. Speed of light is distance divided by time. c squared must therefore have time squared as the denominator. Never heard anybody mention two dimensional time unless time is the real and imaginary parts of a complex number.

[@brynbstn]

Maybe do a conceptual explanation first and do a math presentation second and people like me can drop out but still understand the idea

[@dastutweh]

Nice video, the formulas can explain the phenomena of light deflection in a gravitational field very well. It would be interesting to find an experiment or constellation where the predicted values of general relativity could measurably deviate from the values predicted by Robert Dicke's formulae. I would also be very interested in the announced video about the perihelion motion of the planet Mercury. Furthermore, I would be interested to know how to evaluate the experiment with atomic clocks, the results of which Jacopo Grotti from PTB and his colleagues published in 'Nature Physics' in 2018. They developed a transportable atomic clock, which they brought into a mountain tunnel in the French Alps, complete with finely adjusted lasers and sensitive cooling units. There, the atomic clock was set up in an underground laboratory. The highly sensitive apparatus was specially housed in a vibration-damped and temperature-stabilised car trailer. Although the conditions in the middle of the Frejus Tunnel were not ideal, the researchers achieved precise measurements of time. To obtain a direct comparison, a measurement was taken simultaneously in a laboratory in Turin. The city is 1000 metres lower than the mountain tunnel. In order for an exact clock comparison to be possible, the laboratories had to be connected with a 150-kilometre-long fibre optic cable. And the comparison was successful. The team was able to detect a difference of 47.92 hertz. The difference in gravitational potential at the two locations determined from this agreed with the results of classical methods. This proved the functionality of the transportable clock, but also Einstein's postulate. Translated with www.DeepL.com/Translator (free version)

[@TheMachian]

The clock experiment is easily explained by VSL, as Pound-Rebka. Ther will be other videos on the other issues.

[@atheistaetherist2747]

That atomic clock experiment can't prove Einstein's postulate. Einstein's postulate is wrong. The speed of light is affected by the nearness of mass, not by the gravitational potential. Actually, the NOM & the GP are in effect almost equal if u define the GP as being related to the escape velocity to infinity. They would be equal were it not for our universe being infinite (& i can add that it is eternal, which is not really a factor here). My understanding is that no atomic clock X has ever supported Einstein's equation within a reasonable percentage of error. And i doubt that the 2018 Grotti-X is any better. Larmor derived an equation for the ticking of an atom, based on the effect of (ie the velocity of) the aetherwind. Hence any X should test for the slowing due to Einstein's nearness of mass plus Larmor's aether-wind. NOM should work ok anywhere on Earth. However the aetherwind adds to the slowing of (atomic) ticking due to elevation if near the south pole, & subtracts from the slowing if near the north pole. Did Grotti find that the speed of light was different in the 2 directions in his optic cable (2018)? Torr & Kolen did, in their cable (1983). DeWitte did, in his cables (1991). But Grotti didn’t ?? I smell a rat.

[@islandbuoy4]

your interest in the perihelion motion of the planet Mercury illustrates why physics will NEVER EVER be able to explain our reality ... the '3 body problem' regarding the motion of earth, the moon, and the sun in a cohesive narrative is in itself a 'mind-fu*k' to which let us add all the moving bodies in the cosmos (that we can see and not see) ... end of story ... physics can never be more than just a theoretical response to 'what is?" ... theoretical physics is on par with theoretical theology .. and that is the very best science will be able to achieve ... ahh the ego of the scientist is infinite in its scope ... but Godel saw the future with his 'incompleteness theorem' ... suck it up

[@Chr15T]

"It would be interesting to find an experiment or constellation where the predicted values of general relativity could measurably deviate from the values predicted by Robert Dicke's formulae." The existing and very convincing indirect and direct observations of gravitational waves are an example.

[@davidsault9698]

To me, variable speed of light is just due to a variable density of space itself. I do not understand why physicists think that space is a uniform field with no density variations.

[@koenraad4618]

Variable speed of light, related to gravity, is like a sound wave in the atmosphere with temperature or density gradient. It suggest the presence of an aether with variable temperature/density. So if this gravity theory is correct, do we have relative motion with respect to an absolute aether frame (just one preferred frame of reference exists), such that in all inertial frames of reference we have c' = c + v (where c is the velocity of light with in the preferred reference frame, and v is the velocity of the origin of the arbitrary inertial frame with respect to the preferred absolute reference frame)?? If so, then we are back to Aristotle's 'relativistic' model of absolute space. Lange's concept of equivalent inertial frames, in the context of Galilean relativity, cannot be correct if we extend the equivalence principle from classical mechanics to classical electrodynamics (TEM waves with velocity "c"). Only two options remain: "special" relativity based on the Lorentz coordinate transform with constant c in all inertial frames (which is violated by the presented theory of gravity in this YT), or we return to Aristotle's/Newton's absolute space concept. The speed of atmospheric sound can vary, because of relative motion with respect to the atmosphere, and secondly because of gradients in atmospheric density and temperature. Therefore, in case we can prove a 'variable speed of light model of gravity' by means of experiments, then we are back were it all started, with Aristotle's/Newton's absolute space. Massive astrophysical object might have a thicker and cooler aether "atmosphere" (a very 'soft' form of matter) around its center, that slows down light waves, and that bends light waves. Not only the TEM wave velocity has a 'gravitational' gradient, also the superluminal Coulomb 'near' field velocity has the same gradient, such that charged particles have a slightly (distorted) non-spherical Coulomb field in a gravitation field, which results in an electrostatic 'self' force, aka gravity. This self-force has the same direction for positive charges as for negative charges (see spacetimecentre.org/vpetkov/). There is also a link to Erik Verlinde's 'entropic gravity' theory, where objects fall into the direction of higher "quantum information entropy", if we re-interpret "quantum information entropy" in the context of Pilot wave theory. The velocities and frequencies of pilot waves also shows a 'gravitational' gradient and therefore have a gradient in Pilot wave entropy (a realism view on quantum information entropy: it is the 'form' of Pilot wave energy, in particular, the 'frequencies' of the Pilot wave energy, which depend on the superluminal velocity of the Pilot waves). Valentini's latest articles describe the non-applicability of Born's QM rule with respect to quantum gravity theory in Pilot wave theory context: gravity implies a non-equilibrium and anisotropic interaction of Pilot waves with an elementary particle. I assume that the Pilot wave has an electrodynamic nature: a Pilot wave is the far field aspect of the electric potential, Phi, i.e., the Pilot wave is a longitudinal electrodynamic wave with fields E = -grad(Phi) and B = -d(Phi)/dt which is a wave with superluminal velocity v>>c, which carries considerable energy but very little momentum, such that a non-equilibrium Pilot wave particle interaction results in a very small 'gravitational' force (with respect to the Coulomb force between two charged objects). I love this YT channel and Unzicker's angle/opinions on Physics.

[@frun]

Yes, you're right. Space and time are absolute. There is a preferred reference frame. VSL theory and Lorentz ether theory is the way to go. Moreover they have to be generalized, because of some nonlinearity.

[@tvdmerwe5069]

Thanks for a very interesting video! When you mention c, do you mean the one way light speed? Or the two way light speed measured by a mirror reflecting light beams? It seems like modern science have ‘defined’ the (two way) light speed to be exactly c? This implies that time and length will vary across the universe? If we accept the VSL postulate, it seems incompatible with constant light speed c as defined today. Instead of isotopic light speed as postulated by Einstein, anisotropic light speed is assumed in VSL. This implies that the one way light speed can vary, for example the forward and reverse times of a light beam reflected from a mirror would be different?

[@TheMachian]

I would not expect a difference between 1-way and 2-way speed of light. The assumption here is that c is a scalar, of course there could be anisotropy, but it would comlicate matters.

[@atheistaetherist2747]

@@TheMachian I have mentioned many times on your youtubes that Demjanov in 1968-72 used a twin media version of the traditional MMX & found that the horizontal component of the aetherwind at Obninsk had a speed of 140 km/s to 480 km/s on June 22. Demjanov since about 2005 wrote about 10 papers in English re his MMX & other things. His MMX was 1000 times as sensitive as the oldenday's MMXs, & his error bars are too small to show (about 1 km/s i think). His results are compatible with the well known aetherwind that blows south to north throo Earth at 500 km/s about 20 deg off Earth's axis, RA 4.5 deg. The Einsteinian Dark Age is over, or should be. STR is krapp -- & GTR is mostly krapp. We are presently in the Einsteinian Dark Age of science -- but the times they are a-changin'. The aether will return -- it never left.

[@Oliveir51]

Might this explain red shift ? To me Hubble interpretation using Doppler effect is not satisfactory. Now that we can see further away Doppler interpretation leads to galaxies faster than light... nonsense

[@GH-li3wj]

Mach's principle is certainly very interesting to dig out but I am not sure it could be any help with the problem of flat galactic rotation curves. When you look at MOND theory it seems incompatible with GR results, maybe something wrong with GR. The huge discrepancy between the observation of galactic rotation curves and the theoretical prediction of Newton's law is a major flaw in Newtonian physics and therefore in GR.

[@TheMachian]

There are some intereesting consequences for he dynamics of galaxies I will talk about, but certainly, the DM problem is not solved.

[@jnhrtmn]

Faith in math paves over a lot. It could be merely an analogy, then you will never know that it is fake, because you never second-guess math if it is consistent. Forever fooled is also consistent. Light speed that is constant relative to the observer should be a very impossible pill to swallow. It means that EVERY time you change YOUR velocity, that entire light beam now has a new wavelength as if it knew that you changed velocities. The fix is to say that it is actually a new "time". That is the secret to Relativity. It uses transform equations to change length, mass, and time numbers in the experiment, just so light speed can stay a constant. IT CHANGES YOUR DATA BEFORE IT WORKS! If it is creating itself, you will never know, because you confuse consistent with fact. There is most certainly a "non-transformed" reality that is totally ignored. There is no physical evidence of time outside the brain, and if you send a pendulum into space, it is not a clock anymore. What if I could prove to you that basic mechanics contains consistent math that misses the actual cause (An example of a mistaken analogy that is over 100 years old)?

[@gaemlinsidoharthi]

A bit out of my depth here as my physics and mathematics skills suffer from 30years of neglect but leaving a comment anyway, for the algorithms, to show appreciation.

[@channel-ug9gt]

where is this published in Nature?

[@philipfreeman72]

WTF does light have to do with gravity ?

[@TheMachian]

Think about. Gravity deflects light, let's start from there...

[@odenwalt]

Alexander, Thanks for the info you share with us. I have a question, perhaps you could address in a video, or here. Doesn't the Michelson-Morley experiment disprove the variable speed of light? The principles of the Michelson-Morley experiment is used to show gravitational waves with LIGO and VIRGO, which would put the speed of light at a fixed rate in a vacuum and allow length contraction and expansion of space instead. Am I correct in this interpretation? Also, can't space-time be the aether itself instead of being filled with aether? Thank you, sir.

[@TheMachian]

MM surely does not disprove VSL, as SR does not. GW discussion will follow.

[@odenwalt]

@@TheMachian Thank you for the response. Looking forward to GW discussion.

[@axeman2638]

what is it that contracts when space contracts? what are the physical properties of space? isn't it just the distance between things?

[@odenwalt]

@@axeman2638 People believe vacuum space is literally nothing. This cannot be the case logically speaking. People also confuse space with distance. Most people think they understand time and space, but neither are what people perceive them to be. Time is a measurement of causality using clocks. The problem with using clocks is the "ticks" are variable depending on the configuration of the space that they are in, the energy density in the space, and entropy of the system as well as the space it occupies. Space is not distance but is measured in distance. Some might tell you that space is quantum foam, or that space can be curved, warped, and stretched. Some might tell you space is expanding on cosmic scales, but none of this could be true if space was absolute nothingness. I suspect that space is quantifiable at planck and near planck scales, and space is the causal mass of the universe itself. If you look at length contraction and time dilation in relativity you can draw a conclusion that space itself can be squeezed and stretched. So, when length contraction happens it is space itself. I have reasons to believe that space itself is a fluid made of voxels. Many used to believe space was filled with Aether, no one took the time to question if space itself is "the Aether". Think of each voxel physically making contact with all adjacent voxels. A Voxel is larger than a plank volume, but can be compressed to a plank volume, the energy density increases and maxes out per voxel (a voxel can never be compressed beyond the plank volume). Voxels would also obey the Pauli exclusion principle. Voxels move around and stretch, twist, and compress. Each voxel wants to return to its lowest energy state, but it must wait for the other compressed voxels to move out of the way. This is why black holes are actually a large mass of voxels with each voxel, that composes the black hole, compressed into one planck volume. Because voxels are space, they can not all move at once and must wait for the voxels on the surface of a black hole to expand and move out of the way. This is why the entropy of a black hole is the same as the surface area. As surface voxels return to a lower energy state the black hole evaporates, and the voxels expanding on the surface is Hawking radiation. There is a bit of a causal lag that resembles viscosity in a liquid. This is what I believe the Higgs mechanism is. Think of a small volume of space as a 3D stress tensor. I also suspect that fundamental particles are not fundamental, but harmonic oscillations of groups of voxels, (my interpretation of QFT). All stable particles at the "sub-atomic" scale are quasi particles. This is why smashing a bunch of particles into each other isn't going to give any definitive answers. If I am right, we should be able to calculate masses of particles, by the number of voxels in the quasi-particle system. Gravitational force is the unbound voxels (not ones making up particles) returning to the lowest energy state, applying a small force on matter the unbound voxels surround. This force is cumulative and would follow the inverse squared law. Space tells matter how to move in a similar way to the Navier-Stokes equations. To sum it up..... I like to think of space as the lowest energy state of mass. Going to stop there, but if you have any more questions, I can explain more. Keep in mind My work is conjecture.

[@axeman2638]

@@odenwalt "space tells matter how to move" oh lol, what absolute nonsense. How? what properties does space have? How does it communicate it's intention? where is the experimental evidence for any of this conjecture? Reality is euclidean. "If you look at length contraction and time dilation in relativity" got any experimental evidence for that? Einsteins's relativity is nonsense unproven by experiment and unused in any engineering, physics cannot progress until it is abandoned. Once you do away with it none of this fanciful nonsense speculative is needed.

[@markhughes7927]

What has particulate light to do with a general effect like gravity? Chalk and cheese is it not?

[@PaulMarostica]

If I correctly understand this variable speed of light gravity theory, then the resulting frequency and wavelength of any light wave in a gravitational field are the free space frequency and wavelength of the light wave, each multiplied by the same factor, independent of what the free space frequency and wavelength were, so all free space frequencies and wavelengths of light have the same gravitational acceleration? And all massive objects also have this same gravitational acceleration? So this is unlike refraction, in which different free space frequencies and wavelengths of light refract differently?

[@delischertaucher3494]

Ach, wie nett. Das war eine Frage von mir. Bin gespannt 🙂

[@Robinson8491]

If Einstein hadn't assumed and calculated with the fact space curves, he would have got the factor of deflection of light with the sun wrong by a factor 2. This makes space curvature plausible, as well as the existence of black holes. How he came up with it though I have no clue

[@deltalima6703]

Lorentz invariance was recently discovered, he built on that, rigorously, and one thing leads to another. Thats how einstein came up with it. The real contribution he made was to frame it in the language of tensore, which was also new, and mostly the domain of mathematicians rather than physicists. My take on it anyways, I might be wrong.

[@petertard]

I got an idea that Gravity at the start of the universe was much less than it is now, and that the "inflation" expansion was due to there only being one element at the start, Hydrogen, which in the nucleus has 2 Up Quarks and 1 Down Quark, the Down Quark being in effect what causes Gravity, The Down Quark could be the Graviton.

[@TheMachian]

Forget about inflation, and forget about quarks, too. Yet, the strength of gravity should vary... however it decreases.

[@petertard]

@@TheMachian Inflation at the very beginning of the universe after the Big Bang can be discounted if the force of gravity at that time was much lower than that we experience, as the only element in existence was Hydrogen. Later, with nuclear fusion, Helium was created, which would be the first instance of ordinary gravity. The gravity around a neutron star is much greater than that around the Earth. Is the actual force of gravity the same at all locations and times of the universe, an invariable Gravitational Constant, or can it change according to the density of matter ? If the actual force of gravity is variable, the Speed of Light can remain constant, and invariable. Would physicists prefer to have the Speed of Light constant and invariable, or the actual force of gravity, the Gravitational Constant to be invariable ?

[@petertard]

My theory would simplify the derivation of Gravity.

[@johnlord8337]

Newton was wrong in using C (light speed) in figuring out gravity. Gravity is gravity, neither light nor light speed. You can play all kinds of number and number play with derivatives - but Newton's Gravity constant is an approximization of multiple layers of gravity sources, that are not universal across the entire cosmos, let alone non-gravity locations of cosmic nurseries of gas and dust cloud regions. So G is putting one's finger into the wind, and making an conjecture about gravity. So all other G constants used elsewhere ever afterward, are based upon faulty data and calculations. This means that physics has major problems with such Constants of Nature, and their interactive derivatives developed from C and G !!!

[@ian_b]

I may be wrong, but I still don't see a mechanism as such. I want to know how masses physically alter the refractive index of space, or deform spacetime, whichever it is. What is actually happening "down there"?

[@TheMachian]

It is true that the "mechanism" is not clear yet. However, it is satisfactory to have a reason for the redshift.

[@ianp3112]

If you really want to understand, check out David Butler on KZbin!

[@ian_b]

@@ianp3112 Had a look, appears to be just Standard Model stuff, if well explained. Which has no mechanism/ontology.

[@ianp3112]

@@ian_b YES, it appears you have NO interest in learning 😂 ! What a pity!

[@cgfreeandeasy]

You explain nothing, you only fathom the situation through the geometrical discription and.. new thing: variable Light-speed.

[@TheMachian]

What else do you want to have explained?

[@cgfreeandeasy]

@@TheMachian How exactly gravitation works - not what effect it has. And light may be one of the factor, what does not react to gravity, as we thought. Maybe all effects, we see or interpre of what we see, are only refraction and/or scattering, not deflection by gravitation. The formulas would work, but explain not, what we see.

[@RFQuantumLab]

How is this method supposed to explain gravitational waves?

[@TheMachian]

Will talk about this in a later video. Good question.

[@RFQuantumLab]

@@TheMachian Great! I’d be delighted also to see how we approach explaining additional and important phenomena such as Tidal forces that cannot be dealt with in the Minikowski metric.

[@Hank-x5q]

"Real Physics" you have confused me. Gravity is mass and mass is gravity...🤔

[@keep_walking_on_grass]

The Speed of light dropped between 1928 and 1945 by about 20km/s (per second! ) which is a huge drop - all over the world it dropped people had similar values. 1945 it went back. all over the world people getting similar values again - back to what it was.

[@willjustman829]

For me gravity is the result of motion, because the earth is moving around the sun, it is creating a gravity that holds everything in it including the air and the moon, and because the sun is moving around the milky way, then , it holds all the planets under its gravity, therefore, it is like a chain reaction in the universe that the movement of one thing creates a gravitational force on one thing and on the other hand another motion creates a gravitational force on the thing that creates a gravitational force on another thing. It's like the motion of the earth creates a gravitational force on the moon while the motion of the sun around the milky way creates a gravitational force on our earth and other planets.

[@JungleJargon]

I don’t think you can add all the mass of the universe to determine the amount of gravity everywhere. It seems to me that if you had only two galaxies of the same size, the point between the two galaxies would have an equal amount of gravity being exerted on a mass thus canceling out all gravity. This is very significant because it’s gravity that slows down time and contracts distance. If there’s no gravity, there’s no slowing down of time and no contraction of distance meaning that our observation of the speed C would be instantaneous since everything is closer and time passes by instantly. The space is not as expansive as it appears to us to be and essentially billions of years are passing by while only thousands of years or hundreds of years are passing by for us where we are near Sagittarius A. In between all of the galaxies that are basically pulling equally on a mass there in deep outer space the gravity is being cancelled out so that our observation of light passing between galaxies is that light is arriving instantaneously.

[@kaellum4260]

I think there is more advancement to be gained by exploring thought on local versus non local gravity. Hence Variable gravity. #Philosophyoftimetravel #3767

[@AmbivalentInfluence]

What if we built a centrifuge, one that was powerful enough that the g generated created measurable time-dilation. We then placed a dual-slit experiment within the centrifuge. I would argue that the increased density of spacetime that is caused by the increase in g should have an effect on the interference bands. The light would travel more slowly due to the increased density, but that would need to be observed from outside the centrifuge due to time-dilation. The light should also be more restricted in it's 'movement' producing narrower bands or bands that are closer together (or maybe both). Has anyone tried this ? Is my logic sound ?

[@axle.student]

I think this would come back to the problems that I see with the Hafele-Keating Experiment. It uses angular velocity instead of linear velocity and is conducted inside a gravitational field on a rotating planet that also has a mix of gravitational field and angular velocity. There are too many assumptions made upon the assumptions of the physics at the time when it was conducted.

[@ruparkyitin]

Is light made of many photons ?? Are photons particles?? May I know How photons travels? If we do not know how photons travels ..... How to understand " how light curves?"

[@dustinsoodak6238]

Does anyone know the equation for index of refraction of light up to the event horizon of a black hole?

[@rb8049]

Can all GR observations explainable by this approach?

[@TheMachian]

Yes. But more will follow.