Einstein's Best Idea: Variable Speed of Light - The History

[@howardanderson7569]

In Einstein's paper, "On the Electrodynamics of Moving Bodies", in section 4, he says "For velocities greater than that of light our deliberations become meaningless; we shall, however, find in what follows, that the velocity of light in our theory plays the part, physically, of an infinitely great velocity." I'm 81. That comment in his paper has intrigued me since first reading it at age 17. Your videos are very well done and very interesting!

[@christophertinklerart2020]

Thank you for your careful description of the issue, very insightful and much appreciated

[@danieladmassu941]

Great post. VSL is one of those 'politically incorrect' concepts in modern physics. A lot of today's academics could learn from Einstein about thinking for themselves and not repeating the party line. Thanks.

[@ZeroOskul]

See: Lene Hau slows down light in 1999. See also: Lene Hau stopped light in 2004 There is nothing at all "politically incorrect" about it and it is accepted fact. Popscience wants you to believe the narrative they present about their ideas so they omit it, but within the actual fields of photonics and particle physics, it is perfectly well accepted and respectable. The method involves cooling sodium to very near absolute-zero which causes all the sodium atoms to take on a singular quantum state and hen introducing a single photon pulse to the BEC. The lower the temperature, the slower the light. It has even been brough to a standstill in laboratories.

[@friendlyone2706]

Einstein himself said he never respected "authority" and God punished him by making himself an authority. He understood the best compliment was to find someone's ideas so exciting it made you want to think of ways to challenge the idea.

[@botplays6893]

Well, this is very, super, SUPER misleading. Of course you would find these results if you adapted newton's idea of gravity. It is true that the velocity of light can be a variable but not the SPEED! You could perhaps replace GR with VSL but that would just add unnecessary axioms!

[@iguana1677]

Weaving in the historical context really brings the topic alive!

[@sumdumbmick]

I personally always viewed tensors as intending to explain scalar changes in things like the speed of light. I don't understand how they could be interpreted any other way, and I've never heard anyone explain what they do that doesn't in some way or other admit that this is precisely what's happening. so, for me, it's quite a bit like QM, where the people who are most likely to take issue w/ saying that tensors are simply abstractions that allow us to compute scalar changes in some property through a space, are the 'shut up and compute' people who are aggressively opposed to understanding why they should be using the tools they've been given, and instead only insist that everyone unquestioningly use them.

[@TheMachian]

Tensors are fine, the are a useful tool in geometry. Now in GR, there are a lot of symmetries of the arising tensors (metric tensor, curvature tensor). The question is if in that case, whether the formalism is really necessary or using a variable scalar c allows for an easier description of the observations.

[@martynewport]

Thanks Dr. Unzicker! You may not believe but couple of years ago I thought that variable speed of light is the best way of describing light bending and GR. Even we have the term: GR lenses! Honestly I didn't know Einstein (or anyone else) had worked on it before until I saw your video.... It was exhilarating for me though....Thanks for the historical discussion. If GR was described based on VSL it would have been much much easier to grasp than the abstract geometrical GR , I hated it always...

[@TheMachian]

Right, lenses! I should have mentioned that...

[@riadhalrabeh3783]

Many people don't seem to know that the speed of sound in a homogeneous medium is constant and independent of the source or receiver.. that is because the speed is is c=sqrt(stress/density) and these don't change. For light c=aqrt(1/permeability* permittivity) of empty space. Speed can change in sound if the medium itself moves like shouting upwind or downwind. But in light, the vacuum can't move. The only change due to motion is frequency as in the Doppler shift. Light changes direction near to a massive body like any projectile.. that is because the formula for the change in direction as derived by Newton doesn't not involve the mass of the projectile and can thus be massless... like a feather and steel falling from the top of the Pizza tower at the same speed.. the mass cancels out in the problem.

[@TheIgnoramus]

Hollelula , was waiting for someone to talk about this. Thank you for bringing things to light. It seems pretty apparent any and all reference frames are relative, and all constants are dependent on each other. We just take forever to make all the connections. A few hundred years of the scientific process makes sense.

[@supercobra1746]

Awesome video! I always though that VSL makes total sense! Thank you for pointing out those papers!

[@TheMachian]

Glad it was helpful!

[@glenmartin2437]

Thank you. I started studying relativity at least by the time I was twelve years old. It is still difficult for me to underatand, but I keep studying. Thank you again.

[@paulg444]

Great video, one reason why off the path ideas like VSL are of such great value: Exploring such perspectives gives the student (and we are all students) a far greater understanding of SR and GR. We need more instruction of this type.

[@surendranmk5306]

Something yet to be explained! It is about gravitation and EM radiation.

[@byronwatkins2565]

It seems to me that a careful experiment could distinguish between the two. If space is not curved, then distances are independent of gravitation. Then measuring the distance around a closed loop vs. its diameter would always return the results of plane geometry -- unless we used light to make these measurements. Additionally, there must be a discrepancy between the measurements made with light vs. those made without light.

[@dexter8705]

That was very hard to understand, gravity does "curve" space and c is variable, you can have both. Nothing wrong with cherry picking facts from different theories. People can be wrong and right in studies mathematics and experiments, just use what's right.

[@byronwatkins2565]

@@dexter8705 The product of two numbers less than 1 is always smaller than either number. The probability that two assumptions are valid is always smaller than the probability that either assumption is valid. See 'Occam's razor.' A theory is the study of what follows from a certain set of assumed observations. And God forgot to tell us "what's right." We have only our imperfect observations as a resort. We can assess how these observations vary with and without known perturbations, but we cannot assess the unknown.

[@johneonas6628]

Thank you for the video.

[@Robinson8491]

Very great video. Also at the right time. Thank you

[@playdon9792]

speed of light is variable depend on gravity but when speed of light is different there is no reference for time and space so we are forced to say that speed of light is constant. Right?

[@dastutweh]

I have no problem with the fact that the speed of light can be variable, depending on the medium or the gravitational field through which the photons are moving. However, there seems to be a maximum speed of light in vacuum and weak gravitational fields that is close to 300,000 km per second. This therefore seems to be the limiting speed of electromagnetic radiation.

[@kinngrimm]

From what is that limit an aspect, space or an inherint attribute pf photons?

[@dastutweh]

@@kinngrimm Interesting question! I do not know. I could imagine that it is an interplay of both.

[@FunkyDexter]

Quoting Einstein: "a gravitational field is a place where space is neither isotropic nor homogeneous". Einstein never got rid of the Aether. He modeled space as an elastic solid, as evidenced by the stress energy tensor (which has terms for shear stress and pressure). The reason why light slows down is because space is not homogeneous, it's "denser" near masses. If we depict space as a grid, the grid lines get squashed the closer you are to the masses. This effect changes the properties of the medium in which light propagates (space itself) and in the end we get refraction.

[@JoseSilveira-newhandleforYT]

This is a fascinating subject, that you already touched before. I'm more appealed by the flat space with variable c, than the generally accepted curved space with constant c.

[@douginorlando6260]

What? You find a problem when handed drawings of an Escher stairway and told to manufacture it? Building the Universe with Escher drawings reminds me of GR. And no doubt, anyone saying such blasphemy will be burned as a witch by the institutions worshiping Escher dogmatism.

[@rauladdams5709]

I have been reading and watching videos on physics for 20 years...How have I never stumbled upon VSL?? Thanks so much for this! Would love to hear more!

[@TheMachian]

Happy to help!

[@RFQuantumLab]

PS: If the speed of light does change as it seems from the results of the calculation, this new worldview will solve many mysteries for us. We may understand how the big bang started (please bring t aim to zero as a starting condition and see how the speed of light explodes to infinity), And will explain the properties of cosmic background radiation more accurately than ideas from the distant past. For 35 years physicists believed that c is constant but then discovered that the early universe expanded rapidly, many times faster than light. Such cosmic "inflation" posed many problems, as no possible experiment could test it. And it required physicists to invent imaginary vacuum energy that performs large-scale repulsion with deliberate parameters, in order to achieve the universe we Watch it today. Yes, it's also something physicists do. They invent new forces and energies that will adapt to observations instead of changing the existing model. I will never understand their stubbornness. If light were faster in the early universe, it would explain today's observations without repulsive energy. Changes in the Earth's climate will also explain the "weak young sun" paradox. That according to the theories of astrophysics, life should not have evolved on Earth at all, because 3.5 billion years ago the sun was only 75% luminous compared to today. The earth was frozen and solid, and its frozen surface reflected sunlight back into space. We have also been taught that regardless of human activity, the sun will continue to warm until the earth's oceans boil. Paleontologists found evidence for liquid water and life on Earth 3.5 billion years ago. In 1996, scientists at the Johnson Space Center found signs of fossil life in a 3.5-billion-year-old Martian meteorite. Over the past 20 years spacecraft in orbit and across Mars have discovered that at the beginning of Mars' career it once contained liquid water, and even an ocean. The sun converts its fuel into energy according to E = mc ^ 2. If billions of years ago c was higher in value, as predicted by: GM = tc ^ 3, the sun would be shining almost exactly as it is today. It is possible that if the speed of light had not changed at the predicted rate, we would not be alive to study it. One last note: Nothing like the repulsive "dark energy" that fills space has been observed in nature.

[@supercobra1746]

Alexander, please continue on VSL, need more info on the wavelength you mention.

[@lorandhorvath4466]

I would have really liked to have you as my mentor a few years ago. Perhaps it's not too late, but you manage to pull me back into real fundamental physics like never before. Thank you for that!

[@TheMachian]

Feel free to contact me via ChannelInfo.

[@walterbrownstone8017]

The absolute electromagnetic field varies according to position around a large mass as well. So does the speed of light vary according to the absolute electromagnetic field or the matter?

[@nkchenjx]

Great point and thank you for sharing. I hate fixing speed of light and break the unit time and space from its original definition that I am familiar from learning Newtonian mechanics. If an alternative relativity that doesn’t need to bend time and space, it will be certainly easier for me to understand.

[@xephyr417]

Can you reorder the playlist so this video comes first?

[@crazy8sdrums]

This confuses me. 'c' is a constant only in vacuo. As perfect vacuum exists only in thought, light is pretty much always at some speed less than 'c'. Variable. Even in a theoretical context, with perfect vacuum, the introduction of mass = a gravitational component = some speed less than 'c'. Variable.

[@TheMachian]

Tha'ts not really a problem. In good approximation, a vacuum can be assumed for astrophysical data. The idea is here that even the vacuum c undergoes a variation.

[@martinsoos]

In the book "Extinction Shift Principle" by Edward Henry Dowdye, Jr. One half of one page gives a chart that proves gravity shapes dust, atoms, molecules, and other solid objects into lenses and lenses bend light. That is to say gravity does not bend light and special isn't special. I'm sticking with the explanation given by the double vortex theory.

[@align2source]

Thanks for sharing this info! I suggest that you update the wikipedia page, you seem to be qualified for that task.

[@TheMachian]

I do not have time to waste, I will rather make a video on that...

[@MrApplewine]

I understand that the variable speed of light would be when you combine the velocity/direction of the aether with the light velocity/direction. This would allow light to travel faster or slower and provide the red shift or blue shift.

[@RobertsMrtn]

Einstein abolished the idea of the aether.

[@friendlyone2706]

@@RobertsMrtn No, experiment implied the abolishment of the aether and Einstein ran with the consequences.

[@markwadsworth1254]

Awesome 👍 thanks for your service to science!

[@AWildBard]

I think you have the relevant background to edit the wikipedia page.

[@TheMachian]

But I have no time to engage with these morons.

[@AWildBard]

@@TheMachian Ok, I guess I thought it would be relatively easy. I can understand you wouldn't want to waste time arguing about it.

[@twenty-fifth420]

Dear Professor, I have some questions about VSL. I am a poor at the moment so I cannot purchase anything, but I wanted to ask some general science on VSL. I am a sci fi writer, so this is where these questions framed. But 1. What are your thoughts on VSL theories in an GUT like in a String Theory? Possible or Impossible? 2. Would a VSL imply a flat metric tensor for our cosmology? What about topological defects for something that appears flat but is not/non-euclidean? 3. Could local changes in a VSL be accomplished like say in a space ship? What would the properties of the new adjusted light speed produce in our universe? Thanks! I hope you have a wonderful day. I also would love to say I am glad I found this channel. It feels contrarian sure, but still firmly in the realm of science. There is ALOT of Pseudoscience on KZbin, and I am cautious to just rely on any channel for science advice. Many thanks. 💕💜

[@academicpresentations6062]

May God bless you.

[@TheMachian]

I am not professor. Contact me via ChannelInfo, I can send you a pdf of my book. 1. GUT theories, particulary strings, are bunk. 2. No. for topological defects, you still need a wider geometry than the usual with curvature. Look up the Einstein -Cartan attempt on torsion in the 1930s and the link of torsion to dislocation density established in the 1050s. 3. I do not think so. It is still unclear what exactly causes the spped of light to vary. Thx, you are welcome!

[@manuelcastaneda7838]

C 2.9979 E8 [91] h 6.6262 F34 [192] G 1.1926 E9 [127] Are the standards with which we scientists communicate with each other. Without this we would speaking different languages.

[@biswajitbhattacharjee5553]

Very good review .

[@PavlosPapageorgiou]

Cool. One thing that annoys me about the standard explanation of GR is that it discourages intuition. The books or courses say here's the math, don't try to understand what reality is doing or ask what is absolute vs. measured against something else. VSL seems to offer a much more intuitive conceptual model.

[@zippymax1]

If Wikipedia mentioned VSL in association with Einstein, I would be much more likely to dismiss VSL as quackery.

[@friendlyone2706]

LOL

[@Tzadokite]

An interesting third possibility is as follows: if we have a light beam moving across a spherical non-homogenous gravitational field it will be passing through regions of low gravitational potential to regions of high gravitational potential. we have c = dr/dt or dr*df. we also have E(light)=h*f(light) which gives us dE=h*df or dE=h/dt. this gives us dE=hc/dr. as 'r' decreases due to the light beam traveling across the GF we have dE < 0 with 'c' as constant. but we have P(light) = E(light)/c or dP = h/dr. with dr < 0 we have dP < 0. this means the light must get deflected towards the mass 'M' as it moves across the GF(M). this would be similar to "gravitational refraction" except the 'c' does not change unlike light refracting at the interface between air and water. the light would be "red shifted", deflected towards 'M' and there will be a continuous radiation of energy as the light beam moves along the non-linear path at a rate given by dE/dr = -c (dP/dr). the negative sign showing that the radiation is away from 'M' along 'r'.

[@philoso377]

- Light bends around the sun. - Gravity also present around the sun. - Conclusion? Gravity bends light. - Bending indicates that light speed is variable by g. - Is g the only thing around the sun when we saw light bend? - Einstein said, yes g is it. - What else was there bends light? - Einstein said, nothing else but g. What do you say?

[@roberttheiss6377]

I understand how VSL and GR are basically saying the same thing, so I don't really get the point, both are just hypothesizing a "why" and the "why" is thus far unknown. It is interesting to think about in relation to a black hole; instead of an infinitely curved space time at the event horizon, you have a speed of light of 0. So rather than thinking about a singularity and a bulk of the black hole, the surface area of the black hole BECOMES the black hole, and the black hole essentially becomes a 2D structure. This falls in line better with the holographic principle. Just some thoughts...

[@zachariemelanson485]

It would indeed not change the results of the mathematical predictions to think of it in different way, but it would help get insight on fundamental problems. Like black holes and all the theories around "the singularity", wormholes, etc., it's incredibly easier to have a visual representation in your head with VSL and see that something seems/feels way off with those ideas. Like you said, a region of space where the speed of light (and therefor the rate of all processes in that space) approaches 0 relative to all outside frames, makes it easier to see that the collapsing matter never getting dense enough to form a true event horizon. The BH either evaporates before coordinate time t=infinity, through any mechanism we might know or not know, and that would be before a true horizon is created, Or Matter falls in after t=infinity, whatever that means is obviously currently undefined. (and for some reason the current scientific consensus without question) "the black hole essentially becomes a 2D structure" - Not really. The ratio between proper time near/in the massive object never reaches 0, but it does approaches it to a point where it's practically indistinguishable from that. So its still a 3D object.

[@roberttheiss6377]

@@zachariemelanson485 Great response thanks! I'm trying to do some math to extrapolate the holographic principle in terms of information entropy from 3D->2D->1D to see if anything meaningful pops out but my math is too weak for this kind of stuff, so mostly performing thought experiments.

[@billyoldman9209]

Thank you for this superb piece of archeology! Why do you think there is such a general distaste for science history, especially in physics?

[@TheMachian]

Good point. I guess it is the superficial scientific culture that emerged since 1930, in particular after WWII.

[@friendlyone2706]

For the same reason we have college graduates who think they understand the Constitution but are ignorant of any of the passionate debates that waged during its writing . Too many professors have overwhelming arrogance about today's accomplishments, and therefore have students ignorant of the past giants who made today possible. As a math student years ago, I learned no terms had accidental names and if I learned the history of the name, understanding ALWAYS increased. I think that principle is true in all areas. Modern dictionaries that no longer include word histories are a disservice to today's students. Likewise teaching students to look up words on the net as opposed to in a book where associated words can be noticed.

[@PaulMarostica]

Assuming gravity varies with the speed of light, does that speed of light vary with light frequency, and if so, how does it vary with light frequency?

[@nathanielhellerstein5871]

Consider the Twin Paradox. The twins pass each other; each one thinks the other is aging slower; but they never encounter each other, and get conflicting age measurements, unless there is acceleration or a gravity field. So how does VSL apply if gravity brings the twins together again?

[@dexter8705]

Why would it matter? They make up length contraction and time dilation to fabricate light being constant. Gravity sucks in space and can accelerate light giving it a higher frequency (relatively speaking) approaching mass and it can slow down light giving it a lower frequency (redshifting) it. But the way gravity stretch's space redshifts light both approaching and travelling away from mass. To make things worse it kicks the scientists in the nads that created the star colour and size chart.

[@Brunoscaramuzzi]

I understood that both GR and VSL give the same results, which one is more easy to use to solve problems!? Is VSL used to simulate the effects of gravity close to black holes, spinning black holes or gravitational waves!?

[@stumccabe]

Fascinating -thank you.

[@jaycorrales5329]

Is there any relationship of VSL and the event of SN1987A, where neutrino emissions were detected three hours before visible light?

[@TheMachian]

I do not htink so. The neutrino observations back then were quite contested, for good reason I think. I do not like their after-the-fact squeezing the data.

[@phildurre9492]

Where can i find a precise from scratch VLS model explanation? There must be books about this: Derivation, implications and problems

[@TheMachian]

"Einstein's lost Key"

[@davidzombori54]

Great video and ideas, I had read about Einsteins idea about variable c before, but it seems taht is not well recognized. I think that shapiros delay is experimental proof of variable speed of light deeper in gravitational field, as well gravitational time dilatation is proof for slowing light. Now, I think that all clocks are fundamentally based on light speed, all clocks are based on motion (oscillations), so intrinsicly related to the local speed of light. Anytime (not broken) clocks run slower it is a clue that speed of light have changed, but it deceive us to calculate and conclude that c is always constant! Locally, it is always gonna be "c".

[@motjuste8549]

Could you please edit (correct) the Wikipedia page on this subject? It now mentions Einstein, but only as an opponent to the theory. Thank you.

[@SuperMagnetizer]

In addition to VSL due to gravity fields, there is also the question of the speed of light at a moving source as “measured” from a local point of view. Does light retain its postulated constancy in traveling from star to star, even though the stars all have proper motions wrt each other?

[@TheMachian]

Yes. The "usual" constancy of SRT is not affected by spatial variability.

[@dexter8705]

Well... It's slowed down till it reaches the next stars gravitational field then it starts to speed up due to its gravitational field but... Due to gravity the light wave is redshifted/stretched both leaving a gravitational field and approaching it but... Stars and galaxies can be blue shifted if Thier relative motion overcomes the redshift caused by gravity.

[@rkreike]

Q: There can be a different amount of particles or dust in the vacuum of space? Are such differences of influence to the speed of light?

[@johnjones-jc8be]

In your view, does the [macroscopic] angular momentum of the gravitational source have any influence? In other words, are there higher order terms that might be important in certain situations, e.g., a large body rotating very rapidly? On another topic. If the speed of light can be derived from the electrical and magnetic permittivities, does that mean that electrical and magnetic fields are also influenced by gravity? Finally, it appears that the LIGO signals can only be interpreted because there are theoretical models that they can be compared to. Presumably, the theory they use is that of current General Relativity. Could you use the VSL theory to model LIGO results? Or conversely, if detailed modeling is not possible, would VLS interpret the LIGO signals differently, at least philosophically? Please pardon me if these are really dumb questions.

[@TheMachian]

Not dumb at all. As I will discuss in later videos, VSL does not require gravitational waves, to say the least. Regarding the observations, i have some reservations: medium.com/@aunzicker/five-years-of-gravitational-waves-a-chronicle-of-strange-coincidences-7d22be19319d

[@taylorwestmore4664]

From what I've read, angular momentum of massive objects can induce a gravito-magnetic moment analogous to magnetic fields. Gravitoelectromagnetism induced frame-dragging has been experimentally confirmed with Gravity Probe B, but I'm not aware of any tests involving light curvature due to Gravito-magnetic or Gravito-electric fields.

[@Burevestnik9M730]

Tesla first discovered that gravitation is not a fundamental force but rather a derived, fictitious force, just like centripetal and centrifugal forces.

[@TheMachian]

Can you provide a source? I'd be interested.

[@richardchandler5183]

If the speed of light changes in a gravitational field, that is, it depends on the gravitational potential,phi and from Maxwell’s theory we have the speed plight is given by C^2=1 / (permittivity of free space x permeability of free space) This seems to indicate a gravitational potential is directly related to the values of the electromagnetic constants, the permittivity and permeability of free space, in other words they are a function of the gravitational potential. Does this mean the gravitational field is electromagnetic in origin. Putting it another way how do the constants the permittivity and permeability of free space change. Traditionally the permittivity of free space was related to the electric force ( electric field ) between two electric charges and the permeability of free space was related to the force ( magnetic field) between two magnetic poles (charges ) by a form Coulomb’s inverse square Law. So is the gravitational field electromagnetic in origin. In a similar vein a spherical distribution of charge has an electromagnetic mass. This can be calculated from classical electromagnetism ( see Feynman lectures on physics, vol 2 ) while it may not give the exactly correct value for the mass of the electron it’s quite interesting. What happens to the electromagnetic field of an electron when its accelerated, its accelerating which is equivalent to a gravitational field so the speed of light will change? Just a few thoughts. By the way I like this stuff, another guy is Lorenz, you don’t say much about him, I glanced at a book of his, I think it was called “Electronic properties of materials “ He talks about the velocity of light in materials and local time, I think, funny we use the Lorenz transformation for special relativity. One little comment he made to the effect “ perhaps in the future we know how the electron stretches and vibrates “ we don’t talk about how the electron vibrates or stretches, I think Poincare did , something about stresses on an electron (Feynman vol 2).I have not seen much written about it. Anyway thanks for the video it’s very interesting I bought your book, I think you are right it was one of Einstein’s best ideas. One last thought you can put energy in the vacuum in a magnetic field e.g.: simple dc solenoid, then turn the dc circuit off with a simple breaker, the energy comes back out of the magnetic field fast, turns into an electric field, and sparks across the breaker, burning the contacts. So how did the energy get stored in the vacuum, how did the vacuum store it? Can space be magnetically and electrically polarised. The ether?

[@TheMachian]

Very interesting post I cannot adress in detail now. I promise however there will be a video on that!

[@dexter8705]

VSL and relativity works perfect together If you throw out time dilation and length contraction!

[@jorje58965]

So is it like the different interpretations of quantum mechanics? Is there a way to distinguish the two someway?

[@OldNeoMatrix]

Actually constant C is not a constant because is expressed as distance and time which is variable related to gravity or acceleration.

[@wernerhartl2069]

The curvature of light in an accelerating reference frame is observational, not physical. Photons have no mass- they travel in a straight line in an absolute or inertial reference frame. The tick of a clock is absolute. It occurs when every particle in the universe has a unique position and dynamic status. When you hear or observe it is physics. The condition of a human body or physical phenomenon is absolute- It doesn’t depend on your definition of time. It depends only on physical processes, not on your observations. The fundamental error of relativity is that observations effect physical processes.

[@trescatorce9497]

If c is affected by gravitational fields, 1= it is irrelevant to say that the escape velocity from a black hole exceeds c, or 2= since wavelength, but not frequency is affected by the gravitational field, then wavelength becomes infinitely long, 3= the curving space around the black hole makes light go in an orbit around the hole, 4= in an infinitely strong gravitational field, c goes to zero. Please choose.

[@martinbrennan578]

Does this have a bearing on red shift and Hubble?

[@TheMachian]

There will be a video on this.

[@BartTut]

Maybe next video with examples how this VSL work?

[@TheMachian]

There will be some more videos on VSL.

[@RFQuantumLab]

First and foremost, congratulations on your fantastic video! Both historically and in terms of awareness-building. Using a novel geometric notion called space-time, Einstein assumed a constant speed of c but also backed himself up, in case it did vary (following hidden variables). Indeed, at the end of his life, Einstein said again that relativity could not exist without the Aether and that the present model needed to be revised. However, due to the rapid development of Quantum theory, Einstein and his updated theories were pushed back, leaving him with the present model. Because, with physicists, if it doesn't matter in terms of computation and precision, there isn't much new information you can learn about the "system." It will be interesting to revisit my previous work, which indicated a 0.927 cm decrease in the speed of light per year using the same metric guv. (By the way, this conclusion fits the 12 sigma anomaly of estimating the moon's distance from us to within a fraction of a standard deviation.) However, it can be accomplished using far simpler methods. Take a sheet of paper and a pen with you, at your disposal.. Please write in the left side the energy of the mass m at rest in relation to the mass of the universe M, and you get: E = GMm / r Compare this energy to the energy of the rest mass m: E = mc ^ 2 The mass m doesn't contribute (it's eliminated On both sides) And from recent data, we assume that: r = ct (According to the Hubble Law) You have obtained a relationship between the speed of light, the mass of the universe, gravity constant and the duration t of the universe. c = (GM / t) ^ 1/3 You are welcome. The same result in a much simpler calculation and a minimum number of assumptions.

[@ThurVal]

Eine Frage bitte: ist das Postulat der Invarianz der Lichtgeschwindigkeit nicht einfach eine andere Darstellung oder Teil der Invarianz von Naturgesetzen im Allgemeinen? Wenn die LG tatsächlich variabel im eigentlichen Sinn wäre.. würden die Maxwellschen Gesetze dann nicht auch variabel erscheinen, abhängig von Ort, Zeit und Beobachter?

[@TheMachian]

Darüber gibt es noch ein extra video... bitte Geduld! :-)

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

Light is a wave and a particle, could it have constant speed as a wave and be a variable with particle characteristics? This would happen if three dimensional (spherical) space as in length scales and one variable in the form of time are emergent relative to light interacting with the atoms. It has be said that the speed of light is the speed of causality, could we have potential photon energy continuously exchanging into electron kinetic energy forming a probabilistic uncertain future?

[@TheMachian]

I think there is a problem with thr usual wave-particle distinction. We better think about why nature shows so different phenomenologies with light and matter. In my opinioin, this is related to the existence of the constants c and h, something yet to be explained. See my series on unsolved problems.

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

@@TheMachian Could light and matter (electrons) be waves over a period of time and have particle characteristics as the future unfolds relative to the atoms of the periodic table? in this theory the mathematics of quantum mechanics represents geometry, the Planck Constant ħ=h/2π is linked to 2π circular geometry representing a two dimensional aspect of 4π spherical three-dimensional geometry. We have to square the wave function Ψ² representing the radius being squared r² because the process is relative to the two-dimensional spherical 4π surface. We then see 4π in Heisenberg’s Uncertainty Principle ∆×∆pᵪ≥h/4π representing our probabilistic temporal three dimensions life. The electron e² and the speed of light c² are both squares for the same geometrical reason. We can have a mathematical explanation of creation with the mathematics representing a simple geometrical process! Explained by just one equation (E=ˠM˳C²)∞. With energy ∆E equals mass ∆M linked to the Lorentz contraction ˠ of space and time. The Lorentz contraction ˠ represents the time dilation of Einstein’s Theory of Relativity. We have energy ∆E slowing the rate that time ∆t flows as a universal process of energy exchange or continuous creation. Mass will increase relative to this process with gravity being a secondary force to the electromagnetic force. The c² represents the speed of light c radiating out in a sphere 4π of EMR from its radius forming a square c² of probability. We have to square the probability of the wave-function Ψ because the area of the sphere is equal to the square of the radius of the sphere multiplied by 4π. This simple geometrical process forms the probability and uncertainty of everyday life and at the smallest scale of the process is represented mathematically by Heisenberg’s Uncertainty Principle ∆×∆pᵪ≥h/4π. In such a theory the future is unfolding photon by photon with the movement of charge and flow of EM fields. This gives us a geometrical reason for positive and negative charge with a concaved inner surface for negative charge and a convexed outer surface for positive charge. The brackets in the equation (E=ˠM˳C²)∞ represent a dynamic boundary condition of an individual reference frame with an Arrow of Time or time line for each frame of reference. The infinity ∞ symbol represents an infinite number of dynamic interactive reference frames that are continuously coming in and out of existence.

[@thebeautifulones5436]

Is this variable speed of light methods easier to understand and use the GR?

[@TheMachian]

I think so, yes. But this is not the ultimate criterion. VSL is attractive because of its explanatory power.

[@glenwaldrop8166]

It seems to be wholly impossible for light to be a fixed rate when time itself is a variable due to gravitational fields. It seems that Einstein needed to eliminate a variable to do the math and decided on a fixed speed of light. His own words give a variable speed of light with time being a variable. The rate cannot be fixed if time is also a variable.

[@DougMayhew-ds3ug]

This is very revealing, but what are the downstream consequences for harmonically-ordered atoms? It seems that feedback and conservation of energy forms the rough basis of how atoms hold together. If the speed of light varies under certain circumstances, how might a variable light speed limit present opportunities for new species of interactions to be discovered at the atomic level. Already Weber’s electrodynamics is said to derive the distance within which positrons stop repelling and begin to attract one another, and this distance, discovered by Weber before the atomic model of Rutherford, was consistent with the nucleus radius. (Furthermore Weber derived the speed of light before anyone else, from the ratio of the magnitudes of the units of electrostatic and electromagnetic forces, but he did not measure light propagation speed directly, yet was very close to the actual speed, and yet his figure was even more accurate than result of important experiments done years later by famous others) The fun part of this juncture is that all the old, forgotten ideas that matter are being unearthed again, in an age of the GPU, a tool that these old-school theorists could only dream about. We urgently need to combine the two trends, and use it to plan out which new experiments are worthy of effort. Take a look at shadertoy.com for a powerful, yet relatively simplified software tool for GPU parallel calculations and display of rich animations. The code programming window is right there on the same page as the animation… You physics guys need to team with shader enthusiasts to build brilliant, fast, and mentally vivid models of physics, or take your math knowledge over there yourself, to play in the best sandbox the modern era has to offer, and bring these buried ideas back to life in computer animations of the hypothetical models, to see what happens, what emergent behaviors lie hidden in the formulas, especially for finding where non-linear and feedback attractors may appear.

[@danmiller4725]

Everything that moves starts from zero velocity, speeds up to a point of inflection then slows to a stop again. Your body and its parts too. Light however starts at c and stops at c when it gets to the receiver. There's something wrong with this. Light is a sensation we have after the brief movement from source to receiver. You can't trace the movement from start to stop..

[@atheistaetherist2747]

Photons have a central/internal part (the central helix) & an external part (the photaeno). The central helix has a front end & a rear end, & is (possibly) 1 wavelength long. The wavelength is simply one turn of the helix (there is no wave). The central helix is an annihilation of aether. Annihilation of aether gives gravitational mass & inertial mass. The track of the annihilation forms a helix. The helical annihilation moves axially throo the aether at the speed of light c, & along its helical track at more than c. Photaenos radiate out (to infinity) from the central helix. Photaenos annihilate aether, hence they have gravitational mass & inertial mass. Photaenos include a vibration (excitation) of the aether. Photaenos radiate from fixed locations in the aether, ie from fixed locations along the central helix. Photaenos do not have a sideways velocity in the aether, ie each photaeno is shed from the central helix as the rear end of the central helix passes. In a free photon every photaeno is initially attached to the central helix, & later it detaches. In a confined photon the central helix has formed a continuous loop, in which case the photaenos do not detach (the central helix has no rear end). Electrons & other elementary particle are confined photons. Photaenos give us charge fields & electromagnetic fields. An attached photaeno gives a high field strength, an unattached photaeno gives a weaker field. Hence a free photon has 3 parts, the central helix, the attached photaenos, & the unattached photaenos. A confined photon has 2 parts, it has no unattached photaenos. Man-made radio signals are carried by photaenos, they are not carried by photons. A photon with a (natural) 10 mm wavelength (the length of its central helix), is a different animal to a radio wave with a (forced) 10 mm wavelength (which has no central helix). Free photons are slowed by the nearness of mass (confined photons), as suggested/proven by Shapiro (Shapiro Delay). Shapiro Delay is due to the photaenos (from the free photon)(& from the confined photon) fighting for the limited use of the aether. Fighting/congestion slows the photaenos & this slowing feeds back to the central helix, slowing the central helix. I call this slowing "photaeno drag". It contributes to the bending of light. It gives us diffraction near an edge. Photaeno drag is very strong inside mass (air water glass). It gives us refraction, & reflexion.

[@Robinson8491]

Could you say what was the argument for using space curvature? Is it related to length contraction in Lorentz coordinates, like time dilation is related to the time dimension in Minkowski space? It does correctly predict black holes so there must be something right I am curious because time dilation is enough for Newtonian limit. What motivated him to go beyond that?

[@TheMachian]

There is an elegant formalism, Riemannian Geometry, I think that's it. Regarding black holes, I do not think the evidence is unambiguous.

[@Robinson8491]

@@TheMachian thanks for your answer

[@odenwalt]

What is understood as space-time, I like to think is causal mass that makes up all matter in the universe. The speed of causality is often mistaken with the speed of light in a vacuum. I think length contraction is the encoding of energy density of a vacuum. As you increase the energy density of space (Causal Mass), one would also cause entropy dilation. Variable speed of light is not only intuitive, but also makes sense. The speed of causality never changes. Clocks change speeds due to gravity and acceleration due to, entropy dilation. One can also refer to entropy dilation as Hamiltonian saturation of a system. The quantized amounts of least possible action are slowed due to Hamiltonian saturation of the system. No one should disregard variable speed of light. Of course, the speed of light is going to change as energy densities in a vacuum change due to curvature.

[@nathanielhellerstein5871]

If VSL implies changes in time and length scales, then what does that say about the cosmological redshift?

[@TheMachian]

Good question! There will be a separate video about this :-)

[@wesbaumguardner8829]

It was known before Einstein was even born that the rate of propagation of light waves is variable and dependent upon the medium.

[@trucid2]

Interesting approach and certainly more intuitive than a non-euclidean spacetime, even if the math is identical. Something similar has happened in science a few times where there are two perfectly reasonable alternatives for the nature of reality, and one is picked as the preferred explanation while the other is demonized. Quantum nonlocality is one. Cosmological redshift is another. The consequences of both choices still plague us today: one implies there was a big bang and the other leads to a mindbogglingly incomprehensible view of reality on the quantum scale.

[@davidwilkie9551]

Hyperfluid time-timing->variable relative-timing ratio-rates of QM-TIME. Of course all self-defining spin-spiral condensation in/of log-antilog interference constants are variable. Including Bose-Einsteinian Condensation.

[@norlesh]

Does it simplify the mathematics of GR?

[@paulwolf8444]

Varying speeds ok. Curvature is from refraction. You should get together with the people working on the electric universe at the Thunderbolts Project.

[@JungleJargon]

The speed of light doesn’t change. The rate of time changes and the measure of distance changes… which effectively changes the speed of light as we observe it over great distances. Time runs faster in outer space where there is no matter and much less gravity. This is the reason the outer spiral arms of the galaxies move much faster than expected. It’s because events take place at a faster rate the less gravity there is. Time doesn’t run at the same rate everywhere in the universe. Time runs faster in outer space. It just dawned on me the other day that a thousand years and a single day happen at the same time in different places in the universe. It's simple (observed) general relativity. Time slows down and distance is contracted because of gravity where there is a lot of matter. Conversely, time speeds up and distance is expanded where there is no matter in outer space. This eliminates the need for dark matter since time is sped up in the outer spiral arms of a galaxy where there is not nearly as much matter. It eliminates the need for dark energy where space is expanded in outer space where there is no matter. So the result of general relativity is that billions of years pass by in outer space (13 billion years) at the same time as thousands of years pass by where we are inside of the Milky Way galaxy. ...! Billion of years and mere thousands of years are the same thing *at the same time* in deep outer space and where we are, according to physics and according to relativity. In review, time slows down where we are. Time speeds up with less gravity so the outer spiral arms of galaxies move faster. There is no need for dark matter. Distance increases where there is no matter in outer space. There is no need for dark energy to expand space since the expansion of space is from not having any matter far away from the galaxies. Deep time (billions of years) and thousands of years exist simultaneously in this universe where there is no single rate of time or measure of distance! Conclusion: The time it took for Creation and since Creation in the Bible is absolutely true! Time itself is a (real) fabrication.

[@jaysalbhatt2501]

equivalance princicple is based on the premis that force is an illusion. The conservation of events when a change of perspective happens is what creats this illusion.

[@GamesBond.007]

Light is an electro-magnetic wave. If its somehow slowed, or deflected or curved by a gravitational field, then it means gravity is an electro-magnetic field. Which all scientists say it isnt. So how does gravity slow and deflect light then ?

[@cassiano2704]

Professor, are you familiar with the work of the mathematician and philosopher Wolfgang Smith?

[@TheMachian]

I am not prof. But we are in contact.

[@djelalhassan7631]

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

[@wisdomhappy587]

You should amend the wiki page!

[@kkgt6591]

Intuitively it feels that, speed of light should speed up near mass as the mass will attract light. It does not make sense that light will slow down. It also does not explain, how light senses presence of mass?

[@jaycorrales5329]

Is there a range for VSL? Since it is possible that light can be frozen in a gas at 0 mph, what is the upper bound in the so called vacuum of space? The video describes that speed of light varies within a gravitational field, what are the bounds of its value numerically or by measurement?

[@TheMachian]

I will provide the concrete formulas in a later video. However, the change is small.

[@ferdinandkraft857]

Dr. Unzicker, in geometric GR, roughly speaking, masses "suck" space in, and that gives the illusion of gravitational attraction. What is the corresponding mechanism in VSL? How does it "propagate" throughout space?

[@BreytnerNascimento]

It goes back to being a Field

[@ferdinandkraft857]

@@BreytnerNascimento a field of what?

[@TheMachian]

The potential is jut proportional to c^2. More on that will follow.

[@ferdinandkraft857]

@@TheMachian thanks. It will be great to see a video going deeper is VSL.

[@apolloniuspergus9295]

@@TheMachian It appears to me that, in order for the speed of light to be variable, the electric permittivity and/or magnetic permeability would have to change with the presence of mass according to a certain rule, as indicated by Maxwell equations. So there would be a need for masses or, to put it better, energy, to interact with the electromagnetic field. The presence of energy would distort the value for the magnetic and electric constants in a certain area, which would then not be constants. The gravitational constant would then be a mediator of the relation between energy and the EM field.

[@pghislain]

Hello. If C=λf depends on the gravitation potential... then couldn't we study the variation of C in glass, Boose Einstein concentrated etc... based on the assumption that the gravitation potential vary in condensed matter. Big variation indeed. The diffract of light would be of particular attention. Etc...

[@Skandalos]

Many including many scientists today view science like religion.

[@minkis42]

If a Wikipedia article is incomplete or inaccurate then just click the edit button at the top and fix it... complaining about it just shows you don't understand what Wikipedia is.

[@TheMachian]

I appreciate too much my own time for wasting it for a fight with anonymous morons.

[@zippymax1]

I understand what Wikipedia is...and laugh.

[@curiousmind9287]

I thought it has been known for a long time that 1919 “confirmation” of general relativity was erroneous. Light bending was not due to gravitation of the sun, but due to electrical charge of the corona.

[@surendranmk5306]

Do you think that eletrical charge, positive or negative can bend the light which allways allternating it's charge? Is there any experiment that proved it?

[@Robinson8491]

How about those photo's of black holes gravitational lensing 🤔 although that is obviously not the Newtonian limit

[@curiousmind9287]

@@Robinson8491 well, there are much better explanations for what is referred to as so called “gravitational lensing” that do not have anything to do with gravitation, lensing or black holes.

[@TheMachian]

@Curious mind, charge of corona: I heard this, yet I am not convinced: there appear to be many other observations of light deflection. Would be nice if you can give a sound reference backing this claim.

[@TheMachian]

@Apsteronaldo: I do not believe the M87 BH is good science. Too many theoretical assumptions went into that picture.

[@mathrodite]

You could add that section that's missing in the Wikipedia article!

[@TheMachian]

Too many anonymous morons there who delete valuable content. I do not have time to waste.

[@michaelgonzalez9058]

Because in a room light bends

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

Surly the speed of light as a variable can be seen when it moves through water?

[@TheMachian]

Yes, the idea is that this is basically the same effect - just provoked by the gravity of nearby masses.

[@matterasmachine]

@@TheMachian maybe gravity is provoked by mass - photons for example

[@surendranmk5306]

@@TheMachian Exactly not! It is delayed by the interaction of electric charges of the nearby particles. Gravitational effect of nearby particles is too low to contribute a provocation!

[@BlueGiant69202]

en.m.wikipedia.org/wiki/Fizeau_experiment#:~:text=The%20Fizeau%20experiment%20was%20carried,upon%20the%20speed%20of%20light. D. Funaro, Electromagnetic Radiations as a Fluid Flow, Preprint (2009). arXiv:0911.4848v1 . Weyl gauge theories of gravity do not predict a second clock effect @arXiv by Michael Hobson, Anthony Lasenby. arxiv.org/abs/2009.06407v1

[@TheIgnoramus]

Would Abraham Pais happen to be related to Salvatore Pais?

[@michaeltellurian825]

How can gravity affect a massless particle?

[@TheMachian]

I think VSL provides a good ground for understanding, though the question remains, how this lowering of c actually occurs.

[@johnlord8337]

Einstein's model drawing has flaws, and some of his words and concepts spoke thereof. There are various electro-static and electro-gravitic objects that do NOT interact with gravitational fields (neutrinos/neutrons), and those that do (photons/photinos, (half-EG gravity) bosons. Larger (photons) with higher energy have gravitational lensing and escape, while smaller enegy photinos are gravitationally captured and orbit around the larger gravity object as "glow." Thus, these smaller particles, which have some EG portions in their object, show the hidden truth of variable or less-than-light speed particulates.

[@johnlord8337]

Electro-statics and electro-gravitics correct, reform, and restate General Relativity (GR) and Special Relativity (SR) with greater clarity, helping the union of all of the various physics sectors, that fight back and forth between themselves as being the only truth-tellers, which makes all of them partial liars or self-illusionists, as not being able to connect these sectors together with valid transfer data and models between themselves.

[@CentralScrewtinzer]

Given VSL it is fairly easy to see where “dark matter” of the universe comes from.

[@TheMachian]

Would you elaborate on that? Not easy for me, even if I continue to ponder that question...

[@BloobleBonker]

Yes, but what about the ergosphere around a rotating black hole? A scalar tield can't do it.

[@TheMachian]

I don't think there is convincing evidence for this effect.

[@mowgo9879]

What happens to the expanding of the universe with a variable speed of light.

[@TheMachian]

The material is not expanding, just lights spreads... there will be a video on that.

[@narayankhanal9662]

Great

[@ian_b]

So if space has a refractive index and the presence of matter changes the refractive index, how close is that to saying there is something like an Ether? Seems pretty close to me.

[@TheMachian]

Yes. Einstein, btw was not against the ether from 1920 on.

[@ian_b]

@@TheMachian Wow, thanks for replying! I was watching a video about Copernicus the other day (just a general history one) and it struck me how it took so long to recognise elliptical orbits because everyone thought circles are "more perfect"; i.e. it was a kind of aesthetic argument. I wonder how much of Physics is again trapped in what amounts to aesthetic arguments. It sometimes seems to me it has lapsed from mathematics describing reality to mathematics *being* reality, so we have the aesthetic purity of geometry without any messy "substance" if you see what I mean. And that's blocking new ways forward to think about what is really there.

[@BreytnerNascimento]

@@ian_b the whole theoretical physics is trapped in aesthetics since at least around 1950

[@VoiceTotheEndsOfTheEarth]

@@ian_b You just hit on the fundamental difference between philosophy and science, i.e. idealism vs. realism. Mathematics, particularly the deductive logic of geometry, has traditionally been the language of philosophy from the time of the Greek philosophers. It was for that reason, after a Aristotelian geocentric view of the universe failed to reflect reality as proven by Galileo's telescope, that the mathematician Rene Descartes tried to re-establish philosophy on a firm foundation by seeking the one premise that was absolutely certain, from which all truth could be deduced. That is idealism, for it originates in the mind. Science took the opposite approach. Start with what is really observed, then by induction, produce an overarching theory to explain it. That is realism. Of course, if you start there, you avoid the problem of the real world not conforming with your ideas, but you introduce a problem on the back end -- there could be many theories to explain the phenomena, and you are never certain that the theory is the correct one, or merely one that fits the data you have on hand. Moreover, if you start with the natural realm, you are implicitly eliminating the supernatural realm from consideration. So the debate unfolding in this comment section is an age-old one. As an aside, what's interesting about Copernicus is his heliocentric theory was a last ditch publication as Copernicus was up in age. One of his students encouraged him to publish the work and took it to a Lutheran theologian by the name of Andreas Osiander. Osiander read the piece and knew that the Catholic church, which was by then steeped in the Aristotelian dogma Thomas St. Acquinas had introduced, would object. So he took it upon himself to write an anonymous foreword admitting the theory might be controversial, but that the reader should keep an open mind because even if it weren't proven to be true, at least it would be useful to produce more accurate calendars. When Copernicus found out about it, he was understandably furious. But Osiander actually did him a favor, because Copernicus was spared the harsh treatment that Galileo received some seven decades later. By the way, Osiander was an ancestor of mine. That's why I took an interest in the story.

[@ian_b]

@@VoiceTotheEndsOfTheEarth Interesting points.