The reason why the speed of light is constant is much simpler to understand. It isn't the speed of light at all but the speed of causality. Because we experience time and time is a calculation in speed there must be a minimum amount of time between when a thing is in one place and when it is in another. If it was instant then time and reality as we know it would collapse. But if there is a minimum time there must be a maximum speed based on that time. That is the speed of causality. Now, since light has no mass it can really only move at the maximum speed. Zero mass means that any amount of energy would accelerate it to max possible speed. This is true for all massless "particles"; photons, gluons, and if it turns out there is a gravity particle that one too. This is why you have causality issues, time travel, and all that other sci-fi stuff when you do calculations faster then light. Not because light is special but because the universe we perceive is moving forward through time.
It's constant light speed which has been postulated in special relativity and not the causality. I think constant light speed is much more fundamental than any other thing.
I worked on radar for 21 years. We learned all about the Doppler Effect. We had radar coverage "issues" in the east when the sun rose and to the west when the sun was setting. It was only for about 20-30 mins or so. The angle of the sun to the radar propagation angle lined up at those times...causing loss in radar coverage. Not a big deal. But, if one wanted to evade being detected on radar...fly toward the radar with the sun to your back at those times. Thankfully, there are redundant systems that counteract those kinda threats!
The sun emits a broad spectrum some of it falls below infrared into upper radar band. The shallow entry angle and through a thick curved atmosphere produce a magnifier effect to saturated the RF and baseband Rx channels of the radar.
What "constant in the local frame" means ? ... it should be in respect to a specific way of measurement ? .. what is that measurement method ? ... It's stunning how many and often scientists copy-cat that statement without due scrutiny ... Which is very ambiguous
When light curves around the sun it takes a longer linear trajectory than a straight line (called a geodesic) to get to its destination. Its a curvilinear manifestation of the bending of space time caused by large celestial bodies (i.e. general relativity). And whenever light seemingly slows down, this means time dilation is also in effect, as time and lightspeed maintain a constant equivocal correlation no matter the reference frame or circumstance.
Light slows down since it is a wave as it travels through different media or it is bent by the gravitational force from a planet. Einstein gave us a new model to analyze and make us aware of the fact that the frame of reference has to be considered when trying to measure events, since the speed of light is not infinite, we have to accommodate this fact when measuring.
According to Frank Wilczek, photons also slow in a superconducting environment - yet there isn't enough gravity in that environment to alter spacetime to its required amount to explain that effect. I think it is more likely that any alteration or deviation in light's path is due to a change in its ability to propagate its kink or "ripple" along the pre-existing electric field framework that was traveling in unison with the atoms that created the light to begin with. In my opinion it is more likely that gravity affects the behavior of the ripple in the field with the field itself and as a result we have bending and slowing effects based on that - and not the ever-popular bending of "spacetime" explanation.
There's an error in video @ 2:30 lambda shown should be decreasing not increasing as the source is moving towards object and frequency is increasing hence lambda should decrease
Michelson-Morley's experiment was not null. The values that were measured were smaller than what was expected. They did have direction of about 17h sideral.
In plain English that I can understand pure empty space has a property (permittivity and permeability) that determines the speed of light so the speed of light is constant simply because empty space is constant, total emptiness must look the same for everyone however fast they're travelling. The big mystery is how you can have a property without any substance. If space was any substance at all however tenuous then the speed of light would be relative to that and not be constant for everyone. That's surely the starting point for relativity, I'd love to see a video about how electromagnetism relates to empty space with the great animations that we see here.
Yeah, I would also like to see a concise animation of the propagation of electromagnetic waves: continuous versus pulses. There's is one video about the "size" of the photon, where the author realizes that only attenuating a continuous source of the light with filters won't generate "true" wavepackets aka photons. Maybe PBS spacetime channel has some video on the topic
In my view, space is abstract, pure emptiness. It is just containment. There is no curvature itself. If G-fields bend c, or M-fields, or E-fields bend c, so fields are curved. Time is also abstract. If spacetime is physical, then at one point in space, it will have three different space curvatures, and three different times for G.E.M fields. Therefore, at the same point (space’) there’s three spacetimes, (time’).
@@davez4285 Dave, as I recall, light is an E&M wave. Radio is an E&M wave, as are x-rays, gamma rays, etc. All are E&M waves, just at different frequencies.
It is not a sacred cow. It is an enemy that against space travel and communication. Unfortunately we couldn't find any method to send anything (that could hold ANY information) faster than light, and we probably never will because this would break causality.
Great video, but it does not answer the title question: « why is light speed constant ? ». This fact is measured in experiments and confirmed by the resulting theory(ies) of relativity producing correct predictions with that assumption, but the basic question: (why? ) remains unanswered
The speed that's constant is the speed along any time-like curve (world-line). In the flat space metric we have s^2=d^2-x^2 where s is the distance along the traveler world-line, d is the distance along the observer world-line, and x is the distance projected onto the spatial coordinates of the observer. The speed along any world-line (given by the tangent vector to the curve) is a constant c.. Using D=cT (rate times time is distance) the line element is then c^2τ^2=c^2t^2-x^2. Since the shortest distance is zero and is the distance traveled by a photon, s=0, we have 0=c^2t^2-x^2 which yields the coordinate speed of light x/t=c, but this is ultimately the speed of along the observer world-line.
Reading through the comments it seems obvious that many people missed the part in the video where it says the speed of light is NOT UNCONDITIONALLY equal to c. In their own minds they leap to the wrong conclusion that the speed of light is variable. By CONVENTION we measure the speed of light locally as if there was an observer at each point along the path of a photon and likewise we do NOT measure the speed in a global reference frame. That is what people seem to be failing to grasp....even though this video explains it to them.
The video spends a lot of time on the water wave model and then shows that Michelson-Morley experiment demonstrates that light propagation can't possibly work like the conventional fixed ether water wave example. That is all correct. But it misses the bigger point (which almost everyone else does too) that the M-M experiment used an internal light source that was fixed and moved in unison with the entire apparatus. The final result is consistent with the not-so-exciting knowledge that light is generated when electrons fall to a lower energy position and create a kink or "ripple" in the existing electric field lines that were traveling in unison before, during and after the light was generated. So the experimental apparatus (like all other light generating examples) had its own personal ether or medium that moved in unison with the source and measuring devices. As a result, it turns out that throwing a bowling ball off the side of a moving cruise ship and monitoring the wave propagation in the ocean is not an accurate analogy to light propagation - but making a splash in the cruise ship's swimming pool whose water (ether) is moving in unison with the ship, the generator of the splash and the recipient of the water waves at the other end of the pool is exactly like what Michelson-Morley demonstrated.
@@chriskennedy2846 That "personal aether" sounds workable. It could be tested by driving trucks next to the interferometer I suppose! They should drag the aether along and affect the result, like a boat in the Cruise Ship's pool.
But what even is a global frame of reference? according to Einstein all reference frames are same and will always measure the speed of light to be c. I think the video is misrepresenting the time delay, light takes longer when Sun is nearby not because it becomes slower, but because the Sun's mass warps the space time and now light has to literally travel a longer distance and thus taking longer time to reach its destination. If the speed of light were to vary per "local" or "global" (whatever that means) frames all of our frameworks of physics would fall apart.
06:00 and how the did the measurement? Is there any electromagnetic measurement way to measure the speed of light in one direction? No, so prove to me if the light in the one direction didn't travel 6 time the c and when it is returning the speed wasn't 1/6? That is the reason for the Einstein famous paper where he said that is it impossible to measure the speed of light in one direction, because to do such a measurement you need some synchronization signal of the measuring units to travel faster than light. For that reason we use the same light as a signal and after the time measurement we're dividing the time/2 to say this is the time that the light needs to go or to return the distance. This is also a dogma in our measurement because we do not know something moving faster than the c. About the bending of light around the Sun there isn't Ether, but there are different layers in the Sun atmosphere and the limit between them creates the phenomenon of Refraction of the light which can bent and change even its speed. In diamond, the speed of the light is the half of c.
Regarding the analogy: Surface waves do not travel at a constant velocity - their speed increases with wavelength. The best explanations will be found in discussions of the "hull speed" of displacement boats.
It's called dispersion. Also electromagnetic waves, such as light, reveal dispersion, when the phase velocity of waves depends on their frequency. But that was not important to the concept that was displayed here. The idea was to assume that a certain wave is being observed that comprises a certain wavelength, which depends on the phase velocity and the frequency. Dispersion is a detail that is not necessary to grasp this idea.
5:57 - how did they conclude that "C" is slowed down going around de Sun? speed = distance/time. Distance increases, time increases, and speed must remain (almost) constant. What distance are we counting in, the straight line, or the curved one? The curved one, of course, because the signal cannot go through the Sun. So the distance increases, time increases, and c must be the same. Why is smaller?
The speed of light decreases over time.... a Nobel has been awarded for this little nugget. If space expands, the distance traveled is less and the same redshift occurs....
Examples of how the idea of relative speeds is an illusion, but not any expression of reality: Person A is driving from North to South at the average speed Sp1= 50 km/h, while person B is driving in the opposite direction at the average speed Sp2 = 30km/h, and person C is driving in the same direction at the same speed Sp3 =50km/h, and person D standing by the road. All the speeds Sp1, Sp2, Sp3 are actual and unchanged values from the observation of each insiders of each of such motored vehicles, and those actual speeds are the foundation to calculate how long it will take each of them to get to their different destinations, while to the observation of the person B , the person A is moving at the speed Sp1 = Sp1 +Sp2 = 50km/h + 30 km/h= 80km/h, and similarly from the observation of person A, person B seems to be moving at the Sp2 = Sp2 + Sp21= 30km/h +50km/h = 80 km/h, but the speed 80kn/h is not the actual speed of vehicle1, nor the speed of vehicle 2 , but it is the combination of the speeds of the 2 vehicles moving in 2 opposite direction, and thus, the combined speed is not the foundation for neither of them to calculate how long it will each of them to get to their different destinations. So the combined speed is redundant or merely an illusion in this context. Likewise, person C is moving in the same direction as that of person A at the same speed Sp3 = 50km/h which is the actual speed, and the foundation for both of them to calculate how long it will take each of them to get their different destinations, but not that their speeds Sp1 and Sp3 are both zero km/h which is merely an illusion due to the fact that both of them are moving at the same speed in the same direction, which is if both of them were in the same car. So, the peed = 0km/h is merely an illusion and can never be any foundation for anyone of them to calculate the periods of time nor the distances they will travel. From the observation of person D standing by the road, all the 3 speeds Sp1, Sp2, Sp3 are the actual speed because the concept of speed is established on the displacements of moving objects or particles, but not on any speed of any moving thing. The actual speed of a moving object is dependent on the values of its displacement or the change of its location with respect to the change of time V(t)=( D2 -D1)/ t2-t1. There are some applications of the idea of combined speeds of objects moving in opposite directions, such as 2 missiles being launched from two different locations. One is an attacking missile, and the other is a defending or countering missile. You can apply the idea of combined speed to estimate when you should launch the defensive missile to destroy the attacking missile before it can reach your land. But again, all such combined speeds are not any actual speed to be based on for calculation of actual capabilities
Please answer the following questions to determine the speed of the particles as the base of every model. Imagine there are 4 lanes, 1km each. One lane has a straight line painted in the middle and is 10 meter wide, second one has a wave line painted with a 10 meters wavelength and 10 meters wide, third one has a wave line painted with 20 meters wavelength and 10 meters wide, forth one has a wavelength of 20 and width of 20 meters (not 10, as amplitude). Four runners (particles) at the same speed will run over the lines on the lanes. Which runner will reach the end first? If the runners are asked to reach the end of the lanes at the same time, did they run at the same speed?
The most intuitive way to explain how or why a particle like a photon (or electron, etc) might behave as an uncertain location particle while also like a polarizable axial or helical wave ''packet'', given that everything in the universe from electrons to solar systems are in orbit with something else pulling them into polarizable axial or helical apparent waves depending on the orientation of their orbits as they travel thru space, is that they’re in orbit with an undetectable dark matter particle pulling them into polarizable axial or helical apparent waves as they travel. And given that we know we’re in a sea of undetectable dark matter but don’t know where it’s disbursed, we can imagine that they’re in orbit with an undetectable dark matter particle pulling them into polarizable axial or helical apparent waves as they travel where the speed of their orbit determines the wavelength and the diameter is the amplitude which would explain the double slit, uncertainty, etc. No?
Like quantum theory it’s just a bunch of equations that can’t be described by analogy with our everyday life. The big question for me is how did the whole thing spring into existence, with all its mathematical complexity?
We cannot, as yet, exclude the possibility of a variable speed of light so longs we cannot reduce the magnitude of space or vacuum to test. It is unscientific to treat the concept of the constancy of the speed of light as a dogma or proven fact. It simply isn't proven
The local effect of a constant "c" is produced by the difference in time rate at each, (and every) location. Any relative change in speed is always exactly counteracted by the equivalent change in time rate which negates the change in relative speed. This is the reason WHY "c" is constant at any local position.
There is a new view about C; it's about the quantum oscillation first deduced by Planck. He uses the equation that energy presence comes in discrete form and its value depends on action h and the frequency. This frequency and its energetic wavelength length are related to C. The limit of a quantum package or system is limited by this oscillation (constant speed C), and this is the reason why on 3D the speed limit is C (the package can't move further than its oscillation). The intrinsic reason for light and any object comes from the quantum theory... hope you like this view. You can read more in a short amazon book "Space, main actor of quantum and relativistic theories. regards
Speed of light measured by scientific or atomic time will always have the same speed. But consider the Galilean transformation concept of time. It was based on the rotation of the earth, one second being 1/86400th of the time it takes for the earth to rotate. Now consider a clock in a flying airplane. Einstein says this about that clock. The time which elapses between two strokes of the clock is not one second, but 1/sqrt(1-v^2/c^2) seconds, a somewhat larger time. As a consequence of its motion, the clock goes more slowly than when at rest." So if we have a GPS clock on the surface of the earth that agrees with the rotation of the earth, then the clock in the airplane does not. We then have a difference in the concept of time used by Galileo and Newton and the concept of time used by scientists today. If we take the Galilean transformation equations x'=x-vt y'=y z'=z t'=t these equations say nothing about the time of the clock in the airplane. To show the time of that clock, we would need to use a different set of Galilean transformation equations with different variables for velocity and time. If we are using the time of the clock in the airplane to show relativity from the frame of reference of the airplane, the equations would be x = x' - (-vt/n')n' y = y' z = z' n = n' n' is the time of the clock in the airplane, and (-vt/n') is the velocity of the ground relative to the airplane. If we are saying that both clocks show light to be traveling at c=186,000 miles per second, according to the times of the clocks, then we would say x=ct and x'=cn' instead of x=ct and x'=ct' as Einstein and Lorentz did. Then we get x'=x-vt cn' = ct - vt n' = t-vt/c which is the same as the numerator for Lorentz's equation for t' if we substitute in x=ct. t-vt/c = t-vct/c^2 = t-vx/c^2 This is the part of Lorentz's equation that results in a slower clock in Special Relativity. The length contraction is a result of the denominator of Lorentz's equation. Since there is no length contraction in the Galilean transformation equations we just have n' = t(1-v/c). If t is GPS time, then we can see how faster velocities relate to slower clocks. A clock on Mercury would be slower than a clock on earth because Mercury is traveling at 30 miles per second in its orbit, while the earth is traveling at 20 miles per second. Outer planets would have faster clocks than a GPS clock on earth because they would be traveling slower in their orbits. If we compare the result obtained by this use of the Galilean transformation equations for the time of a clock on Mercury to the time obtained for that clock using the Lorentz equations, the results will agree to several decimal places. Using the Galilean transformation equations with t', which is what Isaac Newton did with his absolute time, results in a greater disparity of results. I have tried to communicate with scientists to get an opinion concerning this since I first thought of it in high school, but science of today is a religion, not a study of reality. If this mathematics works for the solar system, it should work for theoretical science in computing atoms, molecules, etc. Lorentz first derived his equations in calculating electromagnetic fields. Maxwell derived all of his equations using Galilean relativity. He died before the Michelson-Morley experiment took place. But scientists of today will not discuss the Galilean transformation equations at all. They are more interested in keeping the flow of money to themselves from governments than they are in mathematics and science. Do you think they are going to admit that a high school graduate discovered something they missed? I don't.
At some point the use of the word "constant" comes into question, replaced by "as observed in referential localization." I prefer to stop obsessing on the idea of "speed of light" and start thinking about Gravity and its transmutable effect on Time.
the first problem is the reason for the qualifier 'in a vacuum'. you see, even space is not a total vacuum. second light hasn't been measured from point a to b. so on earth, we know that light is slower. we know no one has measured light from 1 source to 2 different observers at different speeds. we know "space' from space-time is totally undefined. but we still assume that light speed is constant. and the differences in speed of light are so small that we wouldnt notice. we arent going that fast.
If nothing travels faster than the speed of light then why don't we take it as a reference or the absolute "speed-zero" and everything else is moving almost at the speed of light?
Suppose two vehicles are chasing each other in vaccum. The leading vehicle is equipped with a rear view mirror. If the speeds of the vehicles are each at 299,000,000m/s and 300,000,000 meters apart. How much time will it take for light from the headbeams of the trailing vehicle to reflect off the mirror of the leading vehicle and reach the driver seated 1m behing the rearview mirror?
Great video! I'm completely on board with a lot of what you said. Particularly the part about planets like Earth are "dragging" aether along with them. Although your graphic shows the Earth moving all the aether in its surrounding area, I suspect the dragged aether is more like a spherical envelope of gravity and aether that stretches out in a way that resembles iron filings over a paper covering 2 magnets. The iron filings allow us to see the spherical envelope of magnetic force emanating toward each other. Something that is not visible without the iron filings. I believe planets and bodies like the moon have similar interactions. And I suspect the Sun has an extremely huge aether dragged flow in a swirling pattern as our solar system races through the universe. I would compare it to distant constellations that appear to be swirling. Their stars are like the iron filings which allow us to see the nature of the dragged aether. Thank you for this video. It is an eye opener.
Listen to it again -- Luminiferous Aether was disproven and isn't really a thing. The video talked about why its failure as a theory led to the development of Special Relativity. Make sure that you do not get that confused with the concept of relativistic frame-dragging, which HAS been successfully observed and is a direct result of relativistic spacetime dilation. You can probably find some PBS Spacetime episodes on this, or if you would prefer a more college-esque approach, the lectures of Leonard Susskind or Kip Thorne may cover this at some point.
@@phoenix042x7 Yes agree. In a way, quantum fields are the new aether (wave carrier) but they are not the old aether (a type of liquid) which cared about inertial motion. Quantum fields let each of us do our thing, man. Zen! In a quantym field everyone has a right to consider themselves at rest on the couch, and still be surfing the waves.
Creators of this Universe also created laws of the universe. We're merely subjected to limitations of these laws. Is there a universal equation to break these laws/barriers?
According to Relativity observers on a moving train and a stationary train platform will disagree on the size of the Train and the passage of time on the Train. This is complete logical contradiction if the size and the passage of time of the train are real. If the size of the train is real, the Train can not be both contracted and not contracted. The same goes for the observed passage of time on the Train. If these effects are observed, then the only possible conclusion is that it is an optical illusion. Things that are real must appear to be same from all frames of reference, if not then it is an illusion.
A person looks at his watch and sees 1 second pass by. In that 1 second, everything that exists crossed an equal distance. In that 1 second, light moved a specific distance across space, while you for instance crossed an equal distance to what the light crossed, although in your case some of that distance extends across the dimension of time, rather that it be across space only. Thus it is not only the magnitude of the motion of light that does not change. Everything is always in motion, and with that exact same magnitude of motion.
Red Shift: Consider the following: a. Current narrative: Space itself is expanding. (Even though science does not fully know yet what 'space' actually is nor how it could actually expand). b. But consider: The net effect of solar winds, particles and energy pushing outward from galaxies, (even modern science claims 'em' has momentum), continuously, over a prolonged period of time, with other galaxies doing the same, with nothing to stop them from doing so, would tend to push galaxies away from each other and even potentially allow the cosmic web to form between galaxies. And then, when we here in our galaxy, look at far away galaxies, with other galaxies in between, the net effect of all those galactic interactions would have galaxies furthest from ours move away faster the further those galaxies were from us, including us perceiving a red shift of energy. c. Now, utilizing the scientific principal of Occam's razor, which way is more probably correct? What the current narrative is ('a' above), or 'b' utilizing known physics? * Added note: Plus, 'if' my analysis is correct that our spiral shaped galaxy is collapsing in upon itself, then consider also: d. When we look at solar systems between ours and the center of the galaxy, those solar systems would be getting pulled faster towards the center than ours, hence also seeing a red shift of energy. e. When we look at solar systems between ours and the outer edge of the galaxy, our solar system would be getting pulled faster towards the center then them, hence also seeing a red shift of energy. f. Only if we looked at solar systems adjacent to ours should we see a blue shift of energy (as the solar systems became closer together as they moved towards the center of the galaxy). I also propose looking for blue shifts of energy between our solar system and adjacent solar systems to confirm or deny this current belief. g. But if true, would also add to our observation of seeing a red shift of energy in this universe as our spiral shaped galaxy collapses in upon itself. Of which, not only would species from this Earth have to get off of this Earth before the Sun becomes a red giant one day and wipes out all life on this Earth if not even the entire Earth itself, but species from this Earth would also have to successfully get out of this collapsing spiral shaped galaxy, otherwise, most probably death awaits us all and this Earth and all on it are all just a waste of space time in this universe. All life from this Earth would eventually die and go extinct. Currently, no exceptions.
將MM實驗移至圍繞地球人造衛星上的太空進行，就會得出與預期一致的結果。光在水中傳播的相對參考系是水，而水很明顯地與真空的介電磁導不同，兩者並非在同一空間。這樣的觀念人人能懂，同樣的觀念將水換成空氣，與真空也非同一空間就不懂了呢？為什麼有人會認為地球大氣層內與真空屬於同一空間呢？ 驗證星光經過重力場是否偏折，在地球的實驗方法！ 作者：林德和 發布日期：2021年12月26日 牛頓（英語：Sir Isaac Newton，1643年1月4日－1727年3月31日）研究光學，主張「光的微粒說」，對於光線經過物體會不會因重力而彎折，找不出可行的實驗方法。於是在他1704年出版的《光學》書中留下「Do not bodies act upon light at a distance, and by their action bend its rays; and is not this action（caeteris paribus）strongest at the least distance?」的疑問。 1783年英國地質學家米契爾（John Michell）和英國著名物理學家卡文迪西（Henry Cavendish）認為光既是粒子，便可被星球的萬有引力吸引。 1801年，德國天文學家馮索德拿(Johann Georg von Soldner)基於牛頓的重力理論，以『(2GM/Rc^2)*(180/π)*3600』的式子計算出光通過太陽表面的偏折角度是0.84弧秒( 1弧秒是1度的1/3600)，僅止於計算，並未提出驗證方法。 愛因斯坦（德語：Albert Einstein，1879年3月14日－1955年4月18日）在其著作的光電效應論文裡認為光束是一群離散的光量子簡稱為光子；在其著作相對論裡，以黎曼幾何的概念認為時空可以彎曲，物質之間的重力來自於時空的彎曲，取代牛頓的萬有引力定律。星光在經過太陽附近時將被彎曲，造成星星在夜空中的位置偏折了大約1.75角秒（一角秒是1/3600度）。 但是 普朗克將輻射能量化E=hv，h是普朗克常數，v是輻射波的頻率，單位為焦耳（J）乘以秒（s）。波是頻率與波幅組成的，因此普朗克常數h就是定義每個波幅攜帶的能量固定值。 愛因斯坦的狹義相對論規定光子的靜止質量嚴格為0。否則光速運動質量會無限大，且頻率不同光速也會不同而矛盾，代之的以質能等價關係取得非0的等價質量。但等價的畢竟不是真實的質量，能受重力影響？ 他的光電效應說，電子一次只能接受一顆光子的能量。但是姑且不論光子碰撞電子的機率微乎其微，而從光打出光電子的時間不超過10^-9秒的事實比對，很明顯的與光子的能量計算式不符。 所以電磁波可能不是一直連續的波，但必定不是粒子。只是把難以計量的，簡化為方便計量的而已。 假設光被物體的重力場彎曲每光秒偏折一公尺，反光鏡直徑1公分正圓，鏡外設置光感應器，光束自反光鏡中心偏移到鏡外，有0.5公分，則光源至少必須有照射c * (5/1000)距離的功率。功率越高，光束發散越小，則可測得越細微的光線偏折。 愛因斯坦星光經過太陽偏折計算式 (4GM/Rc^2)*(180/π)*3600=1.760638516172007弧秒 每光秒偏折距離tanθ*c=2558.973380039165932公尺。 把太陽的數據換成地球則 =0.000574137836393弧秒，每光秒偏折距離tanθ*c=0.834471939140272公尺。 從而光線經過重力場是否會偏折？可在地球做實驗驗證。 驗證星光經過重力場是否偏折的實驗方法！ 光受不受重力影響，在地球就可以做實驗了，只要你有一光秒光程的雷射發射器，二面反射鏡，其中一面中心留半透明鍍銀光孔供雷射光束透射。兩面反光鏡相距適當距離平行相面，雷射發射器光束與反射鏡垂直校准中心後水平放置，在真空環境進行實驗。光束有無向重力方向偏折，表示受不受重力影響。如果相對論的時空彎曲及星光經過太陽偏折計算式正確，往返兩鏡的雷射光在地表每光秒將偏折83公分，肉眼可視。
This is the dogma of the Einstein's philosophy who, like his teacher prof. Mach believed that the material is the mass, and it is like the mass a product of some kind of energy. In this case of his thinking, if something material could be possible to do an action with a speed greater than the speed of light, as it is energy product, that means that the result of a material action could exist before even the action take place. And this for his thought of what was the Universe was out of logic and for that reason in the Universe of relativity where everything depends on the speed of its motion and on the use for study the motion of a referring frame he said his dogma, that you stop this is the greater possible speed. And it is a dogma because the only limit in a world of relativity for anything is only the referring frame, which is a subjective creation of the studying it people. About the speed of light from the law of Snell, it is obvious that it is, depending on the value of the Refractive index of the medium where the light is traveling. If the medium is with a negative Refractive index, like a group of American scientists from the University of California claimed, that they had succeeded to created such medium and that the light in it measure about 300 times the normal c in air. The only problem is who they succeeded to measured it. Probably the used the same laser beam to go and return for to be a measure.
The speed of light is a constant because everything moves at the speed of light all the time. If you move slowly thru space your are moving rapidly thru time. If you move rapidly thru time you move slowly thru space. Your net velocity thru the spacetime is constance.
While it's correct that the our speed along our own world-line has the same value as the local vacuum speed of light, it's wrong to think you can "move through space" and that such movement affects your time - this is emphatically false.
Magnificent graphical video. In 1975 High School Physics I was a slacker, due to a teenage love lost. My reality was emotional without the ability to communicate and share. I have grown over time and become relative. I reckon The Speed Of Light needs, Love and Understanding. It will come to those that understand, (space and time) as we know it, has trouble accounting for the rest of the universe (- space and - time). In all my years, I have finally learned respect for myself. Those that have ideas must continue on and understand the stupidity of Man"s, "Critical Mass" stage. Boo.
Here’s how light moves. A moving photon creates (induces) an electromagnetic wave and then a moving electronic wave creates (induces) a photon. It keeps doing this at the speed of light - never faster, never slower.
Why light travel at 'speed of light' and 'gravity wave' travel at 'speed of light'? Obviously there is a Relationship. It is interesting how these two are related!
In the beginning was the Word, and the Word was with God, and the Word was God. 2He was with God in the beginning. 3Through him all things were made; without him nothing was made that has been made. (John 1:1-3)
@5:50 light is completely curved. If this is the case, why we still see solar eclipse? If Moon is too small, then we shall ecliptic moon during solar eclipse due to bending light. In the light path from earth to Viking, light is slower at 0.9c, 0.95c, but in the local frame , it is still considered as c. What’s the reference for those local frames? That’s the assumption , not experimental. It seems to make up time dilation. The light is curved passing sun by space-time, curved space. In another way, we can say it is passing a gravitational field, the field is nonlinear, but space can be linear. It is the field curvature, not the space curvature. The magnetism also has field, do we have magnetic space-time, and electronic space-time?
I think that they take the mediums REFRACTIVE index in account when adjusting for the change in SPEED upon medium change...like entering earth's atmosphere from the vacuum of space...and if you have a watch station, say, under water or something then there will be further readjustment, and so on. ALSO, vice-versa when its leaving the atmosphere
I'm also in thinking of magnetic fields' space-time. If gravitation affects the time -- so does the Magnetic field. Because it bends the curvature of space-time. I also have an idea about travelling through space -- creates the model of "time travel". And travelling through time dimensions creates the model of "space traveling" (teleportation), means we can travel faster than speed of light if we goes along with the time dimensions. 😊 Speed is the ration of Space/Time -- which is always constant... If we change curvature of Space - ultimately there is a change in Time... Because Speed is always constant. & If we change the Time ultimately there is the changes in Space curvature. & How we gonna do this -- just by magnetic fields. We dont need lots of mass to change the curvature of space time... We need a "potential mass" which can manipulate the space-time such as "magnets"!! That's enough for today! :)
Heat is a medium and light rides depending on gradient of temperature and that's why light bends. On a circular path of heat light can rotate only so much.
For me this is not clear enough whether the light is the material particle ( foton) travelling through the physical space, or it is the material constant of physical space and the vibration of some physical parameter of this space without moving the material ( particles) object in this space. Is somebody able to clarify the issue? Stary
Light speed being constant relative to space and time measurements is different than being absolutely constant under all contexts. This is a big deal because relativity can be true and the 'constant' of light speed (c) can still be something that changes over time.
I was always confused with c and refraction. But this video and the comments cleared it up. Thanks. I will highly recommend others to read the comments as well. 👍
At 3:52, why the 2 waves coming from different sources "should have the same frequency"? They have if they emit at the same frequency! Moreover, the speed is the same, as the medium is the same, you say it earlier at 2:08. I do not get it, I think is a mistake in the script. At 2:23 there is another mistake, if the source is moving to the observer, than the frequency (f) increases, not the wavelength (lambda)!
if speed of light is constant then whole universe would be lit and bright .. speed of light depends on material it travels trough: space(helium) atmosphere (oxygen and others) water (h2o) glass etc .. and its not faster thing in universe .. light cannot escape black holes therefore particles inside black hole move faster than light .. ppl are still medieval in their thinking -> there is always a medium .. nothing aka zero is just a concept that does not exist in our universe .. there is always something there .. and btw infinity isnt just on left or right its also on zoom in zoom out (sorry eng is not my native lang)
What if... there is no speed of light! Why not think of it as a speed of TIME. A sequence of frames per second. We, as a poor observers, can detect very little. So what us the light? A separate dimension interacting with matter? Or just a "fabric" showing the results of matter interactions? Well, I hope some open minds will change the way we think and stick to what we SEE and how we run in circles to calculate things just to confirm what we "observe" is right!
Any uniform medium allows one constant speed of force propagation in three vectors perpendicular to each other, the energy of this being confined in a photon.
I don't think light slows down because of curved spacetime, but travelling a stretched/curved line takes longer than a 1-dimensional straight line. It's still the same velocity, it just takes longer to reach the relative destination.
that is what "it is still at the max speed for each local observer but seems to be slowed down for the observer on the earth" means. still depends on the observers reference frame.
This video arrived at the explanation for the constancy of light in different reference frames when it stated that V =freq x wavelength. ( @ 2.15 ). But then it went on to lose the simplicity of the explanation in more complicated areas. Do not think of light as photons or balls - think of light as waves. When different observers see light at different speeds, the light will be changed by the Doppler Effect. But when each observer calculates the wave speed (V ) by multiplying the freq X wavelength as observed, the wave speed will always be the same. So EM radiation ( light ) does not need a medium for propagation - this is what the Michelson-Morley experimental results showed us, and what Albert Einstein used as a basic assumption when he formulated his Special Theory of Relativity, and presented to the world in 1905.
Could someone tell me how one observer would see the light if the source of it was running in the opposite direction with the speed of the light???? One would see nothing???
The real question is if I am travelling at 1% of speed of light, will it be slower to me by 1% of c or will it be the same, if it will be the same then how?
I gather the speed of light is simply a direction in 4D spacetime. There is only one speed in the universe. The less you travel in space, the more you travel in time. Traveling at the speed of light is simply traveling strait in a 3D direction, a direction other than time. You can't travel faster than light because you can't travel straiter in a direction than strait in that direction.
Hi, in the experiment starting at about 00:35 light and train, when will the observer not on the train see the light in the train hit the mirror in the train? Before, same or after his light hits his mirror? And why, please? And the same question from the perspective of the observer on the train. Thanks
The problem is that the video shows the fixed observer at the opposite end of where the light finally hits the mirror, so the light would then have to reflect backwards in an additional path to the non-moving observer. Not to mention the train illustration (which completes at 0:40) must combine light propagation AND time dilation to make sense, but your question only concerns the arrival time of light. The easier setup to look at first - would be to put a non-moving observer at the right end of the track where the mirror is at the moment it receives the light signal. Then have the person on the train shine his flashlight out the window as the train moves toward the fixed observer. Will the fixed observer see the moving light go by him at exactly "c" ??? No - the light will pass him going faster than the c value. Why? because it is true that the light wave is moving along the grid of electric field lines at exactly "c" but the grid of field lines is also moving to the right in unison with the train (and therefore in unison with the flashlight responsible for generating the light in the first place). All of the electrons in the atoms of the flashlight have existing electric field lines that move in unison with the atoms down the track. when the light is switched on - that causes electrons to rise and then fall back down to lower energy which creates a ripple or "wave" in the existing electric field (in the form of an electromagnetic wave). So if I am riding in an open train car that is moving down the track at 40 mph and I throw the ball in the forward direction at 50 mph with respect to the train - then the person standing along side the track will see the ball go by at 90 mph. It turns out that since light rides along a "moving train" of electric field lines - this can affect the velocity of light as it does with the ball. Don't ever let any fool try to convince you of something different. Now we can answer your question: The atoms in the mirror on the train are moving away from the fixed observer. So the field lines are moving away as well. When the light leaves the atoms of the moving mirror - it moves along the electric field grid at exactly "c." But at the same time - the grid itself is moving away from the observer at some velocity. As a result, the net velocity of the moving train mirror light will be slower when measured by the fixed observer and therefore will arrive slightly later than the light from his own fixed mirror positioned outside of the train, even though at that moment - they are assumed to be the same distance to the fixed observer. Hope that helps.
Speed of light is minimum way outer space, earth travel speed of light around the sun, ,,,sun travel speed of light around the black hole center of galaxy,
I think time travels at a speed of light if some one travels at a speed of light the time seems to be stopped This may give a clues of relativity concepts. Allah knows best
Page 6:30 Light bent by refraction and not by gravity. The presence of gravity is a coincidence, not cause and effect. Light bends by refraction from increasing permittivity in the vicinity caused by solar ejections, adding electrons, ions, molecules, gas, particles : size much smaller than one light wave. Following logic in any theoretical debate puts us on a fast lane to come others finally fall short to our destination, the reality. Forever trapped in a virtual reality paradigm.
Light has no speed, it is infinite. We only perceive light having a speed because it's what is relative to us. We are living in the universe in almost infinitely slow motion. Light itself does not experience time, if a photon were a living thing it would experience the beginning and ending of the universe in 0 seconds. That's truly how fast light is. So yes, no matter where you are in the universe it will have a constant speed but depending on your velocity and/or position in a heavily gravitational field in space, outside observers will see a difference in time relative to you. This is also how people confuse black holes, most think that it is an object in space. Which it IS a singularity but staring at a black hole would not be staring at an object at all. You would be staring into an extraordinarily long time into the future. It is not spacial anymore, it is temporal. That is why no matter and light can escape it, because it is literally red shifting into the future. It's a wild theory, but it kind of makes sense to believe that we're experiencing slices of time that have already existed or is already a whole. We perceive large objects to pass time more slowly due to its gravitational field, when in reality that large object is itself perceiving light as the same constant as us, but to it, we're moving faster through time. So on the scale of the whole universe it could be as quick as a soap bubble forming then popping and it's over. However to us, and how unimaginably tiny we are, we observe that same soap bubble forming then popping for billions-trillions of years. Relativity is a hell of a drug.
The problem is that you are not taking into account general relativity. You aren’t considering the variable rate of time and the differing measures of distance. Einstein burned into peoples minds that the speed of light doesn’t change. The units of measurement to measure the speed of light do change over large distances and galaxies cover large distances. That means that the speed of light does change over large distances as observed by us. 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. Distance is expanded in outer space (not expanding). Plasma jets do not stream of five times the speed of light since the distance is expanded away from gravity wells. 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 greatly 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 distance in outer space is expanded 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! Just think what could be the reality *when* the photons register with our eyes or our cameras/detectors and there is a collapse of the wave function as seen or detected by us within our dilated time and distance. (Our rate of time is not the universal rate of time, especially for photons.) Conclusion: The time it took for Creation and since Creation in the Bible is absolutely true! Time itself is a (real) fabrication.
I struggle to understand the constant speed of light. If light is unable to escape a black hole, what does it do within a black? How can it be constant if it slows down in reaction to gravity? Why is light the constant factor in einstein’s relativity? Which then says time is subjective. It seems time is the constant, earth time as measured on the surface. So no matter where you go, that factor even without travel, sunrise or sunset, you would use the “on earth surface” as a constant, with everything else being subjective. Making travel into the past or future impossible. But i’m just a layperson, what do i know?
Time, as measured by the rotation of the earth, is not constant. In any equation, you need constant in order to take a measurement. EM waves are the closet to being a constant, have not changed for the most part in 2 billion years, so went with light as the constant and adjusted time. Information travels at the speed of light so when we see light slow down or be routed aound a black holes' gravitational field, it is easier to say space is warped or time dilation.
Why do we always say speed of light never changes?!. Speed of light always is relative to its environment in some spot around black hole light will be in shape of plasma just before its property changes and become solid and is not light anymore. Light's behavior is not the same when it is placed deep in planet, for instance as large as Jupiter. Each environment will affect physical property of light.
The vacuum speed of light is a constant for all inertial observers under the condition that either the Riemann curvature is zero on all components or that the measurement is a local enough measure.
Light travels through the space and time coordinates of the observer, but light itself has no world-line, the spacetime distance between any pair of events on the path of the light is zero.
F=ma is the formula for acceleration in space. E=mc^2 is the formula for acceleration in time. Space and time are separate frames of reference Acceleration in space = acceleration in time Not only is the Breakthrough Starshot solar sail being accelerated in space but it is also bring accelerated in time - radiant energy..
@@stewiesaidthatmy perspective is that if the photons don’t interact with the Higgs field (space) hence doesn’t experience moving from point A to point B all it can experience is time and not space.
@@smudds10 in physics, Force decreases with distance. How much Force does a single photon have. I haven't compared the Higgs Boson to see what it's value is compared to a muon's. You are dealing with two separate frames of reference. Space and Time. Photons experience a lot of space but very little time - radioactive decay. But they do redshift and lose force over distance. Given enough time/distance, a Photon's wavelength will become stretched to point that it is no longer a wave. The caveat is that the photon that left the star is not the same photon that arrives at the detector. It's information/force is relayed from one electrical charge to another as it propagates through space.
@@stewiesaidthat thank you for your interaction I would like to know more about the radioactive decay of the photon. As far as the redshift or blueshift of a photon it is due to increasing or decreasing distances of your observed object and not because of information force relaying. A photon will lower its speed depending on the medium it travels through other than the vacuum of space. One experiment that I believe explains this is the Fizeau experiment where there was a delay when light traveled through moving water and its wave interference pattern was disrupted due to superposition of the photon. But my assertion is photon doesn’t experience space while in the vacuum of space it only experiences time, that’s why distance in our universe is measured by light years.
I got lost with the CURVED path of the light. If it is LONGER than a straight path, say 1.053 times then obviously the reciprocal will be 0.95. Anything further before this is resolved is to me baseless. BTW, the two sources of light are shown as independent and synchronous, not an analogy with the Michaelson experiment where the second source is mirrored from the first. I have learnt nothing here and may I say that this video is definitely not moron friendly if that is what it is supposed to be. Thank you.
The reason why the speed of light is constant is much simpler to understand. It isn't the speed of light at all but the speed of causality. Because we experience time and time is a calculation in speed there must be a minimum amount of time between when a thing is in one place and when it is in another. If it was instant then time and reality as we know it would collapse. But if there is a minimum time there must be a maximum speed based on that time. That is the speed of causality. Now, since light has no mass it can really only move at the maximum speed. Zero mass means that any amount of energy would accelerate it to max possible speed. This is true for all massless "particles"; photons, gluons, and if it turns out there is a gravity particle that one too. This is why you have causality issues, time travel, and all that other sci-fi stuff when you do calculations faster then light. Not because light is special but because the universe we perceive is moving forward through time.
Light slows down when it goes through water, glass and other substances.
It's constant light speed which has been postulated in special relativity and not the causality. I think constant light speed is much more fundamental than any other thing.
Photons have dynamic mass. Photons have energy E>0. m=E/c^2, which is also >0. Photon has zero static mass.
The speed of light is constant under any reference frames, that’s the talking point
I also agree with you .Because time is a that what cannot be stopped
I worked on radar for 21 years. We learned all about the Doppler Effect. We had radar coverage "issues" in the east when the sun rose and to the west when the sun was setting. It was only for about 20-30 mins or so. The angle of the sun to the radar propagation angle lined up at those times...causing loss in radar coverage. Not a big deal. But, if one wanted to evade being detected on radar...fly toward the radar with the sun to your back at those times. Thankfully, there are redundant systems that counteract those kinda threats!
There are individuals who don't know this and I would prefer that continued. We are not all friends here.
@@diveron Its a well documented effect. its not top secret
Has any body worked out why? Does the sun emmit in the radar band?
Pretty sure the sun emits in all bands.@@leonhardtkristensen4093
The sun emits a broad spectrum some of it falls below infrared into upper radar band. The shallow entry angle and through a thick curved atmosphere produce a magnifier effect to saturated the RF and baseband Rx channels of the radar.
What "constant in the local frame" means ? ... it should be in respect to a specific way of measurement ? .. what is that measurement method ? ... It's stunning how many and often scientists copy-cat that statement without due scrutiny ... Which is very ambiguous
When light curves around the sun it takes a longer linear trajectory than a straight line (called a geodesic) to get to its destination. Its a curvilinear manifestation of the bending of space time caused by large celestial bodies (i.e. general relativity). And whenever light seemingly slows down, this means time dilation is also in effect, as time and lightspeed maintain a constant equivocal correlation no matter the reference frame or circumstance.
Light slows down since it is a wave as it travels through different media or it is bent by the gravitational force from a planet. Einstein gave us a new model to analyze and make us aware of the fact that the frame of reference has to be considered when trying to measure events, since the speed of light is not infinite, we have to accommodate this fact when measuring.
According to Frank Wilczek, photons also slow in a superconducting environment - yet there isn't enough gravity in that environment to alter spacetime to its required amount to explain that effect. I think it is more likely that any alteration or deviation in light's path is due to a change in its ability to propagate its kink or "ripple" along the pre-existing electric field framework that was traveling in unison with the atoms that created the light to begin with.
In my opinion it is more likely that gravity affects the behavior of the ripple in the field with the field itself and as a result we have bending and slowing effects based on that - and not the ever-popular bending of "spacetime" explanation.
@@chriskennedy2846we also know that gravity and speed have a similar effect on time.
Excellent graphic to help understanding the concept!! The visual/animation helps a lot to see the complex phenomena. Thank you for posting!
Thank you for your nice words!
There's an error in video @ 2:30 lambda shown should be decreasing not increasing as the source is moving towards object and frequency is increasing hence lambda should decrease
Michelson-Morley's experiment was not null. The values that were measured were smaller than what was expected. They did have direction of about 17h sideral.
In plain English that I can understand pure empty space has a property (permittivity and permeability) that determines the speed of light so the speed of light is constant simply because empty space is constant, total emptiness must look the same for everyone however fast they're travelling.
The big mystery is how you can have a property without any substance. If space was any substance at all however tenuous then the speed of light would be relative to that and not be constant for everyone.
That's surely the starting point for relativity, I'd love to see a video about how electromagnetism relates to empty space with the great animations that we see here.
Yeah, I would also like to see a concise animation of the propagation of electromagnetic waves: continuous versus pulses.
There's is one video about the "size" of the photon, where the author realizes that only attenuating a continuous source of the light with filters won't generate "true" wavepackets aka photons. Maybe PBS spacetime channel has some video on the topic
In my view, space is abstract, pure emptiness. It is just containment. There is no curvature itself. If G-fields bend c, or M-fields, or E-fields bend c, so fields are curved. Time is also abstract. If spacetime is physical, then at one point in space, it will have three different space curvatures, and three different times for G.E.M fields. Therefore, at the same point (space’) there’s three spacetimes, (time’).
@@davez4285 Dave, as I recall, light is an E&M wave. Radio is an E&M wave, as are x-rays, gamma rays, etc. All are E&M waves, just at different frequencies.
@@Hank520Tubewhat’s the point?
The constant speed of light is the greatest sacred cow in science.
It is not a sacred cow. It is an enemy that against space travel and communication. Unfortunately we couldn't find any method to send anything (that could hold ANY information) faster than light, and we probably never will because this would break causality.
Great video, but it does not answer the title question: « why is light speed constant ? ». This fact is measured in experiments and confirmed by the resulting theory(ies) of relativity producing correct predictions with that assumption, but the basic question: (why? ) remains unanswered
From Maxwell's point of view: because permitivity and permeability are constant.
@@nmarbletoe8210 The speed of light has nothing to do with the permeability/permittivity which are typically set to unity.
The speed that's constant is the speed along any time-like curve (world-line). In the flat space metric we have s^2=d^2-x^2 where s is the distance along the traveler world-line, d is the distance along the observer world-line, and x is the distance projected onto the spatial coordinates of the observer. The speed along any world-line (given by the tangent vector to the curve) is a constant c.. Using D=cT (rate times time is distance) the line element is then c^2τ^2=c^2t^2-x^2. Since the shortest distance is zero and is the distance traveled by a photon, s=0, we have 0=c^2t^2-x^2 which yields the coordinate speed of light x/t=c, but this is ultimately the speed of along the observer world-line.
@@KaiVieira-jj7di There is no formula for c given u and e?
@@nmarbletoe8210 Sure, but keep in mind that μ and ε don't exist in nature, but in the choice of units. Typically we set μ=ε=1.
Reading through the comments it seems obvious that many people missed the part in the video where it says the speed of light is NOT UNCONDITIONALLY equal to c. In their own minds they leap to the wrong conclusion that the speed of light is variable. By CONVENTION we measure the speed of light locally as if there was an observer at each point along the path of a photon and likewise we do NOT measure the speed in a global reference frame. That is what people seem to be failing to grasp....even though this video explains it to them.
The video spends a lot of time on the water wave model and then shows that Michelson-Morley experiment demonstrates that light propagation can't possibly work like the conventional fixed ether water wave example. That is all correct.
But it misses the bigger point (which almost everyone else does too) that the M-M experiment used an internal light source that was fixed and moved in unison with the entire apparatus. The final result is consistent with the not-so-exciting knowledge that light is generated when electrons fall to a lower energy position and create a kink or "ripple" in the existing electric field lines that were traveling in unison before, during and after the light was generated. So the experimental apparatus (like all other light generating examples) had its own personal ether or medium that moved in unison with the source and measuring devices.
As a result, it turns out that throwing a bowling ball off the side of a moving cruise ship and monitoring the wave propagation in the ocean is not an accurate analogy to light propagation - but making a splash in the cruise ship's swimming pool whose water (ether) is moving in unison with the ship, the generator of the splash and the recipient of the water waves at the other end of the pool is exactly like what Michelson-Morley demonstrated.
@@chriskennedy2846 That "personal aether" sounds workable. It could be tested by driving trucks next to the interferometer I suppose! They should drag the aether along and affect the result, like a boat in the Cruise Ship's pool.
But what even is a global frame of reference? according to Einstein all reference frames are same and will always measure the speed of light to be c.
I think the video is misrepresenting the time delay, light takes longer when Sun is nearby not because it becomes slower, but because the Sun's mass warps the space time and now light has to literally travel a longer distance and thus taking longer time to reach its destination.
If the speed of light were to vary per "local" or "global" (whatever that means) frames all of our frameworks of physics would fall apart.
06:00 and how the did the measurement? Is there any electromagnetic measurement way to measure the speed of light in one direction? No, so prove to me if the light in the one direction didn't travel 6 time the c and when it is returning the speed wasn't 1/6? That is the reason for the Einstein famous paper where he said that is it impossible to measure the speed of light in one direction, because to do such a measurement you need some synchronization signal of the measuring units to travel faster than light. For that reason we use the same light as a signal and after the time measurement we're dividing the time/2 to say this is the time that the light needs to go or to return the distance. This is also a dogma in our measurement because we do not know something moving faster than the c. About the bending of light around the Sun there isn't Ether, but there are different layers in the Sun atmosphere and the limit between them creates the phenomenon of Refraction of the light which can bent and change even its speed. In diamond, the speed of the light is the half of c.
Regarding the analogy: Surface waves do not travel at a constant velocity - their speed increases with wavelength. The best explanations will be found in discussions of the "hull speed" of displacement boats.
It's called dispersion. Also electromagnetic waves, such as light, reveal dispersion, when the phase velocity of waves depends on their frequency.
But that was not important to the concept that was displayed here. The idea was to assume that a certain wave is being observed that comprises a certain wavelength, which depends on the phase velocity and the frequency. Dispersion is a detail that is not necessary to grasp this idea.
5:57 - how did they conclude that "C" is slowed down going around de Sun? speed = distance/time. Distance increases, time increases, and speed must remain (almost) constant. What distance are we counting in, the straight line, or the curved one? The curved one, of course, because the signal cannot go through the Sun. So the distance increases, time increases, and c must be the same. Why is smaller?
The speed of light decreases over time.... a Nobel has been awarded for this little nugget. If space expands, the distance traveled is less and the same redshift occurs....
hillary...you should know better.
I can't tell how much amazing and simpler is this channel. Thanks a lot for all of your efforts
Glad you enjoy it!
@@universeiobut speed of light slows down in water?
Examples of how the idea of relative speeds is an illusion, but not any expression of reality:
Person A is driving from North to South at the average speed Sp1= 50 km/h, while person B is driving in the opposite direction at the average speed Sp2 = 30km/h, and person C is driving in the same direction at the same speed Sp3 =50km/h, and person D standing by the road.
All the speeds Sp1, Sp2, Sp3 are actual and unchanged values from the observation of each insiders of each of such motored vehicles, and those actual speeds are the foundation to calculate how long it will take each of them to get to their different destinations, while to the observation of the person B , the person A is moving at the speed Sp1 = Sp1 +Sp2 = 50km/h + 30 km/h= 80km/h, and similarly from the observation of person A, person B seems to be moving at the Sp2 = Sp2 + Sp21= 30km/h +50km/h = 80 km/h, but the speed 80kn/h is not the actual speed of vehicle1, nor the speed of vehicle 2 , but it is the combination of the speeds of the 2 vehicles moving in 2 opposite direction, and thus, the combined speed is not the foundation for neither of them to calculate how long it will each of them to get to their different destinations. So the combined speed is redundant or merely an illusion in this context. Likewise, person C is moving in the same direction as that of person A at the same speed Sp3 = 50km/h which is the actual speed, and the foundation for both of them to calculate how long it will take each of them to get their different destinations, but not that their speeds Sp1 and Sp3 are both zero km/h which is merely an illusion due to the fact that both of them are moving at the same speed in the same direction, which is if both of them were in the same car. So, the peed = 0km/h is merely an illusion and can never be any foundation for anyone of them to calculate the periods of time nor the distances they will travel. From the observation of person D standing by the road, all the 3 speeds Sp1, Sp2, Sp3 are the actual speed because the concept of speed is established on the displacements of moving objects or particles, but not on any speed of any moving thing. The actual speed of a moving object is dependent on the values of its displacement or the change of its location with respect to the change of time
V(t)=( D2 -D1)/ t2-t1.
There are some applications of the idea of combined speeds of objects moving in opposite directions, such as 2 missiles being launched from two different locations. One is an attacking missile, and the other is a defending or countering missile. You can apply the idea of combined speed to estimate when you should launch the defensive missile to destroy the attacking missile before it can reach your land. But again, all such combined speeds are not any actual speed to be based on for calculation of actual capabilities
My brain has hanged. Need more time to understand.
This channel is amazing. I really love this channel. Please do more
Thank you! Will do!
Please answer the following questions to determine the speed of the particles as the base of every model.
Imagine there are 4 lanes, 1km each. One lane has a straight line painted in the middle and is 10 meter wide, second one has a wave line painted with a 10 meters wavelength and 10 meters wide, third one has a wave line painted with 20 meters wavelength and 10 meters wide, forth one has a wavelength of 20 and width of 20 meters (not 10, as amplitude).
Four runners (particles) at the same speed will run over the lines on the lanes.
Which runner will reach the end first?
If the runners are asked to reach the end of the lanes at the same time, did they run at the same speed?
good job. are you using Blender for your animations?
The most intuitive way to explain how or why a particle like a photon (or electron, etc) might behave as an uncertain location particle while also like a polarizable axial or helical wave ''packet'', given that everything in the universe from electrons to solar systems are in orbit with something else pulling them into polarizable axial or helical apparent waves depending on the orientation of their orbits as they travel thru space, is that they’re in orbit with an undetectable dark matter particle pulling them into polarizable axial or helical apparent waves as they travel.
And given that we know we’re in a sea of undetectable dark matter but don’t know where it’s disbursed, we can imagine that they’re in orbit with an undetectable dark matter particle pulling them into polarizable axial or helical apparent waves as they travel where the speed of their orbit determines the wavelength and the diameter is the amplitude which would explain the double slit, uncertainty, etc. No?
Great graphics and expanation. Subscribed!
So glad you enjoy this video, thank u!
Like quantum theory it’s just a bunch of equations that can’t be described by analogy with our everyday life. The big question for me is how did the whole thing spring into existence, with all its mathematical complexity?
We cannot, as yet, exclude the possibility of a variable speed of light so longs we cannot reduce the magnitude of space or vacuum to test. It is unscientific to treat the concept of the constancy of the speed of light as a dogma or proven fact. It simply isn't proven
The local effect of a constant "c" is produced by the difference in time rate at each, (and every) location. Any relative change in speed is always exactly counteracted by the equivalent change in time rate which negates the change in relative speed. This is the reason WHY "c" is constant at any local position.
There is a new view about C; it's about the quantum oscillation first deduced by Planck. He uses the equation that energy presence comes in discrete form and its value depends on action h and the frequency. This frequency and its energetic wavelength length are related to C. The limit of a quantum package or system is limited by this oscillation (constant speed C), and this is the reason why on 3D the speed limit is C (the package can't move further than its oscillation). The intrinsic reason for light and any object comes from the quantum theory... hope you like this view. You can read more in a short amazon book "Space, main actor of quantum and relativistic theories. regards
God asked Mrs. God, "What do we have for lunch?"
Mrs. God said, "Let's c..."
Also known as background independent, constant speed of light is what makes space and time not absolute but relative.
Speed of light measured by scientific or atomic time will always have the same speed. But consider the Galilean transformation concept of time. It was based on the rotation of the earth, one second being 1/86400th of the time it takes for the earth to rotate. Now consider a clock in a flying airplane. Einstein says this about that clock. The time which elapses between two strokes of the clock is not one second, but 1/sqrt(1-v^2/c^2) seconds, a somewhat larger time. As a consequence of its motion, the clock goes more slowly than when at rest."
So if we have a GPS clock on the surface of the earth that agrees with the rotation of the earth, then the clock in the airplane does not. We then have a difference in the concept of time used by Galileo and Newton and the concept of time used by scientists today. If we take the Galilean transformation equations
x'=x-vt
y'=y
z'=z
t'=t
these equations say nothing about the time of the clock in the airplane. To show the time of that clock, we would need to use a different set of Galilean transformation equations with different variables for velocity and time. If we are using the time of the clock in the airplane to show relativity from the frame of reference of the airplane, the equations would be
x = x' - (-vt/n')n'
y = y'
z = z'
n = n'
n' is the time of the clock in the airplane, and (-vt/n') is the velocity of the ground relative to the airplane. If we are saying that both clocks show light to be traveling at c=186,000 miles per second, according to the times of the clocks, then we would say x=ct and x'=cn' instead of x=ct and x'=ct' as Einstein and Lorentz did. Then we get
x'=x-vt
cn' = ct - vt
n' = t-vt/c
which is the same as the numerator for Lorentz's equation for t' if we substitute in x=ct.
t-vt/c = t-vct/c^2 = t-vx/c^2
This is the part of Lorentz's equation that results in a slower clock in Special Relativity. The length contraction is a result of the denominator of Lorentz's equation.
Since there is no length contraction in the Galilean transformation equations we just have n' = t(1-v/c).
If t is GPS time, then we can see how faster velocities relate to slower clocks. A clock on Mercury would be slower than a clock on earth because Mercury is traveling at 30 miles per second in its orbit, while the earth is traveling at 20 miles per second. Outer planets would have faster clocks than a GPS clock on earth because they would be traveling slower in their orbits. If we compare the result obtained by this use of the Galilean transformation equations for the time of a clock on Mercury to the time obtained for that clock using the Lorentz equations, the results will agree to several decimal places. Using the Galilean transformation equations with t', which is what Isaac Newton did with his absolute time, results in a greater disparity of results.
I have tried to communicate with scientists to get an opinion concerning this since I first thought of it in high school, but science of today is a religion, not a study of reality. If this mathematics works for the solar system, it should work for theoretical science in computing atoms, molecules, etc. Lorentz first derived his equations in calculating electromagnetic fields. Maxwell derived all of his equations using Galilean relativity. He died before the Michelson-Morley experiment took place. But scientists of today will not discuss the Galilean transformation equations at all. They are more interested in keeping the flow of money to themselves from governments than they are in mathematics and science. Do you think they are going to admit that a high school graduate discovered something they missed? I don't.
At some point the use of the word "constant" comes into question, replaced by "as observed in referential localization." I prefer to stop obsessing on the idea of "speed of light" and start thinking about Gravity and its transmutable effect on Time.
the first problem is the reason for the qualifier 'in a vacuum'. you see, even space is not a total vacuum. second light hasn't been measured from point a to b. so on earth, we know that light is slower. we know no one has measured light from 1 source to 2 different observers at different speeds. we know "space' from space-time is totally undefined. but we still assume that light speed is constant. and the differences in speed of light are so small that we wouldnt notice. we arent going that fast.
If nothing travels faster than the speed of light then why don't we take it as a reference or the absolute "speed-zero" and everything else is moving almost at the speed of light?
Everything does travel at the speed of light along the world-line of that thing.
Suppose two vehicles are chasing each other in vaccum. The leading vehicle is equipped with a rear view mirror. If the speeds of the vehicles are each at 299,000,000m/s and 300,000,000 meters apart. How much time will it take for light from the headbeams of the trailing vehicle to reflect off the mirror of the leading vehicle and reach the driver seated 1m behing the rearview mirror?
What's your answer?
@@thetruthaboutscienceandgod6921 Chatgpt
Great video! I'm completely on board with a lot of what you said. Particularly the part about planets like Earth are "dragging" aether along with them. Although your graphic shows the Earth moving all the aether in its surrounding area, I suspect the dragged aether is more like a spherical envelope of gravity and aether that stretches out in a way that resembles iron filings over a paper covering 2 magnets. The iron filings allow us to see the spherical envelope of magnetic force emanating toward each other. Something that is not visible without the iron filings. I believe planets and bodies like the moon have similar interactions. And I suspect the Sun has an extremely huge aether dragged flow in a swirling pattern as our solar system races through the universe. I would compare it to distant constellations that appear to be swirling. Their stars are like the iron filings which allow us to see the nature of the dragged aether. Thank you for this video. It is an eye opener.
wt f are you doing here Richter Belmont. you should be in Castlevania defeating dracula
Listen to it again -- Luminiferous Aether was disproven and isn't really a thing. The video talked about why its failure as a theory led to the development of Special Relativity.
Make sure that you do not get that confused with the concept of relativistic frame-dragging, which HAS been successfully observed and is a direct result of relativistic spacetime dilation.
You can probably find some PBS Spacetime episodes on this, or if you would prefer a more college-esque approach, the lectures of Leonard Susskind or Kip Thorne may cover this at some point.
@@phoenix042x7 Yes agree.
In a way, quantum fields are the new aether (wave carrier) but they are not the old aether (a type of liquid) which cared about inertial motion.
Quantum fields let each of us do our thing, man. Zen! In a quantym field everyone has a right to consider themselves at rest on the couch, and still be surfing the waves.
@@nmarbletoe8210I like this
Why is the speed of light is constant even when the wavelength and frequency have different values?
Your animations and explanations are outstanding!!
Glad you like them!
Check "Time Matters, 5th edition" which starts with Snell's law for time dilation - that changes illusionary perspective to realistic.
Either things and time can slow down, one can, or neither can.
It's circular to say time can move at a comparative rate of time.
We can't have something _move_ absent the time it takes to move, nor can we calculate _time_ absent movement.
Creators of this Universe also created laws of the universe. We're merely subjected to limitations of these laws. Is there a universal equation to break these laws/barriers?
According to Relativity observers on a moving train and a stationary train platform will disagree on the size of the Train and the passage of time on the Train. This is complete logical contradiction if the size and the passage of time of the train are real. If the size of the train is real, the Train can not be both contracted and not contracted. The same goes for the observed passage of time on the Train. If these effects are observed, then the only possible conclusion is that it is an optical illusion. Things that are real must appear to be same from all frames of reference, if not then it is an illusion.
It's not the speed of light, it's the speed of information and causality.
But waves are particles that bump into each other in the classical world. How does it behave with these waves?
A person looks at his watch and sees 1 second pass by. In that 1 second, everything that exists crossed an equal distance. In that 1 second, light moved a specific distance across space, while you for instance crossed an equal distance to what the light crossed, although in your case some of that distance extends across the dimension of time, rather that it be across space only. Thus it is not only the magnitude of the motion of light that does not change. Everything is always in motion, and with that exact same magnitude of motion.
Good information, but I would enjoy the channel more if spoken by a knowledgable human being, not a bot.
1:57 correct but also the light will redshift when you will have depletion of it energy as the law of Planck and the law of Wein suggests.
Red Shift: Consider the following:
a. Current narrative: Space itself is expanding. (Even though science does not fully know yet what 'space' actually is nor how it could actually expand).
b. But consider: The net effect of solar winds, particles and energy pushing outward from galaxies, (even modern science claims 'em' has momentum), continuously, over a prolonged period of time, with other galaxies doing the same, with nothing to stop them from doing so, would tend to push galaxies away from each other and even potentially allow the cosmic web to form between galaxies.
And then, when we here in our galaxy, look at far away galaxies, with other galaxies in between, the net effect of all those galactic interactions would have galaxies furthest from ours move away faster the further those galaxies were from us, including us perceiving a red shift of energy.
c. Now, utilizing the scientific principal of Occam's razor, which way is more probably correct? What the current narrative is ('a' above), or 'b' utilizing known physics?
* Added note: Plus, 'if' my analysis is correct that our spiral shaped galaxy is collapsing in upon itself, then consider also:
d. When we look at solar systems between ours and the center of the galaxy, those solar systems would be getting pulled faster towards the center than ours, hence also seeing a red shift of energy.
e. When we look at solar systems between ours and the outer edge of the galaxy, our solar system would be getting pulled faster towards the center then them, hence also seeing a red shift of energy.
f. Only if we looked at solar systems adjacent to ours should we see a blue shift of energy (as the solar systems became closer together as they moved towards the center of the galaxy). I also propose looking for blue shifts of energy between our solar system and adjacent solar systems to confirm or deny this current belief.
g. But if true, would also add to our observation of seeing a red shift of energy in this universe as our spiral shaped galaxy collapses in upon itself.
Of which, not only would species from this Earth have to get off of this Earth before the Sun becomes a red giant one day and wipes out all life on this Earth if not even the entire Earth itself, but species from this Earth would also have to successfully get out of this collapsing spiral shaped galaxy, otherwise, most probably death awaits us all and this Earth and all on it are all just a waste of space time in this universe. All life from this Earth would eventually die and go extinct. Currently, no exceptions.
將MM實驗移至圍繞地球人造衛星上的太空進行，就會得出與預期一致的結果。光在水中傳播的相對參考系是水，而水很明顯地與真空的介電磁導不同，兩者並非在同一空間。這樣的觀念人人能懂，同樣的觀念將水換成空氣，與真空也非同一空間就不懂了呢？為什麼有人會認為地球大氣層內與真空屬於同一空間呢？
驗證星光經過重力場是否偏折，在地球的實驗方法！
作者：林德和
發布日期：2021年12月26日
牛頓（英語：Sir Isaac Newton，1643年1月4日－1727年3月31日）研究光學，主張「光的微粒說」，對於光線經過物體會不會因重力而彎折，找不出可行的實驗方法。於是在他1704年出版的《光學》書中留下「Do not bodies act upon light at a distance, and by their action bend its rays; and is not this action（caeteris paribus）strongest at the least distance?」的疑問。
1783年英國地質學家米契爾（John Michell）和英國著名物理學家卡文迪西（Henry Cavendish）認為光既是粒子，便可被星球的萬有引力吸引。
1801年，德國天文學家馮索德拿(Johann Georg von Soldner)基於牛頓的重力理論，以『(2GM/Rc^2)*(180/π)*3600』的式子計算出光通過太陽表面的偏折角度是0.84弧秒( 1弧秒是1度的1/3600)，僅止於計算，並未提出驗證方法。
愛因斯坦（德語：Albert Einstein，1879年3月14日－1955年4月18日）在其著作的光電效應論文裡認為光束是一群離散的光量子簡稱為光子；在其著作相對論裡，以黎曼幾何的概念認為時空可以彎曲，物質之間的重力來自於時空的彎曲，取代牛頓的萬有引力定律。星光在經過太陽附近時將被彎曲，造成星星在夜空中的位置偏折了大約1.75角秒（一角秒是1/3600度）。
但是
普朗克將輻射能量化E=hv，h是普朗克常數，v是輻射波的頻率，單位為焦耳（J）乘以秒（s）。波是頻率與波幅組成的，因此普朗克常數h就是定義每個波幅攜帶的能量固定值。
愛因斯坦的狹義相對論規定光子的靜止質量嚴格為0。否則光速運動質量會無限大，且頻率不同光速也會不同而矛盾，代之的以質能等價關係取得非0的等價質量。但等價的畢竟不是真實的質量，能受重力影響？
他的光電效應說，電子一次只能接受一顆光子的能量。但是姑且不論光子碰撞電子的機率微乎其微，而從光打出光電子的時間不超過10^-9秒的事實比對，很明顯的與光子的能量計算式不符。
所以電磁波可能不是一直連續的波，但必定不是粒子。只是把難以計量的，簡化為方便計量的而已。
假設光被物體的重力場彎曲每光秒偏折一公尺，反光鏡直徑1公分正圓，鏡外設置光感應器，光束自反光鏡中心偏移到鏡外，有0.5公分，則光源至少必須有照射c * (5/1000)距離的功率。功率越高，光束發散越小，則可測得越細微的光線偏折。
愛因斯坦星光經過太陽偏折計算式
(4GM/Rc^2)*(180/π)*3600=1.760638516172007弧秒
每光秒偏折距離tanθ*c=2558.973380039165932公尺。
把太陽的數據換成地球則
=0.000574137836393弧秒，每光秒偏折距離tanθ*c=0.834471939140272公尺。
從而光線經過重力場是否會偏折？可在地球做實驗驗證。
驗證星光經過重力場是否偏折的實驗方法！
光受不受重力影響，在地球就可以做實驗了，只要你有一光秒光程的雷射發射器，二面反射鏡，其中一面中心留半透明鍍銀光孔供雷射光束透射。兩面反光鏡相距適當距離平行相面，雷射發射器光束與反射鏡垂直校准中心後水平放置，在真空環境進行實驗。光束有無向重力方向偏折，表示受不受重力影響。如果相對論的時空彎曲及星光經過太陽偏折計算式正確，往返兩鏡的雷射光在地表每光秒將偏折83公分，肉眼可視。
My head is spinning faster than light while watching those waves!
This is the dogma of the Einstein's philosophy who, like his teacher prof. Mach believed that the material is the mass, and it is like the mass a product of some kind of energy. In this case of his thinking, if something material could be possible to do an action with a speed greater than the speed of light, as it is energy product, that means that the result of a material action could exist before even the action take place. And this for his thought of what was the Universe was out of logic and for that reason in the Universe of relativity where everything depends on the speed of its motion and on the use for study the motion of a referring frame he said his dogma, that you stop this is the greater possible speed. And it is a dogma because the only limit in a world of relativity for anything is only the referring frame, which is a subjective creation of the studying it people. About the speed of light from the law of Snell, it is obvious that it is, depending on the value of the Refractive index of the medium where the light is traveling. If the medium is with a negative Refractive index, like a group of American scientists from the University of California claimed, that they had succeeded to created such medium and that the light in it measure about 300 times the normal c in air. The only problem is who they succeeded to measured it. Probably the used the same laser beam to go and return for to be a measure.
The speed of light is a constant because everything moves at the speed of light all the time. If you move slowly thru space your are moving rapidly thru time. If you move rapidly thru time you move slowly thru space. Your net velocity thru the spacetime is constance.
While it's correct that the our speed along our own world-line has the same value as the local vacuum speed of light, it's wrong to think you can "move through space" and that such movement affects your time - this is emphatically false.
Magnificent graphical video. In 1975 High School Physics I was a slacker, due to a teenage love lost. My reality was emotional without the ability to communicate and share. I have grown over time and become relative. I reckon The Speed Of Light needs, Love and Understanding. It will come to those that understand, (space and time) as we know it, has trouble accounting for the rest of the universe (- space and - time). In all my years, I have finally learned respect for myself. Those that have ideas must continue on and understand the stupidity of Man"s, "Critical Mass" stage. Boo.
Here’s how light moves. A moving photon creates (induces) an electromagnetic wave and then a moving electronic wave creates (induces) a photon. It keeps doing this at the speed of light - never faster, never slower.
Where is this theory from?
Why light travel at 'speed of light' and 'gravity wave' travel at 'speed of light'? Obviously there is a Relationship. It is interesting how these two are related!
I heard the speed of light is not a true constant as there is slight variability in its precise measurement but less than 1%.
Thank you, clear n engaging, ❤
In the beginning was the Word, and the Word was with God, and the Word was God. 2He was with God in the beginning. 3Through him all things were made; without him nothing was made that has been made. (John 1:1-3)
@5:50 light is completely curved. If this is the case, why we still see solar eclipse? If Moon is too small, then we shall ecliptic moon during solar eclipse due to bending light.
In the light path from earth to Viking, light is slower at 0.9c, 0.95c, but in the local frame , it is still considered as c. What’s the reference for those local frames? That’s the assumption , not experimental. It seems to make up time dilation.
The light is curved passing sun by space-time, curved space. In another way, we can say it is passing a gravitational field, the field is nonlinear, but space can be linear. It is the field curvature, not the space curvature. The magnetism also has field, do we have magnetic space-time, and electronic space-time?
I think that they take the mediums REFRACTIVE index in account when adjusting for the change in SPEED upon medium change...like entering earth's atmosphere from the vacuum of space...and if you have a watch station, say, under water or something then there will be further readjustment, and so on. ALSO, vice-versa when its leaving the atmosphere
I'm also in thinking of magnetic fields' space-time.
If gravitation affects the time -- so does the Magnetic field. Because it bends the curvature of space-time.
I also have an idea about travelling through space -- creates the model of "time travel". And travelling through time dimensions creates the model of "space traveling" (teleportation), means we can travel faster than speed of light if we goes along with the time dimensions. 😊
Speed is the ration of Space/Time -- which is always constant... If we change curvature of Space - ultimately there is a change in Time... Because Speed is always constant. & If we change the Time ultimately there is the changes in Space curvature.
& How we gonna do this -- just by magnetic fields. We dont need lots of mass to change the curvature of space time... We need a "potential mass" which can manipulate the space-time such as "magnets"!!
That's enough for today! :)
Heat is a medium and light rides depending on gradient of temperature and that's why light bends. On a circular path of heat light can rotate only so much.
For me this is not clear enough whether the light is the material particle ( foton) travelling through the physical space, or it is the material constant of physical space and the vibration of some physical parameter of this space without moving the material ( particles) object in this space. Is somebody able to clarify the issue?
Stary
I do wish folks would drop, "The speed of light," thing.
It's the speed of causality. Light just happens to obey causality.
Light speed being constant relative to space and time measurements is different than being absolutely constant under all contexts. This is a big deal because relativity can be true and the 'constant' of light speed (c) can still be something that changes over time.
Why is it always the dumbest people who open their mouths first?
In tamilnadu 10th book formula is wrongly using alphabets, C = V ( lemda symbol) . Actually velocity of the light V = wave length × frequency.
Time is a distance. Its not how far away we are. Its what wave of time we are on at the same time. Super rare and scary when you really thinkabout it.
I was always confused with c and refraction. But this video and the comments cleared it up. Thanks. I will highly recommend others to read the comments as well. 👍
I m still confused.
At 3:52, why the 2 waves coming from different sources "should have the same frequency"? They have if they emit at the same frequency! Moreover, the speed is the same, as the medium is the same, you say it earlier at 2:08. I do not get it, I think is a mistake in the script. At 2:23 there is another mistake, if the source is moving to the observer, than the frequency (f) increases, not the wavelength (lambda)!
if speed of light is constant then whole universe would be lit and bright .. speed of light depends on material it travels trough: space(helium) atmosphere (oxygen and others) water (h2o) glass etc .. and its not faster thing in universe .. light cannot escape black holes therefore particles inside black hole move faster than light ..
ppl are still medieval in their thinking -> there is always a medium .. nothing aka zero is just a concept that does not exist in our universe .. there is always something there ..
and btw infinity isnt just on left or right its also on zoom in zoom out (sorry eng is not my native lang)
What if... there is no speed of light!
Why not think of it as a speed of TIME.
A sequence of frames per second.
We, as a poor observers, can detect very little.
So what us the light?
A separate dimension interacting with matter?
Or just a "fabric" showing the results of matter interactions?
Well, I hope some open minds will change the way we think and stick to what we SEE and how we run in circles to calculate things just to confirm what we "observe" is right!
Any uniform medium allows one constant speed of force propagation in three vectors perpendicular to each other, the energy of this being confined in a photon.
Should be called Shapiro space delay because space is moving or for the people that can't think relatively it's being stretched.
To move matter at the speed of light, is unachievable. There is no way man will ever be able to move at this speed.
So now we can detect ways of going faster than the speed of light, where does the theory fit with all the new knowledge?
Great Video！ Thanks for your efforts 👍
Isn't measuring the speed of light like measuring the distance of a shoreline using sand? That would be way cooler.
sand could be the ruler and also the clock!
I don't think light slows down because of curved spacetime, but travelling a stretched/curved line takes longer than a 1-dimensional straight line. It's still the same velocity, it just takes longer to reach the relative destination.
That is what I think too. There is no way that I can see that we can tell how far away from the sun that the radio signals went in the bend.
that is what "it is still at the max speed for each local observer but seems to be slowed down for the observer on the earth" means. still depends on the observers reference frame.
version without music?
I have never yet known a speed of anything, anything at all, to have meaning. A word have have meaning applied to it, but a speed?
This video arrived at the explanation for the constancy of light in different reference frames when it stated that V =freq x wavelength. ( @ 2.15 ). But then it went on to lose the simplicity of the explanation in more complicated areas. Do not think of light as photons or balls - think of light as waves. When different observers see light at different speeds, the light will be changed by the Doppler Effect. But when each observer calculates the wave speed (V ) by multiplying the freq X wavelength as observed, the wave speed will always be the same. So EM radiation ( light ) does not need a medium for propagation - this is what the Michelson-Morley experimental results showed us, and what Albert Einstein used as a basic assumption when he formulated his Special Theory of Relativity, and presented to the world in 1905.
The speed of light is not constant with one exception. The speed of light is ONLY constant in a vacuum without any electromagnetic interference.
Could someone tell me how one observer would see the light if the source of it was running in the opposite direction with the speed of the light???? One would see nothing???
This is but one speed in this verse: light speed. Everything moves at light speed. The difference is where each of us is going.
The real question is if I am travelling at 1% of speed of light, will it be slower to me by 1% of c or will it be the same, if it will be the same then how?
I gather the speed of light is simply a direction in 4D spacetime. There is only one speed in the universe. The less you travel in space, the more you travel in time. Traveling at the speed of light is simply traveling strait in a 3D direction, a direction other than time. You can't travel faster than light because you can't travel straiter in a direction than strait in that direction.
Hi, in the experiment starting at about 00:35 light and train, when will the observer not on the train see the light in the train hit the mirror in the train? Before, same or after his light hits his mirror? And why, please? And the same question from the perspective of the observer on the train. Thanks
The problem is that the video shows the fixed observer at the opposite end of where the light finally hits the mirror, so the light would then have to reflect backwards in an additional path to the non-moving observer. Not to mention the train illustration (which completes at 0:40) must combine light propagation AND time dilation to make sense, but your question only concerns the arrival time of light.
The easier setup to look at first - would be to put a non-moving observer at the right end of the track where the mirror is at the moment it receives the light signal. Then have the person on the train shine his flashlight out the window as the train moves toward the fixed observer.
Will the fixed observer see the moving light go by him at exactly "c" ???
No - the light will pass him going faster than the c value.
Why? because it is true that the light wave is moving along the grid of electric field lines at exactly "c" but the grid of field lines is also moving to the right in unison with the train (and therefore in unison with the flashlight responsible for generating the light in the first place). All of the electrons in the atoms of the flashlight have existing electric field lines that move in unison with the atoms down the track. when the light is switched on - that causes electrons to rise and then fall back down to lower energy which creates a ripple or "wave" in the existing electric field (in the form of an electromagnetic wave).
So if I am riding in an open train car that is moving down the track at 40 mph and I throw the ball in the forward direction at 50 mph with respect to the train - then the person standing along side the track will see the ball go by at 90 mph. It turns out that since light rides along a "moving train" of electric field lines - this can affect the velocity of light as it does with the ball. Don't ever let any fool try to convince you of something different.
Now we can answer your question: The atoms in the mirror on the train are moving away from the fixed observer. So the field lines are moving away as well. When the light leaves the atoms of the moving mirror - it moves along the electric field grid at exactly "c." But at the same time - the grid itself is moving away from the observer at some velocity. As a result, the net velocity of the moving train mirror light will be slower when measured by the fixed observer and therefore will arrive slightly later than the light from his own fixed mirror positioned outside of the train, even though at that moment - they are assumed to be the same distance to the fixed observer. Hope that helps.
Speed of light is minimum way outer space, earth travel speed of light around the sun, ,,,sun travel speed of light around the black hole center of galaxy,
I think time travels at a speed of light
if some one travels at a speed of light the time seems to be stopped
This may give a clues of relativity concepts. Allah knows best
Page 6:30
Light bent by refraction and not by gravity. The presence of gravity is a coincidence, not cause and effect. Light bends by refraction from increasing permittivity in the vicinity caused by solar ejections, adding electrons, ions, molecules, gas, particles : size much smaller than one light wave.
Following logic in any theoretical debate puts us on a fast lane to come others finally fall short to our destination, the reality. Forever trapped in a virtual reality paradigm.
Michelson-Morley assumes movement of the earth. The earth isn't moving. The aether exists. Both are stationary.
I love this channel.
Couldn't get past the background noise, could have been interesting.
Light has no speed, it is infinite. We only perceive light having a speed because it's what is relative to us. We are living in the universe in almost infinitely slow motion. Light itself does not experience time, if a photon were a living thing it would experience the beginning and ending of the universe in 0 seconds. That's truly how fast light is. So yes, no matter where you are in the universe it will have a constant speed but depending on your velocity and/or position in a heavily gravitational field in space, outside observers will see a difference in time relative to you.
This is also how people confuse black holes, most think that it is an object in space. Which it IS a singularity but staring at a black hole would not be staring at an object at all. You would be staring into an extraordinarily long time into the future. It is not spacial anymore, it is temporal. That is why no matter and light can escape it, because it is literally red shifting into the future.
It's a wild theory, but it kind of makes sense to believe that we're experiencing slices of time that have already existed or is already a whole. We perceive large objects to pass time more slowly due to its gravitational field, when in reality that large object is itself perceiving light as the same constant as us, but to it, we're moving faster through time. So on the scale of the whole universe it could be as quick as a soap bubble forming then popping and it's over. However to us, and how unimaginably tiny we are, we observe that same soap bubble forming then popping for billions-trillions of years.
Relativity is a hell of a drug.
Thanks for the video ❤️❤️❤️❤️❤️❤️❤️
Is it possible to separate out the electric and magnetic fields in light?
No, magnetism occurs because of charge
No because one is cause of another
The problem is that you are not taking into account general relativity. You aren’t considering the variable rate of time and the differing measures of distance.
Einstein burned into peoples minds that the speed of light doesn’t change. The units of measurement to measure the speed of light do change over large distances and galaxies cover large distances. That means that the speed of light does change over large distances as observed by us.
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.
Distance is expanded in outer space (not expanding). Plasma jets do not stream of five times the speed of light since the distance is expanded away from gravity wells.
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 greatly 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 distance in outer space is expanded 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!
Just think what could be the reality *when* the photons register with our eyes or our cameras/detectors and there is a collapse of the wave function as seen or detected by us within our dilated time and distance. (Our rate of time is not the universal rate of time, especially for photons.)
Conclusion: The time it took for Creation and since Creation in the Bible is absolutely true! Time itself is a (real) fabrication.
I struggle to understand the constant speed of light. If light is unable to escape a black hole, what does it do within a black? How can it be constant if it slows down in reaction to gravity? Why is light the constant factor in einstein’s relativity? Which then says time is subjective. It seems time is the constant, earth time as measured on the surface. So no matter where you go, that factor even without travel, sunrise or sunset, you would use the “on earth surface” as a constant, with everything else being subjective. Making travel into the past or future impossible. But i’m just a layperson, what do i know?
Time, as measured by the rotation of the earth, is not constant. In any equation, you need constant in order to take a measurement. EM waves are the closet to being a constant, have not changed for the most part in 2 billion years, so went with light as the constant and adjusted time. Information travels at the speed of light so when we see light slow down or be routed aound a black holes' gravitational field, it is easier to say space is warped or time dilation.
I think, the speed of Light is constant because it is the fastest thing that the human mind can perceive.
It is deep. The notion of ever observing a standing-still photon is to be universallyy rejected.
Why do we always say speed of light never changes?!. Speed of light always is relative to its environment in some spot around black hole light will be in shape of plasma just before its property changes and become solid and is not light anymore. Light's behavior is not the same when it is placed deep in planet, for instance as large as Jupiter. Each environment will affect physical property of light.
The vacuum speed of light is a constant for all inertial observers under the condition that either the Riemann curvature is zero on all components or that the measurement is a local enough measure.
Could light be considered traveling through time and not space since distance is subjective but time is not in the perspective of a photon?
Light travels through the space and time coordinates of the observer, but light itself has no world-line, the spacetime distance between any pair of events on the path of the light is zero.
F=ma is the formula for acceleration in space.
E=mc^2 is the formula for acceleration in time.
Space and time are separate frames of reference
Acceleration in space = acceleration in time
Not only is the Breakthrough Starshot solar sail being accelerated in space but it is also bring accelerated in time - radiant energy..
@@stewiesaidthatmy perspective is that if the photons don’t interact with the Higgs field (space) hence doesn’t experience moving from point A to point B all it can experience is time and not space.
@@smudds10 in physics, Force decreases with distance. How much Force does a single photon have. I haven't compared the Higgs Boson to see what it's value is compared to a muon's. You are dealing with two separate frames of reference. Space and Time. Photons experience a lot of space but very little time - radioactive decay. But they do redshift and lose force over distance. Given enough time/distance, a Photon's wavelength will become stretched to point that it is no longer a wave. The caveat is that the photon that left the star is not the same photon that arrives at the detector. It's information/force is relayed from one electrical charge to another as it propagates through space.
@@stewiesaidthat thank you for your interaction I would like to know more about the radioactive decay of the photon. As far as the redshift or blueshift of a photon it is due to increasing or decreasing distances of your observed object and not because of information force relaying. A photon will lower its speed depending on the medium it travels through other than the vacuum of space. One experiment that I believe explains this is the Fizeau experiment where there was a delay when light traveled through moving water and its wave interference pattern was disrupted due to superposition of the photon. But my assertion is photon doesn’t experience space while in the vacuum of space it only experiences time, that’s why distance in our universe is measured by light years.
So if the light slow down near the mass of the sun will be redshifted?
It's redshifted not because it slows down but is traveling out of a gravity well
If i get my car up to the speed of light... and turn on my head lights... will anything happen?
Here is your answer: ruclips.net/video/P1MG61R17Ks/видео.html
Guessing fundamental to unlocking secrets of universe. A constant to start from
I got lost with the CURVED path of the light. If it is LONGER than a straight path, say 1.053 times then obviously the reciprocal will be 0.95. Anything further before this is resolved is to me baseless. BTW, the two sources of light are shown as independent and synchronous, not an analogy with the Michaelson experiment where the second source is mirrored from the first. I have learnt nothing here and may I say that this video is definitely not moron friendly if that is what it is supposed to be. Thank you.