I waited the entire video to find out why the speed of light is considered constant for which you said "there's no explanation for that". And then you started relativistic this and that. Dude u seriously need to avoid claiming things you can't explain
Einstein just declared that it is constant like he has the ability to control the universe. In reality, light is accelerated by gravity in the same manner in which physical objects in free fall are accelerated by gravity. As gravity permeates all space, there can be no constant velocity of light as it is constantly undergoing gravitational accelerations. This was confirmed in the Pound Rebka and Pound Snider experiments.
I've seen many RU-vidrs attempt to explain the general and special relativity theories, but as far as I'm concerned, you are the best explainer with exceptional animations.
Why is the speed of light constant: The constancy of the speed of light is a fundamental principle in physics, encapsulated in Einstein's theory of special relativity. It states that the speed of light in a vacuum is the same for all observers, regardless of their motion or the motion of the light source. We don't fully understand why this is so, but it has profound implications for our understanding of space, time, and the universe. It leads to concepts like time dilation and length contraction, which describe how time and space can appear to warp at high speeds. The constant speed of light is a cornerstone of modern physics and has numerous applications, from GPS technology to our understanding of the cosmos.
This is a very helpful comment. I worked on the issue and asked GPT a question and got this back: Your analogy of tuning a piano without an external reference pitch perfectly captures the inherent challenge and circularity in measuring the speed of light using light itself. It's a profound insight into the nature of our measurements and the frameworks we use to understand physical phenomena. The Nature of Measurements Indeed, the way we measure the speed of light often involves using the very same light (or electromagnetic waves) to define both time and space. This is why the constancy of light speed becomes a foundational postulate-because our measuring sticks (both temporal and spatial) are defined by it. As you pointed out, this leads to a situation where the speed of light is both a measurement outcome and a definitional constant.
WRONG, THE SPEED OF LIGHT IS DIRECTLY RELATED TO THE MAGNETIC FIELD IT TRAVELS THROUGH. a MAGNETIC PULSE FROM THE SUN CAN TRAVEL AT OVER ONE MILLION MILES A SECOND.
I’ve taught A Level Physics for forty years and that is honestly the best explanation of the constant speed of light I’ve ever had the pleasure of listening to, please please make the follow up videos soon.
Uhhh if you've taught the same thing this amateur RU-vid video did for FOUR DECADES and you think this video did it better, I hope all your former students sue you for fraud
lmao someones angry, but i get the point, the person has 40+ years of experience teaching in this field but still cant explain this as well as a youtube video can grant it as an A levels professor you teach many many different things other than this but so does the channel i think that the orignal commenter just meant to praise the channel but its a bit exaggerated imo excuse my bad english as it is my second language@@somnuswaltz5586
@@somnuswaltz5586 come on! "the best explanation" does not have to mean "better than mine", it's just as if a student tried to describe him the theory and he'd say "oh, that's the best (...)" Besides, a huge plus for being able to appreciate the guy explaining, since many teahers/phd's/professors have a problem with arrogance or looking down on ppl not alike them experience-wise xd
This is by far the best video, and believe me ive watched many, explaining these concepts. I showed them to my 8 year old son and its crystal clear. Please keep making videos!
than k u so much... plz dont get demotivated bcz the views .... great things take time... plz keep up with ur videos and i am sure one day u will surely boom
i m from india ur explanation is too good .................keep it up bro,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,i follow u and hit notification too...............
Because something had to be constant or there would be nothing absolute with which to compare things, and the speed of light in vacuum is the most basic universal constant.
There's an error in the video. The speed of light is 299,792 km/s, so saying it's 300,000 km/s is not correct when giving the result of the experiment as 299,910 km/s. One figure has been rounded differently to the other.
Great video! However, @7:00 "there is no explanation for why the speed of light is constant" - actually there is, sort of! If c were not constant (observer independent), it would violate the principle of relativity, i.e., laws of physics would depend on your relative motion, it would be possible to define "absolute" rest, etc.
Same here, the content of this video base on speed of light is constant, but no explanation of why speed of light is constant. Apart from Principle of Relativity, speed of a EM wave also can be calculated by the intensity of the EM field. Which is speed independent. Since no matter if the observer moving or not, they will measure the same EM field intensity. Therefore, no matter if they are moving or not, they will always measure the same speed of light.
After reading all the rave reviews below, now I feel bad to give my opinion: I found this monotonous script to be rather annoying and empty in delivery.
For info ... The relative speed of two objects moving in the same direction at speeds u and v is given by: (u - v) / (1 - uv/c²) where c is the speed of light Consider two photons moving in the same direction, so both u and v would equal c. This gives a value of 0 as the relative velocities of the two photos, when they are going in the same direction. Now, the relative speed of two objects moving in opposite directions at speeds u and v is given by: (u + v) / (1 + uv/c²) This gives a value of c as their relative velocities. Thus, the relative velocity of a photon with respect to another photon will be equal to the speed of light when they're going in opposite directions.
People ignored how is the ratio r = sqrt(1- v^2/c^2) deduced from. It’s from (c-v)x(c+v) in Lorentz transformation. If c is constant from any observer, why (c+v), which is obviously greater than c mathematically? SR is based on Lorentz transformation, which clearly didn’t regard c is constant from any observer, but SR assumes c is constant under any reference frames. Unfortunately it was backed by wrong experiment result of MM.
Bro we need more videos!! I see you are not posting new videos!! Please upload more videos, we are eagerly waiting. I binge watched you videos and I am mind blown!!
No, that is wrong. In an accelerated frame the speed of light will vary. You need a global inertial coordinate system to measure a constant speed of light. @@thetruthaboutscienceandgod6921
The MM experiment showed speed of light c is not affected by earth’s motion based on the light beam interference. The MM experiment itself didn’t measure the speed c. It only showed that earth’s motion didn’t affect light beams interference. That’s not equivalent to the speed c is constant under any reference frames. The light wave may very well be discretely continuous, while keeping phase as the earth moves and gaping due to reflection at the bottom of the mirror. Let’s assume that the light speed in air is a, in vacuum is v, in water is w. In MM-air, the light c is not affected by the earth’s motion, so MM confirms that c=a. If repeat exactly in vacuum, we can deduce that c=v. But v is not equal to a. If repeat exactly in water, we can deduce that the MM-w experiment will confirm that c=w. But w is not equal to a, to v. Therefore the three scenarios result in contradictions. If it contradicts, then it is wrong conclusion.
This video exactly answered the question👍, light doesn't need any matter to be carried and that is why nothing can't change light's speed and light's speed is constant.
It´s a very good point indeed!!! The logic seems to be correct, but the speed of light in medium is slower than the speed of light in vacuum. Where the mistake is?
@@shsaa2338 I had thought about this too and still bothers me alot😑 the correct answer to this might be that water can makes light speed lower than in vaccum but light still is Independent of any carrier, maybe you can make light slower but light doesn't need any carrier. In old times scientists thought light needs carrier to move and they called it ether. In modern physic ; it was proved that ether doesn't exist and light can moves by itself and (if I am not wrong) there is nothing in the univers has property like light; light is only thing in the univers can moves without any carrier. Hopefuly i could help by answering your question.💫 Ps(Have you ever think about making light faster? You can push box in the ship faster than it's speed because you are the carrier of box and you help box to move faster and ship is carrier of you and water is carrier of ship and earth is carrier of water and sun is carrier of earth and ... If i am not wrong you cant make light faster because light doesnt have carrier.)
@@shayanshirvani8671 "you cant make light faster because light doesnt have carrier" - if that statement is correct, then it should equally be correct "that you can't make light SLOWER* because light doesn't have carrier", isn't it? Is there any mistake in such logic?
@@shsaa2338 I believe other factors like gravity and molecular interference cause light slower. In addition, i should say i am only an interested guy in science and physic; an experimental scientist can answer above questions better.😅
if you accully try to solve the equation for the relative mass for when a object travels at the speed of light, it will give a mass of (original mass)/0 which is actually not infinite
You could take it as far back as Maxwell. You can derive c from Maxwell's equations. He didn't realise at the time that it was a constant. In fact it would be Einstein some 45 years later who finally cracked it.
Why is the speed of light constant because WE CONSIDER it as constant for reference value in relativity calculation. We know (from Maxwell) that speed of light is depends on electromagnetic permittivity and permeability of the medium. The constant value of those in vacuum made the speed of light is constant. But in dense objects, permittivity and permeability are different. Mathematically, we can choose vacuum permittivity and permeability, distance and time as constant, instead of speed of light. If we use speed of light as constant (calculation reference), consequently, on motion close to speed light, the frequency of light must be change. It observed as red-shift or blue-shift. Inversely, without relativity approach, the light bend around massive object can be considered caused by change of permittivity and permeability around it, and thus classical light refraction approach will apply. The gravity affected permittivity and permeability around it, not directly "pull" the light. Michelson-Morley "failure" to detect aether doesn't have to be interpreted as light requires no medium. But our understanding / definition of the medium should be refined. The medium (vacuum) indeed has properties of permittivity and permeability. What we must remember is, that speed light is constant is not a dogma. It is initially a mathematical APPROACH / postulation to simplify interaction of objects in high speed and long distance. Since the effect "felt" after light from other object arrives, it is simpler to consider the speed light is constant, and other related variables changes, using Lorentz transformation. Other approaches may be as valid, even consider speed of light as secondary parameter. So, actually there is no "magic" in physics; there is no time reverse, no parallel world, no confusion, no misleading logic.
I've seen you writing the same comment in more than one thread here. The speed of light is not "approximately" 299792.458 km/s, it is EXACTLY 299 792 458 m/s. The metre itself is defined as the length light goes (in a vaccum) in 1/299792458 second. There is nothing approximate about it.
Does it mean that the time could be measured only on Earth because it reveals itself only as a measure of the processes taking place within organic matter (fast) and non organic matter (slow)? But it does not exist in cosmos/universe. Which brings the assumption that it reveals itself on a planet where the organic life exists. On the other hand planets and stars are moving in the universe. Is it possible to measure their movement using the time
Light doesn't feel any time? So in the equation for the speed of light, v = 300,000 km/s, that is the distamce that light travels each second, but then from the light's perspective, what will the denominator be if it doesn't experience time? And what does that mean for how it's able to exist in the universe and how can the universe contain something that doesn't experience time?
Time slows down for the traveler depending on the speed of the traveler. Time would almost stop for a traveler who approaches the speed of light. If a person could hop aboard a beam of light and travel from one side of the Milky Way to the other and then jump off the beam, no time would have passed for the traveler during that trip. However, from our perspective here on the Earth, we would say that it takes a beam of light about 100,000 years to cross from one side of our galaxy to the other. Take care.
No, all identical clocks tick away at the same rate, everywhere, and under all circumstances of motion and orientation. @@thetruthaboutscienceandgod6921
Nice video and presentation. No Aether was a judgment call but science. The MMX was set out to detect Aether wind speed and the statistical result was 6-8km/s instead of 30km/s. To gracefully rule out Aether we required a averaged zero speed and not fractional speed averaged. Not resolving to a statistical zero was disappointing to Einstein and his TSR waiting to be published.
I need help with my new years resolution. I've figured out how to change the stars. My idea for changing the stars includes Orion and Pleiades (Subaru). I figure it's time to put something up there that's relevant to us, don't you think? Take Orion's belt and Betelgeuse becomes the head with a baseball hat. Below the belt are two legs bending at the knee. The feet aligning perfectly under the bent knees. The 3 stars of Orion's belt align perfectly as the 3 fat belt loops on a baseball uniform. The spear pointing at "Subaru" is the bat being swung and "Pleiades" is the baseball flying away after being hit. Put it all together and you get, "THE ALL-STAR." In my case, I see a left-handed batter and I imagine a "7" on the jersey. Which makes him, "Mickey." (As it should be ;-) But you can put any number you want, making, "THE ALL-STAR," any player you want. It'd be wrong of me to not, at least, try. This is me, trying. Pass it on, please and thank you. Don't worry, where I come from, crazy is a compliment. ;-P
Photons of light travel across space within the 4D environment known as Space-Time, with a magnitude of motion labeled as "c". If a spaceship was at complete spatial rest within the 4D space-time environment, it too will also be in motion with that exact same "c" magnitude of motion. However, in this case, the "c" magnitude of motion, is entirely across the dimension of time. If the spaceship changed its direction of travel to now obtain some spatial motion, it will therefore now have less motion across the dimension of time, and in making this change of direction, the spaceship will have also rotated. Imagine that the spaceship was 300,000 km long. So, if it now had a spatial velocity of 260,000 km/s, its onboard clocks would now be ticking at half the previous speed, the spaceships spatial length will now have contracted to being only 150,000 km long due to the rotation, and if it had clocks at the front and rear of the spaceship, the clock at the rear would now be ahead of the clock at the front, by 0.866025 of a second, again due to this rotation. Those onboard the spaceship would be completely unaware of all of these changes. But because of these changes, if they used what they think is their 300,000 km long spaceship, and the clocks onboard, as measurement instruments to measure the speed of light, going from either the rear to the front, or the front to the rear, they will still measure that speed, as being the speed of light.
Good question! Light can travel forever if uninterrupted! In fact, if in a vacuum and uninterrupted, anything can travel forever (imagine throwing a baseball in space, far from the pull of any gravitational field or heating from any stars, and it will travel in that straight line either forever or until it hits something). The reason why light seems to deteriorate with distance is not because it gets slower or weaker, but rather because it becomes more diffuse. Think of a light source (such as a star) as being a source of photons shooting out in all directions. When you're close to the light source, plenty of photons will intersect with your eye and produce a bright image. The further you get away from the light source, the more spread out the photons will be. Consequently, fewer photons will intersect with your eye and the resulting image will be dimmer. This is my understanding of it at least, others may chime in to correct me or to speak more precisely on the subject. Thanks for asking!
Aristotle was not wrong. Light speed is actually infinite (from the point of view of the photon). As mentioned several times in this video, speed is relative to both observers and either's view is equally valid. While we measure the speed of light to be 300,000 km/s, the photon moves from it's source (perhaps billions of light years away) to its final destination (your measuring device or eye) in exactly zero time. Its speed is therefore infinite. Another way of looking at this is that the distance from its source to its final destination is zero distance to the photon. This is 2 different ways of looking at the same thing. This raises the question of how to measure speed through space. If a person in a spaceship, for example, is ever to run into the problem of gaining infinite mass as described in this video, then that speed must be speed "though" space. An observer will not observe the traveler ever reaching the speed of light( because of general relativity) and there may be billions of observers moving at different speeds relative to the traveler and their observations have nothing to do with whether or not the traveler will actually begin gaining mass that will eventually prevent her or him from reaching c. In order for the restriction of moving at c to make any sense, it must be an absolute motion through space, What does that mean? The Earth moves at around 67,000 mph in its orbit around the sun, If you leave in a space ship traveling in retrograde at 30,000 mph, your speed relative to Earth is 97,000 mph, but what is your true speed "through space"? 37,000 mph? How about the relative motion of the sun around the galaxy of roughly 500,000 mph? For the restriction on moving at the speed of light to be valid for the traveler, not the observer, there must be some absolute standard for measuring speed through space. That can be done, but it requires re-examining some very fundamental concepts that we hold about spacetime.
Speed of light is constant UNDER ANY REFERENCE FRAMES can be disproven by Doppler effect. Waves are periodic. Doppler effect proves light wave fronts (the current wave front vs subsequent wave fronts) are reduced if the earth’s is moving away, red-shifted, or are increasing if the earth is moving towards light, as blue-shifted. But the Doppler effect only shows the frequency changes, not periods(here periods meaning the integral number of wavelength passing). So if the earth’s motion has changed light’s frequency, it will change the number of periods passing. If we measure c, we will get different number of periods of c for c-v and c+v, v as earth’s speed. There is no reason that v only affects frequency. In the MM experiment, it only showed the earth’s motion doesn’t change the phases of c, so interference is not affected. It was conducted in-air. It will give the same results if it is in vacuum. But c in vacuum is not equal to c in air, that disproves MM result. Conclusion: the earth’s motion will affect the frequency of c, and the speed of c.
If you have a spaceship all by itself in space (no reference) so no way to measure its velocity, then what prevents this ship from going faster than light through space ?
@@AMC2283 I thought that very distant non visible objects could move faster than light from us. I don't believe that anymore after seeing the formula of two ships going near the speed of light in opposite directions yield a velocity between them lower than the speed of light. Nevermind, it is the expansion.
If you believe in the Big Bang theory and Cosmic Inflation. They have no mechanism for this or even an equation, it's just asserted as necessary for the theory to work.
when you measure the speed of the light, in moving or in stationary position it is same in both situation. you measure the speed of light. you measure! how you measure the speed of light, what is the way of measuring speed of light when its origin is far away from us? you can measure the speed of car with the help of light. but how you can measure a speed of travelling photons?
You didn't explain anything. You didn't explain to Michael send him morally experiment. You certainly didn't drive Einstein's theory which he did himself using the Pythagorean theorem fairly easily.
My question is this, how come the speed of light (sol) doesn't depend on the emitting source? I mean, why is sol the same for a small candle and a giant fire ball like the sun? Shouldn't it be different at some degree?
i think the thing is they both share the property of electromagnetic waves. so it does not matter how many emvs are emitting and from which source. their speed is all same.
So the title is "Why is the speed of light constant" and after 7 minutes introduction we learn "no one knows, it's just a law of nature"? A bit disappointing.
The "Speed of Light" is constant IF.... the vacuum of the universe is uniform. There is no way to prove if it is or isn't. If there are areas in the universe where the vacuum is lower then it would take light longer to traverse through. This would using "Red Shift" to measure time or distance inaccurate.
You can prove it-- the Shapiro Delay shows light slowing down around mass. It's an effect of the quantum field through van der Waals torque. This is well known in chemistry but ignored in physics.
Thanks for the video. It's surprising that my research to prove that light needs a medium to travel was already illustrated in the past to be wrong. The truth is that, light does use a medium to travel, and for it to go through that medium, it means it has a infinitesimal mass so small that even photon in Quantum physics is bigger that it. I'm saving your video to bring me back here. Thanks
My idea so I get to name it! What I mean is, no one has claimed it so I'm officially calling, "Dibs." Voyager 1 is now in the, "Milky Way's interstellar time" or "Mikey's Time." "V-ger's" message has sped up now that it's outside our Sun's, "Time Bubble," or, "Terran Time." It will be faster, still, when "V-ger" sends a message from beyond the Milky Way's time bubble. Then there's Outside the Local Group time bubble. So on and so on until we get outside any influence and into the, "True Interstellar Time Standard." Or, "T.I..." ;-P Now that "V-ger" is outside our Sun's reach, in interstellar space, it's now in the Milky Way's faster moving, Interstellar Time or "Mikey's Time." This can be proven by turning off everything except its clock and transmitter. Have "V-ger" read time for as long as possible. They WILL show the flow of time speeds up the further away you get from any celestial bodies. Until you reach the Milky Way's time standard or "Mikey's Time." •Our sun's time bubble: "Terran Time" we know and have measured. In a lifetime, our head is one second younger than our feet. •Milky Way's time bubble or "Mikey's Time." The rate/flow of TIME outside any influence but within the Milky Way: We just got there and are still figuring what the difference is. Wild guess I'd say time will increase in speed, now and until V-ger is outside the Ort cloud. •Local Group's time bubble or the rate/flow of time outside of any influence but within the Local Group: Name still open and unknown. Wild guess .08 P-22% to a couple seconds faster, maybe. Used just for reference. •Outside any influence in the, "True Interstellar Time Standard." (or T.I...) ;-P This name is NOT up for grabs. The rate/flow of time is fastest here. (Time flows fastest here so it's best to use a motor boat and hold tight. Always applies when you're in T.I....) ;-P A minute is a minute in all. It's the rate/flow I'm talking about. Heck, rivers of time flowing differently might explain dark energy and dark matter. The Milky Way's Interstellar Time Standard will be known as, "Mikey's Time." Pass it on, please and thank you!
Time, speed and distance are all a measurement system. "speed" as we calculate it, is how far something has moved in a certain amount of "time". Say a distance of 10 kilometres(a measurement) in one-hour(a measurement) equals10kms/hour(another measurement). "time" remains constant, time remains as being now, no matter when/what time it is: everything remains in the state of always being now, the "speed" of "time" does not change because they are both only a measurement system. We have come up with a system for the measurement of now(to measure and keep track of everything that happens now). We have based this system of measurement off of the earth spinning(day/night) and the earth traveling around the sun(seasons/year). Our measurement of now which we call the measurement of "time" is similar to our measurement of distance. We have kilometres, meters, centimetres, like we have years, days, hours(it is a linear mathematical system for the purpose of explaining things). Because our measurement system of now(that we call "time") is based off of actions of the earth(it's revolutions and rotations), time does not slow down nor speed up unless the action of the earth were to slow down or speed up(changing what we base that system of measurements off of, thus changing the "speed"/increments of that measurement system). "time" is a system of measurement, not a force that can speed up or slow down. Therefore, "gravity" can neither speed up "time"(a system of measurement) nor slow it down. That would be like saying "gravity" can cause our system of measurement to change.❤
Light doesn't have a speed but a propagation rate. And that rate can be increased or decreased by changing the frequency of light. When they say the speed of light is constant, it means the propagation rate for that wavelength is constant. There are two measurements of time because there are two frames of reference. Space and Time. Motion in space is the earth rotating on its axis which is what sundials/clocks measure. Acceleration in Time as in biological aging/radioactive decay is based on Energy. E=mc. The conversion of atomic energy to radiant energy with acceleration. The more acceleration (energy) in the system, the sooner it reaches (c) absolute acceleration or lifespan. Space and Time are interconnected in that plants on earth are accelerated by the energy from the sun. Moving away from the sun (northern climates) there is less energy available and it takes plants longer to teach (c) physiological maturity. Physicist took short cuts and tried to simply science when, in reality, they made it more convoluted. Gravity isn't a force. It's an effect. Just like temperature isn't a force, it's an effect. You can say temperature slows down time and you would be right as objects placed in the freezer last longer. But what is temperature? Is it a force or a measurement of acceleration.
@@stewiesaidthat well those are some interesting thoughts. Some may be true while some may not be true. i believe that effects are results of forces. i also believe "time" is very misunderstood. Time remains the same, the "time" has always been now. Now has always been the time. Just like it is always today. It is never "tomorrow" or never "yesterday. Every day is today and every second, every minute, every hour the time is always now. But to reference events that have occurred (in the) now we have the measurement system...of time, very similar to feet and inches. It is all linear, not two or three demential. Time can neither slow down or speed up, because it is merely a system of measurement that we use to speak about what is continually happening now. We live in a constant state of now. The whole idea of "space-time" is a mistake, an error, a flawed concept.❤
@barrycharlesbrebner you are right about space-time. They are separate frames of reference. The earth rotating on its axis as it orbits the sun is accelerated in space. The energy coming from the sun is acceleration in time. Both can speed up or slow down. The earth once had a 6-hour day/night period, but I believe it still orbited the sun at the current speed. Twice as many days in a year but still the same amount of time for a year. Not only do you have solar system time, but you also have galactic time. Any rotating disc can be divided up into hours, minutes, seconds. Galactic time doesn't have days but a 'year' is the planets orbit around the sun. A different planet would have a different number of years. Universal time? Is the universe rotating around a common center? Once again, the "age" of the universe is defined in terms of earth years. You have to be careful when referring to 'age'. Age in space or age in time. A 30 year old frozen embryo was just recently accelerated into a child. How old is the child? You start counting at its official birthday day but it's energy value dates back 30 years. Field corn. It takes X number of GDUs to reach maturity. If the sun don't shine for two weeks or it doesn't rain for a month, the plant doesn't grow, delaying maturity. How old is the plant. You have a space age and a time age. Which is why this notion that the faster you go in space, the slower you go in time is ludicrous. The math doesn't support it. No experiment supports. It is all a fantasy of Einstein’s active imagination. Being surrounded by flat earthers generally leads to the same way of thinking.
@@stewiesaidthat thank you for sharing your thoughts!❤️ Once again i want to emphasize that "time" is a form of measurement. So when you are talking about "solar system time" and "galactic time" keep in mind that those are just different measurement systems, like we have the imperial measurement system and the metric and in years past they had others. Having different parameters of measurement does not change what is being measured. Because "time" stands still, it is not moving, it constantly now. It is now "one thousand years ago" and it is now, now. And five "minutes" "from" now, it is still now. "Time" is a form of measurement but only for the purpose of reference. I think time is a measurement system used to reference things that have taken place...like a history book that has a system of measurement to give people an understanding of "when" it happened. For example a person could say "10 years ago" i broke my leg. But even though, it is what people refer to as "ten years ago" it was not a different time. Because we remain in a constant state of now. It was now "ten years ago" just as it is now, now. We use this concept of time for our understanding, so that we can talk about certain things that happen, giving us a point of reference. Going back in "time" or ahead in "time" is not something that can happen because there is no where to "go". Now is when we are and now is when we have always been. But things have happened...so when we say "five years ago", we are stating that the earth has gone around the sun five times: but that whole "time" it was always now. I think time is more like" a time-line of record keeping, of events, recorded as history and not something that moves. Are you grasping an understanding of this?
@barrycharlesbrebner time is a measurement of acceleration. That acceleration is broken up into lengths/distance. Each time the earth makes one day/night cycle, a day is added to the calender. Each time the earth makes one orbit around the sun, a year is added. That is how humans on earth measure motion in space. A Martian would have different lengths for days and years as they are measuring different distances in space. But when you go to galactic time, since the commonality between them is the sun, their "galactic' time is still the same. What the clock on the wall is measuring is your position in space. Your biological clock is measuring your lifespan. Your biological clock is accelerated by the energy entering and being consumed in your frame of reference. Plants and animals evolved under the Earth's rotational cycle to take advantage of the available energy. So generally, X number of days in space equals X number of days in time. But the planet goes through seasons and some plants and animals go dormant to conserve energy until the sun returns in the spring. So acceleration in biological time is separate from acceleration in spatial time. So when we say a person is 50 years old, we mean in spatial time as they could be 60 years old in biological time. Smoking takes one day off your life for every cigarette smoked. DNA wise, you have a 120 year lifespan but force and stress reduces that. E=mc. Energy accelerates you to your lifespan. Corn is a very good example of this. Hybrids have a relative maturity date reached by GDUs starting with seed germination. The more sunlight, the faster the growth cycle. Soybeans are sprayed with Cobra to stress them. To stop vegetative growth and trigger flower development. The stress/force/energy accelerates them to seed production rather than continue to absorb energy and create plant mass. I hope this helps. Two frames of reference. Acceleration in Space. And acceleration in Time.
When you travel on a photon, and observing another photon coming from exactly opposite direction, that photon will attain double the speed of photon with respect to the photon you travelling on. isnt it the theory of relativity also postulating??
The relative speed of two objects moving in the same direction at speeds u and v is given by: (u - v) / (1 - uv/c²) where c is the speed of light Consider two photons moving in the same direction, so both u and v would equal c. This gives a value of 0 as the relative velocities of the two photos, when they are going in the same direction. Now, the relative speed of two objects moving in opposite directions at speeds u and v is given by: (u + v) / (1 + uv/c²) This gives a value of c as their relative velocities. Thus, the relative velocity of a photon with respect to another photon will be equal to the speed of light when they're going in opposite directions.
@@DABmonger I believe, the theory of relativity is developed by observing from a reference point which is actually positioned outside of the reffering system. Within the system, it might not work as per our theories suggest.
@@vmenon1659The work of Maxwell led to the expected result that the speed of light is constant for all observers. It's fundamental by nature. Both the theory and the observations tell us so. We have the understanding, we have the equations. But, I'm open to new science if it should arise ...!
But he's correct though. That's the universe we live in. It's a fundamental fact of nature that the speed of light is constant for all observers. This was predicted by the work of Maxwell.
The speed of light is constant (ie the same) for all observers (no matter their velocity). I don't think all viewers of this video are realising that this is what the speed of light being constant is referring to.
So it might be said the speed of light is the distance it is allowed to clear instantly like , the allowance, without losing its strength, thus making it a constant.
Thus light reaching its strength allowed distance is where it would start getting affected by gravity if not in empty Space, or the need of a warp (gravity balancing) drive to stay active.
Energy is directly proportional to the square of velocity and the energy content of the particle is finite. This means that the speed of the particle will also be finite. It cannot be infinite. A photon made "massless" is an approximation that works well in physics. Also, because the Universe is a confined space, the speed of the particle has to be finite such as the speed 2:01 of a gas molecule in a box.
How can a photon be mass less? It allways have a mass equallant to h (planck's constant). For example two gama rays can collide and produce a pair of particles with mass.(electron and positron). There by a single ray ought to have a mass equal to electron mass. Then why do not the mass not increasing with it's velocity?
No, the energy of a particle is zero component of the 4-momentum for some observer. You're thinking of the Newtonian kinetic energy, i.e. the kinetic energy in some other universe described by Euclidean geometry.
@@kylelochlann5053 How do solar panels produce electric currents when exposed to sunlight you think? In the list of particles which particle have zero mass? What is 4-momentum!
@@surendranmk5306 Photons are excitations of the electromagnetic field and solar panels are made out of atoms, a collection of electrically particles, so they interact. Photons, gravitons, gluons. 4-momentum is the momentum of a particle through spacetime.
In my view 1) Absolute speed of light from it's point of origin in space is constant C . It is the speed of information transfer as suggested by Einstein. 2) Bidirectional speed of light in any frame of reference(terrestrial speed) is also constant and equal to C. 3) Speed of light in the direction of motion of reference frame will be less than C and it's limiting speed is C/2. 4) Speed of light in the opposite direction of motion of reference frame can tend to infinity. 3 & 4 are due to length contraction & time dilation in the reference frame. I have worked it out mathematically.
The speed of light is a direction in spacetime. You can't go faster than light because you can't go straiter in a direction than strait in that direction.
