It is so clear and easy to understand here. But in school, they made it so difficult to grasp, probably purposefully, that one just does not want to hear it. Your video was just a few minutes. But school forced us to sit through their agonising explanation for several days. I believe there is an incredible flaw in the way many schools present their learning material. This may be by design to train people to hate to learn. I have heard, "I do not want to know that," or, "Why would I even want to know that?," so much that I believe willing ignorance has become fashionable today. I almost fell into the trap myself. Now, I am addicted to learning because of the way things are presented away from school's methodology.
Just found this. I've watched many 'light clock' examples of relativity, but this is the first one that really breaks it down and takes you through the basic math!
Unfortunately, this video is misleading. Do you know that if you were on the spaceship, you would think it is the Earth moving away at 70% of the speed of light. So after 5 years on Earth, 7 have passed on the spaceship. It is time on Earth that moves more slowly! Totally symmetric! In the formula, the velocity is not absolute but the relative velocity which applies to both Earth and the spaceship. Did you understand this by watching this video?
@@andywason3414 Velocity is relative. How you got to 70% C doesnt matter to the equation( did you see acceleration or mass in the equation? Of course not! Irrelevant) in the spaceship you see time dilation on the Earth, on the Earth you see time dilation on the spaceship. This is the essence of relative. No absolute frames. Nobody is ever at rest, judt relative motion to each other. You get the same value on the spaceship or Earth. If you had 2 spaceships in space, one going left at 35% c and the other ibe to the right at 35% c, you would get the same result. Its the same problem! All that matters is relative motion This is why this video doesnt do a good job. The result is correct only mathematically
@@andywason3414 That is similar to the twin paradox. Where you have twins, one of the two goes out in a spaceship and travels close to the speed of light to a system a few light years away, stops, and comes back to find his brother much older. It’s called a “paradox” because due to relative motion, one of them should not age more than the other. en.wikipedia.org/wiki/Twin_paradox Read that reference. It explains the symmetry breaking once you come back to the initial frame where both twins are together or where you compared clocks. Bottom line, this is poorly explained by teachers and give people the wrong idea that objects close to the speed of light have these effects. But all speed is relative. So an object closed to the speed of light in a non accelerating frame would observe you having these effects.
I love the way you explain maths using thought experiments, can you recommend any physics book that do this. Focusing on the thought experiment but with a little math or other resources
1. "Surely You're Joking, Mr. Feynman!" by Richard P. Feynman: Although not strictly a physics textbook, Feynman's collection of anecdotes gives fascinating insights into the mind of a brilliant physicist. It showcases his unique approach to problem-solving and uses thought experiments to explain various physics concepts. 2. "The Theoretical Minimum: What You Need to Know to Start Doing Physics" by Leonard Susskind and George Hrabovsky: This book is part of a series that aims to provide a basic introduction to theoretical physics. It uses thought experiments and simplified explanations to cover topics like classical mechanics, quantum mechanics, and special relativity. 3. "Six Not-So-Easy Pieces: Einstein's Relativity, Symmetry, and Space-Time" by Richard P. Feynman: In this book, Feynman explores the core ideas of physics, including relativity and quantum mechanics, through six accessible lectures. He uses thought experiments and analogies to illustrate complex concepts in an engaging manner. 4. "The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory" by Brian Greene: This book provides an overview of the cutting-edge theories in theoretical physics, including string theory and the search for a unified theory. Greene uses thought experiments and vivid illustrations to make abstract concepts more comprehensible. 5. "QED: The Strange Theory of Light and Matter" by Richard P. Feynman: In this book, Feynman explains quantum electrodynamics (QED), the theory that describes the interaction between light and matter. Through thought experiments and clear explanations, he demystifies the quantum world and its fundamental principles
We get visual information from photons. When you are still you get information at the normal speed -> time runs and things happen at a normal speed in your mind. When you move nearly at the speed of light the speed of information has noticeably changed -> time seems to slow down. When you move at the speed of light you actually move as fast as the photons that carry information -> you won't get new information -> time seems stopped. When you move faster than light you are reaching old information -> an illusion of moving back in time. It's all physics of the nature, nothing else. You can't time travel.
If you can move with the speed of light and then see information of the past, but can't interact or change it. I think it just like you watch old UA-cam video VR in reverse. 😁
Hey i want to talk about how going lightspeed will cause time to stop? Suppose we are going forward at the speed of light now if we see backwards time(or say objects) will seem to freeze coz of the light carrying photons won't be able to reach us(i think we won't see anything at all) But if we look forward the objects which are in front of us their light also coming towards us and we going towards them at C then we'll recieve their vision, so will they look like time they are getting fast forward like time accelerating nd events happening tremendously faster no??? Be it Anything but Actually Everything is a Illusion
Hey guys, apparently flying in an airplane and seeing how the Earth has a curvature is fake. But let’s not listen to that bullshit, let’s all just stick with the ideologies from the 1500’s cause we were dropped on our heads when we were 2.
What bugs me is that teachers don't bother to tell you that if you simply analyze "Motion" to determine what it is and what it is that is required to make motion possible, you can discover the Special Relativity(SR) phenomena all on your own. And, at the same time, you end up deriving the SR mathematical equations. It is so easy to do that even a high school dropout can do it. I know, because I dropped out. Very frustrating indeed.
"The Physical Reason time slows at the Speed of Light" is a 2 minute video I made which describes the actual, physical reason, for the slow down. It's an original thought I had, which I've not seen anywhere else.
Regarding the holly mirror 1. How do we know the observer who stands still on the ground observes mirror reflection of the man who stands still in front of the mirror 2. How do we know the observer who stands still on the spaceship observes his mirror reflection It doesn't matter whether general relativity theorem correct. But as far as my understanding, Einstein has just assumed that observer who is in front of the mirror must see his reflection. Whole story of general relativity depends on this assumption we have never experienced yet.
This is just a thought experiment which leads to the creation of the formulae. We don't need to know whether people are actually observing anything, but if they were, this is what theory says they'd see. Just because something isn't being observed, doesn't mean it stops existing (we could go into some deep philosophy there!) The bit about the observer seeing his own reflection is to do with Galileo's statement about not being able to know you're moving without reference to the outside. It has always been the leap of faith I've struggled with most, but I suppose everything needs to be built on axioms until those axioms can be disproved.
@@DoingMaths I forgot to ask something else but important Please follow the video from 4:35 to 4:45. The stationary man (who is sitting on earth) sees the speed (direction) of light is changed. But it shouldn't be changed as it is a constant. It should be a constant for all the observers who are sitting on different frames. Am I correct????
@@senakawijayakoon Yes, you are correct, the speed of light is constant. But if the speed of light is constant, the apparent differences observed by the two people need to be explained by something else, hence the change in how time passes.
@@DoingMaths I Just meant, how does the stationary observer see the direction of light changes if the velocity of light should be a constant in speed and direction???
This theory makes sense but also i feel there is something missing, like what if you collide with an object like a planet? Because you are moving at the speed of light so eventually you'll hit something in your way meaning time is still going but if you don't hit anything ever forever then you're not moving meaning that time shouldn't stop since you're not going at any speed now. This is a catch 22 that just doesn't make any sense if you think just a little deeper. But the way we can think about this is that the light always goes the same speed but when the light bounces off you to the mirror it the light travels faster in time but once it returns it slows down time equally, you will never time travel only the light can do so.
You can't travel at the speed of light. The slowing down of time is noticable at speeds approaching the speed of light, so time is still passing, only much slower. Therefore if there was an object in your way, you would still hit it as time has never completely stopped.
@@DoingMaths so really, when you move near or faster than the speed of light, time isn’t truly being distorted? more so.. our perception of time is distorted?
with that thought experiment its easy to see why distortion of vision is expected near the speed of light the approximate angle of 45 degrees is the actual reflection you can expect to see in the mirror instead of the 90 degree reflection in other words the object being reflected would appear to have turned 45 degrees in comparison to the expected reflection Also.... speed is distance covered in an amount of time... if time slows the faster you go then it goes to reason your speed will be an illusion as you will cover more distance in accordance with your very slow one second. than you would in the normal one second.
Let's say I'm the observer. And a train is passing in front of me at the speed of light, and a light is emitted on the train up then back down.. wouldn't the light not travel horizontally with the train and just moved straight upwards.. why would the light move diagonally, relative to me? Shouldnt the light bounce back to the same point in space, a point by which the train has already passed by the time it bounces back?
It's to do with frames of reference. To a person on the train, they see the light beam travel to the mirror and then bounce back to the same point. This doesn't change if somebody happens to be watching the train travel past. To that observer outside the train, the whole frame of reference of the train is moving and the light appears to have take a longer route to the mirror and back.
i agree the light leaving the source towards the mirror would miss the mirror .... but the light leaving the source at 45 degrees in the travel direction of the mirror will hit the mirror giving the impression that the source turned 45 degrees upon being reflected.
If you are in a car and throw your phone in the air and watch it fall, to you it's just gone up and down, but to someone else watching not only did it go up and down but it went forward at the speed the car is moving, thus making it look like it's moving diagonally, the same concept here happens with the example of the beam of light, you are seeing something further in the past than you would otherwise of you were in the vehicle because by the time the light reaches you that vehicle has already moved away from that spot but you see it as it was, the faster it's moving the longer the light will have to travel thus making it look as tho it's slowed
Steven hawking said if you travel 99 or 99.9 percent the speed of light time would slow down so that 1 day would be like 365 days. Is there an algorithm that you could figure out how much time would pass at half the speed of light?
99,9 ---- 365 day 50 ------ x 50X365 /99,9 = 182,682683 This a very good formula works with a lot of things it's the 3 simple rule, it's taught on school lessons on math
Yes, from the point of view of people outside of your spaceship, time has slowed down for you, hence when you return from your travel you will have aged less than they have. You won't notice the slow down yourself until you compare the end result to somebody outside the spaceship.
I also wanna share one thing that by taking speed as a factor for time travel you will never gain success in making time relative. As every thing is moving with some speed. Nothing is at rest. Earth , solar system , galaxy, universe, timeverse ,spaceverse,etc
So what is the quick answer as to what causes time dilation? Motion seems to cause it? But why does motion cause it? In your derivation of the Minkowski factor, Should you not have said "multiply through by 4" but "multiply through by 2?" Multiplying by 4 would create a 2 in each unit? We don't want a 2; we want a 1? Sorry it may be my ignorance of math.
For the first question, I honestly don't know why motion causes it, but I enjoy the mathematics behind it and the idea of the thought experiment. For the second question, we multiply by 4 because each term is being squared. As (1/2)^2 is 1/4, we need to multiply by 4 to get rid of the denominators.
I have a question which might sound dumb but I'm gonna ask it anyway If time freezes as you attain the speed of light, but the fabric of space-time is expanding, then things can still move further away from each other while both at the speed of light, but if the distance between 2 objects can increase, does that mean that time didn't really stop or are both so to speak frozen in time and moving away from each other as 2 uncorrelated entities
"If time freezes as you attain the speed of light, but the fabric of space-time is expanding" where did you get this from? i thought fabric of space-time is shortening, not expanding
The problem is “The fabric of spacetime is expanding” assumes the universe is the fabric of spacetime. It assumes whatever is outside of the universe isn’t spacetime.
When you reach the speed of light, not only does Time equal zero, but distance along the axis of travel also compresses to zero. The spot you leave becomes the same spot you arrive at. If you could travel at the speed of light you could actually get anywhere instantly because of these 2 things. It is personally why I think light is actually instantaneous, but it is just an artifact of us having mass and being subject to relativistic forces that cause us to measure it, and interact with it at a finite speed.
I have a question that I think comes straight down to relativity. I can see how this works from this standpoint, but what about when we place another clock on the ground and also observe it from the spaceship? The observers on the ground still see the clock on the spaceship ticking slower, but if people are to observe the ground clock from the spaceship wouldn't they see that ground clock moving slower? Just in another direction? Thus meaning that for the people in the ship it would be the people on the ground that have the time slowing down? Or if we had 2 spaceships passing each other at 0.7x speed of light, wouldn't it be that for them the other ship's traveling 1.4x the speed of light and the time is moving incredibly slow? But again this would apply for both of them?
Non inertial frames aren’t equal so the clock on the ship falls behind the clock on the ground. They look equally slow to both observers but a force was only applied to one body. Each of the closing spacecraft see themselves as stationary in their own frame and the other ship closing at near light speed. The additional velocity is compensated for with time dilation and length contraction.
Considering the last problem, (just wanted to share my curiosity), assuming the age of the astronaut was 40years during take off, spending 5 years in space while the gap becomes 2 years, so when the astronaut comes back after 7 years from space would he look younger than he was supposed to look had he stayed back on Earth?
@@DoingMaths Would the physical body we have actually age differently though? Why does our physical body age different depending on the speed we are going?
@@DoingMaths since we can, well, people like you who are amazing at math, can do the math to prove how light and time are connected based off how fast we are going, is it actually proven how the body ages differently based off of this or is that just a theory, and if so can you recommend any published studies/books/videos on that topic specifically? All of this stuff is really great and this is the first video I've found that actually breaks down the math behind it and I enjoyed it a lot
@@shade_the Thanks for the great comments, I love the mathematical side of things like this. I don't know where to find any of the studies you are after I'm afraid.
2.13...what is the proof that one would actually see reflection in mirror if mirror along with you is travelling at the speed of light? If 2 spacecraft travels towards each other both at .7c speed of light. Say they have distance of 1 light year between them. Now both are at speed of light with respect to each other. Going by this equation an instance in one ship is equal to infinite time on other ship and vice versa. Am I missing something?
For the mirror, because you are in the same frame of reference as the mirror, your reflection would appear as normal. There isn't a proof of this as such, it is a theory which so far has held up to experimentation. For the two ships moving towards each other, velocity addition breaks down at speeds approaching the speed of light. I would suggest reading this article en.wikipedia.org/wiki/Velocity-addition_formula#Special_theory_of_relativity. I know it's Wikipedia, but it's a good place to start.
i guess i understand why a moving clock would be different than a nonmoving clock. but in both examples the clock is moving. One person just sees that it's moving. To me it doesn't seem like time changes at all, rather your perception of the light does. Therefore, I'd have to assume the astronaut's body still aged the same, even if he perceived it differently (unless the slow of light had a significant effect on the body(it would) but i still doubt it would be the exact 2 years difference). I'd love to see a practical study on this
That's a really good question. The person in the rocket would still see the clock working as they would expect it to i.e. they notice no difference as they travel. For more information about the stationary person's view, there's a good discussion here www.physicsforums.com/threads/time-dilation-in-horizontal-clock.462122/
You are on earth and say goodbye to a friend who gets into a spaceship that can travel at the speed of light. They travel to alpha centauri 6 light years away, so on the spaceship it takes 6 years to get there and 6 years to get back, on the spaceship you have aged 12 years. On the earth you are waiting for the ship to return from its mission, would it not also take 12 years for the crew to return?
Dear Sir can you please clear my confusion? Suppose a planet is a light year away from its sun. When a photon reaches the surface of the sun it sees the planet as it was a year ago right? (Now as they say reaching the speed light will cause time to freeze) So the photon shoots towards the planet at the speed of light, what will be the planets time when that photon reach the planet surface...a year ago?or present? nd how why? Plz explain sir🙏
Hi. I have to admit, I don't know. I love the mathematics of the Lorentz equations and I'm fine with the basics, but I'm not an expert. Sorry I can't help further.
This is actually the reason I think light travels instantly, and that due to relativity we are forced to measure and interact with it at a fixed finite speed even though that isn't what actually happens.
Good point. Mainly because I figured that it would be better for search engines. I think people are more likely to type 'why does time slow down?' than 'how much does time slow down?'
So, if I can travel at 99% of speed of light, I can actually travel to some place 284 light years away using only 40 years of my time. Let's within a life time. So, we could travelled to places that are thousands of light years away within our life time?
@@scoobyDrew247 How about see things further? For example, Alpha Centauri is about 4 light years away, but our telescope can't see that far. If I can travel at 99.99999% of spend of light, Alpha Centauri is like only 0.00005 light years away from me. Can I actually use my super telescope to see Alpha Centauri without even having to visit there? It only takes a second.
@@gopichand4166 Yes I can because my time has slowed down. So it is to you 284 light 284 years of, but to me it is merely 40 years. Please see reply from Andew Martin.
@@YinLawn yes, but that wouldn't make any difference cause, everyone on earth will be dead. (As in interstellar) . And btw, time will be still flowing even slow, so you will die eventually.
I imagine the answer is the same if the clock is orientated in the direction of travel instead of perpendicular and that the reason for saying that perpendicular orientation is an important point is just for visualization/demonstration purposes? A very clear video otherwise.
Hi. Thank you. Yes, you are right. The perpendicular clock is there to show the derivation of the equations. You get the same slow down of time whichever way the clock is facing or even without a clock.
The time does not slow down, at that velocity the matery is converted in light or energy, and the energy doesn't suffer degradation like the matery. That why , we'll think the time doesn't pass.
The same thing happens regardless of the orientation of the light clock or even without the light clock. It being perpendicular just creates great geometry for deriving the Lorentz equations.
So the obvious question then is, does time speed up the slower we go? Since time begins to slow down as soon as we start moving - if we stand still or in a buddist sense or eucharistically adorational sense remain still or 'be still' does time then speed up? We're always harping on about trying to go faster than the speed of light or trying to attain closer to the speed of light, when the results of such efforts with respect to time seem to be very negligible. It seems to be abit like pissing in the wind. Perhaps our approach to interstellar travel is arse about face. Instead of trying to achieve near light speeds where time slows down, if we concentrated on trying to achieve close to 0m/sec, we could simply wait until certain astronomical interests were within Dv range. God is very slow. The earth's orbital velocity around the Sun is approx 30km per sec, so to get that down you would need to move at 30km in retrograde to the earths motion, after you'd burned off the earths rotational speed @ -1037 mph. depending on where you are. But then there is also the Solar system speed on the arm of the milky way and then our galaxy's own speed relative to 0mph of the universe - so theres alot of calculations to be done before you could aquire a workable vector. But you might in some sense then be able to watch everybody else flying around trying to achieve something while your just sitting there enjoying it all. Martha and Mary for instance. Might be worth trying to prove that atomic clocks also speed up on a counter-velocity vector.
I can't fully understand Galileos perspective, because he never went anywhere near light speed, so he can't say that at light speed you would be able to see yourself, I keep imagining it like sound, so like a plane, you see it, but hear it way behind where it is, so your hearing where it use to be a long time ago, see where it was a short time again, but that is not where it is atm. I believe his right, but I just can't understand it and because I can't test it, I get annoyed.
If you’re in a spaceship travelling the speed of light and you experience time slower. Do you actually age slower compared to those on earth surely that’s not possible? Instead you just experience light at a different rate?
I dont fully understand it but yes you do age slower. Time is a real thing that slows down. For example 2 identical twins, one flying around at 0.7c for 20 years and the other on earth doing nothing, when they re-unite one would be aged more than the other. Crazy.
So to clarify, as you approach speed of light time slows. Given black holes stop even light from escaping at 300000kmh means it halts light and would suggest time speeds up but logically you'd think in black holes it stops altogether. Or is that a separate thing in that velocity isn't so relevant there as the gravity is
Hey dont know if this is stupid guestion just trying to understand it better, but what links the light to time. I get that in the example the light has to travel longer distance but would that just effect your perspective on it. Like for example if you take regular clock with you on the space ship would it show that 5 years have passed or 7. Or if you take a clock speed it to the speed of light would it not be more like you perspective of time has been altered not time itself. Well mainly i dont understand why the light and time are linked. Thats the main problem.
It has been done with atomic clocks on planes. Two clocks were sent around the world in opposite directions, one with the Earth's rotation and one against it. Because of the difference in speeds of the planes caused by the Earth's rotation speed, the times on the clocks ended up different to each other and both were different to a stationary clock. The time changing, rather than the perspective of time changing, is to do with Galileo's theory of relativity. This bit is the leap of faith for me, but experiments are consistent with it being correct.
Why is the travel of light waves always used to explain how time slows with velocity. Using light travel this way is very obvious what is going on. I want someone to use a mechanical clock to explain it.
Mechanical clocks fundamentally work by electromagnetism too. A spinning gear can move another because its atoms' electrons repel another gear's atoms. Similarly a hand on a clock is moved. A photon in vacuum simply gives us the limiting case as to what is the fastest possible way for information to travel. In a mechanical clock when a part if moved, its effects do not show up immediately on the other size of the object, but the information about the disturbance has to first travel to the other side (of a gear, a hand, a pendulum etc.). And if we use, say, a some quartz as the source of the rate of ticking, that too comes from electromagnetism.
What if we look at this way : SPEED OF LIGHT ISNT CONSTANT .. instead of thinking that time is changing how do we know for certain speed of light is constant ,
Countless experiments and measurements since 1887, nothing can be accelerated to it, relativity of time and length exhaustively verified, verification of Higgs field.
Okay I can understand why the clock would take longer between clicks than one that is stationary but how does that have to do with anything with humans aging or actual time? From what I understand sure the clock will be slower but why would humans age slower as well?
It's because of the difference between what is seen by the stationary person and what is seen by the travelling person. The two people are seeing the same clock ticking at different rates, rather than the clock itself changing rate. When one person is experiencing the clock ticking at a certain rate and somebody else is experiencing the exact same clock ticking at a different rate, then they must be experiencing the passing of time differently.
@@DoingMaths The clock or light to be exact doesn't define time though. If you see something slower doesn't mean time is slower, it just the updated light is taking a longer time to reach your eye than the other person. So how do people turn this into time travel and that people age slower in space/at very high speed is what I don't understand. Technically everything we are looking at is older than what they are because whatever we are looking at needs to have light reflected into our eye and that takes time then processed by the brain which also takes time but I wouldn't call that time travel. Time is still the same we just see things older than they currently are and that doesn't reflect their true state.
@@tv_wheels8548 This isn't to do with the distance between anybody and the clock or how long the light takes to reach the observers' eyes. We would get the same result with or without taking this into effect. What you are describing explains why everything you see is in the past, but that doesn't explain the difference in the passing of time. If I look at something a light year away, I am looking 1 year into the past; I agree. If I look again 30 minutes later, I still see a year in the past compared to me and 30 minutes will also have passed for the distant object (it just happens to be 30 minutes that happened a year ago). There's no time dilation there (not from the effect of the distance anyway). I can't really explain the concept any better I'm afraid. There are many people out there who understand special relativity and general relativity much better that I do and could give you a better answer, I just enjoy the mathematics behind it all. It's a theory and there is a lot of respectable experimental evidence to back it up so I'm happy to go with it.
Cool. So it’s accurate that a massless photon itself from its perspective does not experience any time. So the moment a photon leaves a star in andromeda 2.4 million years ago & the moment it reaches my eyes right now, from the photons perspective it is the exact same moment?
This is just what happens hypothetically. In reality, the math actually breaks down and just doesn't work AT the speed of light, but right up to an infinitesimally small fraction less than the speed of light, the math works and time is ticking at an infinitesimally small rate of speed - so to make the jump to "time freezes AT the speed of light" even though the math technically doesn't work is not a giant leap.
let us just consider the frame from spaceship, if we consider spaceship to be at rest, everybody else is traveling with 0.7c, then by that logic he would be 7 years older and everyone will be 5 years older, or am i getting something wrong here ?
I still don’t get how you can see your reflection in the mirror if you’re traveling at light speed. And why light always travels at this speed irrespective of reference frame.
assuming the distance traveled is the same for both the traveler and the observer, would the observer then observe the traveler to be travelling at a slower speed than the traveler would observe themselves to be traveling? If that's indeed the case, what else would that signify? 🤔
Won't it look the same for Astronaut if he looks at earth ? I mean if he looks at earth and compare clocks, it should look to him that clock is slowed down on earth relative to his clock. Astronaut should see triangular light path for the light clock on earth. There is some error in my thinking I hope you can clarify.
I still dont understand if you point light sideways inside the spaceship how it doesn't just keep going the way it was pointed at. I don't understand why it travels sideways to the spaceship AND same direction as the spaceship. To me it just sounds logical that it would just miss the mirror
The sideways movement of the light is what is observed by the stationary observer outside. For the observer in the spaceship, they must only see the light travelling to the mirror and back otherwise this would break Galileo's Principle of relativity. If the light missed the mirror, the traveller would know they are moving without having a reference to the outside. To be fair, this is the bit that requires the largest leap of faith for me too.
Heres why I think everyone is just over thinking this, time is always consistent and time is made up by us. A second is determined by a fixed rate of speed in which a few numbers go up to 60, which in turn gives you a second. Therefore time as we made it up is always set at a fixed rate. Light does not affect time, light just travels at a further distance than anything else. In the example of the light clock, maybe the light itself would get distorted by the speed its traveling at but that's about it, also reflection in my opinion would stay the same
The effect on time of travelling at high speeds has been proven by physical experiment. One such experiment put atomic clocks in aeroplanes and flew one set eastwards and another set westwards. Due to the effect of the Earth's rotation on their relative speeds, the eastward clocks lost time, while the westward clocks gained time, all compared to stationary clocks. The speeds involved were very slow compared to the speed of light, so the time difference was tiny ( a few nano-seconds) but it was there nonetheless. www.thevintagenews.com/2016/09/16/hafele-keating-experiment-two-atomic-clocks-flew-twice-around-world-eastward-westward-back-home-showed-different-times/ Also, it's not the light affecting time as such, but the speed of light is inextricably linked to the changes in time via the Lorentz equations given in the video.
How do we know who the observer is? I've heard that acceleration is relevant to answer that, but let's remove acceleration from the equation for a minute and say that the earth and a spaceship are currently on a collision course, traveling towards each other at .99999c, and are currently 100 light years apart. When the earth and the spaceship meet, would the people on earth have died of old age or would the astronaut have died of old age, or neither? Doesn't that depend on where in space they met? How do we decide on a reference point? Edit: assume that everyone dies of old age at 100 and are otherwise invincible XD
Ah ok I think the answer is in the equation: we need to know the value of T' in order to calculate T, meaning that all 3 answers are possible. It's probably more useful to look at it in reverse from the moment of collision. From that point there would be some non-zero acceleration by the spaceship or the earth or both (again depending on your perspective...), which probably means we could retrodict the values of those Ts based on that acceleration. I'm starting to understand why space and time can't be separated with this theory. There's no concept of a "snapshot of all of space" at a particular "moment in time." The only snapshot we can take is of a point in space at a point in time. If anyone can identify any problems with this, please let me know.
in reality, both traveler and observer should hear the click of the clock at the same time, right? The observer may see the light beam travels further to reach the sensor, but he and the traveler should hear the click at the same time since the speed of light is constant. Or is it because the speed of sound is slower than light so it takes longer time to reach our ears?
Unfortunately, on all relativity videos, it is suggested (by mistake) that there is a preferred or special frame of reference on which relativity has no effect. On the example on the ship that left Earth and is travelling at 70% the speed of light, the question is how much time has elapsed on the spaceship after 5 years, suggesting that it is the spaceship that feels “relativity” But, from the point of view of the spaceship as an observer, it is the Earth that is moving at 70% of the speed of light and it is the Earth that is aging more slowly. The formula is for the observer since there is no Absolute Frame! This is why people misunderstand relativity since they incorrectly think that because the ship sped away, there is some special about the Earth reference frame. There isnt! The calculation applies to both the observer on Earth or an observer on the spaceship and yields the same result. The correct way of presenting this would be to calculate if you are on the spaceship and after 5 years on Earth you want to know how much time passed on the soaceship 7 years! same result! The conclusion at the end is wrong and misleading. If you are seating on Earth after 7 years by the Esrth clock, 5 years have elspsed by the spaceship clock. But if you are on the spaceship, after 5 years on Earth 🎉7 have elapsed on the spaceship clock (ignoring acceleration) This is relativity. No special frame of reference. Why nobody gets this right?
There have been many experiments which back the theory up e.g. flying extremely accurate atomic clocks around the world in opposite directions (one with the Earth's rotation, the other one against it) and seeing the difference in time on the clocks. Obviously, these are still very slow in comparison to the speed of light, but the equations I mention in the video still hold up.
I get how the equation manipulation works to arrive at this, but it seems impossible to my brain. Is there a way to test this? Like, does this actually happen, or is it just what our current theories says should happen?
So like, for a frame of reference, Earth is traveling around the sun at 30 km/s and Pluto is going around at about 5 km/s. Does that mean a person sitting on Earth would age slower than a person sitting on Pluto?
So for fun, ran the numbers and found that for a 100 years on Pluto, 99.99 years would pass on Earth. I guess the speed difference compared to the speed of light doesn't matter as much. I feel like I would need to see this happen in an experiment to believe it.
@@jeffsmith3550 There have been experiments flying atomic clocks around the Earth in opposite directions to create as much speed difference as possible and the clocks did show slightly different times to each other afterwards. Like in you example, it was minimal, but it was there.
Great vid, but I respectfully disagree. Light clocks work on the basis that the speed of light is constant and so too is the shortest distance light must travel to bounce off the mirror and hit the receiver. That delay is measured and they are calibrated to that effect when stationary. As the vid correctly points out, the light that hits the mirror and bounces back to the receiver must travel further, yet the moving light clock isn't recalibrated for this new distance. Surely this is a case of not having a fit for purpose clock rather than a time dilation theory?
The light on the moving clock is only moving further from the point of view of the stationary observer. From within the spaceship it still appears to be moving its original distance at the speed of light.
@Doing Maths that would violate the constancy of light. Light travels in its own frame of reference. Both observers would see the light go straight up and down. You are confused by the bouncing ball analogy, which shows the ball traveling in an arch as it has forward momentum.
@@DoingMaths I still disagree with this video. It's all going really well until 7:10. The statement "t'=(2L)/c" is however, incorrect. If the speed of light is constant and physically travels along h, then it cannot travel the distance of just L in the same time. That would imply h=L, which it clearly doesn't. To the observer in the ship, yes it appears like it's moving back and forth directly along L due to the ships velocity, but no, it doesn't look like it's travelling at the speed of light. It looks slower, the speed of the beam of light observed in the spaceship along L (let's call it c') could be calculated as c' = c*(L/h). I didn't bother with the rest of your calculation since you don't distinguish between c and c'.
@@stewiesaidthat The violation that you mention is the whole point. Trying to apply the bouncing ball analogy to the light doesn't work if we say that the speed of light is constant. Something has to give. Einstein decided that as the speed of light stays constant, the things that give must be time and distance. So far, experimentation has backed up Einstein's theories, with nothing to suggest he is wrong.
@@pd4689 You are correct in saying that the speed of light is constant which then gives the apparent contradiction of h equalling L, but that is the whole point of the thought experiment. If the velocity can't change to allow these two different distances to be travelled in the same time, then it must be time itself that is changing. There is no c' as that would imply a different speed of light, but as we have mentioned, the speed of light is constant.
No, time not getting slower on that spaceship, spaceship's speed just make that light-mirror clock run slower. After 7years of earth time, body of the astronaut had grown 7years too, the only problem is he need to adjust the date on his light-mirror watch, add 2 years for specifically.
If you on the spaceship fly repeatedly around the earth at near light speed in one earth year, there will be no time-cheating for you. You'll spend a whole year living in that ship, experience fully through 365 days, fly ~85million times around the earth - clock just not work on your spaceship. And if you keep flying after 80 years of earth time, you may die old too.
Would it be equivocal to reframe that last example as: "after 5 years have passed on the Earth, how much time has passed on the spaceship?" After all, the spaceship guy could say hey, I'm the one at rest it's the Earth that's moving 0.7c away from me! The answer would be the same 7 years, thus both the Earth and the spaceship see the other as younger. Then would I be correct in saying the difference is made up when one of the observers accelerates back into the other's frame of reference? Because as you bend space everything outside of that "space-bending" should speed up in time. Then their clocks would match back up again. So the only reason it's not a paradox is because teleportation to a certain velocity without some degree of space-bending aka acceleration aka gravity cannot exist?
Let me rephrase, not that their clocks would "match up" but that the observer who does more accelerating to catch up/slow down to the other's frame of reference will definitively be the younger one. That's what I meant.
Because humans are technically moving at the speed of light. Your brain is processing at light speed. Each cell in your body responding at that speed. The slower the body gets the faster the vibration gets. Why because the slower non distracted body becomes aware of the speed of the objects around it. Each moving at its own speed through time. Say in a living room with a child, a cat, and a dog. You and the other for beings are in different time zones. Each moving at a different velocity through time. Each being on a different wavelength. Now let's add the TV and it's data, the couch, the floor, etc... Each in its own time reference and each having to jointly connect to create one time space that can be referenced by each morning molecule in the room and that's just one living room. You think humans are gonna understand time globally let alone cosmically?
Yes. There's something about the acceleration of the travelling person that is needed for the return journey, that makes the slowing down of time only happen to them. I think it's the twin paradox, but I have to admit, that bit is beyond my understanding.
Time doesn't tick for you if you are moving at the speed of light even if an observer was able to observe that on their time frame you have traveled millions of light-years.
@@neloysinha8098, unless you don't understand what a light year is. But a light year is the distance covered by the speed of light in one year. If you were moving at the speed of light, it will take you one year to cover one light year. This is a very basic understanding.
@@pjbpiano oh fuck! If only I knew what a light-year was than my original comment would have meant that no matter how far you travel it'll be a moment for you cause time doesnt fucking tick for you at lightspeed, but i didnt know what light year was ..damn!
How light photon changed angle is it due to light photon gets attracted to the mirror I mean for say if iam travelling in a bus and if i jumped at certain speed to touch the roof of the bus and bus also moving at the speed at which i am jumping than i wouldn't touch the same point of roof that is opposite to from where i jump
If you jumped straight upwards when standing on a moving bus, then anybody on the bus with you would just see you go up and down with no forward movement. If somebody standing outside was watching you as the bus went pass, then they would see you go up and down, but would also see you move forwards at the same speed as the bus. This is the idea behind the two frames of reference - one person moving with the clock and another person watching the clock travelling past.
This clearly is a theory that is wrong. I’m telling you now if I have my clock on me travelling at the speed of light I promise you not speed will change the time on my phone
I don't think this answers the question. You are demonstrating a side effect of time dilation, just like with gravity. We don't know what gravity is, but we can measure it, know it exists, and make calculations and predictions about it. But why does time dilation happen? Imagine we have a charged battery that can last 30 days on standby. If we sent that battery at 99.999999999% of the speed of light for 30 days of Earth time, when we checked the charge, it would still be almost at 100%. I don't think we can answer why this happens unless we understand what happens at the quantum level.
It's not so much the atom slowing down but the amount of force being applied is decreasing. Increase the amount of force (GPS satellite calibration) and the clock stays in sync. Time speeds up as you approach the speed of light (information). It's essential the same as watching a 2 hour movie in 1 hour.
But if astronaut would be travelling with C, then? 5÷0 would be infinite, which means if we travell with speed of light, in earth infinite time would have been passed, so might be someone was travelling😀
According to Einsteinian physics, the astronaut would never be able to quite reach the speed of light, but yes, if the speed is really close to c, then the time will really stretch out.
Common sense tells you that time does not slow down, it only appears to do so. Physicists need a lesson in logic because they're theories are full of logical inconsistenties with no basis in reality.
But how can you ignore the speed of earth. The path of light for the observer is when observer is at rest. We should not forget that as we talk about space the earth is no longer relative. By the way what you say can be true if that space ship travels on earth. But believe me the 'Theory of speed of light and time relation ' is not reliable. The theory which will come with actual time travel is far beyond imagination. For example the solution of P vs NP set has contributed a lot to the space research. Best of luck.
This is my opinion: In Galileo system, x=vt, if only if dx/dt is constant. Lorentz transformation goal is distances (x, x’) x=f(v,t)and x’=g(c, t’) are mathematically equal in both systems with symmetry. So c is not Galileo or classic velocity, and t’ is not classic time. In Galileo, v varies, t is uniform at any point in space; whilst in Lorentz, t’ varies, c is constant in space. c =eu , is really the property of the space, or medium, or Ether. It is not velocity in Galileo.( v, C),(t,t’), they are (Apple, Orange), (Peach,Grape) in two math systems. People are still thinking they are same things. That causes confusion. Saying 1) if an object moves at speed of light, time stops. Moving object slows clock, etc. That’s wrong. It should be said t’ in Lorentz stops, or equal to 0. In Galileo, t is uniform, it doesn’t stop or slow. 2). Speed of light C is constant from any observer at different speeds. That is wrong. c in Galileo changes from observers, C in Lorentz as the property of space is constant. Then there is no ambiguity, confusing, both accurate in their own system for/from measurements. Time dilution, space-time curvature, etc. are all bogus by mixing concepts in two systems. If you use Fourier series to express a signal S, it is not the signal in time domain, it’s amplitude A in frequency domain. Nobody treats A-S as “signal dancing”. But sigma of all these series by frequency goes back to the value of signal in time domain. They are just mathematically equivalent, not necessarily physically same. There are many ways to do it mathematically, too. Relativity is just another way of measuring of the nature using electric magnetic wave in Lorentz system. It has advantages over Galileo system in Astronomy, because Maxwells equations describe electromagnetic wave in vacuum with eu as constant, which is the space property and its value equals to speed of light in Galileo.
THE ULTIMATE AND CLEAR MATHEMATICAL PROOF OF THE FACT THAT E=MC2 IS F=MA: Ultimately and truly, TIME is NECESSARILY possible/potential AND actual IN BALANCE; AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. This NECESSARILY represents, INVOLVES, AND DESCRIBES what is possible/potential AND actual IN BALANCE. SO, time DILATION ULTIMATELY proves ON BALANCE that E=mc2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity. The stars AND PLANETS are POINTS in the night sky. A PHOTON may be placed at the center of THE SUN (as A POINT, of course), AS the reduction of SPACE is offset by (or BALANCED with) the SPEED OF LIGHT; AS ELECTROMAGNETISM/ENERGY IS GRAVITY; AS E=mc2 IS F=ma. Great !!! "Mass"/ENERGY IS GRAVITY. ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity IS ELECTROMAGNETISM/energy. E=MC2 IS F=MA. Consider the man who IS standing on what is the EARTH/ground. Touch AND feeling BLEND, as ELECTROMAGNETISM/energy is gravity; as E=mc2 IS F=ma. GREAT !!! E=mc2 IS F=ma. The linked AND BALANCED opposite of what is THE SUN is A POINT in the night sky. The stars AND PLANETS are POINTS in the night sky. A PHOTON may be placed at the center of THE SUN (as A POINT, of course), AS the reduction of SPACE is offset by (or BALANCED with) the SPEED OF LIGHT; AS ELECTROMAGNETISM/ENERGY IS GRAVITY; AS E=mc2 IS F=ma. This NECESSARILY represents, INVOLVES, AND DESCRIBES what is possible/potential AND actual IN BALANCE. Therefore, the linked AND BALANCED opposite of what is THE EARTH is ALSO A POINT in the night sky. Great. Gravity IS ELECTROMAGNETISM/energy. ELECTROMAGNETISM/ENERGY IS GRAVITY. E=mc2 IS F=ma. Gravity AND ELECTROMAGNETISM/ENERGY are linked AND BALANCED opposites, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Accordingly, the Earth AND the Sun are linked AND BALANCED opposites; AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity IS ELECTROMAGNETISM/energy, AS E=mc2 IS F=ma. The stars AND PLANETS are POINTS in the night sky. It ALL CLEARLY makes perfect sense. Great !!!!!! Energy has/involves GRAVITY, AND ENERGY has/involves inertia/INERTIAL RESISTANCE. E=MC2 IS F=MA. The EARTH and the SUN thus constitute and comprise what are the MIDDLE AND THE FULL DISTANCE in/of SPACE (IN BALANCE) in full and BALANCED compliance and conformity with the CLEAR and universal fact that E=mc2 IS F=ma, AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Great !!!! It ALL CLEARLY does make perfect sense. (The stars AND PLANETS are POINTS in the night sky.) INDEED, BALANCE and completeness go hand in hand. Now, very importantly, outer "space" involves full inertia; AND it is fully invisible AND black. Great. NOW, OVERLAY what is THE EYE in BALANCED RELATION to/WITH what is THE EARTH. Notice the black space of THE EYE. The stars AND PLANETS are POINTS in the night sky. THE DOME of a person's EYE is ALSO VISIBLE. Now, carefully consider what is the semi-spherical, translucent, QUANTUM GRAVITATIONAL, AND BLUE SKY. Great. E=mc2 IS F=ma. It is CLEAR. THE EARTH is ALSO BLUE (AS WATER). GREAT. "Mass"/ENERGY IS GRAVITY. ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity IS ELECTROMAGNETISM/energy. INSTANTANEITY is thus FUNDAMENTAL to what is the FULL and proper UNDERSTANDING of physics/physical experience, as E=mc2 IS F=ma; as ELECTROMAGNETISM/energy is gravity. Gravity IS ELECTROMAGNETISM/energy. It ALL CLEARLY makes perfect sense. Inertia/INERTIAL RESISTANCE is proportional to (or BALANCED with/as) GRAVITATIONAL force/energy, as this unifies AND balances gravity AND ELECTROMAGNETISM/energy; as this balances gravity AND inertia. (This clearly explains BOTH F=ma AND E=mc2, AS ELECTROMAGNETISM/ENERGY IS GRAVITY !!!) ACCORDINGLY, gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. SO, the BALANCE of being AND EXPERIENCE is essential; AS E=mc2 IS F=ma. Our EXPERIENCE is NECESSARILY that of what is the FULL DISTANCE in/of SPACE, AS we are BALANCED between what are THE SUN AND c (A POINT); AS E=mc2 IS F=ma. The stars AND PLANETS are POINTS in the night sky. SO, a given PLANET (INCLUDING WHAT IS THE EARTH) sweeps out equal areas in equal times; AND this is THEN consistent WITH/as F=ma, E=mc2, AND what is perpetual motion; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity IS ELECTROMAGNETISM/energy. E=mc2 IS F=ma. BALANCE and completeness go hand in hand. It ALL CLEARLY does make perfect sense. THINK about what is QUANTUM GRAVITY. "Mass"/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent with/as what is BALANCED electromagnetic/gravitational force/ENERGY, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Indeed, gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE; AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Therefore, the rotation of WHAT IS THE MOON matches it's revolution !!! Objects fall at the SAME RATE (neglecting air resistance, of course), AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity IS ELECTROMAGNETISM/energy. Gravitational force/ENERGY is proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE; AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Stellar clustering ALSO proves ON BALANCE that ELECTROMAGNETISM/energy is gravity, AS E=mc2 IS F=ma. Magnificent !!! E=mc2 IS F=ma. Is a two dimensional surface or SPACE visible or invisible ? The answer is that it is BOTH. So, the electron AND photon are structureless. A PLANET (INCLUDING WHAT IS THE EARTH) is a balanced MIDDLE DISTANCE form in relation to E=mc2 AS F=ma. A PLANET (INCLUDING WHAT IS THE EARTH) is a balanced MIDDLE DISTANCE form in relation to the Sun AND c (A POINT). The stars AND PLANETS are POINTS in the night sky. E=MC2 IS F=MA. ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity IS ELECTROMAGNETISM/energy. Gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. BALANCE AND completeness go hand in hand. Very importantly, outer "space" involves full inertia; AND it is fully invisible AND black. E=MC2 IS F=MA. It ALL CLEARLY makes perfect sense. The BALANCE of being AND EXPERIENCE is essential. The INTEGRATED EXTENSIVENESS of THOUGHT (AND description) is improved in the truly superior mind. INSTANTANEITY is thus FUNDAMENTAL to what is the FULL and proper UNDERSTANDING of physics/physical experience. (THOUGHTS ARE INVISIBLE.) It is a very great truth that THE SELF represents, FORMS, and experiences a COMPREHENSIVE approximation of experience in general by combining conscious and unconscious experience. MOREOVER, the ability of THOUGHT to DESCRIBE OR RECONFIGURE sensory experience is ULTIMATELY dependent upon the extent to which THOUGHT IS SIMILAR TO sensory experience. Beautiful. It ALL CLEARLY makes perfect sense. E=mc2 IS F=ma. By Frank Martin DiMeglio
That's all very well but since we accept the principle of relativity, who is to say that the spaceship isn't stationary and the observer is the one who is moving, in which case the same calculations would imply that the observer is experiencing time dilation, and not the bloke on the spaceship. There is a second case that merits our attention. Suppose that a right angle triangle isn't formed because the ship isn't flying past the observer but away from him, possibly in parallel to a beam of light from the observer's torch. In that instance the beam the astronaut is shining on the mirror and the beam reflected from the mirror form no triangle and the effect that the ship's motion is having on the beam inside the spaceship is cancelled once it is reflected from the mirror. What happens in that case? There are at least those two additional cases that need to be looked at to clarify this theory.
I think velocity is just a potential energy that you can see, and space does not know velocity. Every velocity has INFINITE definitions, which is exactly like NO DEFINITION. So that relative line everyone draws is the source of misunderstanding. There is no time outside of your brain, and constant light relative you your eyes ONLY was a DECLERATION, not an observation. The result is that Relativity creates an ADJUSTABLE time and tells you that if you move your head, then the entire Universe INSTANTLY changes shape along that axis JUST FOR YOU, and scientists BELIEVE IT! There is no evidence that this happens or needs to happen. It is 100% math telling you this AFTER it changes your numbers to create it ON PAPER, AND it leaves a NON-transformed reality behind IGNORED. This is the goofiest human farce in history, and it's gone long enough for me. There is plenty of evidence that it's wrong, it is just a matter of opinion.
It is so clear and easy to understand here. But in school, they made it so difficult to grasp, probably purposefully, that one just does not want to hear it. Your video was just a few minutes. But school forced us to sit through their agonising explanation for several days. I believe there is an incredible flaw in the way many schools present their learning material. This may be by design to train people to hate to learn. I have heard, "I do not want to know that," or, "Why would I even want to know that?," so much that I believe willing ignorance has become fashionable today. I almost fell into the trap myself. Now, I am addicted to learning because of the way things are presented away from school's methodology.
Thank you. I'm glad it helped.
Well said.
Just found this. I've watched many 'light clock' examples of relativity, but this is the first one that really breaks it down and takes you through the basic math!
Unfortunately, this video is misleading. Do you know that if you were on the spaceship, you would think it is the Earth moving away at 70% of the speed of light. So after 5 years on Earth, 7 have passed on the spaceship. It is time on Earth that moves more slowly! Totally symmetric!
In the formula, the velocity is not absolute but the relative velocity which applies to both Earth and the spaceship.
Did you understand this by watching this video?
It would be symmetrical if the earth was the same mass as the spaceship. Only the spaceship undergoes acceleration, not the earth.
@@andywason3414 Velocity is relative. How you got to 70% C doesnt matter to the equation( did you see acceleration or mass in the equation? Of course not! Irrelevant) in the spaceship you see time dilation on the Earth, on the Earth you see time dilation on the spaceship. This is the essence of relative. No absolute frames. Nobody is ever at rest, judt relative motion to each other. You get the same value on the spaceship or Earth.
If you had 2 spaceships in space, one going left at 35% c and the other ibe to the right at 35% c, you would get the same result. Its the same problem! All that matters is relative motion
This is why this video doesnt do a good job. The result is correct only mathematically
So atomic clocks that fly in opposite directions around the world and come back reading different times are wrong?@@pedrosura
@@andywason3414 That is similar to the twin paradox. Where you have twins, one of the two goes out in a spaceship and travels close to the speed of light to a system a few light years away, stops, and comes back to find his brother much older. It’s called a “paradox” because due to relative motion, one of them should not age more than the other.
en.wikipedia.org/wiki/Twin_paradox
Read that reference. It explains the symmetry breaking once you come back to the initial frame where both twins are together or where you compared clocks.
Bottom line, this is poorly explained by teachers and give people the wrong idea that objects close to the speed of light have these effects. But all speed is relative. So an object closed to the speed of light in a non accelerating frame would observe you having these effects.
I have watched more than a dozen time dilation videos. This is the first one that I have understood! Thank you!
I'm glad it helped. Thank you for the feedback.
I love the way you explain maths using thought experiments, can you recommend any physics book that do this. Focusing on the thought experiment but with a little math or other resources
Sorry, I'm not sure about anything specific, but most books that look into Einstein's work talk about his thought experiments.
@dave randell Cheers Dave, Ill check it out
1. "Surely You're Joking, Mr. Feynman!" by Richard P. Feynman: Although not strictly a physics textbook, Feynman's collection of anecdotes gives fascinating insights into the mind of a brilliant physicist. It showcases his unique approach to problem-solving and uses thought experiments to explain various physics concepts.
2. "The Theoretical Minimum: What You Need to Know to Start Doing Physics" by Leonard Susskind and George Hrabovsky: This book is part of a series that aims to provide a basic introduction to theoretical physics. It uses thought experiments and simplified explanations to cover topics like classical mechanics, quantum mechanics, and special relativity.
3. "Six Not-So-Easy Pieces: Einstein's Relativity, Symmetry, and Space-Time" by Richard P. Feynman: In this book, Feynman explores the core ideas of physics, including relativity and quantum mechanics, through six accessible lectures. He uses thought experiments and analogies to illustrate complex concepts in an engaging manner.
4. "The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory" by Brian Greene: This book provides an overview of the cutting-edge theories in theoretical physics, including string theory and the search for a unified theory. Greene uses thought experiments and vivid illustrations to make abstract concepts more comprehensible.
5. "QED: The Strange Theory of Light and Matter" by Richard P. Feynman: In this book, Feynman explains quantum electrodynamics (QED), the theory that describes the interaction between light and matter. Through thought experiments and clear explanations, he demystifies the quantum world and its fundamental principles
As taught by C3PO human cyborg relations. Smiles
We get visual information from photons.
When you are still you get information at the normal speed -> time runs and things happen at a normal speed in your mind.
When you move nearly at the speed of light the speed of information has noticeably changed -> time seems to slow down.
When you move at the speed of light you actually move as fast as the photons that carry information -> you won't get new information -> time seems stopped.
When you move faster than light you are reaching old information -> an illusion of moving back in time.
It's all physics of the nature, nothing else. You can't time travel.
If you can move with the speed of light and then see information of the past, but can't interact or change it. I think it just like you watch old UA-cam video VR in reverse. 😁
Actual you can time travel to the future
Not sure about the past though
Thinking that Moving faster than Light is possible is itself a Illusion 😂
@@humourunified Of course we are talking about things in theory and hypotheses.
Hey i want to talk about how going lightspeed will cause time to stop?
Suppose we are going forward at the speed of light now if we see backwards time(or say objects) will seem to freeze coz of the light carrying photons won't be able to reach us(i think we won't see anything at all)
But if we look forward the objects which are in front of us their light also coming towards us and we going towards them at C then we'll recieve their vision, so will they look like time they are getting fast forward like time accelerating nd events happening tremendously faster no???
Be it Anything but Actually Everything is a Illusion
damn my head is now full of questions because im just a 10 year old wondering about time and space
and a lot of physics
And you are cake ( ya that’s the reality
@MASK NAZI I see we are still holding onto ideologies from the 15th century
@MASK NAZI your brain is flat not the earth
Hey guys, apparently flying in an airplane and seeing how the Earth has a curvature is fake. But let’s not listen to that bullshit, let’s all just stick with the ideologies from the 1500’s cause we were dropped on our heads when we were 2.
What bugs me is that teachers don't bother to tell you that if you simply analyze "Motion" to determine what it is and what it is that is required to make motion possible, you can discover the Special Relativity(SR) phenomena all on your own. And, at the same time, you end up deriving the SR mathematical equations. It is so easy to do that even a high school dropout can do it. I know, because I dropped out. Very frustrating indeed.
"The Physical Reason time slows at the Speed of Light" is a 2 minute video I made which describes the actual, physical reason, for the slow down. It's an original thought I had, which I've not seen anywhere else.
I'll go and check it
I like how you Britishy types pronounce the letter H as "haych" lol.
Wrong. We pronounce H as “aych”
There is no “h” when we produce h
It’s a sharp “aych”
🇬🇧
@@GeeTheBuilder 6:05
I think it is meant to be 'aych' in standard English. Saying 'haych' is a bad habit. I seem to alternate between the two though.
How about ketch?
Regarding the holly mirror
1. How do we know the observer who stands still on the ground observes mirror reflection of the man who stands still in front of the mirror
2. How do we know the observer who stands still on the spaceship observes his mirror reflection
It doesn't matter whether general relativity theorem correct. But as far as my understanding, Einstein has just assumed that observer who is in front of the mirror must see his reflection. Whole story of general relativity depends on this assumption we have never experienced yet.
This is just a thought experiment which leads to the creation of the formulae. We don't need to know whether people are actually observing anything, but if they were, this is what theory says they'd see. Just because something isn't being observed, doesn't mean it stops existing (we could go into some deep philosophy there!)
The bit about the observer seeing his own reflection is to do with Galileo's statement about not being able to know you're moving without reference to the outside. It has always been the leap of faith I've struggled with most, but I suppose everything needs to be built on axioms until those axioms can be disproved.
@@DoingMaths I forgot to ask something else but important
Please follow the video from 4:35 to 4:45.
The stationary man (who is sitting on earth) sees the speed (direction) of light is changed. But it shouldn't be changed as it is a constant. It should be a constant for all the observers who are sitting on different frames.
Am I correct????
@@senakawijayakoon Yes, you are correct, the speed of light is constant. But if the speed of light is constant, the apparent differences observed by the two people need to be explained by something else, hence the change in how time passes.
@@DoingMaths I Just meant, how does the stationary observer see the direction of light changes if the velocity of light should be a constant in speed and direction???
This theory makes sense but also i feel there is something missing, like what if you collide with an object like a planet? Because you are moving at the speed of light so eventually you'll hit something in your way meaning time is still going but if you don't hit anything ever forever then you're not moving meaning that time shouldn't stop since you're not going at any speed now. This is a catch 22 that just doesn't make any sense if you think just a little deeper. But the way we can think about this is that the light always goes the same speed but when the light bounces off you to the mirror it the light travels faster in time but once it returns it slows down time equally, you will never time travel only the light can do so.
You can't travel at the speed of light. The slowing down of time is noticable at speeds approaching the speed of light, so time is still passing, only much slower. Therefore if there was an object in your way, you would still hit it as time has never completely stopped.
@@DoingMaths so really, when you move near or faster than the speed of light, time isn’t truly being distorted? more so.. our perception of time is distorted?
@@sopwith2721 Time is being distorted for the person travelling, but we can't reach or exceed the speed of light.
Fun fact: as yo mama reaches the speed of light she becomes infinitely heavier
Niceeee
with that thought experiment its easy to see why distortion of vision is expected near the speed of light
the approximate angle of 45 degrees is the actual reflection you can expect to see in the mirror instead of the 90 degree reflection
in other words the object being reflected would appear to have turned 45 degrees in comparison to the expected reflection
Also....
speed is distance covered in an amount of time... if time slows the faster you go then it goes to reason your speed will be an illusion as you will cover more distance in accordance with your very slow one second. than you would in the normal one second.
Let's say I'm the observer. And a train is passing in front of me at the speed of light, and a light is emitted on the train up then back down.. wouldn't the light not travel horizontally with the train and just moved straight upwards.. why would the light move diagonally, relative to me? Shouldnt the light bounce back to the same point in space, a point by which the train has already passed by the time it bounces back?
It's to do with frames of reference. To a person on the train, they see the light beam travel to the mirror and then bounce back to the same point. This doesn't change if somebody happens to be watching the train travel past.
To that observer outside the train, the whole frame of reference of the train is moving and the light appears to have take a longer route to the mirror and back.
i agree the light leaving the source towards the mirror would miss the mirror .... but the light leaving the source at 45 degrees in the travel direction of the mirror will hit the mirror giving the impression that the source turned 45 degrees upon being reflected.
If you are in a car and throw your phone in the air and watch it fall, to you it's just gone up and down, but to someone else watching not only did it go up and down but it went forward at the speed the car is moving, thus making it look like it's moving diagonally, the same concept here happens with the example of the beam of light, you are seeing something further in the past than you would otherwise of you were in the vehicle because by the time the light reaches you that vehicle has already moved away from that spot but you see it as it was, the faster it's moving the longer the light will have to travel thus making it look as tho it's slowed
awesome explaination. it caused a bigbang in my mind! thanks a lot!
You're welcome
Steven hawking said if you travel 99 or 99.9 percent the speed of light time would slow down so that 1 day would be like 365 days. Is there an algorithm that you could figure out how much time would pass at half the speed of light?
if it was half the speed of light wouldnt it be 182.5 days per day...since light is constant and only half the time has passed?
99,9 ---- 365 day
50 ------ x
50X365 /99,9 = 182,682683
This a very good formula works with a lot of things it's the 3 simple rule, it's taught on school lessons on math
if you traveled at exactly the speed of light than time would stop completely
This title is wrong. Time doesn't just slow down as you approach the speed of light - it slows down as soon as you start moving.
You are completely correct. The current title is more search engine friendly though.
does slowing time down causes cell division in the body to slow down?
Yes, from the point of view of people outside of your spaceship, time has slowed down for you, hence when you return from your travel you will have aged less than they have. You won't notice the slow down yourself until you compare the end result to somebody outside the spaceship.
Best review of this I’ve seen, thanks!
You're welcome. Thanks for the comment.
I also wanna share one thing that by taking speed as a factor for time travel you will never gain success in making time relative. As every thing is moving with some speed. Nothing is at rest. Earth , solar system , galaxy, universe, timeverse ,spaceverse,etc
Einstein's mind even travelled more than the speed of light. He thought about a spaceship before it was invented.
I'd never thought about it like that before.
So what is the quick answer as to what causes time dilation? Motion seems to cause it? But why does motion cause it? In your derivation of the Minkowski factor, Should you not have said "multiply through by 4" but "multiply through by 2?" Multiplying by 4 would create a 2 in each unit? We don't want a 2; we want a 1? Sorry it may be my ignorance of math.
For the first question, I honestly don't know why motion causes it, but I enjoy the mathematics behind it and the idea of the thought experiment.
For the second question, we multiply by 4 because each term is being squared. As (1/2)^2 is 1/4, we need to multiply by 4 to get rid of the denominators.
Well presented even for a math layperson.
Thank you!
He forgot to carry the one!!
I have a question which might sound dumb but I'm gonna ask it anyway
If time freezes as you attain the speed of light, but the fabric of space-time is expanding, then things can still move further away from each other while both at the speed of light, but if the distance between 2 objects can increase, does that mean that time didn't really stop or are both so to speak frozen in time and moving away from each other as 2 uncorrelated entities
"If time freezes as you attain the speed of light, but the fabric of space-time is expanding" where did you get this from? i thought fabric of space-time is shortening, not expanding
The problem is “The fabric of spacetime is expanding” assumes the universe is the fabric of spacetime. It assumes whatever is outside of the universe isn’t spacetime.
When you reach the speed of light, not only does Time equal zero, but distance along the axis of travel also compresses to zero. The spot you leave becomes the same spot you arrive at.
If you could travel at the speed of light you could actually get anywhere instantly because of these 2 things.
It is personally why I think light is actually instantaneous, but it is just an artifact of us having mass and being subject to relativistic forces that cause us to measure it, and interact with it at a finite speed.
Beautiful explanation!
Thanks!
I have a question that I think comes straight down to relativity.
I can see how this works from this standpoint, but what about when we place another clock on the ground and also observe it from the spaceship? The observers on the ground still see the clock on the spaceship ticking slower, but if people are to observe the ground clock from the spaceship wouldn't they see that ground clock moving slower? Just in another direction? Thus meaning that for the people in the ship it would be the people on the ground that have the time slowing down?
Or if we had 2 spaceships passing each other at 0.7x speed of light, wouldn't it be that for them the other ship's traveling 1.4x the speed of light and the time is moving incredibly slow? But again this would apply for both of them?
Non inertial frames aren’t equal so the clock on the ship falls behind the clock on the ground. They look equally slow to both observers but a force was only applied to one body. Each of the closing spacecraft see themselves as stationary in their own frame and the other ship closing at near light speed. The additional velocity is compensated for with time dilation and length contraction.
Considering the last problem, (just wanted to share my curiosity), assuming the age of the astronaut was 40years during take off, spending 5 years in space while the gap becomes 2 years, so when the astronaut comes back after 7 years from space would he look younger than he was supposed to look had he stayed back on Earth?
Yes, he would be younger as less time would have passed for him than has passed on Earth.
@@DoingMaths Would the physical body we have actually age differently though? Why does our physical body age different depending on the speed we are going?
@@shade_the Hi. Yes, the physical body would age at the same speed as you experience time, so slower if you are travelling near the speed of light.
@@DoingMaths since we can, well, people like you who are amazing at math, can do the math to prove how light and time are connected based off how fast we are going, is it actually proven how the body ages differently based off of this or is that just a theory, and if so can you recommend any published studies/books/videos on that topic specifically? All of this stuff is really great and this is the first video I've found that actually breaks down the math behind it and I enjoyed it a lot
@@shade_the Thanks for the great comments, I love the mathematical side of things like this. I don't know where to find any of the studies you are after I'm afraid.
When I'm running and trip I was flying and time slow down after I impact the ground. My last words after impact is Oh no.
It was 2 years ago
2.13...what is the proof that one would actually see reflection in mirror if mirror along with you is travelling at the speed of light? If 2 spacecraft travels towards each other both at .7c speed of light. Say they have distance of 1 light year between them. Now both are at speed of light with respect to each other. Going by this equation an instance in one ship is equal to infinite time on other ship and vice versa. Am I missing something?
For the mirror, because you are in the same frame of reference as the mirror, your reflection would appear as normal. There isn't a proof of this as such, it is a theory which so far has held up to experimentation.
For the two ships moving towards each other, velocity addition breaks down at speeds approaching the speed of light. I would suggest reading this article en.wikipedia.org/wiki/Velocity-addition_formula#Special_theory_of_relativity. I know it's Wikipedia, but it's a good place to start.
i guess i understand why a moving clock would be different than a nonmoving clock. but in both examples the clock is moving. One person just sees that it's moving. To me it doesn't seem like time changes at all, rather your perception of the light does. Therefore, I'd have to assume the astronaut's body still aged the same, even if he perceived it differently (unless the slow of light had a significant effect on the body(it would) but i still doubt it would be the exact 2 years difference). I'd love to see a practical study on this
What if the light clock ticks horizontally?
That's a really good question. The person in the rocket would still see the clock working as they would expect it to i.e. they notice no difference as they travel. For more information about the stationary person's view, there's a good discussion here www.physicsforums.com/threads/time-dilation-in-horizontal-clock.462122/
You are on earth and say goodbye to a friend who gets into a spaceship that can travel at the speed of light. They travel to alpha centauri 6 light years away, so on the spaceship it takes 6 years to get there and 6 years to get back, on the spaceship you have aged 12 years. On the earth you are waiting for the ship to return from its mission, would it not also take 12 years for the crew to return?
Dear Sir can you please clear my confusion?
Suppose a planet is a light year away from its sun.
When a photon reaches the surface of the sun it sees the planet as it was a year ago right?
(Now as they say reaching the speed light will cause time to freeze)
So the photon shoots towards the planet at the speed of light, what will be the planets time when that photon reach the planet surface...a year ago?or present? nd how why?
Plz explain sir🙏
Hi. I have to admit, I don't know. I love the mathematics of the Lorentz equations and I'm fine with the basics, but I'm not an expert. Sorry I can't help further.
@@DoingMaths hey sir no problem, btw thanks for quick reply🙏😀keep up the great content👍
This is actually the reason I think light travels instantly, and that due to relativity we are forced to measure and interact with it at a fixed finite speed even though that isn't what actually happens.
Thanks
Curious that a math channel would put "Why" in the title when that is the one question that math can never answer.
Good point. Mainly because I figured that it would be better for search engines. I think people are more likely to type 'why does time slow down?' than 'how much does time slow down?'
Thanks For Such A Great Explanation.
You're welcome
So, if I can travel at 99% of speed of light, I can actually travel to some place 284 light years away using only 40 years of my time. Let's within a life time. So, we could travelled to places that are thousands of light years away within our life time?
Yes but everyone you left on earth would be 284 years older
@@scoobyDrew247 How about see things further? For example, Alpha Centauri is about 4 light years away, but our telescope can't see that far. If I can travel at 99.99999% of spend of light, Alpha Centauri is like only 0.00005 light years away from me. Can I actually use my super telescope to see Alpha Centauri without even having to visit there? It only takes a second.
@@YinLawn You can't travel 284 light years in 40 years, cause thats why its called light years. It would not make any sense.
@@gopichand4166 Yes I can because my time has slowed down. So it is to you 284 light 284 years of, but to me it is merely 40 years. Please see reply from Andew Martin.
@@YinLawn yes, but that wouldn't make any difference cause, everyone on earth will be dead. (As in interstellar) . And btw, time will be still flowing even slow, so you will die eventually.
I imagine the answer is the same if the clock is orientated in the direction of travel instead of perpendicular and that the reason for saying that perpendicular orientation is an important point is just for visualization/demonstration purposes? A very clear video otherwise.
Hi. Thank you. Yes, you are right. The perpendicular clock is there to show the derivation of the equations. You get the same slow down of time whichever way the clock is facing or even without a clock.
@@DoingMaths Thank you.
The time does not slow down, at that velocity the matery is converted in light or energy, and the energy doesn't suffer degradation like the matery.
That why , we'll think the time doesn't pass.
4:14
Why light clocks need to be perpendicular?
If light clock is parallel to rocket then what happens?
The same thing happens regardless of the orientation of the light clock or even without the light clock. It being perpendicular just creates great geometry for deriving the Lorentz equations.
So the obvious question then is, does time speed up the slower we go? Since time begins to slow down as soon as we start moving - if we stand still or in a buddist sense or eucharistically adorational sense remain still or 'be still' does time then speed up? We're always harping on about trying to go faster than the speed of light or trying to attain closer to the speed of light, when the results of such efforts with respect to time seem to be very negligible. It seems to be abit like pissing in the wind. Perhaps our approach to interstellar travel is arse about face. Instead of trying to achieve near light speeds where time slows down, if we concentrated on trying to achieve close to 0m/sec, we could simply wait until certain astronomical interests were within Dv range. God is very slow. The earth's orbital velocity around the Sun is approx 30km per sec, so to get that down you would need to move at 30km in retrograde to the earths motion, after you'd burned off the earths rotational speed @ -1037 mph. depending on where you are. But then there is also the Solar system speed on the arm of the milky way and then our galaxy's own speed relative to 0mph of the universe - so theres alot of calculations to be done before you could aquire a workable vector. But you might in some sense then be able to watch everybody else flying around trying to achieve something while your just sitting there enjoying it all. Martha and Mary for instance. Might be worth trying to prove that atomic clocks also speed up on a counter-velocity vector.
Is the spaceship 3.5 light-years away or 4.9 light-years away?
I can't fully understand Galileos perspective, because he never went anywhere near light speed, so he can't say that at light speed you would be able to see yourself, I keep imagining it like sound, so like a plane, you see it, but hear it way behind where it is, so your hearing where it use to be a long time ago, see where it was a short time again, but that is not where it is atm.
I believe his right, but I just can't understand it and because I can't test it, I get annoyed.
How does the astronaut see a similar clock held by the observer on ground? As per him isn’t the ground observer speeding away?
There's an interesting article on it here: www.scientificamerican.com/article/how-does-relativity-theor/
If you’re in a spaceship travelling the speed of light and you experience time slower. Do you actually age slower compared to those on earth surely that’s not possible? Instead you just experience light at a different rate?
I dont fully understand it but yes you do age slower. Time is a real thing that slows down. For example 2 identical twins, one flying around at 0.7c for 20 years and the other on earth doing nothing, when they re-unite one would be aged more than the other. Crazy.
You can’t travel at the speed of light. It’s impossible.
The energy needed to propel any mass to the speed of light is infinite.
So to clarify, as you approach speed of light time slows. Given black holes stop even light from escaping at 300000kmh means it halts light and would suggest time speeds up but logically you'd think in black holes it stops altogether. Or is that a separate thing in that velocity isn't so relevant there as the gravity is
Hey dont know if this is stupid guestion just trying to understand it better, but what links the light to time. I get that in the example the light has to travel longer distance but would that just effect your perspective on it. Like for example if you take regular clock with you on the space ship would it show that 5 years have passed or 7. Or if you take a clock speed it to the speed of light would it not be more like you perspective of time has been altered not time itself. Well mainly i dont understand why the light and time are linked. Thats the main problem.
It has been done with atomic clocks on planes. Two clocks were sent around the world in opposite directions, one with the Earth's rotation and one against it. Because of the difference in speeds of the planes caused by the Earth's rotation speed, the times on the clocks ended up different to each other and both were different to a stationary clock.
The time changing, rather than the perspective of time changing, is to do with Galileo's theory of relativity. This bit is the leap of faith for me, but experiments are consistent with it being correct.
Why is the travel of light waves always used to explain how time slows with velocity. Using light travel this way is very obvious what is going on. I want someone to use a mechanical clock to explain it.
Mechanical clocks fundamentally work by electromagnetism too. A spinning gear can move another because its atoms' electrons repel another gear's atoms. Similarly a hand on a clock is moved. A photon in vacuum simply gives us the limiting case as to what is the fastest possible way for information to travel. In a mechanical clock when a part if moved, its effects do not show up immediately on the other size of the object, but the information about the disturbance has to first travel to the other side (of a gear, a hand, a pendulum etc.). And if we use, say, a some quartz as the source of the rate of ticking, that too comes from electromagnetism.
What if we look at this way : SPEED OF LIGHT ISNT CONSTANT .. instead of thinking that time is changing
how do we know for certain speed of light is constant ,
Countless experiments and measurements since 1887, nothing can be accelerated to it, relativity of time and length exhaustively verified, verification of Higgs field.
Okay I can understand why the clock would take longer between clicks than one that is stationary but how does that have to do with anything with humans aging or actual time? From what I understand sure the clock will be slower but why would humans age slower as well?
It's because of the difference between what is seen by the stationary person and what is seen by the travelling person. The two people are seeing the same clock ticking at different rates, rather than the clock itself changing rate.
When one person is experiencing the clock ticking at a certain rate and somebody else is experiencing the exact same clock ticking at a different rate, then they must be experiencing the passing of time differently.
@@DoingMaths The clock or light to be exact doesn't define time though. If you see something slower doesn't mean time is slower, it just the updated light is taking a longer time to reach your eye than the other person. So how do people turn this into time travel and that people age slower in space/at very high speed is what I don't understand.
Technically everything we are looking at is older than what they are because whatever we are looking at needs to have light reflected into our eye and that takes time then processed by the brain which also takes time but I wouldn't call that time travel. Time is still the same we just see things older than they currently are and that doesn't reflect their true state.
@@tv_wheels8548 This isn't to do with the distance between anybody and the clock or how long the light takes to reach the observers' eyes. We would get the same result with or without taking this into effect.
What you are describing explains why everything you see is in the past, but that doesn't explain the difference in the passing of time. If I look at something a light year away, I am looking 1 year into the past; I agree. If I look again 30 minutes later, I still see a year in the past compared to me and 30 minutes will also have passed for the distant object (it just happens to be 30 minutes that happened a year ago). There's no time dilation there (not from the effect of the distance anyway).
I can't really explain the concept any better I'm afraid. There are many people out there who understand special relativity and general relativity much better that I do and could give you a better answer, I just enjoy the mathematics behind it all. It's a theory and there is a lot of respectable experimental evidence to back it up so I'm happy to go with it.
Outstanding!
Thank you
Cool. So it’s accurate that a massless photon itself from its perspective does not experience any time. So the moment a photon leaves a star in andromeda 2.4 million years ago & the moment it reaches my eyes right now, from the photons perspective it is the exact same moment?
That's a really interesting point which I hadn't considered, but yes, according to the maths, that would be the case.
Interesting point. And if there were a light clock in both locations in which location would time slow down?
@@james56038 time would be passing at the same rate at both the star and here on Earth, but time has stopped for the travelling photon.
This is just what happens hypothetically. In reality, the math actually breaks down and just doesn't work AT the speed of light, but right up to an infinitesimally small fraction less than the speed of light, the math works and time is ticking at an infinitesimally small rate of speed - so to make the jump to "time freezes AT the speed of light" even though the math technically doesn't work is not a giant leap.
let us just consider the frame from spaceship, if we consider spaceship to be at rest, everybody else is traveling with 0.7c, then by that logic he would be 7 years older and everyone will be 5 years older, or am i getting something wrong here ?
I still don’t get how you can see your reflection in the mirror if you’re traveling at light speed. And why light always travels at this speed irrespective of reference frame.
assuming the distance traveled is the same for both the traveler and the observer, would the observer then observe the traveler to be travelling at a slower speed than the traveler would observe themselves to be traveling?
If that's indeed the case, what else would that signify? 🤔
light would actually be the same, it's like shooting bullet horizontal to the ground that will reach the floor at the same time as a bullet dropped.
You forgot that speed is relative at the end of the video. So one might as well say that on Earth it moves at 0.7 of the speed of light.
Won't it look the same for Astronaut if he looks at earth ? I mean if he looks at earth and compare clocks, it should look to him that clock is slowed down on earth relative to his clock. Astronaut should see triangular light path for the light clock on earth. There is some error in my thinking I hope you can clarify.
I still dont understand if you point light sideways inside the spaceship how it doesn't just keep going the way it was pointed at. I don't understand why it travels sideways to the spaceship AND same direction as the spaceship. To me it just sounds logical that it would just miss the mirror
The sideways movement of the light is what is observed by the stationary observer outside. For the observer in the spaceship, they must only see the light travelling to the mirror and back otherwise this would break Galileo's Principle of relativity. If the light missed the mirror, the traveller would know they are moving without having a reference to the outside. To be fair, this is the bit that requires the largest leap of faith for me too.
@@DoingMaths thank you 🙂
Heres why I think everyone is just over thinking this, time is always consistent and time is made up by us. A second is determined by a fixed rate of speed in which a few numbers go up to 60, which in turn gives you a second. Therefore time as we made it up is always set at a fixed rate. Light does not affect time, light just travels at a further distance than anything else. In the example of the light clock, maybe the light itself would get distorted by the speed its traveling at but that's about it, also reflection in my opinion would stay the same
The effect on time of travelling at high speeds has been proven by physical experiment. One such experiment put atomic clocks in aeroplanes and flew one set eastwards and another set westwards. Due to the effect of the Earth's rotation on their relative speeds, the eastward clocks lost time, while the westward clocks gained time, all compared to stationary clocks.
The speeds involved were very slow compared to the speed of light, so the time difference was tiny ( a few nano-seconds) but it was there nonetheless.
www.thevintagenews.com/2016/09/16/hafele-keating-experiment-two-atomic-clocks-flew-twice-around-world-eastward-westward-back-home-showed-different-times/
Also, it's not the light affecting time as such, but the speed of light is inextricably linked to the changes in time via the Lorentz equations given in the video.
Time was the old constant. But Einstein proved that the speed of light is the universal constant, and it's not time. Both could not be constants.
@@nomanvardag1 Exactly this. @luis wronk
An incredible video
Thank you, I'm glad you liked it.
How do we know who the observer is?
I've heard that acceleration is relevant to answer that, but let's remove acceleration from the equation for a minute and say that the earth and a spaceship are currently on a collision course, traveling towards each other at .99999c, and are currently 100 light years apart. When the earth and the spaceship meet, would the people on earth have died of old age or would the astronaut have died of old age, or neither? Doesn't that depend on where in space they met? How do we decide on a reference point?
Edit: assume that everyone dies of old age at 100 and are otherwise invincible XD
Ah ok I think the answer is in the equation: we need to know the value of T' in order to calculate T, meaning that all 3 answers are possible.
It's probably more useful to look at it in reverse from the moment of collision. From that point there would be some non-zero acceleration by the spaceship or the earth or both (again depending on your perspective...), which probably means we could retrodict the values of those Ts based on that acceleration.
I'm starting to understand why space and time can't be separated with this theory. There's no concept of a "snapshot of all of space" at a particular "moment in time." The only snapshot we can take is of a point in space at a point in time.
If anyone can identify any problems with this, please let me know.
in reality, both traveler and observer should hear the click of the clock at the same time, right? The observer may see the light beam travels further to reach the sensor, but he and the traveler should hear the click at the same time since the speed of light is constant. Or is it because the speed of sound is slower than light so it takes longer time to reach our ears?
lol
Unfortunately, on all relativity videos, it is suggested (by mistake) that there is a preferred or special frame of reference on which relativity has no effect. On the example on the ship that left Earth and is travelling at 70% the speed of light, the question is how much time has elapsed on the spaceship after 5 years, suggesting that it is the spaceship that feels “relativity”
But, from the point of view of the spaceship as an observer, it is the Earth that is moving at 70% of the speed of light and it is the Earth that is aging more slowly. The formula is for the observer since there is no Absolute Frame!
This is why people misunderstand relativity since they incorrectly think that because the ship sped away, there is some special about the Earth reference frame.
There isnt! The calculation applies to both the observer on Earth or an observer on the spaceship and yields the same result.
The correct way of presenting this would be to calculate if you are on the spaceship and after 5 years on Earth you want to know how much time passed on the soaceship 7 years! same result!
The conclusion at the end is wrong and misleading. If you are seating on Earth after 7 years by the Esrth clock, 5 years have elspsed by the spaceship clock. But if you are on the spaceship, after 5 years on Earth 🎉7 have elapsed on the spaceship clock (ignoring acceleration)
This is relativity. No special frame of reference. Why nobody gets this right?
The whole formula fucks off if you move faster than the speed of light LMAO
you would be going back in time LOL
Has time slowing down near the speed of light been proven or is it still a theory/thought experiment?
There have been many experiments which back the theory up e.g. flying extremely accurate atomic clocks around the world in opposite directions (one with the Earth's rotation, the other one against it) and seeing the difference in time on the clocks. Obviously, these are still very slow in comparison to the speed of light, but the equations I mention in the video still hold up.
@@DoingMaths Ah, I see. Thank you for your response.
This sounds like Chronokinesis
*i like it*
I get how the equation manipulation works to arrive at this, but it seems impossible to my brain. Is there a way to test this? Like, does this actually happen, or is it just what our current theories says should happen?
So like, for a frame of reference, Earth is traveling around the sun at 30 km/s and Pluto is going around at about 5 km/s. Does that mean a person sitting on Earth would age slower than a person sitting on Pluto?
So for fun, ran the numbers and found that for a 100 years on Pluto, 99.99 years would pass on Earth. I guess the speed difference compared to the speed of light doesn't matter as much. I feel like I would need to see this happen in an experiment to believe it.
@@jeffsmith3550 There have been experiments flying atomic clocks around the Earth in opposite directions to create as much speed difference as possible and the clocks did show slightly different times to each other afterwards. Like in you example, it was minimal, but it was there.
Great vid, but I respectfully disagree. Light clocks work on the basis that the speed of light is constant and so too is the shortest distance light must travel to bounce off the mirror and hit the receiver. That delay is measured and they are calibrated to that effect when stationary. As the vid correctly points out, the light that hits the mirror and bounces back to the receiver must travel further, yet the moving light clock isn't recalibrated for this new distance. Surely this is a case of not having a fit for purpose clock rather than a time dilation theory?
The light on the moving clock is only moving further from the point of view of the stationary observer. From within the spaceship it still appears to be moving its original distance at the speed of light.
@Doing Maths that would violate the constancy of light. Light travels in its own frame of reference. Both observers would see the light go straight up and down. You are confused by the bouncing ball analogy, which shows the ball traveling in an arch as it has forward momentum.
@@DoingMaths I still disagree with this video. It's all going really well until 7:10. The statement "t'=(2L)/c" is however, incorrect. If the speed of light is constant and physically travels along h, then it cannot travel the distance of just L in the same time. That would imply h=L, which it clearly doesn't.
To the observer in the ship, yes it appears like it's moving back and forth directly along L due to the ships velocity, but no, it doesn't look like it's travelling at the speed of light. It looks slower, the speed of the beam of light observed in the spaceship along L (let's call it c') could be calculated as c' = c*(L/h). I didn't bother with the rest of your calculation since you don't distinguish between c and c'.
@@stewiesaidthat The violation that you mention is the whole point. Trying to apply the bouncing ball analogy to the light doesn't work if we say that the speed of light is constant. Something has to give. Einstein decided that as the speed of light stays constant, the things that give must be time and distance. So far, experimentation has backed up Einstein's theories, with nothing to suggest he is wrong.
@@pd4689 You are correct in saying that the speed of light is constant which then gives the apparent contradiction of h equalling L, but that is the whole point of the thought experiment. If the velocity can't change to allow these two different distances to be travelled in the same time, then it must be time itself that is changing. There is no c' as that would imply a different speed of light, but as we have mentioned, the speed of light is constant.
Ty! It finally clicked.
You're welcome. Glad it helped.
Would have upvoted, but your usage of comic sans hurt my feelings.
Lol. Fair enough. I did my teacher training when this was all the rage. Old habits die hard.
No, time not getting slower on that spaceship, spaceship's speed just make that light-mirror clock run slower. After 7years of earth time, body of the astronaut had grown 7years too, the only problem is he need to adjust the date on his light-mirror watch, add 2 years for specifically.
If you on the spaceship fly repeatedly around the earth at near light speed in one earth year, there will be no time-cheating for you. You'll spend a whole year living in that ship, experience fully through 365 days, fly ~85million times around the earth - clock just not work on your spaceship.
And if you keep flying after 80 years of earth time, you may die old too.
Would it be equivocal to reframe that last example as: "after 5 years have passed on the Earth, how much time has passed on the spaceship?" After all, the spaceship guy could say hey, I'm the one at rest it's the Earth that's moving 0.7c away from me! The answer would be the same 7 years, thus both the Earth and the spaceship see the other as younger. Then would I be correct in saying the difference is made up when one of the observers accelerates back into the other's frame of reference? Because as you bend space everything outside of that "space-bending" should speed up in time. Then their clocks would match back up again. So the only reason it's not a paradox is because teleportation to a certain velocity without some degree of space-bending aka acceleration aka gravity cannot exist?
Let me rephrase, not that their clocks would "match up" but that the observer who does more accelerating to catch up/slow down to the other's frame of reference will definitively be the younger one. That's what I meant.
This fries my brain but nonetheless fascinating
Most useful video
Thank you
@@DoingMaths you are amazing subscribed
Because humans are technically moving at the speed of light. Your brain is processing at light speed. Each cell in your body responding at that speed. The slower the body gets the faster the vibration gets. Why because the slower non distracted body becomes aware of the speed of the objects around it. Each moving at its own speed through time. Say in a living room with a child, a cat, and a dog. You and the other for beings are in different time zones. Each moving at a different velocity through time. Each being on a different wavelength. Now let's add the TV and it's data, the couch, the floor, etc... Each in its own time reference and each having to jointly connect to create one time space that can be referenced by each morning molecule in the room and that's just one living room. You think humans are gonna understand time globally let alone cosmically?
isn't relativity symmetrical so each observes the other's clock as running slower?
You are completely correct. I have tried to address this in the video description now.
But its all relative. The earth is moving away from the ship at near the speed of light so time would be slowing down on earth too.
Yes. There's something about the acceleration of the travelling person that is needed for the return journey, that makes the slowing down of time only happen to them. I think it's the twin paradox, but I have to admit, that bit is beyond my understanding.
ok but if the time on the clock is slowing down, it doesnt mean that the time is slowing down fr?
So if you were moving at speed of light no matter how many millions of light years you travel, it'll only be a moment for you.
Time doesn't tick for you if you are moving at the speed of light even if an observer was able to observe that on their time frame you have traveled millions of light-years.
If you were moving at the speed of light, then it will take you a million years to cover a million light years. Not a moment.
@@pjbpiano to you maybe, but its not millions of light-years to me moving at light speed
@@neloysinha8098, unless you don't understand what a light year is. But a light year is the distance covered by the speed of light in one year.
If you were moving at the speed of light, it will take you one year to cover one light year. This is a very basic understanding.
@@pjbpiano oh fuck! If only I knew what a light-year was than my original comment would have meant that no matter how far you travel it'll be a moment for you cause time doesnt fucking tick for you at lightspeed, but i didnt know what light year was ..damn!
How light photon changed angle is it due to light photon gets attracted to the mirror
I mean for say if iam travelling in a bus and if i jumped at certain speed to touch the roof of the bus and bus also moving at the speed at which i am jumping than i wouldn't touch the same point of roof that is opposite to from where i jump
If you jumped straight upwards when standing on a moving bus, then anybody on the bus with you would just see you go up and down with no forward movement. If somebody standing outside was watching you as the bus went pass, then they would see you go up and down, but would also see you move forwards at the same speed as the bus. This is the idea behind the two frames of reference - one person moving with the clock and another person watching the clock travelling past.
This clearly is a theory that is wrong. I’m telling you now if I have my clock on me travelling at the speed of light I promise you not speed will change the time on my phone
I don't think this answers the question. You are demonstrating a side effect of time dilation, just like with gravity. We don't know what gravity is, but we can measure it, know it exists, and make calculations and predictions about it. But why does time dilation happen? Imagine we have a charged battery that can last 30 days on standby. If we sent that battery at 99.999999999% of the speed of light for 30 days of Earth time, when we checked the charge, it would still be almost at 100%. I don't think we can answer why this happens unless we understand what happens at the quantum level.
You are correct. I think this title is more SEO friendly than anything I could think of about time dilation. That's the main reason for it.
@@DoingMaths I appreciate your reply. Thank you
Time does not slow down and it does not exist. Rather, the atoms used to count clock ticks are slowing down as they approach light speed.
It's not so much the atom slowing down but the amount of force being applied is decreasing. Increase the amount of force (GPS satellite calibration) and the clock stays in sync.
Time speeds up as you approach the speed of light (information). It's essential the same as watching a 2 hour movie in 1 hour.
But if astronaut would be travelling with C, then?
5÷0 would be infinite, which means if we travell with speed of light, in earth infinite time would have been passed, so might be someone was travelling😀
According to Einsteinian physics, the astronaut would never be able to quite reach the speed of light, but yes, if the speed is really close to c, then the time will really stretch out.
Let me say, light can not beat the speed of a mirror
Common sense tells you that time does not slow down, it only appears to do so. Physicists need a lesson in logic because they're theories are full of logical inconsistenties with no basis in reality.
No one said it did, it’s simply relative. And it’s exhaustively verified
1. what is light?
2. u said time stopped when in speed of light? u wanna say that sun's light is forever?
But how can you ignore the speed of earth. The path of light for the observer is when observer is at rest. We should not forget that as we talk about space the earth is no longer relative. By the way what you say can be true if that space ship travels on earth. But believe me the 'Theory of speed of light and time relation ' is not reliable. The theory which will come with actual time travel is far beyond imagination. For example the solution of P vs NP set has contributed a lot to the space research. Best of luck.
Got it🔥
i thinkbwe are looking at it at the wrong side its not the speed that slow downs the time
This is my opinion:
In Galileo system, x=vt, if only if dx/dt is constant. Lorentz transformation goal is distances (x, x’) x=f(v,t)and x’=g(c, t’) are mathematically equal in both systems with symmetry. So c is not Galileo or classic velocity, and t’ is not classic time. In Galileo, v varies, t is uniform at any point in space; whilst in Lorentz, t’ varies, c is constant in space. c =eu , is really the property of the space, or medium, or Ether. It is not velocity in Galileo.( v, C),(t,t’), they are (Apple, Orange), (Peach,Grape) in two math systems. People are still thinking they are same things. That causes confusion. Saying 1) if an object moves at speed of light, time stops. Moving object slows clock, etc. That’s wrong. It should be said t’ in Lorentz stops, or equal to 0. In Galileo, t is uniform, it doesn’t stop or slow. 2). Speed of light C is constant from any observer at different speeds. That is wrong. c in Galileo changes from observers, C in Lorentz as the property of space is constant. Then there is no ambiguity, confusing, both accurate in their own system for/from measurements. Time dilution, space-time curvature, etc. are all bogus by mixing concepts in two systems. If you use Fourier series to express a signal S, it is not the signal in time domain, it’s amplitude A in frequency domain. Nobody treats A-S as “signal dancing”. But sigma of all these series by frequency goes back to the value of signal in time domain. They are just mathematically equivalent, not necessarily physically same. There are many ways to do it mathematically, too.
Relativity is just another way of measuring of the nature using electric magnetic wave in Lorentz system. It has advantages over Galileo system in Astronomy, because Maxwells equations describe electromagnetic wave in vacuum with eu as constant, which is the space property and its value equals to speed of light in Galileo.
So, did I miss it? What DO you see in the mirror?
You should still be able to see yourself in the mirror because within your frame of reference (the spaceship) everything works for you as usual.
@@DoingMaths thank you!
Someone said, light is the day you were born till the day you die. That is life and is light.
I have a theory that might prove einstein wrong... im just not far enough on my studies to prove it with calculations
Nice
THE ULTIMATE AND CLEAR MATHEMATICAL PROOF OF THE FACT THAT E=MC2 IS F=MA:
Ultimately and truly, TIME is NECESSARILY possible/potential AND actual IN BALANCE; AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. This NECESSARILY represents, INVOLVES, AND DESCRIBES what is possible/potential AND actual IN BALANCE. SO, time DILATION ULTIMATELY proves ON BALANCE that E=mc2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity. The stars AND PLANETS are POINTS in the night sky. A PHOTON may be placed at the center of THE SUN (as A POINT, of course), AS the reduction of SPACE is offset by (or BALANCED with) the SPEED OF LIGHT; AS ELECTROMAGNETISM/ENERGY IS GRAVITY; AS E=mc2 IS F=ma. Great !!! "Mass"/ENERGY IS GRAVITY. ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity IS ELECTROMAGNETISM/energy. E=MC2 IS F=MA.
Consider the man who IS standing on what is the EARTH/ground. Touch AND feeling BLEND, as ELECTROMAGNETISM/energy is gravity; as E=mc2 IS F=ma. GREAT !!!
E=mc2 IS F=ma. The linked AND BALANCED opposite of what is THE SUN is A POINT in the night sky. The stars AND PLANETS are POINTS in the night sky. A PHOTON may be placed at the center of THE SUN (as A POINT, of course), AS the reduction of SPACE is offset by (or BALANCED with) the SPEED OF LIGHT; AS ELECTROMAGNETISM/ENERGY IS GRAVITY; AS E=mc2 IS F=ma. This NECESSARILY represents, INVOLVES, AND DESCRIBES what is possible/potential AND actual IN BALANCE. Therefore, the linked AND BALANCED opposite of what is THE EARTH is ALSO A POINT in the night sky. Great. Gravity IS ELECTROMAGNETISM/energy. ELECTROMAGNETISM/ENERGY IS GRAVITY. E=mc2 IS F=ma.
Gravity AND ELECTROMAGNETISM/ENERGY are linked AND BALANCED opposites, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Accordingly, the Earth AND the Sun are linked AND BALANCED opposites; AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity IS ELECTROMAGNETISM/energy, AS E=mc2 IS F=ma. The stars AND PLANETS are POINTS in the night sky. It ALL CLEARLY makes perfect sense. Great !!!!!! Energy has/involves GRAVITY, AND ENERGY has/involves inertia/INERTIAL RESISTANCE. E=MC2 IS F=MA.
The EARTH and the SUN thus constitute and comprise what are the MIDDLE AND THE FULL DISTANCE in/of SPACE (IN BALANCE) in full and BALANCED compliance and conformity with the CLEAR and universal fact that E=mc2 IS F=ma, AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Great !!!! It ALL CLEARLY does make perfect sense. (The stars AND PLANETS are POINTS in the night sky.) INDEED, BALANCE and completeness go hand in hand. Now, very importantly, outer "space" involves full inertia; AND it is fully invisible AND black. Great.
NOW, OVERLAY what is THE EYE in BALANCED RELATION to/WITH what is THE EARTH. Notice the black space of THE EYE. The stars AND PLANETS are POINTS in the night sky. THE DOME of a person's EYE is ALSO VISIBLE. Now, carefully consider what is the semi-spherical, translucent, QUANTUM GRAVITATIONAL, AND BLUE SKY. Great. E=mc2 IS F=ma. It is CLEAR. THE EARTH is ALSO BLUE (AS WATER). GREAT. "Mass"/ENERGY IS GRAVITY. ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity IS ELECTROMAGNETISM/energy.
INSTANTANEITY is thus FUNDAMENTAL to what is the FULL and proper UNDERSTANDING of physics/physical experience, as E=mc2 IS F=ma; as ELECTROMAGNETISM/energy is gravity. Gravity IS ELECTROMAGNETISM/energy. It ALL CLEARLY makes perfect sense. Inertia/INERTIAL RESISTANCE is proportional to (or BALANCED with/as) GRAVITATIONAL force/energy, as this unifies AND balances gravity AND ELECTROMAGNETISM/energy; as this balances gravity AND inertia. (This clearly explains BOTH F=ma AND E=mc2, AS ELECTROMAGNETISM/ENERGY IS GRAVITY !!!) ACCORDINGLY, gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. SO, the BALANCE of being AND EXPERIENCE is essential; AS E=mc2 IS F=ma.
Our EXPERIENCE is NECESSARILY that of what is the FULL DISTANCE in/of SPACE, AS we are BALANCED between what are THE SUN AND c (A POINT); AS E=mc2 IS F=ma. The stars AND PLANETS are POINTS in the night sky. SO, a given PLANET (INCLUDING WHAT IS THE EARTH) sweeps out equal areas in equal times; AND this is THEN consistent WITH/as F=ma, E=mc2, AND what is perpetual motion; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity IS ELECTROMAGNETISM/energy. E=mc2 IS F=ma. BALANCE and completeness go hand in hand. It ALL CLEARLY does make perfect sense. THINK about what is QUANTUM GRAVITY.
"Mass"/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent with/as what is BALANCED electromagnetic/gravitational force/ENERGY, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Indeed, gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE; AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Therefore, the rotation of WHAT IS THE MOON matches it's revolution !!! Objects fall at the SAME RATE (neglecting air resistance, of course), AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity IS ELECTROMAGNETISM/energy. Gravitational force/ENERGY is proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE; AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY.
Stellar clustering ALSO proves ON BALANCE that ELECTROMAGNETISM/energy is gravity, AS E=mc2 IS F=ma. Magnificent !!!
E=mc2 IS F=ma. Is a two dimensional surface or SPACE visible or invisible ? The answer is that it is BOTH. So, the electron AND photon are structureless. A PLANET (INCLUDING WHAT IS THE EARTH) is a balanced MIDDLE DISTANCE form in relation to E=mc2 AS F=ma. A PLANET (INCLUDING WHAT IS THE EARTH) is a balanced MIDDLE DISTANCE form in relation to the Sun AND c (A POINT). The stars AND PLANETS are POINTS in the night sky. E=MC2 IS F=MA. ELECTROMAGNETISM/ENERGY IS GRAVITY. Gravity IS ELECTROMAGNETISM/energy. Gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites, AS E=mc2 IS F=ma; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. BALANCE AND completeness go hand in hand. Very importantly, outer "space" involves full inertia; AND it is fully invisible AND black. E=MC2 IS F=MA. It ALL CLEARLY makes perfect sense.
The BALANCE of being AND EXPERIENCE is essential. The INTEGRATED EXTENSIVENESS of THOUGHT (AND description) is improved in the truly superior mind. INSTANTANEITY is thus FUNDAMENTAL to what is the FULL and proper UNDERSTANDING of physics/physical experience. (THOUGHTS ARE INVISIBLE.) It is a very great truth that THE SELF represents, FORMS, and experiences a COMPREHENSIVE approximation of experience in general by combining conscious and unconscious experience. MOREOVER, the ability of THOUGHT to DESCRIBE OR RECONFIGURE sensory experience is ULTIMATELY dependent upon the extent to which THOUGHT IS SIMILAR TO sensory experience. Beautiful. It ALL CLEARLY makes perfect sense. E=mc2 IS F=ma.
By Frank Martin DiMeglio
That's all very well but since we accept the principle of relativity, who is to say that the spaceship isn't stationary and the observer is the one who is moving, in which case the same calculations would imply that the observer is experiencing time dilation, and not the bloke on the spaceship. There is a second case that merits our attention. Suppose that a right angle triangle isn't formed because the ship isn't flying past the observer but away from him, possibly in parallel to a beam of light from the observer's torch. In that instance the beam the astronaut is shining on the mirror and the beam reflected from the mirror form no triangle and the effect that the ship's motion is having on the beam inside the spaceship is cancelled once it is reflected from the mirror. What happens in that case? There are at least those two additional cases that need to be looked at to clarify this theory.
I think velocity is just a potential energy that you can see, and space does not know velocity. Every velocity has INFINITE definitions, which is exactly like NO DEFINITION. So that relative line everyone draws is the source of misunderstanding. There is no time outside of your brain, and constant light relative you your eyes ONLY was a DECLERATION, not an observation. The result is that Relativity creates an ADJUSTABLE time and tells you that if you move your head, then the entire Universe INSTANTLY changes shape along that axis JUST FOR YOU, and scientists BELIEVE IT! There is no evidence that this happens or needs to happen. It is 100% math telling you this AFTER it changes your numbers to create it ON PAPER, AND it leaves a NON-transformed reality behind IGNORED. This is the goofiest human farce in history, and it's gone long enough for me. There is plenty of evidence that it's wrong, it is just a matter of opinion.