I'm sorry to say it, but you haven't even begun to understand the solution to the paradox. You only see time dilation, but completely ignore length contraction and the resulting relativity of simultaneity. You get caught up in the fact that the twin travels back and forth. But that is not necessary. Even if the route is only flown once, the traveling twin ages less. Even acceleration phases are superfluous; it is sufficient for the twin to send a light signal back to earth with his age when he reaches his destination. The traveler does not have to change his frame of reference, accelerate or do anything else, so the time dilation is absolutely symmetrical, yet he has aged less than the twin on Earth when he reaches his destination. And as long as you don't understand this, the twin paradox is far from being solved.
Since we all move through spacetime at the same rate and Bob travels the longest distance (and not Alex because Bob is the one that had the acelleration (which is absolute)). Therefore Bob travelled more quickly through space and hence less through time. Why make it difficult when it really is this simple ?
Thank you! Finally after all those years of being unsatisfied with answers given for the twin paradox the kind of video I'd been waiting for! I just wish at 5:37 the calculations to "prove" that Bob indeed aged less than Alex (in that frame of reference, Bob's inital one) were on screen since it's not very intuitive, but then again, none of this really is^^
The very reason for the assimtry has nothing to do with changing frame or acceleration. We can see it by only considering the going to the star. In fact if the twin stopped a clock at the arrival, it would show half of its aging when he met his brother. Both formulas (see below) are right: t'=t/g (for x'=0) and t=t'/g (for x=0) . But the first is only valid when x'=0 and the second only x=0. What happens is that the end conditions are compatible only with the first formula but not with the second one. In fact at the end= x'=0, x=L. Because the second formula is for x=0 we cannot apply it. Then the very reason for the assimetry is that one twin is moving "inside" the space of the other (seeing the path shortening).
What you are overlooking is the fact that space and time are separate frames of reference. The caesium-133 atom is chilled to absolute zero to prevent it from being accelerated in time when a force is applied. Are either of the twins in cryostasis? Both twins experience the same amount of time. One just experiences more space.
Hello can you explain what happen when two twin go in opposite direction and come back. My answer will be there age will be same but they are moving near speed of light they should feel time dilation and one one of them get older but which one? Can you explain
The paradox is in the final outcome. Before the final outcome, is Alex aging faster near uniformly relative to Bob's aging if the turn around by Bob is very rapid? That to me is the paradox. If Alex goes and catches up to Bob before the turn around, Alex will be younger. If Alex goes and catches up to Bob after the turn around, they can be the same age or Alex can be older or younger depending on where they meet. That is the real paradox. Alex can make himself relatively younger by going out to meet Bob and Bob can employ tactics to ensure that does not happen.
Sorry, the thought experiment is made in a clear and interesting way, but imo the equivalence principle must be used to solve the twin paradox, physically. Initial statement (mine): A relative motion (or position) between objects (any objects in the universe) can not come into existence without acceleration (a force). You seem to use this logic, initially: Premise 1. "I assume that I can solve the paradox, without accounting for all acceleration processes in my thought experiment". Disregarding Carols acceleration. But, she can not just "be moving". Doing so can be called the "cosmic magic hands" - error, moving (or placing) other observers relative to the twins with pure magic. 4:00, what you do here is neglect/disregard her physical ageing when she accelerated (which is the same added ageing that Bob would have experienced if he had returned normally from Betelgeuse, instead of Carol). The twin experiment is about physical ageing of the TWINS, not measuring clocks/time handed over in different ways with external experiment participants.
Conclusion. "I perform my thought experiment, do not include all accelerations in it, and have showed that acceleration is not the (only) cause for physical time dilation". This is called "assuming the conclusion" - error in a premise, in a logical reasoning. 4:25 you state: "In Bob's reference frame, the situation is the reverse, Alex's clock will have ticked less by the time Bob reaches Betelgeuse". No, time dilation is a physical process (clocks and other matter), and in reality Bob did use a force to accelerate also here. His clock ticked less also here, going to Betelgeuse. You can not avoid a real physical solution without the equivalence principle, with only acceleration phases affecting matter, and there is mathematical proof of that. The time dilation equation in GR is equivalent with the time dilation equation in SR. They just have a different set of variables in them (include the escape velocity equation in the GR equation and you get the SR-equation). v^2 is a velocity after an acceleration phase (v^2 = 2 • acceleration • distance), not an average velocity or an instantaneous velocity when coasting. Which means: - The two equations can not physcally affect matter in different ways (an atom must react in the same way, affected by gravitation or by an accelerating rocket). It has experimentally been proven in a lab that time dilation is the decrease of certain frequencies in atoms, both in a gravitational environment and during mechanical acceleration.
- Only acceleration/deceleration phases in relative movement affect clocks/matter. - The SR time dilation equation is an acceleration based equation, it can not be used calculating time dilation between objects during coasting phases (inertial objects). Nothing physically happens to a coasting clock (coasting matter), relative to another object (inertial frames). This is often misunderstood in thought experiments and calculations with the SR time dilation equation.
Your conclusions are not entirely correct. Try this thought experiment: Bob makes his stated trip and is 1 day younger when he returns. Then he makes the exact same trip again and is now 2 days younger than Alex. Carol also takes a trip (at the same time as Bob), going the same speed Bob, but goes twice the distance and returns to Alex (same trip as 1 of Bob's trips but scaled 2x). She has accelerated less than Bob (1 turnaround vs 3 for Bob) but is also 2 days younger: same as Bob. One interpretation is that Bob's 2nd and 3rd accelerations "cancel out" (your interpretation). The alternate interpretation is that they followed paths of the same length. They key point is that WHEN (or relatively where) they accelerate matters. If they accelerate in exactly the same way but at different times in their journey, the resulting time dilation is different.
@@mitymi Thanx for your reply ."If they accelerate in exactly the same way but at different times in their journey, the resulting time dilation is different." No, only the acceleration phases produce physical time dilation for both of them, and it doesn't matter where/when these phases in space take place for any of them. In other words, you can't in calculations use the SR time dilation equation with the v^2 variable in it , other than when an object is actually accelerating. v^2 is not valid when coasting, without a force on the object. That is because v^2 mathematically and physically is equal to 2 • acceleration • distance (it is called the Torricelli equation). It is very usual to make these calculation mistakes, they are all over the place, for example concerning the twins. Einstein himself was possibly not aware of this 1905 (Minkowski was almost certainly not 1908), until GR was developed. Then he certainly became aware 1915 (or before), when he found the equivalence between the SR and GR time dilation equations. Schwarzschild helped him to form the GR time dilation equation. This equivalence between these two equations is actually a mathematical proof of the (strong) equivalence principle.
Time is fascinating. I worked the subway stations for nearly 10 years. From one end of the city to the other. Every so often I would notice the city would be saying that, "Today just flew by" or "The day was just dragging along." How can an entire city, with no interaction with each other until they used the subway, complain about the same time paradox unless it was effected by it? Maybe a time distorted bubble the earth passes through in its revolution around the sun. Maybe random waves of time distortion hitting the earth? Maybe they're given off by the sun. Maybe they're from outside our Terran system and reach us in intervals. ???? Ti-i-i-ime, is on my side. Yes, it is
You can resolve the “paradox” without regard to acceleration. All you have to do is add a 3rd observer at a distant point. Imagine a straight line from left to right with Earth>Rocket>3rd Observer. From the Earth’s pov, it’s the rocket that is going away, but the 3rd observer is stationary relative to the Earth. From the rocket’s pov, it’s the earth that’s going away, but the 3rd observer is getting closer. From the 3rd observer’s pov, the earth is stationary, but the rocket is coming closer. Therefore the Earth & 3rd observer agree that the rocket is the one that is moving, it’s the rocket that breaks the symmetry. Forget acceleration, just imagine you have a ship that can instantly go 99% the speed of light. Btw, the rocket does NOT need to return to earth to experience the slowing of time. Here's another way to think about it: imagine a very large sphere with many observers positioned on the shell of the sphere. A spaceship is traveling inside the sphere from one side to the other. All observers will agree that they are stationary relative to other observers on the sphere AND they will also agree that it's the spaceship that's moving. A person inside the spaceship looking at multiple observers on the sphere can no longer claim that the ship is stationary because in effect there are now many reference points (some moving away, while others are moving closer).
Nothing is stationary, nothing is ever in the same place for more than an instant. Time seeks its end, that all matter ends up in the same place. The more matter you have in one "place" the slower time flows. Enough matter in one place, time stops.
Clocks in motion run slower than stationary clocks due to the simple fact that the frame of the clock is accelerated and not its power source. The easiest wave to visualize it is two objects traveling in space, one accelerates, and the other one doesn't. You are an observer only. The cells of your body are in a different frame, being accelerated in time by the action of the heart and lungs. You are trying to apply the workings of a mechanical clock to those governing biological processes. There is no correlation other than the 24-hour day/night cycle in which plants and animals have evolved. Have you actually changed how much force is being applied to each cell in your body simply by traveling faster in space?
@DeepBean time-dilation in mechanical clocks is due to a change in APPLIED FORCE. This change in applied force can be caused by a multitude of factors. Like operating temperature, electromagnetic interference, and gravity. Einstein’s light clock just shows one way of changing the amount of applied force. The key observation is that this ONLY APPLIES to electronic devices that are accelerated by an electromagnetic wave. Are the cells of your accelerated by an electrical current metered out at a constant rate like the hands of an atomic clock? How about the cells of a plant? If I took a sundial and flew it around the earth at the speed of noon and came back and proclaimed I hadn't aged a day because the clock didn't change time, you'd label me a lunatic. Well, that is EXACTLY what the Hafele-Keating lunatics did. All of these attempts to resolve the Twin Paradox without understanding what controls the acceleration rate of plant and animal cells prove that Einstein was a lunatic who was out of his league.
Alex and Carol are not twins, they don't resolve anything. Talking about multiple inertial reference frames isn't really helpful either. Lets just consider Alice and Bob, because the special thing about twins is that they start in the same location, with the same velocity, and same acceleration. Therefore when they start, their clocks tick at the same rate. If one Twin accelerates, the clocks immediately fall out of sync. If the clocks ever come back together to allow a comparison, it's the spacetime travel distance that always determines the discrepancy.
Used it in class today to start discussion. We were thinking about the time dilation effect due to gravity and how it would compensate for the speed of the spacecraft. Students found the video helpful and clear in approach.
I don't see how this solution materially differs from others that recognize the lack of symmetry between Alex and Bob and ultimately rely on acceleration/gravitation and General Relativity. Bob very definitely feels acceleration that Alex does not and that has very noticeable consequences in the real world. (If you don't believe this, calculate the forces generated if Bob, travelling at 0.98c in one direction, slows down and accelerates to 0.98c in the opposite direction in, say, one second. Guess whether a human body can survive that. For grins, try it over a period of a month.) Your statements that, this is Physics and we can tell who is right and who is wrong, and that "it's down to some elementary physical principles" to make that determination are correct. But if I may, I'd like to expand and modify them slightly to point out that, in Physics (and, indeed, all of science) it is actual observation that is the ultimate arbiter of scientific truth, and that even "elementary physical principles" must give way if they prove to differ from what is actually observed. The appeal of the Twin Paradox over what is now more than one-hundred years comes from asking, "If my twin brother actually does go off on a high-speed trip and comes back years later, will he really remain a young man, while I've grown old and gray?" Until and unless that experiment can actually be performed, we cannot know for certain. Theory and experimentation to date certainly suggest that's the case. But until and unless we actually see it with our own eyes, who really knows?
The short answer is the both twins are the same age because both twins experience the same amount of time. One just experiences more space as shown by the clock readouts. Synchronized clocks use the same amount of energy. Therefore. E=mc or Energy equals Acceleration with Time being a measurement of Acceleration we get Energy Equals Time. Since both clocks used the same amount of energy, both clocks experience the same amount of time. Astronaut's experience accelerated heart rates during lift-off, increase in g-force. Accelerated heart rates = shorter lifespan as evidenced by hummingbirds. The only way to tell an actual age difference is to determine how much energy (food) each twin consumes. E=mc or Energy equals Time.
My idea so I get to name it! What I mean is, no one has claimed it so I'm officially calling, "Dibs." Voyager 1 is now in the, "Milky Way's interstellar time" or "Mikey's Time." "V-ger's" message has sped up now that it's outside our Sun's, "Time Bubble," or, "Terran Time." It will be faster, still, when "V-ger" sends a message from beyond the Milky Way's time bubble. Then there's Outside the Local Group time bubble. So on and so on until we get outside any influence and into the, "True Interstellar Time Standard." Or, "T.I..." ;-P Now that "V-ger" is outside our Sun's reach, in interstellar space, it's now in the Milky Way's faster moving, Interstellar Time or "Mikey's Time." This can be proven by turning off everything except its clock and transmitter. Have "V-ger" read time for as long as possible. They WILL show the flow of time speeds up the further away you get from any celestial bodies. Until you reach the Milky Way's time standard or "Mikey's Time." •Our sun's time bubble: "Terran Time" we know and have measured. In a lifetime, our head is one second younger than our feet. •Milky Way's time bubble or "Mikey's Time." The rate/flow of TIME outside any influence but within the Milky Way: We just got there and are still figuring what the difference is. Wild guess I'd say time will increase in speed, now and until V-ger is outside the Ort cloud. •Local Group's time bubble or the rate/flow of time outside of any influence but within the Local Group: Name still open and unknown. Wild guess .08 P-22% to a couple seconds faster, maybe. Used just for reference. •Outside any influence in the, "True Interstellar Time Standard." (or T.I...) ;-P This name is NOT up for grabs. The rate/flow of time is fastest here. (Time flows fastest here so it's best to use a motor boat and hold tight. Always applies when you're in T.I....) ;-P A minute is a minute in all. It's the rate/flow I'm talking about. Heck, rivers of time flowing differently might explain dark energy and dark matter. The Milky Way's Interstellar Time Standard will be known as, "Mikey's Time." Pass it on, please and thank you!
The assumption made at ua-cam.com/video/rLhr-2OQNrs/v-deo.html is wrong. If Carol moves relative to Bob, they cannot agree on the simultaneity of the moment when they sync their clocks. You are assuming that Carol syncs her clock with Bob's at the same time Bob meets her at Betelgeuse. This is not the same moment Bob measures on his own clock. Syncing clocks is not possible unless the observers are at rest relative to each other. That is the reason why both twins are needed to be at rest on Earth at the start of the experiment. For the same reason why you cannot measure the one-way speed of light, you cannot solve twin's paradox in special relativity.
Let's say all these space cadets are physically identical, including a convenient anatomical appendage that works just like a pendulum. Set them loose on their various journeys through space and gather them together after their journeys. Whoever's pendulum swung the most is youngest.
Mechanical clocks don't measure time. They measure motion in space. A slower running running clock just means it is experiencing more space. They neophyte Einstein combined space and time and has you all confused. Riddle me thus. Why, when you shine a light on a solar sale, is it accelerated in space. And yet that same force accelerates a plant in time. Why do synchronized clocks, one mobile, the other stationary, use the same amount of energy. One is experiencing more space/gravity than the other. The ONLY way to age less in space for humans is cryostasis. For plants, if you don't allow for the redshifting of electromagnetic waves when in motion, the plant will receive less sunlight and thus have less growth. But that's not relativity. That's elementary physics. Which the majority of you don't understand because you live in Einstein’s fantasy universe.
@wesjohnson6833 do you really believe that time - a measurement of acceleration - slows down just because you are traveling faster in space? Clocks are accelerated by force that is emitted at a constant frequency that redshifts with motion. Plants are accelerated through their lifespan by radiant energy from the sun as measured by growing degree units. How does the amount of sunlight a plant receives change just by doubling the Earth's rotational spin? FYI. It doesn't. The cells of your body are accelerated by the food you eat and distributed to the individual cells via the blood stream. An astronaut's heart rate is in an accelerated state during lift-off. How are they experiencing less time if consuming more energy? The one thing these charlatans aren't telling you about synchronized clocks is that they use the same amount of energy. Where is the time-dilation? Clocks measure the Earth's rotational spin. Other than the 24-hour day night cycle plants have evolved under, increasing the motion in space has very little to do with one's time frame. In fact, the exact opposite has been shown to occur. Objects age at a faster rate due to the extra force being applied. Relativity is mathematical nonsense. You just can't see the fundamental error because it gives a reverse image from reality. Mass decreases with acceleration. Objects are accelerated in time as well as in space under certain conditions. Gravity is the result of acceleration, not the cause of it. Relativity is flat earth science. It's been disproven countless times. The fact that it is still being promoted as valid science is a testament to the collective stupidity of mankind.
Oh no, so close! But then at 5:35 you lose the plot. In the second half of the journey, Bob does not move in his own reference frame! In special relativity an observer is always at rest in their own reference frame! Most of the twin paradox explanations explain more or less how we can figure out who is actually moving relative to whom, and who isn't. What they don't explain, is why Bob will always see Alex's clocks run slow--both on the way out and on the way in, he will see Alex's clocks run slow--and yet when he arrives at earth, he will learn that it was actually his own clock that ran slow the entire time. The video by Minute Physics is the only one I've seen that attempts to account for this. But while he explains the difference mathematically, he doesn't explain it in a way that makes any physical sense. Basically, at the instant that Bob turns around (or at the instant that Bob and Carol pass each other in your no-acceleration example), Alex's clock jumps way forward and there's a bunch of missing time from Bob and Carol's perspective. To me that doesn't resolve the paradox, rather, it proves conclusively that the paradox exists.
@@wesjohnson6833 The instantaneous turnaround is an oversimplification. In the video I referenced, this is explained, and it is suggested that it would be a gradual process as Bob slows, turns around, and then speeds back up on the return to earth. That said, it's not justified mathematically, and I'm not convinced that's the case. I've never found any UA-camr who covers how time dilation works during acceleration on a rigorous way. But as I understand it, time dilation during an acceleration involves taking the integral of all of the instantaneous speeds within the acceleration. Which means that to Bob, Alex's clock should be ticking slower any time Bob is in motion relative to Bob, accelerating or not, so it really is the change of reference frame that does the job and that is instantaneous. Of course no time disappears. From Bob's perspective, his idea of of what "now" means for Alex does take a leap, but that is just a perception related to something happening far outside of his light cone, related to his personal slice of simultaneity through spacetime. This is closely related to the Andromeda paradox.
@@wesjohnson6833 Here is a really excellent video that also covers the jump in time based on changing reference frames. The whole video is fantastic, but the meat of what I'm refering to is around the 13 minute mark: ua-cam.com/video/3V00tAfcHCI/v-deo.html Instantaneous acceleration isn't possible of course, but with every change in reference frame, the definition of simultenaity changes. But that definition is just that, it's just a perception.
@@erinm9445 It's not just a perception, it's reality. Your "now" changes. We agree on most. What I was saying is, just as acceleration must be continuous, so is the change in reference frame and the relativity of simultaneity ( the "plane of simultaneity" as we used to call it). The way that "now" changes for the traveling twin is that the earth bound twin's clock rapidly speeds up ( from his frame). But it is continuous, fluid. I think you might find better answers about the magnitude of acceleration in general relativity, where it is treated as equivalent to a gravitational field. To make matters worse, two types of acceleration are used. I don't understand that, and the walls around here are tired of my head hitting them, so I try to keep to SR and flat space.
@@wesjohnson6833 When I say it's perception, I don't mean that it's not reality. The metaphor for what I mean is this. Say you stand on a tall building and look through a telescope to the horizon, and see mountains. Then you turn 90 degrees, look through the telescope again, and you no longer see mountains, but ocean. The world has not changed, only your perception of it, or maybe it would be more precise to say your orientation relative to it. Same with relative simultenaity in spacetime, in which your relative speed determines which direction you are "looking" in time. Yeah, I don't do the math, so I don't even try to understand general relativity, beyond the very basic conceptual stuff. In terms of the "missing time" (which, I agree, must be accounted for gradually), here is my only lingering confusion. As the spaceship decelerates, turns around, and re-accelerates: from a purely time dilation standpoint, Alex's clock back on earth should still be ticking more slowly from Bob's perspective the entire time he is in motion. Accelerated motion is just a smooth series of inertial reference frames, so time dilation shouldn't work fundamentally differently, though its effect will lessen the closer Alex's speed is relative to Bob's. However, as you say, for there to not be a paradox, then Alex's clock must actually appear to tick *faster* than Bob's while he's accelerating/decelerating, not slower. I think the answer must be that as Bob is rotating on a curved (accelerated) path through spacetime, his perception of simultenaity--ie his perception of Alex's "now" is also changing. So he is "skipping forward" through time, it's just a continual process as the acceleration/deceleration occurs, and this phenomenon is enough to more than cancel out the time dilation. (It's also possible that I'm overcomplicating this, and that the time dilation and relativity of simultenaity are the same thing, but this helps me think about it).
Special relativity is a mathematical theory that can not give a correct answer to the so called twin paradox. The solution proposed was to invoke an ad hoc physics solution to a contradictory mathematics problem. You can not do that, since it is an invalid solution. You can not solve a mathematics contradiction by changing the rules of mathematics to suit an ad hoc physics claim. There is no strictly mathematical solution, since the problem has no mathematics solution, because the relativity theory is based upon faulty mathematics. The relativity postulate regarding inertial frames is therefore defective, since no correct mathematics solution is possible using this postulate. This problem proves relativity is false physics, because there is no correct solution based upon the mathematics of relativity.
The solution can be derived by understanding the simple fact that space and time are dependent frames of reference. That clocks are instruments that measure motion in space and space along. The clock's atom is chilled to absolute zero and shielded from electromagnetic interference. Is the observer also in cryostasis? Shielded from UV rays? The observer is not even on the same time frame of reference as the clock on the wall. Only the same space frame. What is conveniently left out in all of this relativity nonsense is the fact that both clocks use the same amount of energy. There is no time-dilation simply by traveling faster in space. The basic answer is that both twins are the same age because they experienced the same amount of time. One just experiences more space is all. If you want to dig deeper and ascertain the effects of space travel on the human body, Nasa shows accelerated heart rates during lift-off returning to near normal in zero gravity. Accelerated heart rates equals shorter lifespan as evidenced by hummingbirds. If you want to calculate the 'age' difference between the twins, you are going to have to compare heart beats and the amount food/calories consumed. High protein diets = early puberty. Since none of this data is available, the only logical answer is both twins are the same age.
You failed to prove that Einstein's relativity is not based upon incorrect mathematics. The fact that a contradiction is always produced for the twins, shows the SR mathematics is based upon false postulates.
@harryr.6744 you speek with forked tongue. SR and GR is based on the false notion that gravity is a force. It's not. Ots an effect. The resistance of the mass to being accelerated by another frame of reference. Walking down the street, you are accelerating yourself. So no g-force. Riding on the bus, the seat back is accelerating you, so there is a g-force effect. Relativity is junk science because you have an absolute reference marker in light. What are the postulates of relativity? Neither can claim the high ground? That's false as has been shown by synchronized clocks. Time slows down with acceleration in space? Where is your evidence? You have none because space and time are separate frames of reference and clocks are instruments that measure motion in space. Your acceleration in time will vary depending upon the forces acting upon your frame of reference. Sunlight for example. How does motion on space change the amount of sunlight a plant receives when you can easily employ artificial lighting. Relativity was never properly reviewed just like Newton's gravitational attraction was never properly reviewed. So now you are on here preaching the gospel according to St Einstein and completely ignoring the evidence that refutes his Spacetime fantasy universe. If you think you can fly around the universe and not experience as much time as if stationary, you are dumber than the flat earth earthers. All you have is mathematical nonsense that is easily debunked.
I believe that the twin on Earth is younger, if we consider the motion of the Earth in the frame of the spaceship. (round trip) And this is not a defeat, the motion of the spaceship (in the frame of the Earth) is different from the motion of the Earth. (in the frame of the spaceship) I understand that we can disagree on this, but time dilation is symmetrical. In my opinion the acceleration is not important, accelerating means moving at a constant speed during infinitesimal instants of time dt. You did a great job though, I enjoyed your video!😊
Hi Massimiliano, Thank you for the comment! 😀 I agree that acceleration is not by itself the main factor, though I think what is important is the fact that the space twin has two reference frames while the earth twin has one. But let me know what you think!
@@deepbean I would like to tell you about your scenario. (the star S is Betelgeuse) A spaceship moves in the frame of the Earth, and travels a distance L. (to reach a star S, suppose the Earth-star distance is L in the frame of the Earth) The nose of the spaceship (the astronaut twin) and the Earth twin occupy the same position at the initial times (t = t’ = 0) ... and the twins are in relative motion to each other at speed v. If we consider the uniform linear motion of the spaceship in the frame of the Earth: 1) the astronaut twin reaches the star S at time t = L/v, in the frame of the Earth 2) the star S reaches the astronaut twin at time t’ = L / (gamma*v) in the frame of the spaceship In the spaceship frame the Earth-star distance is CONTRACTED ! But in my opinion if we consider the uniform linear motion of the Earth in the frame of the spaceship, then we need to consider SOMETHING ELSE: in this case it is necessary to consider the uniform linear motion of the star S in the frame of the spaceship. And if we consider the uniform linear motion of the star S in the frame of the spaceship: 1) the star S reaches the astronaut twin at time t ’ = L/v in the frame of the spaceship 2) the astronaut twin reaches the star S at time t = L / (gamma*v) in the frame of the Earth In my opinion the uniform linear motion of the star is hidden but it exists and happens. If we wait for the arrival of the star, the astronaut twin is younger, but if we wait for the arrival of the spaceship's tail, the earth twin is younger. (And the return journey is similar to the outward journey)
I disagree. Clocks do not change rates just because they are moving unless there is some vibration or other mechanism causing the rate change, and such mechanisms almost always increase the clock rate, which is the exact opposite of what Einstein postulated. The observer on the ground will observe the same time for the wheel of the train as he will for the point on the wheel is contacting the ground, even though the wheel is moving. Einstein was wrong. The Hafele Keating Experiment used fraudulent data to make it appear that special relativity was correct when it is not correct.
You have solved nothing other than creating a scenario that allows you to control the events to your liking. The paradox remains, because making up weak excuses like "swapping frames" or "gravity" or "acceleration" only mean that we have not defined a fool proof scenario in the first place. No one really HAS to return to Earth to compare clocks to demonstrate time dilation. The paradox is that a moving observer will experience less time, but its also impossible to tell which is moving, because either can claim to be the stationary one. And they both can not be experiencing less time that each other. That is the core of the paradox, not men in ships going out and coming back. We can develop some scenario that removes all possible objections, and still have the paradox, still unsolvable, because Einstein's theory is irrational nonsense.
" No one really HAS to return to Earth to compare clocks to demonstrate time dilation. " : Okay, you are right. Imagine a spaceship with a long tail. a) The clock of the astronaut twin slows down as the nose of the spaceship reaches the star, b) and the clock of the earth twin slows down as the earth twin reaches the tail end of the spaceship. There is no contradiction. The motion of the spaceship (in the frame of the Earth) is different from the motion of the Earth (in the frame of the spaceship)
Your disagreement is clearly with Einstein's theory of special relativity and its implications, including the symmetry of time dilation - if you disagree with that, then we'll for sure disagree about our analysis of the twin paradox.
@@massimilianodellaguzzo8571 Both clocks cant run slower than each other, that is the paradox. You have not solved it. The motion of both the ship or the earth, (lets call it another ship) are identical according to each observer, so the paradox remains unsolvable, because the whole theory is nonsense.
@@deepbean Your analysis of the paradox is nothing if the theory is wrong, which it is, and the paradox demonstrates that its wrong. Before you get to thinking about the paradox, you ought to be able to defend the theory, a task which you will surely fail, because the hypothesis is irrational and illogical. But you don't care.
@@everythingisalllies2141 I like to imagine two clocks (clock A and clock B) at a certain distance L, and in relative motion to each other at speed v. If we consider the uniform linear motion of clock B (in the frame of clock A), then clock B slows down: t_A = L / v t_B = L / (gamma * v) ... In this case the L distance contracts in the frame of the clock B. (and the L distance does not contract in the frame of the clock A) And if we consider the uniform linear motion of clock A (in the frame of clock B) then clock A slows down: t_A = L / (gamma * v) t_B = L / v ... In this case the L distance contracts in the frame of the clock A. (and the L distance does not contract in the frame of the clock B) The two uniform linear motions both occur (even if we can "hide" one of the two motions), and each of the two uniform linear motions determines a different temporal pair (t_A; t_B) " so the paradox remains unsolvable, because the whole theory is nonsense. " : I do not agree. If we consider the motion of the spaceship in the frame of the Earth then the astronaut twin is younger. The spaceship reaches the star and flies back to Earth (GAME OVER, the astronaut twin is younger) But when you consider the journey in the frame of the spaceship, then earth twin is younger. (and this is another trip, different from the previous trip)
I'm sorry to say it, but you haven't even begun to understand the solution to the paradox. You only see time dilation, but completely ignore length contraction and the resulting relativity of simultaneity.
You get caught up in the fact that the twin travels back and forth. But that is not necessary. Even if the route is only flown once, the traveling twin ages less. Even acceleration phases are superfluous; it is sufficient for the twin to send a light signal back to earth with his age when he reaches his destination. The traveler does not have to change his frame of reference, accelerate or do anything else, so the time dilation is absolutely symmetrical, yet he has aged less than the twin on Earth when he reaches his destination. And as long as you don't understand this, the twin paradox is far from being solved.
From the traveller’s point of view Earth is length contracted, do you have a video with your explanation?
Since we all move through spacetime at the same rate and Bob travels the longest distance (and not Alex because Bob is the one that had the acelleration (which is absolute)). Therefore Bob travelled more quickly through space and hence less through time.
Why make it difficult when it really is this simple ?
Thank you! Finally after all those years of being unsatisfied with answers given for the twin paradox the kind of video I'd been waiting for!
I just wish at 5:37 the calculations to "prove" that Bob indeed aged less than Alex (in that frame of reference, Bob's inital one) were on screen since it's not very intuitive, but then again, none of this really is^^
The very reason for the assimtry has nothing to do with changing frame or acceleration. We can see it by only considering the going to the star. In fact if the twin stopped a clock at the arrival, it would show half of its aging when he met his brother.
Both formulas (see below) are right:
t'=t/g (for x'=0) and
t=t'/g (for x=0) .
But the first is only valid when x'=0 and the second only x=0.
What happens is that the end conditions are compatible only with the first formula but not with the second one. In fact at the end=
x'=0, x=L. Because the second formula is for x=0 we cannot apply it.
Then the very reason for the assimetry is that one twin is moving "inside" the space of the other (seeing the path shortening).
What you are overlooking is the fact that space and time are separate frames of reference. The caesium-133 atom is chilled to absolute zero to prevent it from being accelerated in time when a force is applied. Are either of the twins in cryostasis?
Both twins experience the same amount of time. One just experiences more space.
Hello can you explain what happen when two twin go in opposite direction and come back. My answer will be there age will be same but they are moving near speed of light they should feel time dilation and one one of them get older but which one? Can you explain
The paradox is in the final outcome. Before the final outcome, is Alex aging faster near uniformly relative to Bob's aging if the turn around by Bob is very rapid? That to me is the paradox. If Alex goes and catches up to Bob before the turn around, Alex will be younger. If Alex goes and catches up to Bob after the turn around, they can be the same age or Alex can be older or younger depending on where they meet. That is the real paradox. Alex can make himself relatively younger by going out to meet Bob and Bob can employ tactics to ensure that does not happen.
Sorry, the thought experiment is made in a clear and interesting way, but imo the equivalence principle must be used to solve the twin paradox, physically.
Initial statement (mine): A relative motion (or position) between objects (any objects in the universe) can not come into existence without acceleration (a force).
You seem to use this logic, initially:
Premise 1. "I assume that I can solve the paradox, without accounting for all acceleration processes in my thought experiment". Disregarding Carols acceleration. But, she can not just "be moving". Doing so can be called the "cosmic magic hands" - error, moving (or placing) other observers relative to the twins with pure magic. 4:00, what you do here is neglect/disregard her physical ageing when she accelerated (which is the same added ageing that Bob would have experienced if he had returned normally from Betelgeuse, instead of Carol). The twin experiment is about physical ageing of the TWINS, not measuring clocks/time handed over in different ways with external experiment participants.
Conclusion. "I perform my thought experiment, do not include all accelerations in it, and have showed that acceleration is not the (only) cause for physical time dilation".
This is called "assuming the conclusion" - error in a premise, in a logical reasoning.
4:25 you state: "In Bob's reference frame, the situation is the reverse, Alex's clock will have ticked less by the time Bob reaches Betelgeuse". No, time dilation is a physical process (clocks and other matter), and in reality Bob did use a force to accelerate also here. His clock ticked less also here, going to Betelgeuse.
You can not avoid a real physical solution without the equivalence principle, with only acceleration phases affecting matter, and there is mathematical proof of that. The time dilation equation in GR is equivalent with the time dilation equation in SR. They just have a different set of variables in them (include the escape velocity equation in the GR equation and you get the SR-equation). v^2 is a velocity after an acceleration phase (v^2 = 2 • acceleration • distance),
not an average velocity or an instantaneous velocity when coasting.
Which means:
- The two equations can not physcally affect matter in different ways (an atom must react in the same way, affected by gravitation or by an accelerating rocket). It has experimentally been proven in a lab that time dilation is the decrease of certain frequencies in atoms, both in a gravitational environment and during mechanical acceleration.
- Only acceleration/deceleration phases in relative movement affect clocks/matter.
- The SR time dilation equation is an acceleration based equation, it can not be used calculating time dilation between objects during coasting phases (inertial objects). Nothing physically happens to a coasting clock (coasting matter), relative to another object (inertial frames). This is often misunderstood in thought experiments and calculations with the SR time dilation equation.
Your conclusions are not entirely correct. Try this thought experiment: Bob makes his stated trip and is 1 day younger when he returns. Then he makes the exact same trip again and is now 2 days younger than Alex. Carol also takes a trip (at the same time as Bob), going the same speed Bob, but goes twice the distance and returns to Alex (same trip as 1 of Bob's trips but scaled 2x). She has accelerated less than Bob (1 turnaround vs 3 for Bob) but is also 2 days younger: same as Bob. One interpretation is that Bob's 2nd and 3rd accelerations "cancel out" (your interpretation). The alternate interpretation is that they followed paths of the same length. They key point is that WHEN (or relatively where) they accelerate matters. If they accelerate in exactly the same way but at different times in their journey, the resulting time dilation is different.
@@mitymi Thanx for your reply ."If they accelerate in exactly the same way but at different times in their journey, the resulting time dilation is different."
No, only the acceleration phases produce physical time dilation for both of them, and it doesn't matter where/when these phases in space take place for any of them.
In other words, you can't in calculations use the SR time dilation equation with the v^2 variable in it , other than when an object is actually accelerating. v^2 is not valid when coasting, without a force on the object. That is because v^2 mathematically and physically is equal to 2 • acceleration • distance (it is called the Torricelli equation). It is very usual to make these calculation mistakes, they are all over the place, for example concerning the twins. Einstein himself was possibly not aware of this 1905 (Minkowski was almost certainly not 1908), until GR was developed. Then he certainly became aware 1915 (or before), when he found the equivalence between the SR and GR time dilation equations. Schwarzschild helped him to form the GR time dilation equation. This equivalence between these two equations is actually a mathematical proof of the (strong) equivalence principle.
Time is fascinating. I worked the subway stations for nearly 10 years. From one end of the city to the other. Every so often I would notice the city would be saying that, "Today just flew by" or "The day was just dragging along." How can an entire city, with no interaction with each other until they used the subway, complain about the same time paradox unless it was effected by it? Maybe a time distorted bubble the earth passes through in its revolution around the sun. Maybe random waves of time distortion hitting the earth? Maybe they're given off by the sun. Maybe they're from outside our Terran system and reach us in intervals. ???? Ti-i-i-ime, is on my side. Yes, it is
You can resolve the “paradox” without regard to acceleration. All you have to do is add a 3rd observer at a distant point. Imagine a straight line from left to right with Earth>Rocket>3rd Observer. From the Earth’s pov, it’s the rocket that is going away, but the 3rd observer is stationary relative to the Earth. From the rocket’s pov, it’s the earth that’s going away, but the 3rd observer is getting closer. From the 3rd observer’s pov, the earth is stationary, but the rocket is coming closer.
Therefore the Earth & 3rd observer agree that the rocket is the one that is moving, it’s the rocket that breaks the symmetry.
Forget acceleration, just imagine you have a ship that can instantly go 99% the speed of light.
Btw, the rocket does NOT need to return to earth to experience the slowing of time.
Here's another way to think about it: imagine a very large sphere with many observers positioned on the shell of the sphere. A spaceship is traveling inside the sphere from one side to the other. All observers will agree that they are stationary relative to other observers on the sphere AND they will also agree that it's the spaceship that's moving.
A person inside the spaceship looking at multiple observers on the sphere can no longer claim that the ship is stationary because in effect there are now many reference points (some moving away, while others are moving closer).
I don't get it what's the use of adding a 3rd observer which is in the exact same reference frame.
Nothing is stationary, nothing is ever in the same place for more than an instant. Time seeks its end, that all matter ends up in the same place. The more matter you have in one "place" the slower time flows. Enough matter in one place, time stops.
Clocks in motion run slower than stationary clocks due to the simple fact that the frame of the clock is accelerated and not its power source.
The easiest wave to visualize it is two objects traveling in space, one accelerates, and the other one doesn't. You are an observer only. The cells of your body are in a different frame, being accelerated in time by the action of the heart and lungs.
You are trying to apply the workings of a mechanical clock to those governing biological processes. There is no correlation other than the 24-hour day/night cycle in which plants and animals have evolved. Have you actually changed how much force is being applied to each cell in your body simply by traveling faster in space?
Time Dilation is due not to relative acceleration, but to relative speed; you can see this by thought experiments such as the Einstein clock.
@DeepBean time-dilation in mechanical clocks is due to a change in APPLIED FORCE. This change in applied force can be caused by a multitude of factors. Like operating temperature, electromagnetic interference, and gravity. Einstein’s light clock just shows one way of changing the amount of applied force.
The key observation is that this ONLY APPLIES to electronic devices that are accelerated by an electromagnetic wave.
Are the cells of your accelerated by an electrical current metered out at a constant rate like the hands of an atomic clock? How about the cells of a plant?
If I took a sundial and flew it around the earth at the speed of noon and came back and proclaimed I hadn't aged a day because the clock didn't change time, you'd label me a lunatic. Well, that is EXACTLY what the Hafele-Keating lunatics did.
All of these attempts to resolve the Twin Paradox without understanding what controls the acceleration rate of plant and animal cells prove that Einstein was a lunatic who was out of his league.
Alex and Carol are not twins, they don't resolve anything. Talking about multiple inertial reference frames isn't really helpful either. Lets just consider Alice and Bob, because the special thing about twins is that they start in the same location, with the same velocity, and same acceleration. Therefore when they start, their clocks tick at the same rate. If one Twin accelerates, the clocks immediately fall out of sync. If the clocks ever come back together to allow a comparison, it's the spacetime travel distance that always determines the discrepancy.
Best explanation I have seen online.
Used it in class today to start discussion. We were thinking about the time dilation effect due to gravity and how it would compensate for the speed of the spacecraft. Students found the video helpful and clear in approach.
I don't see how this solution materially differs from others that recognize the lack of symmetry between Alex and Bob and ultimately rely on acceleration/gravitation and General Relativity. Bob very definitely feels acceleration that Alex does not and that has very noticeable consequences in the real world. (If you don't believe this, calculate the forces generated if Bob, travelling at 0.98c in one direction, slows down and accelerates to 0.98c in the opposite direction in, say, one second. Guess whether a human body can survive that. For grins, try it over a period of a month.)
Your statements that, this is Physics and we can tell who is right and who is wrong, and that "it's down to some elementary physical principles" to make that determination are correct. But if I may, I'd like to expand and modify them slightly to point out that, in Physics (and, indeed, all of science) it is actual observation that is the ultimate arbiter of scientific truth, and that even "elementary physical principles" must give way if they prove to differ from what is actually observed.
The appeal of the Twin Paradox over what is now more than one-hundred years comes from asking, "If my twin brother actually does go off on a high-speed trip and comes back years later, will he really remain a young man, while I've grown old and gray?" Until and unless that experiment can actually be performed, we cannot know for certain. Theory and experimentation to date certainly suggest that's the case. But until and unless we actually see it with our own eyes, who really knows?
The short answer is the both twins are the same age because both twins experience the same amount of time. One just experiences more space as shown by the clock readouts.
Synchronized clocks use the same amount of energy. Therefore. E=mc or Energy equals Acceleration with Time being a measurement of Acceleration we get Energy Equals Time. Since both clocks used the same amount of energy, both clocks experience the same amount of time.
Astronaut's experience accelerated heart rates during lift-off, increase in g-force. Accelerated heart rates = shorter lifespan as evidenced by hummingbirds.
The only way to tell an actual age difference is to determine how much energy (food) each twin consumes. E=mc or Energy equals Time.
My idea so I get to name it! What I mean is, no one has claimed it so I'm officially calling, "Dibs." Voyager 1 is now in the, "Milky Way's interstellar time" or "Mikey's Time."
"V-ger's" message has sped up now that it's outside our Sun's, "Time Bubble," or, "Terran Time." It will be faster, still, when "V-ger" sends a message from beyond the Milky Way's time bubble. Then there's Outside the Local Group time bubble. So on and so on until we get outside any influence and into the, "True Interstellar Time Standard." Or, "T.I..." ;-P
Now that "V-ger" is outside our Sun's reach, in interstellar space, it's now in the Milky Way's faster moving, Interstellar Time or "Mikey's Time." This can be proven by turning off everything except its clock and transmitter. Have "V-ger" read time for as long as possible. They WILL show the flow of time speeds up the further away you get from any celestial bodies. Until you reach the Milky Way's time standard or "Mikey's Time."
•Our sun's time bubble: "Terran Time" we know and have measured. In a lifetime, our head is one second younger than our feet.
•Milky Way's time bubble or "Mikey's Time." The rate/flow of TIME outside any influence but within the Milky Way: We just got there and are still figuring what the difference is. Wild guess I'd say time will increase in speed, now and until V-ger is outside the Ort cloud.
•Local Group's time bubble or the rate/flow of time outside of any influence but within the Local Group: Name still open and unknown. Wild guess .08 P-22% to a couple seconds faster, maybe. Used just for reference.
•Outside any influence in the, "True Interstellar Time Standard." (or T.I...) ;-P This name is NOT up for grabs. The rate/flow of time is fastest here. (Time flows fastest here so it's best to use a motor boat and hold tight. Always applies when you're in T.I....) ;-P
A minute is a minute in all. It's the rate/flow I'm talking about. Heck, rivers of time flowing differently might explain dark energy and dark matter.
The Milky Way's Interstellar Time Standard will be known as, "Mikey's Time."
Pass it on, please and thank you!
The assumption made at ua-cam.com/video/rLhr-2OQNrs/v-deo.html is wrong.
If Carol moves relative to Bob, they cannot agree on the simultaneity of the moment when they sync their clocks. You are assuming that Carol syncs her clock with Bob's at the same time Bob meets her at Betelgeuse. This is not the same moment Bob measures on his own clock.
Syncing clocks is not possible unless the observers are at rest relative to each other. That is the reason why both twins are needed to be at rest on Earth at the start of the experiment.
For the same reason why you cannot measure the one-way speed of light, you cannot solve twin's paradox in special relativity.
Let's say all these space cadets are physically identical, including a convenient anatomical appendage that works just like a pendulum. Set them loose on their various journeys through space and gather them together after their journeys. Whoever's pendulum swung the most is youngest.
Finally thats the counterargument that came to my mind
Mechanical clocks don't measure time. They measure motion in space. A slower running running clock just means it is experiencing more space.
They neophyte Einstein combined space and time and has you all confused.
Riddle me thus. Why, when you shine a light on a solar sale, is it accelerated in space. And yet that same force accelerates a plant in time.
Why do synchronized clocks, one mobile, the other stationary, use the same amount of energy. One is experiencing more space/gravity than the other.
The ONLY way to age less in space for humans is cryostasis. For plants, if you don't allow for the redshifting of electromagnetic waves when in motion, the plant will receive less sunlight and thus have less growth. But that's not relativity. That's elementary physics. Which the majority of you don't understand because you live in Einstein’s fantasy universe.
I honestly can't tell whether you are serious or being comedic.
@wesjohnson6833 do you really believe that time - a measurement of acceleration - slows down just because you are traveling faster in space? Clocks are accelerated by force that is emitted at a constant frequency that redshifts with motion. Plants are accelerated through their lifespan by radiant energy from the sun as measured by growing degree units. How does the amount of sunlight a plant receives change just by doubling the Earth's rotational spin? FYI. It doesn't. The cells of your body are accelerated by the food you eat and distributed to the individual cells via the blood stream. An astronaut's heart rate is in an accelerated state during lift-off. How are they experiencing less time if consuming more energy?
The one thing these charlatans aren't telling you about synchronized clocks is that they use the same amount of energy. Where is the time-dilation?
Clocks measure the Earth's rotational spin. Other than the 24-hour day night cycle plants have evolved under, increasing the motion in space has very little to do with one's time frame. In fact, the exact opposite has been shown to occur. Objects age at a faster rate due to the extra force being applied.
Relativity is mathematical nonsense. You just can't see the fundamental error because it gives a reverse image from reality. Mass decreases with acceleration. Objects are accelerated in time as well as in space under certain conditions. Gravity is the result of acceleration, not the cause of it. Relativity is flat earth science. It's been disproven countless times. The fact that it is still being promoted as valid science is a testament to the collective stupidity of mankind.
@@stewiesaidthat Stupidity. Yes, it must be all them.
paradox..is..staying..unsolved..by..SRT--and--GRT--too..
Oh no, so close! But then at 5:35 you lose the plot. In the second half of the journey, Bob does not move in his own reference frame! In special relativity an observer is always at rest in their own reference frame! Most of the twin paradox explanations explain more or less how we can figure out who is actually moving relative to whom, and who isn't. What they don't explain, is why Bob will always see Alex's clocks run slow--both on the way out and on the way in, he will see Alex's clocks run slow--and yet when he arrives at earth, he will learn that it was actually his own clock that ran slow the entire time. The video by Minute Physics is the only one I've seen that attempts to account for this. But while he explains the difference mathematically, he doesn't explain it in a way that makes any physical sense. Basically, at the instant that Bob turns around (or at the instant that Bob and Carol pass each other in your no-acceleration example), Alex's clock jumps way forward and there's a bunch of missing time from Bob and Carol's perspective. To me that doesn't resolve the paradox, rather, it proves conclusively that the paradox exists.
You seriously mean time that is "missing". You know that can't happen, right? That classical theories are continuous?
@@wesjohnson6833 The instantaneous turnaround is an oversimplification. In the video I referenced, this is explained, and it is suggested that it would be a gradual process as Bob slows, turns around, and then speeds back up on the return to earth. That said, it's not justified mathematically, and I'm not convinced that's the case. I've never found any UA-camr who covers how time dilation works during acceleration on a rigorous way. But as I understand it, time dilation during an acceleration involves taking the integral of all of the instantaneous speeds within the acceleration. Which means that to Bob, Alex's clock should be ticking slower any time Bob is in motion relative to Bob, accelerating or not, so it really is the change of reference frame that does the job and that is instantaneous.
Of course no time disappears. From Bob's perspective, his idea of of what "now" means for Alex does take a leap, but that is just a perception related to something happening far outside of his light cone, related to his personal slice of simultaneity through spacetime. This is closely related to the Andromeda paradox.
@@wesjohnson6833 Here is a really excellent video that also covers the jump in time based on changing reference frames. The whole video is fantastic, but the meat of what I'm refering to is around the 13 minute mark: ua-cam.com/video/3V00tAfcHCI/v-deo.html
Instantaneous acceleration isn't possible of course, but with every change in reference frame, the definition of simultenaity changes. But that definition is just that, it's just a perception.
@@erinm9445 It's not just a perception, it's reality. Your "now" changes.
We agree on most. What I was saying is, just as acceleration must be continuous, so is the change in reference frame and the relativity of simultaneity ( the "plane of simultaneity" as we used to call it). The way that "now" changes for the traveling twin is that the earth bound twin's clock rapidly speeds up ( from his frame). But it is continuous, fluid.
I think you might find better answers about the magnitude of acceleration in general relativity, where it is treated as equivalent to a gravitational field. To make matters worse, two types of acceleration are used. I don't understand that, and the walls around here are tired of my head hitting them, so I try to keep to SR and flat space.
@@wesjohnson6833 When I say it's perception, I don't mean that it's not reality. The metaphor for what I mean is this. Say you stand on a tall building and look through a telescope to the horizon, and see mountains. Then you turn 90 degrees, look through the telescope again, and you no longer see mountains, but ocean. The world has not changed, only your perception of it, or maybe it would be more precise to say your orientation relative to it. Same with relative simultenaity in spacetime, in which your relative speed determines which direction you are "looking" in time.
Yeah, I don't do the math, so I don't even try to understand general relativity, beyond the very basic conceptual stuff.
In terms of the "missing time" (which, I agree, must be accounted for gradually), here is my only lingering confusion. As the spaceship decelerates, turns around, and re-accelerates: from a purely time dilation standpoint, Alex's clock back on earth should still be ticking more slowly from Bob's perspective the entire time he is in motion. Accelerated motion is just a smooth series of inertial reference frames, so time dilation shouldn't work fundamentally differently, though its effect will lessen the closer Alex's speed is relative to Bob's.
However, as you say, for there to not be a paradox, then Alex's clock must actually appear to tick *faster* than Bob's while he's accelerating/decelerating, not slower. I think the answer must be that as Bob is rotating on a curved (accelerated) path through spacetime, his perception of simultenaity--ie his perception of Alex's "now" is also changing. So he is "skipping forward" through time, it's just a continual process as the acceleration/deceleration occurs, and this phenomenon is enough to more than cancel out the time dilation. (It's also possible that I'm overcomplicating this, and that the time dilation and relativity of simultenaity are the same thing, but this helps me think about it).
Special relativity is a mathematical theory that can not give a correct answer to the so called twin paradox. The solution proposed was to invoke an ad hoc physics solution to a contradictory mathematics problem. You can not do that, since it is an invalid solution. You can not solve a mathematics contradiction by changing the rules of mathematics to suit an ad hoc physics claim. There is no strictly mathematical solution, since the problem has no mathematics solution, because the relativity theory is based upon faulty mathematics. The relativity postulate regarding inertial frames is therefore defective, since no correct mathematics solution is possible using this postulate. This problem proves relativity is false physics, because there is no correct solution based upon the mathematics of relativity.
The solution can be derived by understanding the simple fact that space and time are dependent frames of reference. That clocks are instruments that measure motion in space and space along.
The clock's atom is chilled to absolute zero and shielded from electromagnetic interference. Is the observer also in cryostasis? Shielded from UV rays? The observer is not even on the same time frame of reference as the clock on the wall. Only the same space frame.
What is conveniently left out in all of this relativity nonsense is the fact that both clocks use the same amount of energy. There is no time-dilation simply by traveling faster in space.
The basic answer is that both twins are the same age because they experienced the same amount of time. One just experiences more space is all.
If you want to dig deeper and ascertain the effects of space travel on the human body, Nasa shows accelerated heart rates during lift-off returning to near normal in zero gravity. Accelerated heart rates equals shorter lifespan as evidenced by hummingbirds. If you want to calculate the 'age' difference between the twins, you are going to have to compare heart beats and the amount food/calories consumed. High protein diets = early puberty.
Since none of this data is available, the only logical answer is both twins are the same age.
You failed to prove that Einstein's relativity is not based upon incorrect mathematics. The fact that a contradiction is always produced for the twins, shows the SR mathematics is based upon false postulates.
@harryr.6744 you speek with forked tongue. SR and GR is based on the false notion that gravity is a force. It's not. Ots an effect. The resistance of the mass to being accelerated by another frame of reference. Walking down the street, you are accelerating yourself. So no g-force. Riding on the bus, the seat back is accelerating you, so there is a g-force effect.
Relativity is junk science because you have an absolute reference marker in light.
What are the postulates of relativity? Neither can claim the high ground? That's false as has been shown by synchronized clocks.
Time slows down with acceleration in space? Where is your evidence? You have none because space and time are separate frames of reference and clocks are instruments that measure motion in space. Your acceleration in time will vary depending upon the forces acting upon your frame of reference. Sunlight for example. How does motion on space change the amount of sunlight a plant receives when you can easily employ artificial lighting.
Relativity was never properly reviewed just like Newton's gravitational attraction was never properly reviewed. So now you are on here preaching the gospel according to St Einstein and completely ignoring the evidence that refutes his Spacetime fantasy universe.
If you think you can fly around the universe and not experience as much time as if stationary, you are dumber than the flat earth earthers.
All you have is mathematical nonsense that is easily debunked.
I believe that the twin on Earth is younger, if we consider the motion of the Earth in the frame of the spaceship. (round trip)
And this is not a defeat, the motion of the spaceship (in the frame of the Earth) is different from the motion of the Earth. (in the frame of the spaceship)
I understand that we can disagree on this, but time dilation is symmetrical.
In my opinion the acceleration is not important, accelerating means moving at a constant speed during infinitesimal instants of time dt.
You did a great job though, I enjoyed your video!😊
Hi Massimiliano,
Thank you for the comment! 😀
I agree that acceleration is not by itself the main factor, though I think what is important is the fact that the space twin has two reference frames while the earth twin has one. But let me know what you think!
@@deepbean I would like to tell you about your scenario. (the star S is Betelgeuse)
A spaceship moves in the frame of the Earth, and travels a distance L. (to reach a star S, suppose the Earth-star distance is L in the frame of the Earth)
The nose of the spaceship (the astronaut twin) and the Earth twin occupy the same position at the initial times (t = t’ = 0) ... and the twins are in relative motion to each other at speed v.
If we consider the uniform linear motion of the spaceship in the frame of the Earth:
1) the astronaut twin reaches the star S at time t = L/v, in the frame of the Earth
2) the star S reaches the astronaut twin at time t’ = L / (gamma*v) in the frame of the spaceship
In the spaceship frame the Earth-star distance is CONTRACTED !
But in my opinion if we consider the uniform linear motion of the Earth in the frame of the spaceship, then we need to consider SOMETHING ELSE: in this case it is necessary to consider the uniform linear motion of the star S in the frame of the spaceship.
And if we consider the uniform linear motion of the star S in the frame of the spaceship:
1) the star S reaches the astronaut twin at time t ’ = L/v in the frame of the spaceship
2) the astronaut twin reaches the star S at time t = L / (gamma*v) in the frame of the Earth
In my opinion the uniform linear motion of the star is hidden but it exists and happens.
If we wait for the arrival of the star, the astronaut twin is younger,
but if we wait for the arrival of the spaceship's tail, the earth twin is younger.
(And the return journey is similar to the outward journey)
It's the acceleration 😆
I disagree. Clocks do not change rates just because they are moving unless there is some vibration or other mechanism causing the rate change, and such mechanisms almost always increase the clock rate, which is the exact opposite of what Einstein postulated. The observer on the ground will observe the same time for the wheel of the train as he will for the point on the wheel is contacting the ground, even though the wheel is moving. Einstein was wrong. The Hafele Keating Experiment used fraudulent data to make it appear that special relativity was correct when it is not correct.
The Hafele Keating experiment has been verified multiple times since first being conducted. Do they all use fraudulent data?
You have solved nothing other than creating a scenario that allows you to control the events to your liking. The paradox remains, because making up weak excuses like "swapping frames" or "gravity" or "acceleration" only mean that we have not defined a fool proof scenario in the first place. No one really HAS to return to Earth to compare clocks to demonstrate time dilation. The paradox is that a moving observer will experience less time, but its also impossible to tell which is moving, because either can claim to be the stationary one. And they both can not be experiencing less time that each other. That is the core of the paradox, not men in ships going out and coming back. We can develop some scenario that removes all possible objections, and still have the paradox, still unsolvable, because Einstein's theory is irrational nonsense.
" No one really HAS to return to Earth to compare clocks to demonstrate time dilation. " : Okay, you are right.
Imagine a spaceship with a long tail.
a) The clock of the astronaut twin slows down as the nose of the spaceship reaches the star,
b) and the clock of the earth twin slows down as the earth twin reaches the tail end of the spaceship.
There is no contradiction.
The motion of the spaceship (in the frame of the Earth) is different from the motion of the Earth (in the frame of the spaceship)
Your disagreement is clearly with Einstein's theory of special relativity and its implications, including the symmetry of time dilation - if you disagree with that, then we'll for sure disagree about our analysis of the twin paradox.
@@massimilianodellaguzzo8571 Both clocks cant run slower than each other, that is the paradox. You have not solved it.
The motion of both the ship or the earth, (lets call it another ship) are identical according to each observer, so the paradox remains unsolvable, because the whole theory is nonsense.
@@deepbean Your analysis of the paradox is nothing if the theory is wrong, which it is, and the paradox demonstrates that its wrong. Before you get to thinking about the paradox, you ought to be able to defend the theory, a task which you will surely fail, because the hypothesis is irrational and illogical. But you don't care.
@@everythingisalllies2141 I like to imagine two clocks (clock A and clock B) at a certain distance L, and in relative motion to each other at speed v.
If we consider the uniform linear motion of clock B (in the frame of clock A), then clock B slows down:
t_A = L / v
t_B = L / (gamma * v)
... In this case the L distance contracts in the frame of the clock B.
(and the L distance does not contract in the frame of the clock A)
And if we consider the uniform linear motion of clock A (in the frame of clock B) then clock A slows down:
t_A = L / (gamma * v)
t_B = L / v
... In this case the L distance contracts in the frame of the clock A.
(and the L distance does not contract in the frame of the clock B)
The two uniform linear motions both occur (even if we can "hide" one of the two motions), and each of the two uniform linear motions determines a different temporal pair (t_A; t_B)
" so the paradox remains unsolvable, because the whole theory is nonsense. " : I do not agree.
If we consider the motion of the spaceship in the frame of the Earth then the astronaut twin is younger.
The spaceship reaches the star and flies back to Earth (GAME OVER, the astronaut twin is younger)
But when you consider the journey in the frame of the spaceship, then earth twin is younger. (and this is another trip, different from the previous trip)