The problem with the Lines of Simultaneity analysis is that neither Alice nor Bob can simultaneously observe each other''s clocks when they are separated by a distance of three light years. At best, Alice can send a signal to Bob at the moment she reaches the distant star, but it will take three years for that message to reach Bob. By the time Bob receives Alice's message, eight years will have elapsed in his frame of reference. He can then calculate that Alice sent the message at the point when Bob's clock read five elapsed years, while the message indicates that Alice's clock read four years. When Alice finally returns and once again acquires Bob's frame of reference, her clock will read eight elapsed years, while Bob's will read ten years. Simple, no paradox. Using the Lines of Simlutaneity analysis, you would calculate that at the point Alice reached the distant star, her clock read four years, while Bob's read about three elapsed years (in Alice's frame of reference). But this is purely hypothetical, since in reality, they don't share the same inertial frame of reference and cannot simultaneously observe each other's clocks. Since Alice never actually observes Bob's clock, it's irrelevant what she would have seen had she been able to instantaneously bridge the spacetime gap between them. The only things that actually count are their clock readings at the end of Alice's journey, at which point they once again share the same inertial frame of reference.
All this explanation hangs on one delicate thread, and that's the change of the frame of reference. Okay then, how about the situation where no changing of the FOF occurs? If Alice and Bob were at a distance and had their clocks synchronized, and then one of them starts moving towards the other one - if we can so generously consider the acceleration moment negligible? Or they both start moving to meet one another and experience absolutely symmetrical accelerations? Or just make Alice stop at that planet and send to Bob the information with her clock's reading?
@silverrahul Ah, I remember you, Rahul! We once had a friendly if somewhat heated conversation about relativity. But I'm not going to dive in it again: now I know exactly what SR is, and how LT was obtained, and what it all means -- and it's 100% bogus. To give you a hint (I don't want to go into detail): look at Par. 3 of Einstein's 1905 paper. It's all there!
@silverrahul Dear Rahul, I don't know how you can't remember a week-long conversation here on RUclips comment section. I said then that although I don't agree with you, I'd rather hang out with you than with someone whose views I share but who are too headstrong to listen. As for SR, I was arguing with you then, but now I'm not arguing, I'm just telling you, because I simply know. You may pay heed or stick to what's yours, I don't mind. If you care to listen to what I've got to say, I will easily explain to you and you will see it all for yourself. Stay well.
In the first case Alice and Bob synchronize their clocks when they are at rest with respect to each other, so they are in the same frame of reference. If then Alice starts to move towards Bob as she accelerates she is shifting her frame of reference, just like in the video. So the same line of reasoning applies.
I think the problem is that if you "start moving" you change fof. We need to consider acceleration an absolute: the observer accelerating "feels a force". When acceleration happens, as explained in the video, all other clocks run faster during the acceleration. The further away they are, the faster they run. This compensates the slowing down due to movement and as A and B meet, their clocks will read the same time (in the case they are stationary and both accelerate towards each other)
I've binged on these videos, and it appears no one solves this paradox. This is all still making Bob the "stationary" clock. That violates the basic principle of SR. Yikes!
Yes! Like in Textbooks and videos! Scandalous: this video is a JUnk. There is a perfect symmetry in both situations (one switches or exchanges only the position of an apostrophe in equation(s) for the time and position parameter)and isometry in graphical presentation -as assumed according to the term "Relativity" Theory! Already M.Sachs tried to correct it in 1972 in Physics Today but he also made a little mistake in treating the atomic clock as a macro clock and was therefore confused, but atomic clocks simply work according to the Doppler Relativity effect (rather the gravitation potential effect of the Earth mass). The misuse of the Minkowskian diagram is fooling students
A force is required to change velocity. Bob - the stationary twin - experiences no such force. Alice does. And both observers agree that Alice is really the one who changes velocity. She's the one who suffers a severe case of whiplash at the point of the u-turn. There is no symmetry.
@@user-lb8qx8yl8k In my comment in the general thread to this video I wrote: "All this explanation hangs on one delicate thread, and that's the change of the frame of reference. Okay then, how about the situation where no changing of the FOR occurs? If Alice and Bob were at a distance and had their clocks synchronized, and then one of them starts moving towards the other one - if we can so generously consider the acceleration moment negligible? Or they both start moving to meet one another and experience absolutely symmetrical accelerations? Or just make Alice stop at that planet and send to Bob the information with her clock's reading?" You may join the discussion there.
? cont. of BS; he wrongly on a diagram presents the affair from Alice at rest,i.e her time axis is straight up (like the former t (for B), now t (for A) is up because her position is at x=0 all the time! The expression as if "Alice changes her reference frame is" is senseless: she all the time in the same reference frame, but now from her perspective, Bob is "turning"- don't you the case with the Earth and Sun, both moving or at rest depending from which reference system! (Ps. Historically, A.Einstein reconciled physically (formally it was obvious for Leibnitz and Copernicus) the opponents in Galileo/Copernicus Trial in 17th cent.
We proved that if you travel with a constant acceleration of 2 g's then you can traverse the known universe in about 45 years or less. Simple algebra will give you the answer. Turnarounds, accelerations, deceleration, etc., have absolutely nothing to do with the phenomena of time dilation. Only your average velocity counts. Time dilation occurs only because you are traveling near the speed of light for some duration of time. As you travel through your local star matrix (one billion lightyears in diameter more or less) your mass will increase (very easy to calculate) towards infinity. Now you are in trouble! The intergalactic police (men in black?) frown on those who drag their local star matrix behind them.
At some point in the past you accelerated to near light speed, thereby making yourself exceptional to the bulk of the visible material universe, which is approximately at rest relative to the speed of light.
The Twin Paradox just showcases how stupid Einstein really was. Whats even worse, the entire scientific community bought into his flat earth fantasy universe. Gravity is the force that keeps objects from floating away on a stationary plane. Do people really think that the earth is flat? Why are they still using physics developed for a stationary plane? Relativity? F=ma depicts an unbounded, infinite universe. Motion is relative. E=mc. The universe is bounded by (c). Motion is absolute. Relativity only comes in to play when dealing with how fast two frames are accelerating towards (c). Synchronized clocks? They measure relative motion in space. The one with the slower running clock is measuring more motion/distance in space. There is no special relativity because motion is absolute. The laws of physics apply equally in all frames of reference. Including the separate frames of space and time. Whether vertical or horizontal or a rotating disc. Whether 2d, 3d or 1d in the case of a photon. Its mass is its wavelength. E=mc. Acceleration defines/creates mass. Not the other way around. Mass attraction was disproved in the 1590s. And yet, the scientific community is still using stationary plane physics. Why?
@Just a guy who is an idiot the only way this works is if Alice and Bob are robots. Acceleration and deceleration cancel each other out. The difference between the two clocks gets added to the stationary clock to which is the age of the twin in motion.
This is just horrible teaching(no offense). And its the reason most of us still cant undersand a pretty simple thing. First, start with the general question-what happens to the two clocks moving around with whatever speed, accelerations and directions, do they tick at the same rate. The answer is no. Here is the question "why" one clock is faster than the other. Next, take a particular example with two rockets but not forget that trajectory does not matter. Whatever trajectory it is, the general question is the same. There is nothing special in move away straight line and turn around. Then do the math. Anyway, "instance of turning around" is just bs.
Finally, I got this conundrum resolved.
Thanks so much or helping students understand this concept.
The problem with the Lines of Simultaneity analysis is that neither Alice nor Bob can simultaneously observe each other''s clocks when they are separated by a distance of three light years. At best, Alice can send a signal to Bob at the moment she reaches the distant star, but it will take three years for that message to reach Bob. By the time Bob receives Alice's message, eight years will have elapsed in his frame of reference. He can then calculate that Alice sent the message at the point when Bob's clock read five elapsed years, while the message indicates that Alice's clock read four years. When Alice finally returns and once again acquires Bob's frame of reference, her clock will read eight elapsed years, while Bob's will read ten years. Simple, no paradox.
Using the Lines of Simlutaneity analysis, you would calculate that at the point Alice reached the distant star, her clock read four years, while Bob's read about three elapsed years (in Alice's frame of reference). But this is purely hypothetical, since in reality, they don't share the same inertial frame of reference and cannot simultaneously observe each other's clocks. Since Alice never actually observes Bob's clock, it's irrelevant what she would have seen had she been able to instantaneously bridge the spacetime gap between them. The only things that actually count are their clock readings at the end of Alice's journey, at which point they once again share the same inertial frame of reference.
thanks a lot sir..and thank you to whoever posted this
All this explanation hangs on one delicate thread, and that's the change of the frame of reference. Okay then, how about the situation where no changing of the FOF occurs? If Alice and Bob were at a distance and had their clocks synchronized, and then one of them starts moving towards the other one - if we can so generously consider the acceleration moment negligible? Or they both start moving to meet one another and experience absolutely symmetrical accelerations? Or just make Alice stop at that planet and send to Bob the information with her clock's reading?
@silverrahul Ah, I remember you, Rahul! We once had a friendly if somewhat heated conversation about relativity.
But I'm not going to dive in it again: now I know exactly what SR is, and how LT was obtained, and what it all means -- and it's 100% bogus. To give you a hint (I don't want to go into detail): look at Par. 3 of Einstein's 1905 paper. It's all there!
@silverrahul Dear Rahul, I don't know how you can't remember a week-long conversation here on RUclips comment section. I said then that although I don't agree with you, I'd rather hang out with you than with someone whose views I share but who are too headstrong to listen.
As for SR, I was arguing with you then, but now I'm not arguing, I'm just telling you, because I simply know. You may pay heed or stick to what's yours, I don't mind. If you care to listen to what I've got to say, I will easily explain to you and you will see it all for yourself.
Stay well.
In the first case Alice and Bob synchronize their clocks when they are at rest with respect to each other, so they are in the same frame of reference. If then Alice starts to move towards Bob as she accelerates she is shifting her frame of reference, just like in the video. So the same line of reasoning applies.
@@jeromemalenfant6622 the real clock paradox isn't about that at all
I think the problem is that if you "start moving" you change fof.
We need to consider acceleration an absolute: the observer accelerating "feels a force".
When acceleration happens, as explained in the video, all other clocks run faster during the acceleration. The further away they are, the faster they run. This compensates the slowing down due to movement and as A and B meet, their clocks will read the same time (in the case they are stationary and both accelerate towards each other)
Who is this professor?
I've binged on these videos, and it appears no one solves this paradox. This is all still making Bob the "stationary" clock. That violates the basic principle of SR. Yikes!
Yes! Like in Textbooks and videos! Scandalous: this video is a JUnk. There is a perfect symmetry in both situations (one switches or exchanges only the position of an apostrophe in equation(s) for the time and position parameter)and isometry in graphical presentation -as assumed according to the term "Relativity" Theory! Already M.Sachs tried to correct it in 1972 in Physics Today but he also made a little mistake in treating the atomic clock as a macro clock and was therefore confused, but atomic clocks simply work according to the Doppler Relativity effect (rather the gravitation potential effect of the Earth mass). The misuse of the Minkowskian diagram is fooling students
If you think it's an incorrect explanation, where can I find a correct explanation?
@@vaishnavi2608 The truth is, there's no correct explanation.
A force is required to change velocity. Bob - the stationary twin - experiences no such force. Alice does. And both observers agree that Alice is really the one who changes velocity. She's the one who suffers a severe case of whiplash at the point of the u-turn. There is no symmetry.
@@user-lb8qx8yl8k In my comment in the general thread to this video I wrote:
"All this explanation hangs on one delicate thread, and that's the change of the frame of reference. Okay then, how about the situation where no changing of the FOR occurs? If Alice and Bob were at a distance and had their clocks synchronized, and then one of them starts moving towards the other one - if we can so generously consider the acceleration moment negligible? Or they both start moving to meet one another and experience absolutely symmetrical accelerations? Or just make Alice stop at that planet and send to Bob the information with her clock's reading?"
You may join the discussion there.
? cont. of BS; he wrongly on a diagram presents the affair from Alice at rest,i.e her time axis is straight up (like the former t (for B), now t (for A) is up because her position is at x=0 all the time! The expression as if "Alice changes her reference frame is" is senseless: she all the time in the same reference frame, but now from her perspective, Bob is "turning"- don't you the case with the Earth and Sun, both moving or at rest depending from which reference system! (Ps. Historically, A.Einstein reconciled physically (formally it was obvious for Leibnitz and Copernicus) the opponents in Galileo/Copernicus Trial in 17th cent.
We proved that if you travel with a constant acceleration of 2 g's then you can traverse the known universe in about 45 years or less. Simple algebra will give you the answer. Turnarounds, accelerations, deceleration, etc., have absolutely nothing to do with the phenomena of time dilation. Only your average velocity counts. Time dilation occurs only because you are traveling near the speed of light for some duration of time. As you travel through your local star matrix (one billion lightyears in diameter more or less) your mass will increase (very easy to calculate) towards infinity. Now you are in trouble! The intergalactic police (men in black?) frown on those who drag their local star matrix behind them.
At some point in the past you accelerated to near light speed, thereby making yourself exceptional to the bulk of the visible material universe, which is approximately at rest relative to the speed of light.
Boss.
The Twin Paradox just showcases how stupid Einstein really was.
Whats even worse, the entire scientific community bought into his flat earth fantasy universe.
Gravity is the force that keeps objects from floating away on a stationary plane.
Do people really think that the earth is flat? Why are they still using physics developed for a stationary plane?
Relativity?
F=ma depicts an unbounded, infinite universe. Motion is relative.
E=mc. The universe is bounded by (c). Motion is absolute.
Relativity only comes in to play when dealing with how fast two frames are accelerating towards (c). Synchronized clocks? They measure relative motion in space. The one with the slower running clock is measuring more motion/distance in space.
There is no special relativity because motion is absolute. The laws of physics apply equally in all frames of reference. Including the separate frames of space and time. Whether vertical or horizontal or a rotating disc. Whether 2d, 3d or 1d in the case of a photon. Its mass is its wavelength.
E=mc. Acceleration defines/creates mass. Not the other way around.
Mass attraction was disproved in the 1590s. And yet, the scientific community is still using stationary plane physics. Why?
Completely wrong. Sorry to see even a Stanford professor not understand relativity
@Just a guy who is an idiot the only way this works is if Alice and Bob are robots. Acceleration and deceleration cancel each other out. The difference between the two clocks gets added to the stationary clock to which is the age of the twin in motion.
This is just horrible teaching(no offense). And its the reason most of us still cant undersand a pretty simple thing.
First, start with the general question-what happens to the two clocks moving around with whatever speed, accelerations and directions, do they tick at the same rate. The answer is no. Here is the question "why" one clock is faster than the other.
Next, take a particular example with two rockets but not forget that trajectory does not matter. Whatever trajectory it is, the general question is the same. There is nothing special in move away straight line and turn around.
Then do the math.
Anyway, "instance of turning around" is just bs.