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@shadesmarerik4112
3 жыл бұрын
hey, i know u wanted to leave out insignificant information, to focus on the most important parts, but to make this example more realistic: u could let the space ship accelerate with near g , so the passenger can actually survive the flight. Then the accelerations (both away from earth and back to earth) up to near c relative to the earth frame would be taking some years. That wouldnt change much in the physics, especially not with the time dilation.
@EugeneKhutoryansky
2 жыл бұрын
Gravitational time dilation is not just a function of the strength of the gravity. It is also a function of the distance between the two clocks, along the direction of the gravitational field. When Adam fires his rockets to turn around, there is a very large distance between his clock and Sarah's clock, hence the effect of gravitational time dilation (from Adam's point of view) due to the external gravitational field is very significant.
@EugeneKhutoryansky
2 жыл бұрын
The Earth's gravitational field is negligible far away from the Earth. By contrast, the external gravitational field which only Adam thinks exists is present throughout the entire universe. If "h" is the distance from the Earth, and g(h) is the strength of the gravitational field, the time dilation between two clocks is the integral (from 0 to h) of g(h)dh.
@EugeneKhutoryansky
2 жыл бұрын
I am simply explaining what Einstein's General Theory of Relativity says about this. You are welcome to disagree with his theory.
@stewiesaidthat
2 жыл бұрын
@Physics Videos by Eugene Khutoryansky Adam sees Sarah's clock speed slow down because of the speed of light. It takes longer and longer to receive the information. Think of it as a slinky. When compressed, on object moves from end to end in a short amount of time. As it is being stretched out, it is taking longer to move from end to end. Has time really slowed down for Adam?
@EugeneKhutoryansky
9 жыл бұрын
Everyone, if you liked this video, you can help more people find it in their search engine by clicking the like button and writing a comment. Also, if you haven't already seen it, two days ago I uploaded a video on gravity's effect on the flow of time. Thanks.
@EugeneKhutoryansky
9 жыл бұрын
Everyone, although I briefly covered the Twin Paradox in my main video on Relativity, the Twin Paradox is the topic that I keep receiving by far the most number of questions on. This is why I felt I needed to do this separate video to address this issue in much more detail.
@EugeneKhutoryansky
9 жыл бұрын
Lots more videos are coming very soon.
@ariav6582
9 жыл бұрын
***** Thank you! That's nice to hear.
@whoatemyhummus
9 жыл бұрын
Eugene Khutoryansky Hi Eugene. If Adam could detect Gravitons while accelerating towards earth could he be able to tell if it's him moving or not?
@EugeneKhutoryansky
9 жыл бұрын
whoatemyhummus Adam would never be able to tell if he is moving. This is because it is entirely consistent with the laws of physics to have a uniform gravitational field throughout the entire universe without an object with mass to create it. The existence of objects with mass only dictates how the gravitational field varies from one point in space to another.
@saragct1
9 жыл бұрын
This is the only best explanation of twin paradox that I have ever read. This topic had always troubled me but not anymore. Thank you!
@EugeneKhutoryansky
9 жыл бұрын
+Saran Paramanantham, I am glad that you liked my video that much. Thanks.
@kondrahtiz7370
2 жыл бұрын
You are arguingby acceleration alone to explan the difference who is staynh younger. But You firgot, thta there is a solution without any acceleration phases by using 2 ships. Also- main part of the trip can be passed without accelerazion. The lenhth jf thta phase is independent of the acceleration rate. This is surely most wrong explain of twin paradox.
@paulomanuelsendimairespere3901
2 жыл бұрын
As a teacher, I realized that good explanations are almost always good because they are fancy. People will understand the twin paradox when you say the values of the following problem (having or not similar results). Until then, you are running away from the main point. Imagine twin A on Earth. Earth and the Star are going left with v/2. Imagine twin B in a spaceship to the right with v/2. When twin A calculates twin B to reach the Star, he reverses (and the Earth and the Star go together with him.) When twin B sees reaching the Star, he reverses too. Twin B stops a clock just after leaving the Earth, another just before reaching the Star, another just after leaving the Star, and another just before reaching the Earth. I want to know the values of those stopped clocks when they meet.
@vinnv226
9 жыл бұрын
This is shaping up to be one of my favorite channels. A love seeing new videos of yours in my feed. Great video, as always.
@EugeneKhutoryansky
9 жыл бұрын
vinnv226 Thanks. I am glad to hear that this is one of your favorite channels, and I am glad that you liked this video. Lots more videos are coming very soon.
@mikegale9757
4 жыл бұрын
No need to invoke GR to break the symmetry. The older twin sees more redshifted light from the younger one. If you can use Matlab or Octave, try this: function ageDiff = TwinParadox(v2, v1=0, vo=0) % SYNOPSIS: Plot worldlines and time ticks for the Twin Paradox scenario % v2 is velocity of the 2nd twin in the CoM frame % v1 is velocity of the 1st twin in the CoM frame % vo is the velocity of the observer in the CoM frame v = [vo v1 v2]; worldline{1} = zigzag(0,v(1)); [ worldline{2} age1 red1 white1 blue1] = zigzag(v(2),v(1)); [ worldline{3} age2 red2 white2 blue2] = zigzag(v(3),v(1)); % Minkowski grid lines xm2 = linspace(-1,1,201); tm2 = []; for i=0:11 tm2 = [tm2; sqrt((i/10)^2+xm2.*xm2)]; endfor xm3 = tm2(:,101:201); tm3 = xm2(101:201); xm1 = -xm3; tm1 = tm3; % Lines of sight v(1) = -v(1); for i=2:3 v(i) = (v(i)+v(1))/(1+v(i)*v(1)); endfor los = {}; for i=1:3 los{i} = [[0 0]; [sign(v(i)) abs(v(i))]]; endfor % Plot results figure, hold on, grid on ageDiff = age2 - age1; title (['Twin Paradox (\DeltaT = ',num2str(ageDiff), ')']) xlabel ('Space') ylabel ('Time') xlim([-1 1]) ylim([0 1.5]) color = 'kmg'; names = {'CoM'; 'Twin #1'; 'Twin #2'}; for i=1:3 plot(worldline{i}(:,2), worldline{i}(:,1), [ color(i) ';' names{i} ' (v = ' num2str(v(i)) ');'], 'linewidth', 2); endfor for i=1:11 plot(xm1(i,:),tm1,'k-.') plot(xm2,tm2(i,:),'k-.') plot(xm3(i,:),tm3,'k-.') endfor for i=1:length(red1) plot(red1{i}(:,2), red1{i}(:,1),'r') endfor for i=1:length(red2) plot(red2{i}(:,2), red2{i}(:,1),'r') endfor for i=1:length(blue1) plot(blue1{i}(:,2), blue1{i}(:,1),'b') endfor for i=1:length(blue2) plot(blue2{i}(:,2), blue2{i}(:,1),'b') endfor for i=1:3 data = los{i}; plot(data(:,1), data(:,2), color(i), 'linewidth', 2); endfor plot(white1(:,2), white1(:,1),'k') plot(white2(:,2), white2(:,1),'k') endfunction function [ worldline age red white blue] = zigzag(v,vo) g = 1 / sqrt(1 - v^2); t = g * [0:0.1:1]; x = v * t; secondleg = find(t > 0.5); x(secondleg) = v * (1 - t(secondleg)); roundtrip = find(sign(v) * x >= 0); ticks = [t(roundtrip)' x(roundtrip)']; worldline = [[0 0]; [0.5 v * 0.5]; [1 0]]; firstleg = find(ticks(:,1) 0.5); blue = {}; for i=1:length(secondleg); j = secondleg(i); blue{i} = [[ticks(j,1) ticks(j,2)]; [ticks(j,1) + abs(ticks(j,2)) 0]]; blue{i} = boost(blue{i}, vo); endfor white = [0.5, v/2]; white = [white; [0.5 + abs(v)/2, 0]]; white = boost(white, vo); age = 1 / g; worldline = boost(worldline, vo); endfunction function [result] = boost(data, v) g = 1 / sqrt(1 - v^2); t = g * (data(:,1) - v * data(:,2)); x = g * (data(:,2) - v * data(:,1)); result = cat(2, t, x); endfunction
@wills8288
5 жыл бұрын
First video I have seen on this subject which comes close to resolving the twins paradox. Acceleration and gravity are indistinguishable when it comes to the gravity effects on time. One exception, however. The distance between clocks does not matter. You could accelerate Adam into orbit around the earth, bring Adam back to earth and Sarah and Adam would also be a different age. This experiment was done with the shuttle.
@HollywoodF1
5 жыл бұрын
You're describing a third case where Adam is still in the gravity well, just not as deep as Sarah. "Orbit" means your path is curved by gravity because you are traveling perpendicular to a radial field. In the video, Adam was traveling parallel to the field.
@Matt-pq4tq
3 жыл бұрын
They would be slightly off due to the earths gravity. But what you are missing is that its impossible to accelerate to relativistic speeds in an orbit very close to earth. Due to orbital dynamics, you would move to a much further orbit. They only way to orbit that quickly would be if the earth had extremely strong gravity. Which would then be the source of the dilation from Adam's perspective. The shuttle does not experience any measurable time dilation due to its speed. All of the dilation is due to the difference in gravity at the surface and in orbit. The distance between the clocks does matter, because gravity weakens with the distance. If we think of Adam as the source of the hypothetical gravitational field, in order for the Earth to accelerate towards him at 1g from FOUR LIGHT YEARS away, this field would have to be EXTREMELY strong. And since he is at the source he would experience time MUCH more slowly than Earth would. Kind of like being near the event horizon of a black hole and seeing the rest of the universe moving extremely quickly around you. Meanwhile when he is right next to Earth, for Earth to accelerate towards him at 1g would take a gravitational field many times weaker. Similar in strength to Earth's gravitational field.
@marcossidoruk8033
2 жыл бұрын
You are totally confused. The source of your confusion seems to be the presence of the earth in the animation, notice that the effects of the earths gravity are not taken in account in the video, you can't put someone to orbit under this assumptions, what you are describing is a totally different problem. That being said, the distance totally matters, do the math.
@TinaGong819
9 жыл бұрын
I love your videos! Also, the music includes some of my classical favorites :)
@bartkwezelstaart9306
9 жыл бұрын
1812 Overture. A great physics youtuber and a great taste of music... Is this going to get any better?
@EugeneKhutoryansky
9 жыл бұрын
Bart Kwezelstaart Thanks for the compliment.
@Neme112
8 жыл бұрын
Adam shouldn't leave Sarah :(
@buzzwerd8093
7 жыл бұрын
His sister. He went to find another woman.
@comic4relief
6 жыл бұрын
Neme Dinner and a movie with Sarah :)
@nateshrager512
6 жыл бұрын
Come back adam! Before it is too late!
@zes7215
5 жыл бұрын
wrr, doens't matter
@jexk2985
4 жыл бұрын
'xD
@hamidghorbanbeigi2857
8 жыл бұрын
Thank you! I had this question in my mind for so long and you explained it in such an elegant way
@EugeneKhutoryansky
8 жыл бұрын
+Hamid Ghorbanbeigi, Glad I was able to help. Thanks.
@SamuelWesley_samwesprem
8 жыл бұрын
I have a sincere question... What if Adam's space-ship, say, hit a wall, and exhibited a perfectly elastic collision... Wouldn't the acceleration you're talking about in this video be for an infinitesimally small time? How would we explain twin paradox in this case? Thank you!
@thomasdahl4169
2 жыл бұрын
@@SamuelWesley_samwesprem kzitem.info/news/bejne/knuE0YRmoWqfdJw I know its a little late, but anyhow ... In Eugene's 'Gravity's effect on the flow of time in General Relativity', notice what the narrator tells us: 9:00: "Suppose we are in a region of space where the strength of the gravitational field is the same everywhere" 9:15: "Clocks that are far apart along the direction of the gravitational field will run at different speeds" 9:28: "The difference in the rates at which the two clocks run increases as we increase the distance between the two clocks along the direction of the gravitational field" 9:58: "The difference in the rates atwhich the two clocks run also increases if we increase the strength of the gravitational field" Therefore, what's essential here is two things: a) The strength of the gravitational field, say g, and b) The distance between Alice's and Bob's clocks, say D In this way we can conclude: Difference between the rates at which the clocks tick = K x g x D (for some constant K) So I think what you're asking is what happens if the turnaround is nearly infinitesimal small ... Well, then the corresponding force (felt by Bob) will make the gravitational field strength even more strong, because what counts is the amount K x g x D. In it, there's no time-dependence ...
@mau_lopez
7 жыл бұрын
Absolutely great video ! (as many many others from Eugene). After years of looking for a clear, comprehensive and simple explanation of the Twins Paradox, finally, for me this has been the one! Thanks a lot Eugene !
@EugeneKhutoryansky
7 жыл бұрын
Thanks.
@NeedsEvidence
4 жыл бұрын
Nice video. Note that, since special relativity is a self-contained theory, it's also possible to resolve the twin paradox without reference to general relativity by invoking *relativity of simultaneity* in the context of the frame change experienced by the twin at the return point at large distance from earth.
@trsomas
2 жыл бұрын
You are right. This is what I showed in a video I posted. kzitem.info/news/bejne/zpB434qDiqKVdH4
@MrCmon113
Жыл бұрын
The frame-change depends on who experiences acceleration. If you've established proper acceleration, the symmetry is already broken and there's already no more paradox before you even start calculating.
@Alex-02
3 жыл бұрын
Great video, but I'm still confused about what is different for the two people. From Adam's point of view (when he accelerates) he experiences a gravitational field for the entire universe (which cancels out with his engine thrust) which results in Sarahs clock moving really fast compared to his clock. If this is correct couldn't you also say that from Sarah's point of view a gravitational field is applied on Adam's ship which makes his clock move really fast as well...
@EugeneKhutoryansky
3 жыл бұрын
Sarah does not believe this gravitational field exists, because this is what is necessary for her to believe that she is standing still.
@vincemarenger7122
2 жыл бұрын
FINALLY. For EVERY twin paradox explanation, I was always left with the same freaking question : “Well, from the traveler's point of view, he is standing still and the earth is the one accelerating mid journey. So how does he know he’s the one accelerating ?” NOW I understand ! THANK YOU 😊
@EugeneKhutoryansky
2 жыл бұрын
Thanks.
@jianweisatasata1195
8 жыл бұрын
Why isn't it such that Adam is actually stationary and the Earth is the one accelerating back to Adam and hence won't the aging of Sarah being observed by Adam, also be observed on Adam by Sarah? It seems you sort of establish the fact that it is Adam that is moving and accelerating and not Sarah. But isn't it relative? Like if Sarah is on a rocket ship instead of the Earth?
@meobliganaponerunnom
8 жыл бұрын
+Jian Wei SataSata I'm not sure about the answer. But remember that for the Earth's perspective only Adam is moving, from Adam's perspective the whole Universe is moving, not only the Earth. So there might be a difference, I guess.
@septitais
8 жыл бұрын
+Jian Wei SataSata He does't just establish that Adam is moving and accelerating, he also establishes that Adam is not moving and accelerating- it depends on the perspective. Why do you think that Adam was the one moving? Maybe there really was a gravitational field present, and in order to stay stationary, he fired his thrusters at the very moment when the whole universe started accelerating towards him. Since he was closest to the gravitational field, and Sarah was the furthest, it makes sense that he would see Sarah age faster. From Sarah's point of view though, Adam was not standing still, and was not in a gravitational field. From Sarah's point of view Adam simply accelerated towards her. Note that acceleration itself has nothing to do with Sarah aging faster, but the fact that from Adams point of view he was in a gravitational field, but from Sarah's point of view he was simply accelerating until he reached near the speed of light, with no gravitational field present for Sarah to make her age slower than Adam.
@jianweisatasata1195
8 жыл бұрын
Ray Thank you for clarifying, that was very helpful.
@spirit-teacher
8 жыл бұрын
Eugene, you are the best teacher of theoretical physics in KZitem. Hands down.
@EugeneKhutoryansky
8 жыл бұрын
+The Tiger Koley, thanks for the compliment.
@wenniezhao9835
8 жыл бұрын
The twin paradox is seemly solved by considering the turning-around trip. However, let us pause for a second. The way to solve the twin paradox doesn't solve the time dilation paradox itself at all. Let's use two atomic clocks, one on the earth and the other one on the spaceship traveling at half speed of light. From my perspective, the clock on the spaceship runs slowly, r = 1.15. So at the noon of the first day on spaceship, the clock on spaceship shows the time 12:00 and the one on the earth shows the time 13:48. Now from the astronauts’ perspective, the clock on the earth runs slowly with the same value of time dilation. So when the clock on spaceship shows the time 12:00, the one on earth shows the time 10:26. So how can a clock show two different times at the same spaceship time? To solve this time dilation paradox, I think we have to use Einstein's relativity of simultaneity. By using the spaceship space-time frame, the two events, the clock on the spaceship showing12:00 and the clock on earth showing 10:26, happened at the same time. However, by using the earth space-time frame, these two events no long happened at the same time. Because of the spaceship is travelling away from the earth, so the clock on earth showing 10:26 happened earlier. So when the clock on space shows 12:00, the clock on earth shows a time later than 10:26, that is 13:48. Likewise for the two events happened at the time by using the earth space-time frame, the clock on the space showing 12:00 and the clock on earth showing 13:48, also no long happened at the same time by using the spaceship space-time frame. Since the spaceship is travelling away from the earth, the clock on earth showing 13:48 happened later. So when the clock on spaceship shows12:00, the clock on earth shows the time earlier than 13:48, that is 10:26. So now the time dilation paradox is solved :)
@mireazma
6 жыл бұрын
Very well put but this has nothing to do whatsoever with the twin paradox.
@RobertsMrtn
5 жыл бұрын
It does because it explains how two clocks can not be going slower than each other.
@javierpicazo2107
5 жыл бұрын
In fact, theres no paradox in that, just because no one could ever check both clocks at the same time.
@alezionedimatematicaefisic7
4 жыл бұрын
Eugene, thanks for these videos. I use Matlab for simulations and I decided to add your videos in my playlist of Relativity because your videos are so beautiful. With my students this summer i want to translate in italian these videos!
@EugeneKhutoryansky
4 жыл бұрын
Thanks. I am glad you like my videos. And thanks for wanting to add Italian subtitles. You can do this by clicking on the link in my message at the top of this comment section. Thanks!!
@EugeneKhutoryansky
5 жыл бұрын
You can help translate this video by adding subtitles in other languages. To add a translation, click on the following link: kzitem.info_video?v=bjHLboK2M1g&ref=share You will then be able to add translations for all the subtitles. You will also be able to provide a translation for the title of the video. Please remember to hit the submit button for both the title and for the subtitles, as they are submitted separately. Details about adding translations is available at support.google.com/youtube/answer/6054623?hl=en Thanks.
@blacktigershearthstoneadve6905
4 жыл бұрын
So, let me summarime it. Suppose two ship fly in different directions, then turn back at the "same" time or not, does not matter (it is relative anyway). So whoever's ship applied less force with it's engines will be older when they meet.
@starwarsjk99
9 жыл бұрын
1 observer observes special relativity, while the other observes general relativity. That sounds fun xD
@alessandroboer6099
2 жыл бұрын
This is simply outstanding. I have never seen an explanation so clear, simple and complete.
@EugeneKhutoryansky
2 жыл бұрын
Thanks for the compliment. I am glad you liked my explanation.
@tonraz4441
9 жыл бұрын
Omg, I still don't understand why Adam would think it's gravity and not his rockets which are moving the ship. I know, I know, in theory it's because "he can't tell where it's him or the rest of the world which is moving", but why then wouldn't he think the same on the way from the Earth?
@isaacclark9825
8 жыл бұрын
+Vladislav Koripenko Great question. It is also possible to calculate a time dilation effect based on Adam assuming he is accelerating. But in this case, the author has chosen to provide a General Relativity explanation by using the equivalence principle which equates acceleration to gravitational fields. Although General Relativity is harder to understand than Special Relativity, resolving the twin paradox using the equivalence principle may actually be a little easier to understand than a Special Relativity explanation.
@zakariamusse1117
8 жыл бұрын
+Vladislav Koripenko Adam thinks that he is standing still and the earth is accelerating towards him. This happens when he turns around the ship and fires the rockets. At this time Adam will think that there is a gravitational pull that is cancelling the rockets which means that Adam will not move but stay still. Now that there is a gravitational pull, Earth is accelerating towards the gravitational pull (Adam).
@tonraz4441
8 жыл бұрын
+The Long Lost Brother Who Has Forgotten His Name thanks! but again, why doesn't he think so on the way from the Earth? I mean, he would be moving toward another planet, Mars for example ... My question is: why wouldn't he think the same on the way FROM the Earth ...
@zakariamusse1117
8 жыл бұрын
Vladislav Koripenko It is the same when he is "leaving" Earth. When he fires the rockets, Adam will think that there is a gravitational pull that will cancel the rockets. Now this causes Adam to stand still and the Earth to move towards the gravitational pull (away from Adam). Adam will always think that he is standing still and it is the rest of the universe that is moving.
@lasinart5202
8 жыл бұрын
if we are moving in uniform velocity we cant explain who is moving... but if we accelerate.. we can feel the acceleration... so then its worthless to say the otherone is accelerating...and we are still..
@mirkozenkert7716
7 жыл бұрын
I think the video focused too much on gravity and is missing an important factor which is the light. When Adam and Sarah each hold a flashlight giving each day one light impulse then the time has to slow down when they move away from each other. So the light can catch up its speed. But both will see less impulse coming in from the other side. And light is red (doppler effect). When they later approach to each other then clocks are faster to compensate the accelerated and blue light. Now each side sees more impulses coming in than sent out. Both effects don't neutralize because of the turning point. When Adam turns his ship he sees Sarahs flashlight immediately turning blue (and impulses speeding up) while Sarah will see Adams turn many years later. She sees his red signals much longer.
@cgaccount3669
7 жыл бұрын
Adam isn't looking at Sarah's clock... unless he's gay
@md.alaminpatwary8268
6 жыл бұрын
oh...! yea!
@HollywoodF1
5 жыл бұрын
He's gay. Now focus.
@RobertsMrtn
5 жыл бұрын
This is the best video I have seen on the clock paradox. You have to include general relativity and not just stay with special as other explanations have tried to do.
@EugeneKhutoryansky
5 жыл бұрын
Thanks for the compliment about my video. Yes, the explanations which just stick to Special Relativity miss the whole point of what this paradox is supposed to be about.
@corwin-7365
5 жыл бұрын
You can explain the paradox in Special Relativity if you are careful to show why you are applying a specific Lorentz Boost... but they never do. :-)
@moiquiregardevideo
6 жыл бұрын
Nice attempt to explain the paradox. Here is a simpler explanation: When the Sarah is flying away from Earth at 95% the speed of light, the radio communication is impaired because of a Doppler shift. Both sister need to tune their 1 GHz frequency to 50 MHz, which electrical engineers call carrier frequency. The AM or FM modulated signal, a slower wave which modify slightly the carrier frequency amplitude or frequency is equally slower. All embedded binary code are also streaming 20 times slower. The decoded voice of Sarah is deeper, like playing a vinyl disc or magnetic cassette in slow motion and the video are almost still pictures. A year later, Sarah turn around and come back toward Earth at 95% the speed of light, the following happen: That day, one year after their separation, Alice on Earth keep receiving the slow stream of radio at 50 MHz. She just received the video from Sarah telling how boring it is now, after 2 weeks of travel. She think her sister is crazy, talking about 2 weeks when in reality she his gone for a year and she is supposed to turn around now. Sarah also receive old news from her sister on Earth. She see the video telling her that she already miss her after two weeks of separation. However, the radio is fucked up because Sarah at the switch frequency from 50 MHz (for the 1 GHz carrier frequency) to 20 GHz. Also, the voice sound like chip monks and the videos are 20 times too fast. As the time pass between 12 month and 24 month of the total duration, the video that Sarah receive from Alice catch-up with the real time. Everything synchronize just right so that the last day of this 2 years voyage, Sarah can see a video of her sister recorded only 20 days earlier. For Alice, the second year events are a little more complicated to explain. She keep receiving outdated video on the radio station tuned at 50 MHz. Suddenly, 2 weeks before the end of the 2 years trip, the frequency jump from 50 MHz to 20 GHz. The video from Sarah describe that she now prepare to turn around. Alice think that she is crazy to announce that after 23.5 months. Then, during these last 2 weeks, Alice receive all the videos from Sarah describing that entire year where she is flying back to Earth. Finally, both sisters re-unite and they both aged by exactly 2 years. End of paradox.
@TheMyrkiriad
5 жыл бұрын
Christian Gingras this is the best explanation I have read so far. Thank you.
@MultiMind100
9 жыл бұрын
hi eugene,what r u doing is extra ordinary,i have searched all the you tube in order to understand the conceptual meaning of entropy,e.m waves ,relativity so on but i could not find because no one has done this type of work like you have done...keep doing this ,it is very helpful for people like me who educate ourselves from these types of educational videos.....hats off
@EugeneKhutoryansky
9 жыл бұрын
Gaurav Sharma Thanks for that really great compliment. I am glad to hear that my videos are helping people understand the conceptual meaning of these topics in a way that is difficult to find elsewhere. Thanks.
@whoatemyhummus
9 жыл бұрын
Both Sarah and Adam were traveling through the spacetime continuum at the same speed, Adam only traveled more in the space variable and Sarah only traveled more in the time variable.
@SiddiqueSukdiki
9 жыл бұрын
+whoatemyhummus Thanks that cleared up a lot of things
@tempname8263
7 жыл бұрын
But from Adam's perspective, Sarah traveled more in space, and he traveled more in time. Not to mention, that it doesn't sound like an explanation of physics.
@andrewfrank7222
6 жыл бұрын
Since these two things are linked, i.e. time and space. When a photon is traveling through a vacuum, we measure it's speed (c). The 299792458 meters per second. That would mean the particle is not traveling through time at all, correct?
@tempname8263
6 жыл бұрын
According to relativity, photon's "time" stands still indeed.
@akh345
6 жыл бұрын
This does not explain the paradox. From Adam's perspective you can say the same thing: Sarah traveled more in the space and he traveled more in the time variable. So he should have been older. He is not. The key is acceleration/deceleration of Adam when he is far away from Earth.
@saragct1
9 жыл бұрын
But there is still some trouble left in my understanding, 1. Einstein's theory is based on one point that you can't do experiment to identify who is in velocity. However, you say that the twin in the spaceship is experiencing the gravitational field. Gravitational fields do converge to a point. But the objects in different points inside the spaceship do not converge. So experimenting inside the spaceship would reveal it is gravity or acceleration. I am assuming that the spaceship is big enough to be sensitive enough to the convergence experiment. 2. Wat about the case where the spaceship has stopped accelerating. For e.g the spaceship accelerates only for a very short period of time in the entire journey time like 1%. Once the acceleration stops then no gravitational field will be experienced in the spaceship. However the majority of the time dilation experienced by the twin in the spaceship is due to its velocity and not sure to acceleration. Having the acceleration for a short period of time, how will it account for the time dilation for the entire trip?
@EugeneKhutoryansky
9 жыл бұрын
+Saran Paramanantham, gravitational fields do not necessarily have to converge on a point. Having a uniform gravitational field throughout the entire universe is consistent with the laws of physics. Objects with mass only determine how the gravitational field varies from one point to another, but there is nothing preventing a uniform gravitational field from being present everywhere added to these variations. In reply to your other question, during the 1% of the trip when the acceleration occurs, the effect on the difference in the rates of the two clocks is so great that it more than compensates for the remaining 99% of the journey.
@saragct1
9 жыл бұрын
Don't you think you are missing something? Imagine that the spaceship accelerated to near speed of light in 3 months from an external observer's point of view in both the directions of the journey? So the acceleration happened only for a total of 6 months from extremal observer's point of view. This can't account for 4 years of time dilation. Moreover time dilation takes the velocity component and not acceleration. What would the twin in the spaceship think during the period of constant velocity of the spaceship with the earth approaching him or moving away from him?
@saragct1
9 жыл бұрын
Do you think a light photon accelerates in order for it to not experience time? Acceleration merely transports an object from one position in time dimension to another. But wat matters is that how long was the spaceship in that near speed of light velocity. Of course acceleration matters but it matters only because it comes with a velocity.
@saragct1
9 жыл бұрын
+Eugene Khutoryansky With regards to the universal gravitational field without convergence, please state how that is a possible to become practical? I agree that gravity to be almost equivalent to accelerated reference frame but there is definitely a difference between these 2, that difference is convergence. Gravity being an effect due to the spacetime distortion produced by the presence of mass/enerygy and every mass/energy should have a center for its gravity hence convergence can't be avoided. The convergence only can be reduced but not made zero. May be this minor difference is what is playing a bigger role in the mystery of velocity of stars remaining constant even if the distance increases from its center. May be I am wrong. It could be possible that General relativity is a better approximation of Newtonian Gravity but not the perfect theory of Gravity.
@saragct1
9 жыл бұрын
+Eugene Khutoryansky I would be glad to hear a response from you on my other questions.
@robertgraham1049
8 жыл бұрын
sarah is really hot...
@meobliganaponerunnom
8 жыл бұрын
+Robert Graham But she's old now.
@buzzwerd8093
7 жыл бұрын
Wilma or Betty kind of thing?
@md.alaminpatwary8268
6 жыл бұрын
hmm...
@zes7215
5 жыл бұрын
wrr
@chillboy8116
5 жыл бұрын
no she is on the groenland
@somethingness
9 жыл бұрын
This was an awesome explanation. Thank you. I'm studying physics at degree level and someone asked me about this and I couldn't figure out the resolution of the paradox. Now I know!
@EugeneKhutoryansky
9 жыл бұрын
+somethingness, thanks for the compliment, and I am glad that my video was helpful.
@zodiacfml
7 жыл бұрын
The paradox is wrong from the start because it assumes that both observes a slower clock of the other. The paradox is also misleading by staying on Earth means standing still but in reality is also accelerating in spacetime and we can replace Earth with another spaceship . Imagine an empty space with only the twins and no visible reference. Then suddenly, they went far apart in opposite directions. No one would be able to tell who left, who stayed still, or if both accelerated. It is only through the comparison of their clocks where they can tell who accelerated faster.
@alexmir1763
6 жыл бұрын
If they would have moved in constant speeds, then you are correct. But in reality, one (or both) of them would have to accelerate, which is equivalent to putting himself in a gravitational field. So there IS a difference between them: one experiences a strong gravitational field, while the other does not.
@thealleys
6 жыл бұрын
But the person on Earth, or any planet, is subject to gravity which in itself warps space time. So yes the Earth is moving but unlike the rocket, Sarah is subject to gravity.
@alexmir1763
6 жыл бұрын
The earth's gravity is not very strong. The twin paradox would work the same if Sara was floating in space, because unlike velocity, acceleration/gravity is something a person feels and can measure. If Sara and Adam would float in empty space, and then suddenly Adam would accelerate, both their measurements will show that Adam accelerated, not Sara. (The same measurements can be interpreted as if Adam was in a sudden gravity field, and Sara was not). zodiacfml wrote in his comment that we can't know which one of them accelerated, but that is not true. While we can only measure our velocity relative to someone else, we can measure our acceleration/gravity even if we are flying alone in a vacuum.
@AstralTraveler
6 жыл бұрын
I think, that there's a big flaw in some parts of SR, so it has to add GR and the acceleration, to solve this issue. Adam doesn't have to slow down during his trip to a distant star - he can for example move along a circular path and gain speed "behind" Earth, so he will move with a constant velocity all the time. We can as well exclude the planet, so there won't be no gravity involved. In such case, telling that any of twins will get older, than the other, is a direct violation of SR own rules...
@alexmir1763
6 жыл бұрын
Astral Traveler, moving in a circular path requires continuous acceleration, therefore you cannot talk about it in terms of SR alone.
@juggernaut93
8 жыл бұрын
Finally I've found a very clear explanation of the twin paradox! Great video!
@EugeneKhutoryansky
8 жыл бұрын
+Gioele Ciaparrone, thanks. I am glad you liked my explanations.
@ViciousViscount
9 жыл бұрын
I still don't get it, hopefully I'm not the only one :)
@maisonm.1151
6 жыл бұрын
SabakuSouSou87 watch more videos, this theory is somewhat confusing, remember it was made by one of the most genius human ever. i had to watch more theory of relativity, im starting to understand it.
@mariaclemenciagonzalezguti5232
8 жыл бұрын
I have already shared this fabulous input to some of my colleagues from the ELT area to use them in their English classes
@fattyz1
5 жыл бұрын
Trying to see up her skirt is relative from my perspective as the observer.
@CulusMagnus
4 жыл бұрын
:D
@MrCristie1
9 жыл бұрын
This clarified all the confusion I had. Thanks!
@EugeneKhutoryansky
9 жыл бұрын
MrCristie1 Thanks. That was what I was hoping for, as there seems to be a lot of confusion about this topic.
@Playitalready
7 жыл бұрын
What if Adam won't turn around or accelerate?
@Arkalius80
7 жыл бұрын
Well then it doesn't matter. You can't really compare two clocks unless they are either in the same location at the same time, or stationary relative to each other. So, if he flies off and never returns, neither of those requirements are true, so you can't really definitively say which one is older. It depends on your frame of reference at that point.
@Playitalready
7 жыл бұрын
Arklius what if he traveled only far enough for minimal time dilation with a neutral observer in between earth and him who can see the faces with a supertelescope...who would look older? or, what if they both had an electric bomb strapped before he left and whomever ages faster 1st dies...who's bomb would go off?
@Arkalius80
7 жыл бұрын
Well the neutral observer scenario depends on a lot of variables you haven't defined, such as his position relative to Earth and the traveler, his relative velocity, the velocity of the traveler, whether you want to know what he would observe, or what he would calculate after the fact after accounting for the travel time of light, etc. The second scenario is basically saying you have two time bombs with the same timer, one flying off into space, which one goes off first? That depends on your frame of reference. Simultaneity is not absolute in relativity. Things that are simultaneous in one frame of reference are not in another, and for some events, the relative order in time they occur in can depend on your frame of reference as well.
@jleal666
7 жыл бұрын
Please consider this scenario: 2 stationary points in space, A and B, One bomb in A, one bomb in the ship. One Bomb in B. The bombs have a start button. The bombs are identical. The bomb in A and the bomb in B are synchronized to start at the same time. The experiment starts.... the ship travels from far far away and when pass the point A (traveling at constant speed) The bomb in A, B and the bomb in the ship start the count down (one stationary observer at the same distance from A and B can tell the 3 clocks start at the same time. When the ship reaches the point B at constant speed (0.9c) the pilot take a picture of his bomb and one observer in the point B take a picture of the bomb B when the ship passes B so the 2 pictures are taken at the same time because they are in the same point B. Then the ship stops turn around and return to the point B to compare the pictures. Are the pictures showing the same time? Is one bomb near to explode more than the other? The acceleration does not affect the pictures. All the pictures were taken at constant speeds. Please explain the maths for this experiment. Ty
@Arkalius80
7 жыл бұрын
Your scenario is a little confusing, I think you may have mistyped part of it. You say that the bomb ship arrives at point B where the pilot and observer at B take a picture. You then say it turns around and returns to point B. That doesn't really make sense. Do you mean it turns around and returns to point A?
@rushunnhfernandes
3 жыл бұрын
Finally I get it!! Thanks... But, what if the universe is like the surface of a sphere so that going in one direction gets you back? In that case there would be no acceleration, right?... Or is it not a valid case because of the Minkowski metric doesn't apply?
@harambesson1098
3 жыл бұрын
The universe is hyperbolic and relatively flat actually. But in theory this is an interesting concept. The closest of a concept that you can get to this is a wormhole. I recommend Leonard susskinds lectures he explains it very clearly and simply!
@RubyCheetahCub
8 жыл бұрын
Scientists had two synchronized atomic clocks and put one in an airplane trip around the world. After the trip, the two clock were no longer synchronous. Sure the difference was negligible, but there still was a difference. I've also heard that "light speed" isn't the cosmic speed limit for matter, it's the speed of causality or how fast two things can "relay information" or interact and light just happens to go this fast.
@blake301987
9 жыл бұрын
Thanks again Eugene for another great video, its been exciting to see so many come out in such a short amount of time!
@EugeneKhutoryansky
9 жыл бұрын
blake301987 Thanks for the compliment, and I am glad you liked the video. Many more videos are coming very soon.
@nathanos23
4 жыл бұрын
We need to address this problem without involving gravity and acceleration. Assume instant acceleration so that 100%of journey is spent in constant speed. In this case it will be impossible to solve the paradox with just the two observers. They both need to be measured relative to a third reference frame, that being the universe itself. Only one of them is moving faster than the other relative to the whole universe.
@hieudang1789
8 жыл бұрын
how can it not violate the theory when you can clearly tell who is moving just by seeing if he or she aged. In the video, it said that they both agree about who is aging. Can someone explain?
@mrpotatohead161
8 жыл бұрын
+hieu dang you dont really know if when adam left earth if he has left a staionary object, or if the object is speeding through space towards a gravitaional field and that his rockets simply opposed this forced so that he sat still while the universe was pulled away. then upon returning, the gravitational field reversed and sucked everything the other way and his rockets again simply opposed the force to keep him still. the effects of time dont confirm who is moving, only their relative position in the 2 gravitational fields. The fields are only felt when accelerating. so if he accelerates to leave and is close to sarah, the effects on both of them should be close. when he turns to return to earth. they are far apart and the field is now behind adam. so his time will be effected much more than sarah's, because the effects of gravity on time have to do with the position along the field as it increases, just as gravity's forces is related to the distance between the two objects of mass. the effects on time are also increased with this field.
@se7964
4 жыл бұрын
You say a uniform gravitational field throughout "the entire universe" is entirely consistent, but I don't see how. My understanding is that the uniform gravitational field picture is only valid locally (via the equivalence principle.) What are the equations that show a uniform, source-less field for all space?
@dicksoncheung581
4 жыл бұрын
I guessed she was thinking in the non-inertial frame of reference (the person in the rocket during the acceleration). During the acceleration in the non-inertial frame of reference, the observer in the rocket sees himself as stationary while the entire universe accelerates (uniform gravitation field) in the same direction.
@offchan
9 жыл бұрын
I have questions. From the video you said, the amount by which one clock will flow faster than another will depend on how far apart the two clocks are along the direction of the gravitational field. 1) How can we tell which clock will flow faster? Is it about the direction of the field? 2) Does the strength of the field also affect the clock rate? 3) If Adam rapidly moving back and forth (like shaking at 99% speed of light) on his spaceship without going far away from Earth, how would Sarah see Adam? Who will age more?
@EugeneKhutoryansky
9 жыл бұрын
Yes, it is the direction of the gravitational field which determines which clock will flow faster. And yes, the strength of the gravitational field also determines the amount by which the two clocks will run differently. In reply to your third question, if Adam doesn't go far away from Earth, then these effects will be negligible, due to the fact that the distance between his clock and Sarah's clock is very small.
@paradoxicaluniverse
9 жыл бұрын
Eugene Khutoryansky When you say 'clock', what do you actually mean? If you mean time can you please give a definition of what time actually is?
@EugeneKhutoryansky
9 жыл бұрын
Andrew Millar No one presently knows for sure what time actually is, and for now, that remains more of a philosophical question. But, what General Relativity does it allows us to predict what the different clocks will be reading.
@jleal666
7 жыл бұрын
thanks for the video. I have a question: Suppose Adam is not alone in the ship, and his travel takes (T0) time to reach the 0.9 speed of light and then he travels 10 years (T1) at constant speed... At the exact time (T0) (when he is at constant speed. I have a stationary base in the path previously arranged for the experiment ) his first child is born in the chip, take a picture and leave it in the stationary base when he passes without stopping. In the same base I take a picture to an other child born the same day (each pict show a new born baby). Then 5 years later of his traveling at constant speed he takes a new picture of his 5 years old son and leaves it again in a new stationary base (the de-acceleration of the picture does not affect the age of the person on it... or yes?). If we compare the picture of the child in the stationary base taken at the same time that the ship passes the 2nd base at constant speed with the 2nd picture of the traveling baby... who is older? why? all the pictures occur in a time interval (T1) with everybody at constant speeds. thanks a LOT PD: I want to see the maths from both sides
@michaelzoran
3 жыл бұрын
QUESTION: What if Adam decided not to stop his ship in an environment in the middle of space that lacked gravity? What if Adam decided to stop his ship in an environment close to a planet that had a mass equal to the mass of Earth? Wouldn't this decision make it so the time of Sarah never "speeds up" from the point of view of Adam?
@mnada72
3 жыл бұрын
Amazing approach to the explanation explanation , what puzzles me is that 2 different explanations from 2 different viewpoints attribute to the same result.
@mikegale9757
5 жыл бұрын
Nice, but the problem can be reformulated without acceleration by giving Adam an initial velocity and adding a 3rd observer (Bob) with equal and opposite velocity at the turn-around point. Bob and Adam can compare clocks as they pass at the halfway point. The paradox can only be resolved if you know how each observer moves with respect to their combined centre of mass. (We are presumably talking about flat spacetime so we can ignore the Earth and the rest of the universe.) The speed of time is evidently maximal in the centre of mass reference frame. Clocks run more slowly in all other frames.
@imaginingPhysics
2 жыл бұрын
What if Adam performs the "accelerations" without any g-forces by employing gravitomagnetic effects of a rotating torus? ( Referring to your video on GEM, by rotating a mass torus in a "smoke ring manner" one can induce a gravitational field.)
@AstralTraveler
6 жыл бұрын
I think, that there's a big flaw in some parts of SR, so it has to add GR and the acceleration, to solve this issue. Adam doesn't have to slow down during his trip to a distant star - he can for example move along a circular path and gain speed "behind" Earth, so he will move with a constant velocity all the time. We can as well exclude the planet, so there won't be no gravity involved. In such case, telling that any of twins will get older, than the other, is a direct violation of SR own rules...
@1203scott
7 жыл бұрын
best vid I have ever seen on this subject. So easy to understand. great job
@EugeneKhutoryansky
7 жыл бұрын
Thanks for the compliment about my video.
@Mrgameplay100
7 жыл бұрын
I think its confusing cause adam is moving near the speed of light. and sarah isnt moving at all. So if this was playing at real speeds, adam and sarah wouldnt even see each other cause adam would be moving to fast, right?
@prozmystery
4 жыл бұрын
Your video is awesome. Best of All time.
@EugeneKhutoryansky
4 жыл бұрын
Thanks for the compliment.
@jessehng9866
6 жыл бұрын
Best twin paradox ever explained
@morten3219
2 жыл бұрын
best explanation and i've read and looked alot on other stuff. Well Done Eugene
@EugeneKhutoryansky
2 жыл бұрын
Thanks for the compliment about my explanation.
@addul1996
9 жыл бұрын
I did not expect a video this fast after the waves video, let alone two. Anyways great job, very helpful video, thanks and keep it up!
@EugeneKhutoryansky
9 жыл бұрын
Amer Amodi Thanks for the compliment. Lots and lots more videos are coming very soon.
@estevedelacebo
7 жыл бұрын
Thanks a lot. This video (almost) solved doubts I've had for years
@goerizal1
8 жыл бұрын
if sarah(the twin left on earth) has an equally valid perception that she is the one moving away from adam her twin in the spaceship whom she assumes is standing still, why would her clock be the one to show a faster rate of time compared to adam when he gets back to earth to her? is it the distance of adam's clock from the earth's center of mass and his speed of motion that is causing adam's clock to slow down compared to sarah's.
@bobphin6454
8 жыл бұрын
your obvious observation falsifies relativity. in one reference frame she ages faster than him, in another he ages faster than her. there's no use trying to accept relativity, the whole thing is an exercise of mathemagical mental masturbation.
@ahall9839
6 жыл бұрын
If only Einstein and every reputable scientist in the past century could have read this youtube comment and realized how foolish they were!
@GoomySmash
9 жыл бұрын
Mindblowing! Great video on the topic, helped clear things up for me. Also, what are the songs used in this video? You always have the best music choice.
@EugeneKhutoryansky
9 жыл бұрын
Goomy Smash Thanks for the compliment, and I am glad that it helped clear things up. In reply to your question, the song is from the free KZitem audio library, and it is called "1812_Overture_by_Tchaikosvky".
@Virusnzz
9 жыл бұрын
Goomy Smash You're not familiar with Tchaikovsky? Well, you've got a ride ahead of you.
@juliusgroenjes8115
9 жыл бұрын
soo many videos lately, and all high quality, keep it up :D
@EugeneKhutoryansky
9 жыл бұрын
julius groenjes Thanks. I am glad that you feel that all the videos are high quality.
@kornelijekovac9793
6 ай бұрын
Do you happen to have a graph with two lines, one for Adams age from Sarah's point of view, and other line for Sarah's age from Adam's point of view?
@ChristianGriffioen
2 жыл бұрын
Hi, I have 1 question. If both Adam and Sarah would see the other going slower through time, what would happen if Adam were to 'teleport' (if that were possible) back to Sarah before he turns around? Sarah still must be older right, how does that work?
@jonwebb2417
2 жыл бұрын
Hey Eugene your videos are amazing but I have one question.... you say that Einstein says that there should be no way of telling the difference between acceleration and gravity. But highly accurate clocks can show clock speed differences at small distances. This means that you can always tell if a spaceship is in a planet's gravitational field because a clock will run slower at the edge nearest the planet and faster at the edge furthest from the planet. If it were simply accelerating, the two clocks would run at exactly the same speed. Have I misunderstood?
@EugeneKhutoryansky
2 жыл бұрын
Two clocks in a gravitational field will run at different rates, but this is actually what prevents us from telling the difference between acceleration and gravity. I cover this in my video at kzitem.info/news/bejne/knuE0YRmoWqfdJw
@jonwebb2417
2 жыл бұрын
@@EugeneKhutoryansky Amazing thanks so much for replying! So even to the person inside the box, if the box is accelerating at 1G (with a rocket, not in gravity) - the clocks will run at different speeds at one end than at the other - right?
@EugeneKhutoryansky
2 жыл бұрын
Jon, from the point of view of the person inside the box, the clocks at the top and bottom of the box are running at different speeds, because he believes that there is a gravitational field present throughout the entire universe, and that this gravitational field is exactly balancing the force from the rockets, causing the box to stand still.
@jonwebb2417
2 жыл бұрын
@@EugeneKhutoryansky 👍👍👍💪🤗
@Cosmalano
9 жыл бұрын
Awesome! Thanks for all of the videos about gravitation!
@EugeneKhutoryansky
9 жыл бұрын
electrocat1 I am glad you like them. Thanks.
@moiquiregardevideo
6 жыл бұрын
Christian Gingras 5 months ago Nice attempt to explain the paradox. Here is a simpler explanation: When the Sarah is flying away from Earth at 95% the speed of light, the radio communication is impaired because of a Doppler shift. Both sister need to tune their 1 GHz frequency to 50 MHz, which electrical engineers call carrier frequency. The AM or FM modulated signal, a slower wave which modify slightly the carrier frequency amplitude or frequency is equally slower. All embedded binary code are also streaming 20 times slower. The decoded voice of Sarah is deeper, like playing a vinyl disc or magnetic cassette in slow motion and the video are almost still pictures. A year later, Sarah turn around and come back toward Earth at 95% the speed of light, the following happen: That day, one year after their separation, Alice on Earth keep receiving the slow stream of radio at 50 MHz. She just received the video from Sarah telling how boring it is now, after 2 weeks of travel. She think her sister is crazy, talking about 2 weeks when in reality she his gone for a year and she is supposed to turn around now. Sarah also receive old news from her sister on Earth. She see the video telling her that she already miss her after two weeks of separation. However, the radio is fucked up because Sarah at the switch frequency from 50 MHz (for the 1 GHz carrier frequency) to 20 GHz. Also, the voice sound like chip monks and the videos are 20 times too fast. As the time pass between 12 month and 24 month of the total duration, the video that Sarah receive from Alice catch-up with the real time. Everything synchronize just right so that the last day of this 2 years voyage, Sarah can see a video of her sister recorded only 20 days earlier. For Alice, the second year events are a little more complicated to explain. She keep receiving outdated video on the radio station tuned at 50 MHz. Suddenly, 2 weeks before the end of the 2 years trip, the frequency jump from 50 MHz to 20 GHz. The video from Sarah describe that she now prepare to turn around. Alice think that she is crazy to announce that after 23.5 months. Then, during these last 2 weeks, Alice receive all the videos from Sarah describing that entire year where she is flying back to Earth. Finally, both sisters re-unite and they both aged by exactly 2 years. End of paradox.
@TheAirpirate28
9 жыл бұрын
Nice animations.. Nice narrations.. Again easy-to-comprehend.. But i have a question: How is "Khutoryansky" pronounced ? :)
@EugeneKhutoryansky
9 жыл бұрын
TheAirpirate28 In Russian, the "Kh" sound is signified by a single letter, and there is no equivalent sounding letter in the English language, so "Kh" is the closest translation. Thanks for the compliment about the video.
@ratamacue0320
8 жыл бұрын
What do you mean when you speak of an observer's "beliefs"?
@Luisitococinero
7 жыл бұрын
Not religious, but an opinion.
@TheMyrkiriad
5 жыл бұрын
Great point ratamacue. The video constantly makes the confusion between what one observer perceive or can tell from the other observer and what really is.
@siddheshgawali7764
6 жыл бұрын
How does adam's body know that he was moving at speed of light... so we will also age same as sarah
@davidking8361
6 жыл бұрын
It is unfortunate that Adam's girlfriend Sarah was not the space traveller...whereas, Sarah would have returned youthful and bouncy to an old Adam, who would have appreciated her all the more. This would have proven the Groucho Marx theorem: "You are only as old as the woman you feel"
@robertpirker
6 жыл бұрын
as soon as instantaneous communication will be established, e.g. via means of quantum entanglement, this discussion will get a truer and more easily understandable direction
@colxplosion
8 жыл бұрын
Did you create these cute animations in POSER?
@EugeneKhutoryansky
8 жыл бұрын
Yes, I use Poser for my 3D animations.
@pedrocarvalho6423
6 жыл бұрын
Great video! I tought I already understood the twin paradox, but this explanation is awesome! Thanks again, Eugene and Kira!
@EugeneKhutoryansky
6 жыл бұрын
Thanks. Glad you liked my explanation.
@TheChrasse
9 жыл бұрын
Now I feel that I finally understood why Sarah and Adam disagree on why more time has passed for Sarah during Adam's voyage. It seems so obvious now, why didn't I get it when I watched your earlier videos? Anyway, big thanks to you Eugene, again!
@EugeneKhutoryansky
9 жыл бұрын
***** I am glad I was able to clear that up. There were a lot of people who were having trouble understanding this, as I only had time to cover this very briefly in my main video on Relativity. Thanks.
@Ellipsum
8 жыл бұрын
Mind if I ask. I could save myself the math if you know the answer. Say Adam is going at 99.9 c. If the acceleration Adam is subjected is 99.9 c/s when he turns around, that means he has only been accelerating for 2 seconds (for himself) (the time to reverse his speed)(Adam is a very strong guy), while being subject to extreme time dilatation relative to Sarah. If the acceleration Adam is subject to was instead, say, 9.99 c/s, then he would take 20 seconds to reverse his speed, while being subject to not-so-extreme time dilatation. According to the Twin Paradox and Sarah's explanation being based on Adam's velocity, that means the time dilatation rate of an object exposed to 9.99c/s is 10% of the time dilatation rate of an object exposed to 99.9c/s, else the two would disagree on how much time has passed. Well then be, it means gravity (or acceleration) dilates time in a linear way?
@TheBiochemist809
2 жыл бұрын
So basically when I accelerate, I can think of it as experiencing a higher intensity gravitational field (faster I go, closer to the gravitational "center" I am) which slows down time, and I can see gravity as acceleration, which slows down time. These things are one and the same!
@rzrbck84
9 жыл бұрын
What Randy Savage said below is what's always confused me about Relativity: why does one's point of view have any effect on the outcome? Why does Adam remain young if he "believes" time is moving more slowly for him? How does Relativity affect biology? If I'm traveling at the speed of light, forever, will I remain young?
@FcoMp
9 жыл бұрын
anna dani for you one year will last one year, but for the others, yours ill be much more time.
@prakashpaudel2708
9 жыл бұрын
I liked the video which made me understand about drawing the higher dimensions. But later on knew that it was your video. Your all videos are great. Eugene I can't wait for your next video making everything clear about the movie "interstellar".
@EugeneKhutoryansky
9 жыл бұрын
Prakash Paudel Thanks for the compliment. By the way, if you haven't already seen it, a few days ago I made and uploaded a video on gravity's effect on the flow of time, and it explains why time near a black hole moves slowly, as was shown in the movie Interstellar. Thanks.
@joeyadesantis
5 жыл бұрын
I don’t understand how someone “believes” gravity is effecting them and that Sarah is accelerating towards him. He KNOWS he’s the one who left, who accelerated away, and gravity exists due to massive objects, so no one could plausibly “believe” it’s slowing them down if there is no mass actually doing it. I’m so confused.... :/ Any help?
@NomalGuy369
9 жыл бұрын
Eugene, can you specifically make one video based on Higgs Field and Higgs Boson? Many thanks :)
@ResoluteGryphon
4 жыл бұрын
From Adam's point of view, when he fires his rockets, it's Sarah who is accelerating towards him. Why is it Adam is the only one who feels the effects of the artificial gravitation? I'm sure it has something to do with the application of force but I can't quite wrap my head around it.
@EugeneKhutoryansky
4 жыл бұрын
It is only Adam that believes that this external gravitational field exists. This field does not exist from Sarah's perspective. I explain this in detail in my video at kzitem.info/news/bejne/knuE0YRmoWqfdJw
@appuppanandtheboys
6 жыл бұрын
Great video!! Keep up the good work!
@EugeneKhutoryansky
6 жыл бұрын
Thanks. Glad you liked my video.
@vinven7
8 жыл бұрын
Does this mean that all accelerated motion will involve this "pseudo-gravitational" force and consequent time effects? In other words, can we still discuss accelerated motion in terms on special relativity alone?
@buzzwerd8093
7 жыл бұрын
The effects at short (on galactic scale) distances is very small.
@Travizeno92
10 ай бұрын
Hey Eugene, can we assume the travelling twin is in constant acceleration and attribute that to a gravitational force? How would that effect the experiment? Would the travelling twin still age less? Is the turn around necessary for the two to age differently?
@EugeneKhutoryansky
10 ай бұрын
I am not sure I understand your question. If the question is if Adam can be in constant acceleration from the time he left to the time he returned, then yes, Adam can attribute all the effects to an external gravitational field, and he will still have aged less than Sarah when he returns.
@Travizeno92
10 ай бұрын
@EugeneKhutoryansky I'm trying to think of a hypothetical where the travelling twin is accelerated in a different path. For instance in this video he leaves and comes back to Earth. But what if he was simply sitting in some machine that accelerated him forward and back or in circles while still on Earth. Would his age still decrease relative to those around him?
@EugeneKhutoryansky
10 ай бұрын
Yes. Moving in a circle requires a constant acceleration towards the center of the circle.
@stewiesaidthat
9 ай бұрын
Newton's law of motion, F=ma. Force equals Acceleration. The accelerating rocketship also accelerates the astronaut in time as evidenced by an accelerated heart rate and a shorter lifespan. The traveling twin will be the same age as the stationary twin as evidenced by the synchronized clock experiments showing no difference in the amount of energy the clocks used. The clock and the observer are in different frames of reference. Its like putting a banana on the counter and one in the freezer. It's like putting a plant under a growlight and one in natural sunlight. Atomic clocks are designed specifically to prevent the caesium-133 atom from being accelerated in time when a force is applied.
@buzzwerd8093
7 жыл бұрын
I finally understand why planet gravity does not make the deep universe run super fast. Gravity diminishes with distance, and it is acceleration over the distance that matters which only to the spaceship view is the same into infinity.
@luluke8686
8 жыл бұрын
I like it very much. the explanation is great and the 3D effect is great!
@EugeneKhutoryansky
8 жыл бұрын
Thanks. Glad you liked it.
@dylanthompson6716
9 жыл бұрын
I love your videos! Keep them coming! As well as, what if the universe is a sphere, and there for he never had to turn around, and completely went around the universe never turning his rockets the other way. Would that change anything? Thanks!
@charlesmcmillion5118
5 жыл бұрын
Using phrases such as "Adam will believe" and "Adam's point of view" is not good - it will leave those who don't know Physics with the impression that time dilation and length contractions are just illusions. In any case, the twin paradox can be resolved using on SR - no need to invoke GR.
@corwin-7365
5 жыл бұрын
Indeed. It really is best to define those terms more succinctly before launching into the explanation. :-) And, yeah. Use GR... or use SR with acceleration. The picture is the same... only the terminology changes! :-)
@asysjr
8 жыл бұрын
But what will happens if ADAM did NOT turn around, and just continue in straight line until he circumnavigate the entire universe (let´s say it´s a small and closed universe). If he circumnavigate the universe, he will return back to Earth, without doing any turn around and acelerating. I think this explanation actually don´t resolve the paradox...
@TeacherFlash
8 жыл бұрын
So, if we were to run a quantum clock and shut down Adams clock before the acceleration back and the information was instantly transported. It would disprove what they're saying and you'd realize that the effect was not due to "gravity". China launched the rocket 2 days ago and they're about to test this. Einstein was wrong.
@stevedahlberg8680
2 жыл бұрын
There is one slight bit of this I don't quite understand. It has to do with reconciling the two frames. From the perspective of the twin on Earth, time dilation for the astronaut piles up along all three segments of the trip - a certain and same amount for the trip out and back and then very heavily during the turn around (a + B + c). But from the perspective of the astronaut, the trip out and back essentially subtract from his overall time dilation against the swamping amount of the turnaround (B - a - c). So to me they would largely agree with each other, except that from the astronaut point of view, the time dilation affect overall would have been slightly less than what the twin on Earth would estimate. It seems like they should exactly match.
@EugeneKhutoryansky
2 жыл бұрын
From the perspective of the twin on Earth, the time dilation during the turnaround is negligible, and almost all the time dilation was due to segments (a) and (c). Keep in mind, from the point of view of the twin on Earth, this extra gravitational field never existed.
@pedrolopa2
Жыл бұрын
are there any published papers that support this explanation of the paradox? I'm doing a paper with a new look on the twin's paradox that shares some similarities with this video.
@prakashpaudel2708
9 жыл бұрын
what is the cause of death? Is it time? You said that time of adam will slow down. But what about his speed of thoughts, metabolic rate, heartbeat, and all the biological phenomenon going on inside his body? How does our body cope with the time? Next Question: If Sarah does some work here on earth and it takes 1 hour. Will Adam take more time or less time to finish the same work if both have equal efficiency?
@EugeneKhutoryansky
9 жыл бұрын
Prakash Paudel When time slows down inside a space ship, this means that all physical processes, including all of Adam's biological functions, will slow down by the same amount.
@goldtaker95
3 жыл бұрын
Ok, but what about the 2 spaceships flying in different direction version of this paradox?
@zakirhussain-js9ku
2 жыл бұрын
Relative motion between a stationary and moving object creats an illusion for moving object as if stationary object is moving. To find out which object is stationary and which is moving we need to check motion relative to space. Relativistic effects are restricted to object moving relative to space.
@Mysoi123
Жыл бұрын
There does not exist an ultimate frame of reference, which we call space. There also does not exist an ultimate moment termed "now." All of these depend on frames of reference.
@harshalagrawal1263
6 жыл бұрын
You nailed it!!! Thank you for such an easily understandable video
@Demintika
8 жыл бұрын
Let's say, it take 100 years for Adam to go and return in Sarah's point of view, but it's a small amount of time for Adam. Let's imagine a Worm Hole at the furthest point Adam get to, linking that point to Earth. Adam would reach that Worm Hole 50 years after his take-off in Sarah's pov. But in his pov, Sarah's time hasn't passed (much). If he used the Worm Hole, what would happen? Would he return to a old Sarah or the young Sarah? What about the old Sarah seeing Adam enter the worm hole? Would he return (to old Sarah) or disappear (to young Sarah)? Or, from Sarah's pov, Adam would take off, then immediately appear out from the Worm Hole. But there would be still another forever-young Adam moving toward the Worm Hole and would reach it in 50 years.
@slipknnnot
8 жыл бұрын
What if Adam was really just Sara the whole time ? and JFK was never assassinated when he jumps into the black hole from which he gets out of using 'Ludicrous' speed ?
@SC-zq6cu
8 жыл бұрын
If the wormhole is not inside Adam's vehicle then Adam returns to an older(About 50 yrs) Sarah. If the wormhole is inside his vehicle i.e. travelling with Adam (I have no idea how!) then Adam returns to young Sarah i.e. the wormhole is now a time machine, which happens only if Adam somehow manages to enter and exit the wormhole without feeling any acceleration. However in the first case the result only applies if Adam attempts to stop and measure Sarah's age, otherwise if he somehow measures Sarah's age while moving at const. velocity Sarah will still appear young. From Sarah's pov : In the first case Adam takes 50 years to reach wormhole. He then instantly reaches Sarah. In the second case Adam's vehicle takes off and Sarah can see an Adam riding his vehicle for 50 years. But right after the start of the journey another Adam pops out of the wormhole at Sarah's location. Notice that now, for 50 years Sarah is going to see two Adams - one at earth and another at the ship. This case is actually briefly discussed by Kip Thorne in one of his books on relativity and gravitation and black holes and stuff. All this however is purely speculative.
@robertbrandywine
3 жыл бұрын
I suspect that when Adam fires his rocket engines he isn't going to believe that a gravitational field suddenly appeared from nowhere. He'll realize he is accelerating. Good explanation though. In fact, the best I've seen. Some of the others talk about "rotating in time" which is confusing to me. What does rotating in time even mean?
@dinitroacetylen
6 жыл бұрын
There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that this has already happened. -- Douglas Adams, "The Hitchhiker's Guide to the Galaxy" series.
@akhilnair1451
5 жыл бұрын
What if adam had taken a circular path? Then there is no need to fire the rockets right? Oh or does he need to fire rockets to maintain ciruclar trajectory hence centripetal acceleration makes adam think he is in orbit around a gravitational field.
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