"Terra and Stella now both have a better understanding of how spacetime works" Me: "you'd think they'd have an understanding BEFORE becoming astronauts.
Thank you. You saved my life. I had no means to cook food this morning but after watching this video I was able to cook my breakfast on the top of my head as this video set my brain on fire.
Theres a famous story of a British Submarine in the war that used to tey to surface each week minimum to get the news on the BBC World service. One week, they detected a German boat and had to delay their ascent. When they did surface, they caught the very end of the broadcast which was "Arsenal, nil"
I feel like the video is more about consequences of this not why this exists. I mean they talk about how the twin see the other one and where time goes slower but i didnt get why. Only this formula at the start saying that "faster u go, slower the time". Mayeb i missed sth or its just too complex to explain.
Here I was thinking "Oh! So they'll both end up the same age when they're back together" and getting it completely wrong means I understood pretty much nothing
its pretty simple she is traveling at 86.6% of the speed of light, thus due to special relativity she experiences time twice as fast. thus it will take 11.5 years 11 years* where for the other twin on earth the journey takes 23 years
@@Serquest how can you say Terra has zero inertial reference frame relative to the universe. There is no absolute zero velocity reference point in the universe that everything else is moving relative to. So Terra and Stella from each persons perspective, Stella is moving at 86% C away from Terra or Terra is moving at 86% C away from Stella. I don't understand the explanation of the paradox.
I think you’re getting mixed up between velocity and acceleration she is in a non inertial reference frame relative to the universe that’s where the paradox comes in the part that’s overlooked is that when she changes directions she forgets to account for her new reference frame
Honestly i think i understand it less. I'd heard that time changes speed when in space. Fine i don't get it but it's none of my business Now theres all the details that i'm not going to remember the order in but i'll still try to spit it out as a thing i know and get it super wrong.
Basically the faster you get to the speed of light the slower time moves for you. So to people on earth it would have taken 23 years meanwhile it only took 11.5 years to the people on the spaceship. So if both twins were 20, the one who stayed on Earth would be biologically 43 while the one who traveled through space would be biologically 31.5 years old.
Thats not actually how it works, is it?Youre still going to die in 6 months, but if youre in space and travelling close to speed of light, youd still be dead in 6 months but a year would have passed only for non moving people on Earth.If i understood it correctly.
“Terra and Stella now both have a better understanding of how spacetime works.” Good for them because now even the only functioning brain cell I have is malfunctioning.
@Belial Made it confusing on purpose? They're _"Explaining"_ it in a more detailed, technical way. Why? Well because as you already said, you already knew the answer. But then, _how can it be the answer?_ That's is what they're on about. Also no, it's not really that confusing - I suggest you to give it another try.
@@Caiyde yes, clever, but their names sounded very similarly and were mentioned very often. They should have gone with very different sounding names or label the little faces on the screen.
One thing that's subtle and may further make difficult to understand is the following fact: Stella is moving at the speed of 86% of the light you have to keep remembering that so by the time the light signal from terra covers a light year, Stella would have further moved and the distance between the signal and her would be 72 % of a light year and so on so forth. Hence in about 7 years the first light signal reaches her.
But isn’t the whole premise of c being constant that I can’t tell how fast I’m moving by how long it takes c to reach me? C moves towards all moving objects at c, no?
Also if she sends the light signal does that actually move at the speed of light which should catch up to Stella quicker since she’s only going 86% the speed of light 🤔🤔🤔
@@maxmersmann-jones1222 Think of it as light coming out of a distant star to Earth. There are so many stars that are so far away that their light hasn’t reached even till now. So although c is constant, it still has to cover the distance to reach from point A to B.
Wait so Stella actually physically aged slower and is biologically 11 years younger than Terra ? Like in appearance and anatomy and all? That is absolutely mind blowing
@@AMC2283 wait but in documents they are the same age??? Did they experience time differently? I dont get it:((( Lets say hypoteticly they both are gonna start playing guitar, one on the space ship and other on the earth, and lets say that learning it goes identically for both twins, so does that mean that tera is gonna be much better player then stella when they reunite??
It reminds me of this conversation from one of the Discworld books: -He was a good, clever kid. To be honest, before his lectures I never really understood magic -Me neither. But do you now? -Well...no. But at least I know how much I don't know now The two mages then felt a surge of pride from their ignorance being superior to the average person
Yeah like you got the ideia, but have no understanding of the science behind it XD like spaceship goes swooooch very fast and then very slow and batabi batabo they are 11 years apart
This is why I always accelerate when running. Start slow, accelerate constantly, and keep the warm-down short. You will age a little less. Same with driving.
@@Disfatt_Bidge_01 (Thank you. You saved my life. I had no means to cook food this morning but after watching this video I was able to cook my breakfast on the top of my head as this video set my brain on fire ) this yours?
@@ohcool8314 bassicly the faster you move the slower you age Terra was not moving but Stella was (relatively) and because time slows down the faster you move Stella is younger Moving = younger Stationary = older
@@erikchristian3894 I also thought the graph was excellent. I do see why many people struggle understanding this video though because it doesn’t actually explain what special relativity is and how it works in much detail at all. This video is great though once you come back to it after understanding SR.
I’m always so intrigued by relativity theory. I just can’t wrap my head about it… perhaps one day, technology will advance so much, that we can experience it in one lifetime. 😌
the key is the word itself- relativity i understand whats going on with relativity but what freaks me out is knowing that something out there is happening simultaneous to this exact moment but due to vast distances that the light reflected off it must travel for us to see it it hasnt happened yet
Aaron L. I thought planet of the apes was about the Simian Flu and it’s infection of humanity in an attempt to cure Alzheimer’s. Are we thinking of the Dawn/Rise/War of the Planet of the Apes? Or something else entirely?
That's absolutely correct. In fact, even people who spend a lot of time traveling at a high rate of speed, such as flight attendants, do in fact experience a slower rate of time than others. But that's only as a miniscule rate, adding up to a fraction of a fraction of a second even over the course of a lifetime. modern rocketry is faster but (I think) still wouldn't cause more than a few minutes of "time travel" after a journey of years.
Oh I just realized. Stella went into space and terra stayed on the ground. Huh. I found it super confusing cuz I couldn't keep track and kept forgetting which was which. But now that I see this it makes it so much easier to understand
Actually they don't, within their own time reference. It's not the biological processes themselves slowing down, it's time itself in their frame of reference. The video didn't really do a great job with that particular part, but it's a tough concept to wrap a mind around to begin with.
The closer you get to the speed of light, the more "time compresses". This is hypothetical and can't be tested in large with our current technology, but it has been observed that faster objects do experience a measurable time dilation. I personally suspect it has to do with the particles that make up individual atoms can't move as fast if the object is traveling closer to the speed of light so everything relatively moves slower.
@@NFITC1 No, that is not it at all. Your time slows down RELATIVE to other people's times. Right now there's a neutrino in space that's moving at .99999c from it's point-of-view you're time had almost stopped. From say the moon's point-of-view your time is going at full speed.
You can think of biological processes as a type of clock, so if a mechanical clock slows down so must a biological clock otherwise you can make a clock out of biological material
@@joepierson3859 So time is a physical quantity or stuff??? I always thought that it was processes that slowed down instead of time itself! We live in a bizarre reality!
- At the start of their journey, both Terra and Stella assumed their observations, or what they experience, could equally qualify as a frame of reference. In other words, they thought they could both use their observations as the point of reference when measuring things like how much time has passed. - At the end of the journey, Terra would say to Stella, "I observed 11 flashes of light from you, which means you aged 11 years, but I aged 23 years. Time felt like it passed normally for me, so you must have experienced time more slowly than usual. Compared to my clock, your clock was running slowly. " - Stella would reply, "No, time felt like it passed normally for me. You must have experienced time faster than normal. Compared to my clock, your clock was running faster." -They both can't be right. - Terra would be correct in this situation, because her frame of reference is the one that must be used. This is because she was the inertial observer, as she was on Earth. To be an inertial observer, you must move at a constant velocity and in a constant direction. Stella changed direction when she started her journey back home. She can't be an inertial observer, hence her observations can't be used as the basis, or point of reference, when trying to measure how much time has passed. - This means that Terra's observations are the correct point of reference for measuring things like time and distance.
Yes. First, you need to be familiar with inertial and non-inertial reference frames. An inertial frame of reference is the perspective of an observer, whose motion is such that other objects with no net forces acting on them appear to not accelerate. In other words, a perspective from which Newton's first law is valid. When someone is in a non-inertial frame of reference, fictitious forces need to be introduced to account for the accelerations of other things from their perspective. Now, imagine you are in deep space and your twin goes past you in a spacecraft at some high speed. From the perspective of the spacecraft, you go past the spacecraft at the same speed. Now the only way for both of you to meet up again is if either you or your twin (or both) reverses your initial direction. In other words, relative to your original frame of reference, you need to acquire a velocity in the direction of the spacecraft (i.e accelerate till you are moving fast enough so you can catch up with the spacecraft), or else your twin has to accelerate relative to his original reference frame so he can catch up with you. If we assume that you remain in the same inertial reference frame throughout the journey of the spacecraft whereas your twin in the spacecraft is the only one who experiences acceleration at some point between his first encounter with you and his second encounter with you, then your twin will have aged much less than you. From your perspective, the spacecraft goes past you in one direction, then when the spacecraft is some distance away, it decelerates and then accelerates towards you, and finally, he goes past you a second time in the opposite direction. From the perspective of the spacecraft's original inertial reference frame, the spacecraft simply accelerates towards you and thus ends up shifting from one inertial frame to another inertial frame in which you are moving towards the spacecraft instead of away. From the perspective of a third observer who is stationary with respect to the spacecraft's original inertial reference frame, you go past the spacecraft first and then keep going in the same direction forever. After you have gained some distance, the stationary spacecraft starts to accelerate towards you, and then the spacecraft is traveling at a constant speed, greater than your speed, and the spacecraft will overtake you eventually. There is no inertial frame in which you change direction or speed at any point. Your twin in the spacecraft is in a non-inertial reference frame during the period that he experiences acceleration and he will observe you slowing down and moving towards him. However, the spacecraft's acceleration is of a different nature to yours. You do not feel any of the effects of acceleration whereas your twin does. There is a physical phenomenon associated with the spacecraft's acceleration; rocket thrusters have to fire in order for the spacecraft to accelerate towards you. From the perspective of a fourth observer who is stationary with respect to the spacecraft's final inertial frame, both you and the spacecraft move towards this observer at constant velocities. First, the spacecraft overtakes you since it's moving faster toward this observer. Afterward, the spacecraft decelerates to a stop. Eventually, you go past the stationary spacecraft. You maintain the same velocity always. The magnitude and direction of acceleration of any body is relative. However, the nature of the acceleration of a body that accelerates with respect to a single inertial frame is different from the nature of the acceleration of a body that only accelerates with respect to a non-inertial frame. It's the difference in the nature of the two accelerations that breaks the symmetry between the twins. Instruments carried by both can record a difference. Associated with any pair of events that are 'causally connected' (i.e. there exists a cause and effect relationship between the pair of events), there is an inertial reference frame in which the time experienced between the pair of events is a maximum among all the reference frames in which the time interval between both events can be measured locally with a clock that is situated at both events while they are occurring. Since you remain in the same inertial reference frame throughout the journey of the spacecraft and you are obviously present locally during both twin encounters, then you are in this special frame in which the time experienced between the two encounters with your twin is a maximum. Any reference frame whose state of motion deviates from yours will experience less time than you, between the two encounters. The greater the deviation from your state of motion, the greater the difference in time experienced. If your twin travels very fast and very far then he will age a lot less compared to if he travels slow and nearby (from your point of view); even if both these journeys take the same amount of time for you. The difference in time experienced is not due to acceleration per se, instead, it depends on the extent to which your twin's state of motion differs from yours.
@@Fmcela I started reading up on Relativity theory when I was a teenager. Over the course of several years, I picked up many aspects of the theory. However, it's only a couple of years ago that I understood the resolution of the twin paradox. I worked it out by considering each of the different perspectives that I mentioned. When I finally understood it, I felt euphoric. I hope more people to be able to experience that rare delight, so I consider my efforts worthwhile.
I understood: "There are twins name Stella and Tara, one is going to space one is staying on earth...." after that everything started sounding like the teacher in a Charlie Brown movie.
Is no one going to mention the brilliant pun at the end of the video? "And as twins who are eleven years apart in age, they are a perfect example of a special relativity." This is so clever, because it both references the topic of the video, and the fact that Stella and Terra are twins, and thus, relatives. They're also special, because all twins are the same age, but they are not, making them one of a kind! That's why they are a special relativity! Omg this is so clever!
Seriously, it blew my mind that it’s not only incredibly difficult to follow but then it’s also clever at the same time - yes, very cool and so cool of you to get that inference 👍
First, you need to be familiar with inertial reference frames. An inertial frame of reference is the perspective of an observer, whose motion is such that other objects with no net forces acting on them appear to not accelerate. In other words, a perspective from which Newton's first law is valid. When someone is in a non-inertial frame of reference, fictitious forces need to be introduced to account for the accelerations of other things from their perspective. Now, imagine you are in deep space and your twin goes past you in a spacecraft at some high speed. From the perspective of the spacecraft, you go past the spacecraft at the same speed. Now the only way for both of you to meet up again is if either you or your twin (or both) reverses your initial direction. In other words, relative to your original frame of reference, you need to acquire a velocity in the direction of the spacecraft (i.e accelerate till you are moving fast enough so you can catch up with the spacecraft) or else your twin has to accelerate relative to his original reference frame so he can catch up with you. If we assume that you remain in the same inertial reference frame throughout the journey of the spacecraft whereas your twin in the spacecraft is the only one who experiences acceleration at some point between his first encounter with you and his second encounter with you, then your twin will have aged much less than you. From your perspective, the spacecraft goes past you in one direction, then when the spacecraft is some distance away, it decelerates and then accelerates towards you and finally he goes past you a second time in the opposite direction. From the perspective of the spacecraft's original inertial reference frame, the spacecraft simply accelerates towards you and thus end up shifting from one inertial frame to another inertial frame in which you are moving towards the spacecraft instead of away. From the perspective of a third observer who is stationary with respect to the spacecraft's original inertial reference frame, you go past the spacecraft first and then keep going in the same direction forever. After you have gained some distance, the stationary spacecraft starts to accelerate towards you and then the spacecraft is travelling at a constant speed, greater than your speed, and the spacecraft will overtake you eventually. There is no inertial frame in which you change direction or speed at any point. Your twin in the spacecraft is in a non-inertial reference frame during the period that he experiences acceleration and he will observe you slowing down and moving towards him. However, the spacecraft's acceleration is of a different nature to yours. You do not feel any of the effects of acceleration whereas your twin does. There is a physical phenomena associated with the spacecraft's acceleration; rocket thrusters have to fire in order for the spacecraft to accelerate towards you. From the perspective of a fourth observer who is stationary with respect to the spacecraft's final inertial frame, both you and the spacecraft moves towards this observer at constant velocities. First, the spacecraft overtakes you since it's moving faster towards this observer. Afterwards the spacecraft decelerates to a stop. Eventually you go past the stationary spacecraft. You maintain the same velocity always. The magnitude and direction of acceleration of any body is relative. However, the nature of the acceleration of a body that accelerates with respect to a single inertial frame is different from the nature of the acceleration of a body that only accelerates with respect to a non-inertial frame. It's the difference in the nature of the two accelerations that breaks the symmetry between the twins. Instruments carried by both can record a difference. Associated with any pair of events which are 'causally connected' (i.e. there exists a cause and effect relationship between the pair of events), there is an inertial reference frame in which the time experienced between the pair of events is a maximum among all the reference frames in which the time interval between both events can be measured with a clock that is situated at both events while they are occurring. Since you remain in the same inertial reference frame throughout the journey of the spacecraft, then you are in this inertial frame in which the time experienced between the two encounters with your twin is a maximum. Any reference frame whose state of motion deviates from yours will experience less time than you, between the two encounters. The greater the deviation from your state of motion, the greater the difference in time experienced. If your twin travels very fast and very far then he will age a lot less compared to if he travels slow and nearby (from your point of view); even if both these journeys take the same amount of time for you. The difference in time experienced is not due to acceleration per se, instead it depends on the extent to which your twin's state of motion differs from yours.
For people who do not understand, basically the twin paradox is where the saying that time goes slower in space is challenged, when in reality it goes extremely slow in the beggining and extremely fast at the end, equalling it out.
@@juliaannabobrek No. As the video explained, they are biologically going to be 11 years apart, when stella returns from her journey. @ezmeeplays2125 is wrong in saying that it all 'equals out'
@@juliaannabobrek no. only the perception equals out. the biological truth bears the difference, since the one on the ship would age slowly because time itself is moving slower on the ship. when i say time, i mean physical time, not just theoretical time. think about it this way. Stella on the ship would have her cells divide more slowly. Terra on earth would have her cells dividing faster, which is why she is going to age more while Stella will be younger.
It doesn't equal out. Stella is more than 10 years younger than Terra because she flew at 86% of the speed of light. If Stella flew slower they'd be closer in age, except it would take so long that they would both die of old age before seeing each other again. The human lifespan is too short for space travel. If we can live longer then it can be possible but this doesn't refute the fact that faeter travel means slower motion. That's what it comes down to. Slower motion means slower cell turnover which means others will die before you because their cells moved more than yours. Less motion means less aging.
Don't be... I didn't catch it at first but the one who was on space was "Stella" ( Stellar, star ) and the one who stayed on earth was Terra ( Land, Earth )
For those that need a little assistance, I'll do my best to Feynman the situation: Part of Relativity says when something observes something else moving, time passes more slowly for the Mover. Stella thought the universe 'moved' around her as she would observe that happening during flight, so the universe would have less time passed. Terra thought the spaceship would move more slowly in time because she would see the spaceship moving. Terra's idea was proved because their Lightspeed Texts traveled a tiny bit faster than the ship moves. So when Stella was going away, the yearly texts reached earth years apart. When coming back the texts reached earth all at once because she was traveling in the same direction almost as fast as the texts could move. This let Terra count the years, 5 texts in 21 years going out, then another 5 texts in 2 years on her way back. The point of the video (and the paradox) is to fix the misunderstanding that the observer is always the one who sees time move slower. It's about more about what direction they move compared to you. (The physicists will know this is heavily simplified and leaves out the movement of earth compared to the ship, but Concept, Toddler, Gaps, Simplify.)
Yo you did it. I actually understand what the video is trying to say now. I assume you actually know what you talking about so i have another question for you.
so in summary: for the one that went to space (Stella): length contracted by a factor of two, and (inside the spaceship) time seemingly passed normally. Therefore she was able to Make the journey in 11.5 (spaceship) years. For the one on earth (terra), the journey would take 23 years, but if she could see Stella she would witness time inside the ship passing at half the rate time passed on earth. Thus when the twin returns to earth, 23 earth years would have passed but Stella would have only experienced 11.5 and would be biologically 11.5 years younger than her twin. This is true because to be in an inertial frame of reference you must move at constant velocity, the earth is therefore an inertial Frame of reference but the ship is not as changing direction requires acceleration and deceleration.
When you say: ''23 earth years would have passed but Stella would have only experienced 11.5'', I think you are wrong. Considering that 1 ''earth year'' means 1 ''year'' (there is o such thing as earth year), It is not that 23 years have passed but Stella only experienced 11.5, in reality, it depends on who you ask this question to (depends on the observer). It is not that Stella only experienced 11.5 out of the 23 that have passed, for Stella, only 11.5 years HAVE PASSED (and for Terra, 23 years have passed, this is relativity (I believe (yes, I just put a parentesis inside a parentesis inside a parentesis)))
4 года назад+1
@@Artzera824 Anyway, Stella and Terra (=Langevin's twins) are just a thought experiment, it's not a real experience, it's an *imaginary prediction,* you can make it say whatever you want. _To know more: __ruclips.net/video/vruCJAUxI0M_/видео.html_ (English subtitles available)_
I feel like this is the level of confusion that babies experience when looking at adults having a conversation
Same and so the first quote was an attack on us :(
@@shiningstar2843 so we are the cat ?
Hahahahah
😂😂😂
Wrong.....this is the look of adults listening to babies talk.
Imagine telling someone you're twins, and them saying, "oh, who's older," and you being like, "Terra, by 11 years."
Orange juice noise
Grucci _ *noice*
I was in a important lecture and out of no where I bust out
Ginny Potter wait the video is basically saying you age slower in space than in earth
Rest is history
"Terra and Stella now both have a better understanding of how spacetime works"
Me : Ok, but I don't
Light-speed traveling equals Time-travel into future
Have in mind that Stella was already an astronaut to begin with. So they were a couple of steps ahead
Terra? Stella? Hey, I just got it!
"Terra and Stella now both have a better understanding of how spacetime works"
Me: "you'd think they'd have an understanding BEFORE becoming astronauts.
Me toooooo, I dnt get it
Thank you. You saved my life. I had no means to cook food this morning but after watching this video I was able to cook my breakfast on the top of my head as this video set my brain on fire.
🤣🤣🤣🤣🤣
This was a genuinely good joke lmao
that was genius
I was watching this at work (slow friday) and freakin laughed out loud. Goddammit. 10/10
😂😂😂👌
Imagine not having contact for a year only to receive a message saying “your fish died”
Four years actually. You need to pay attention.
And you responding some 20 years later :" Oh no! I am coming back home right away "
Theres a famous story of a British Submarine in the war that used to tey to surface each week minimum to get the news on the BBC World service.
One week, they detected a German boat and had to delay their ascent.
When they did surface, they caught the very end of the broadcast which was "Arsenal, nil"
@@zachbailey457 Its a J O K E
@@havesomerubicon6097 jokes are funnier when they make sense
I love how their names represent where they are! Stella (meaning star) for the astronaut and Terra (meaning earth) for the one at home :)
I couldn't even understand which one was on Earth and the one in space
underrated comment
wow
never thought of that.
you have a great mind
@@Meshack_Muli Terra was the twin on earth and Stella was one in space
Im calling the fbi
If I ever have twin girls, I'm naming them terra and stella and telling them stella gets to be an astronaut but terra has fish to babysit
If you are unaware of this comment, I will tell you that this comment has blown up to over 1k likes.
This made my night thanks
I think she meant Tara not Terra
@@shahinazmeerriza5377 It's Terra. Terra means earth, while Estella means star. They are Spanish words derived from Latin words with the same meaning.
@@reinebautistamercado4286 Thanks for explaining ❤️
I knew terra was Italian for land but didn't think about Stella
I love how they reunite and how surprised stella looks when an apple falls because it has been 11 years since she has experienced earth gravity
Wow. You have incredible observation skills.
Imagine sending a message into space, waiting 2 years to only get a "👍" back
That would be my dad
@@wangspijker lol
Or an “lol”
Ok
Or being left on read.
For everyone not getting it, we're the cat in the quote at the beginning of the video.
That's the only thing that I understood! LOL
I feel like the video is more about consequences of this not why this exists. I mean they talk about how the twin see the other one and where time goes slower but i didnt get why. Only this formula at the start saying that "faster u go, slower the time". Mayeb i missed sth or its just too complex to explain.
wise words!
I had an exam on general relativity and this is literally the topic that took the most for me to grasp
Meow?
Imagine saying "Yeah she's my twin but she's 11 years older than me"
Fantastic thought 👏
how?? can you explain it?
"Yes, she's my mother, but I'm 20 years older than her"
@@bursendogan2338 Did you even watch the video?
@@cinegraphics 💀
This video reminds me of when I came back to class after missing a few important days.
Here I was thinking "Oh! So they'll both end up the same age when they're back together" and getting it completely wrong means I understood pretty much nothing
The same
*but both twins know that it’s not that simple*
No offense but that line was meant to be for you XD
its pretty simple she is traveling at 86.6% of the speed of light, thus due to special relativity she experiences time twice as fast. thus it will take 11.5 years 11 years* where for the other twin on earth the journey takes 23 years
@@Serquest how can you say Terra has zero inertial reference frame relative to the universe. There is no absolute zero velocity reference point in the universe that everything else is moving relative to.
So Terra and Stella from each persons perspective, Stella is moving at 86% C away from Terra or Terra is moving at 86% C away from Stella.
I don't understand the explanation of the paradox.
I think you’re getting mixed up between velocity and acceleration she is in a non inertial reference frame relative to the universe that’s where the paradox comes in the part that’s overlooked is that when she changes directions she forgets to account for her new reference frame
5:47 "Terra and Stella now have a better understanding of how spacetime works"
oh good that makes one of us
two*
Honestly i think i understand it less. I'd heard that time changes speed when in space. Fine i don't get it but it's none of my business
Now theres all the details that i'm not going to remember the order in but i'll still try to spit it out as a thing i know and get it super wrong.
Ikr
Basically the faster you get to the speed of light the slower time moves for you. So to people on earth it would have taken 23 years meanwhile it only took 11.5 years to the people on the spaceship. So if both twins were 20, the one who stayed on Earth would be biologically 43 while the one who traveled through space would be biologically 31.5 years old.
Doctor: you have six months to live
Stella: lets make that a year
Let's make it infinite!
md ridoy that’s what I was going to say!
Thats not actually how it works, is it?Youre still going to die in 6 months, but if youre in space and travelling close to speed of light, youd still be dead in 6 months but a year would have passed only for non moving people on Earth.If i understood it correctly.
@@TheNighKnight yeah
Stella will be dead in 6 months but to everyone else she will die in a year
Special relativity is making a 6 minute video feel like an hour long
For reeaall
Exactly!!
😂
“Your fish died”
“1 year old, r.i.p”
how is the fish 1 year old if the message is after 1 year idu
GaBoX17 DA the text says "1 yr old rip" as in "this rip was sent 1 yr ago"
@@darkboy2216 but stella receive it many years later so yeah
@@iPlayDotaReligiously ya so for terra 2 yrs had passed
1st yr - msg frm terra to Stella
2nd yr - msg frm Stella to terra.
Many year passed in earth where only 1 year passed for stella
Normal twins: oh let’s dress up alike and confuse everyone
Terra and Stella: hold my beer
😂
Underrated
Oooh blblblblblbl🧎♀️🧎♀️🙇♀️
🤣🤣
Terra and Stella : Hold our dress
@@pokechannel9758 ?
smart of you to name them "terra" and "stella" for "earth" and "star" so we can easily remember which is which
I def didnt remember either ones name when i made a terrible comment about earth being flat lol
It took me half the video to realize it and I am fricking italian
And you're still beautiful...😍
Yea im able to tell them apart because they have completely different names
They (Ted Ed) always do this. Specially if you check the Riddles, they have names starting with A, B, C... like typical math variables.
Oh I get it now.
Terra -> means "earth" -> stays behind on earth.
and "Stella" -> stellar -> stars -> goes to space
That's all i understood though
“Terra and Stella now both have a better understanding of how spacetime works.”
Good for them because now even the only functioning brain cell I have is malfunctioning.
😂😂
As a 42 year old, I'm slightly offended by how old you made 43-year-old Terra look.
42 likes damn
I think that's the result of pollution on Earth rather than her aging itself! So don't worry, if Earth stays greener, you stay younger!!
Hahaha right!
@@PingYJ7750 443 now loll
Ok boomers😂
Still very confused, but on a much higher level now. Thanks.
@Belial Made it confusing on purpose? They're _"Explaining"_ it in a more detailed, technical way. Why? Well because as you already said, you already knew the answer. But then, _how can it be the answer?_ That's is what they're on about. Also no, it's not really that confusing - I suggest you to give it another try.
same
Loool saaammmeee
they dont understand the root of the peoblem themselves
lmao my name is stella so I'm even more confused, dude
"We`re twins!"
"Really? Who's the older twin?"
Terra: "Me, by 11 years."
lmaaao
I didn't understand that until my cat explained it to me.
this should be top comment
Did you stole the cat from Schrodinger?
HAHAHHAHAHA
Damn that's a good weed indeed
is it dead
Teacher: Don't worry class, the test is going to be easy.
The test:
yess
But this is easy
@@randomfacts9588 Well no it was quite confusing
The spelling test is fun
@@vedantsridhar8378 actually it's pretty simple
has that one opportunity to send one message per year to twin: "I bought you a fish"
theEXOaudio genius
Whenever I get this feeling that I might be good at physics, I watch this video to humble myself
Really helps
Thank you.
FR
Don't worry if you can't understand anything in 6 minutes ,it took 23 years for terra and 11 years for stella to understand 😂
💀💀💀
Took me a year just to understand who was Terra and who was Stella 🤣
Terra is Latin for Earth, & Stella is Latin for Star. Their names correspond with their location
@@Caiyde 😯 oh nice
@@Caiyde yes, clever, but their names sounded very similarly and were mentioned very often. They should have gone with very different sounding names or label the little faces on the screen.
I didnt know Einstein had a twin named Paradox
You don't know the great Paradox Einstein? He had the famous math formula E= MC² ≠E
😑
Hi, i like ur profile picture, its the same as mine, god loves you😊
Ya he was the old guy in ben 10 that learned how to travel through time
If Einstein will see you comment he will die again
Meanwhile, I'm here confused about which one is Stella and Tera.
stella=star, terra=earth
@@aidenaune7008 Yeah, that's how I remembered
Same
yes same
@@aidenaune7008 en español: earth - tierra, star - estrella
One thing that's subtle and may further make difficult to understand is the following fact: Stella is moving at the speed of 86% of the light you have to keep remembering that so by the time the light signal from terra covers a light year, Stella would have further moved and the distance between the signal and her would be 72 % of a light year and so on so forth. Hence in about 7 years the first light signal reaches her.
THANAAANK YOOOUUU
But isn’t the whole premise of c being constant that I can’t tell how fast I’m moving by how long it takes c to reach me? C moves towards all moving objects at c, no?
Also if she sends the light signal does that actually move at the speed of light which should catch up to Stella quicker since she’s only going 86% the speed of light 🤔🤔🤔
@@maxmersmann-jones1222 Think of it as light coming out of a distant star to Earth. There are so many stars that are so far away that their light hasn’t reached even till now. So although c is constant, it still has to cover the distance to reach from point A to B.
I'll pretend I understood everything
this, lmao
Swastik Sahu. Same
Honestly, this is a mood whenever I watch a Ted-Ed video
lol
@@sarahnunez318 me too
"Stella" means 'star'
"Terra" means 'Earth'
Well that's one easy way to distinguish them! I forgot which is which along the video
Is it Spanish or Latin @Yan Wong
Perfect, as everything should be.
@@princezhedricksilvestre8168 latin. In Spanish star is "Estrella" and earth is "Tierra"
Thought it was pretty obvious...
"Wibby wobbly timey wimey stuff"
I see the writers are people of culture
@Manan Karnik it's from doctor who
Naw that’s just how British people really actually speak
@@BusterDarcy Indeed it is how we speak
Whovianssss
Where in the video?
Wait so Stella actually physically aged slower and is biologically 11 years younger than Terra ? Like in appearance and anatomy and all? That is absolutely mind blowing
Correct, it’s the poor man’s hyperdrive.
NASA already did this with the Kelly twins ( one now a senator ).
Same thing happened in the movie Flight of the Navigator. I loved that movie as a kid.
@@AMC2283 wait but in documents they are the same age??? Did they experience time differently? I dont get it:((( Lets say hypoteticly they both are gonna start playing guitar, one on the space ship and other on the earth, and lets say that learning it goes identically for both twins, so does that mean that tera is gonna be much better player then stella when they reunite??
@@juliaannabobrek if you need a year of lessons to get good, terra will be better, since a year for terra could be a month for Stella
Watching this and I was like..
"Damn, I'm dumber than I actually thought I was"
Same
i already knew this...i watched because i'm bored
too many distractions to think this one through
It reminds me of this conversation from one of the Discworld books:
-He was a good, clever kid. To be honest, before his lectures I never really understood magic
-Me neither. But do you now?
-Well...no. But at least I know how much I don't know now
The two mages then felt a surge of pride from their ignorance being superior to the average person
Nope, the video just didn’t explain it properly
114 years today since The Theory of Special Relatively was published!
114 years? ... Or is it?
**Vsauce theme plays**
Its 100 years older than me
115th like
Depending on your frame of reference
@@night_mare_1172 same
Whew, the relief I feel reading the comments and realizing I’m not the only one that gets everything and nothing all at the same time. Thanks guys!!
Lori Williams I don’t get any of it.
I won't push the like button cause the number is nice
@@nurindahsaloka9491 i missed it what was it at😂
@@adambaker4581 123 😂
Yeah like you got the ideia, but have no understanding of the science behind it XD like spaceship goes swooooch very fast and then very slow and batabi batabo they are 11 years apart
This is why I always accelerate when running. Start slow, accelerate constantly, and keep the warm-down short. You will age a little less.
Same with driving.
"They both have a better understanding of how spacetime works"
Good for them. Meanwhile me...
Copied😒😏
Correction "us"
1:18 -> me trying to understand this Ted Ed video
#relatable
im screaming 💀💀💀
Yup
"Uh huh, oh yes of course, makes perfect sense ... wtf is she even saying!"
@LagiNaLangAko23 same po, 😂
Noone:
Absolutely none:
Terra: i BoUghT yOu a fIsH
very funny right?
hahahah i died laughing
@@HeLow005 R.I.P. only 1 year old
“Your fish died :( “
LMFAO 💀💀
POOR GUY just like the fish
This is the best produced Ted-Ed animation I've seen. The music and the animation are beautiful.
What I’ve learned: I’m as smart as a cat.
cats are smart
I would aim even lower.
Something like this
Assuming that your cat is good at sarcasm 😁
@@Disfatt_Bidge_01 (Thank you. You saved my life. I had no means to cook food this morning but after watching this video I was able to cook my breakfast on the top of my head as this video set my brain on fire ) this yours?
Wibbly wobbly timey wimey like.
David tennant just sneezed
Whovians are everywhere 👀, even in TED-ED
Allons-y Alonzo!!
I read your comment right at the moment she said it. XD
GERONEMOOOOOOOOOOOOOOOOOOOO
Everything was alright untill stela left the Earth 😵
She should never have left. lol 😂
**returned** to Earth. It's the change in reference frame and bringing the two twins back together that makes one definitively older than the other.
:D
😂😂😂
That's quite... Well... Stella(r) ;)
VERY WELL DONE. The graph made it so easy to understand.
All I got from this was a prime example of sibling rivalry.
Like, who tf goes to space just to prove a point
That's the exact reason the U.S. went to the moon :)
Teacup _ ikr it’s not like it’s an example or anything
@@okas425 its not like it's a joke or anything either right? 😂
I’d totally do that to my sister. Since she thinks she’s soooo much better. I went to space!!! I’d rub it in her smug face!
Teacup _ It was more of a hypothetical statement but if it’s intended use was a joke then sure why not
Me: Lets watch this video to understand the Twin Paradox
Brain: Error 404 - explanation not found
Catastrophic error
🤣🤣🤣
Bruh same, i even bought a comic kid about this thing and still confused
Normie
@@ohcool8314 bassicly the faster you move the slower you age Terra was not moving but Stella was (relatively) and because time slows down the faster you move Stella is younger
Moving = younger
Stationary = older
“Let’s pick the most convoluted way of explaining time dilation with the cutest animations.” Them, probably.
@@erikchristian3894 I also thought the graph was excellent. I do see why many people struggle understanding this video though because it doesn’t actually explain what special relativity is and how it works in much detail at all. This video is great though once you come back to it after understanding SR.
It even gets the answer wrong after all that ....
I’m always so intrigued by relativity theory. I just can’t wrap my head about it… perhaps one day, technology will advance so much, that we can experience it in one lifetime. 😌
the key is the word itself- relativity i understand whats going on with relativity but what freaks me out is knowing that something out there is happening simultaneous to this exact moment but due to vast distances that the light reflected off it must travel for us to see it it hasnt happened yet
Them: Her journey should take 23 years
Me: Great! That seems pretty straightforward.
Them: Pulls out the real science
Me: Brain no work
Aaron L. I thought planet of the apes was about the Simian Flu and it’s infection of humanity in an attempt to cure Alzheimer’s. Are we thinking of the Dawn/Rise/War of the Planet of the Apes? Or something else entirely?
So if you travel faster than light... would that mean you are able to upend time backwards?
@@lued123 Does antimatter contain negative mass?
@@lued123 so why is antimatter anti?
I’ve just realized that this could be a time machine. Go into space for 10 years, see the earth 20 years later.
That's the general outline of time travel
You can't go back tho
depresso
thats basically the movie interstellar lol
That's absolutely correct. In fact, even people who spend a lot of time traveling at a high rate of speed, such as flight attendants, do in fact experience a slower rate of time than others. But that's only as a miniscule rate, adding up to a fraction of a fraction of a second even over the course of a lifetime.
modern rocketry is faster but (I think) still wouldn't cause more than a few minutes of "time travel" after a journey of years.
Yes but to truly travel time you need to get time to go backwards too
This was the most confusing 6 minutes and 15 seconds of my life.
Really? It was only about 3 minutes and 7 seconds for me.
@@weckar are you watching this from space then?😂
@@Ariadne4 no they just watched it at 2.0x speed
ON GOD 😂😂
Im like half asleep rn so it makes even less sense
This was a fantastic refresher of my college quantum physics unit. Succinctly summarized a few weeks of lectures into a few minutes.
*me 2 minutes into the video*
"so which is stella again?"
Stella = stellar = relating to stars = in space
Terra = terrestrial = relating to earth = on earth
Lol hahahha
@@donkberg fascinating
Whenever I have trouble sleeping , I watch this video and fall asleep halfway through it
Genius. I will do the same from now on
🤣🤣🤣
Saving it for that
@@vedantsridhar8378 Bruh why you be stating the obvious ?
Whenever I have trouble sleeping, I watch this video only to realize I'm 3 days awake just by understanding this
The cure to anti-aging: live in space and never come back
Actually you age at the same rate for you but slowly for others...
@@vandanaasthana1216 Yeah, but from the perspective of someone on Earth, you'd be much longer lived.
@@Lord_Of_Night and how does that matter to you?
@@ni3070 It doesn't. I was just pointing it out.
But why you didn't have boyfriend/girlfriend in space?
While reading my Physics textbook,I had this exact confusion,now I am clear.Though I dont understand it deeply,you guys has solved my confusion❤
"Terra" meaning Earth stayed on Earth, wheras "Stella" relating to stars went to space. Love that clever addition!
finally someone noticed that!
The only thing I completely understood in the entire video
Smart you are!!!!!
this was the only thing thst made me feel smart in this video
Stella in my country is a beer
is noone talking about how the fish died
Because time flows too fast
Oh 2:43 🤣😂🤣😂
Rip fish
it was a car accident
drunk driver. they say he drank like a fish
I like the names terra and stella, makes it easy to remember which is which.
Oh I just realized. Stella went into space and terra stayed on the ground. Huh. I found it super confusing cuz I couldn't keep track and kept forgetting which was which. But now that I see this it makes it so much easier to understand
This is best twin paradox explanation on youTube.
But it's wrong.
I like watching things that are far from my brains capacity because it gives me some thoughts to think of and it really improves my thinking
Really? It just make me want to return to monkey
I agree give u like a purpose to know there is more out there you don’t know. Who know what we don’t know.
Me : Why am not understanding anything..?
Me (checks the comment): I am not ALONE..🙂
😂
I see how this mathematically makes sense, but I don't understand why biological processes would slow down.
Actually they don't, within their own time reference. It's not the biological processes themselves slowing down, it's time itself in their frame of reference. The video didn't really do a great job with that particular part, but it's a tough concept to wrap a mind around to begin with.
The closer you get to the speed of light, the more "time compresses". This is hypothetical and can't be tested in large with our current technology, but it has been observed that faster objects do experience a measurable time dilation. I personally suspect it has to do with the particles that make up individual atoms can't move as fast if the object is traveling closer to the speed of light so everything relatively moves slower.
@@NFITC1 No, that is not it at all. Your time slows down RELATIVE to other people's times. Right now there's a neutrino in space that's moving at .99999c from it's point-of-view you're time had almost stopped. From say the moon's point-of-view your time is going at full speed.
You can think of biological processes as a type of clock, so if a mechanical clock slows down so must a biological clock otherwise you can make a clock out of biological material
@@joepierson3859 So time is a physical quantity or stuff??? I always thought that it was processes that slowed down instead of time itself! We live in a bizarre reality!
One of the top 10 videos on RUclips!
*Terra:* I'm feeling sad, I'm not sure I can do this anymore.
*Stella:* Apologies for the delay are you still there?
i actually laughed out loud at this
Oh my
This one got dark...still funny though
Wonder what that says about us....
lmaoo these comments are gold
I felt like Chidi trying to understand the dot in the “i” of Jeremy Bearimy while watching this
Jo Roz I love how I instantly got this reference
the good place fans unite :)
perfect example
What's chidi
this was the perfect reference, i just finished the last season today
- At the start of their journey, both Terra and Stella assumed their observations, or what they experience, could equally qualify as a frame of reference. In other words, they thought they could both use their observations as the point of reference when measuring things like how much time has passed.
- At the end of the journey, Terra would say to Stella, "I observed 11 flashes of light from you, which means you aged 11 years, but I aged 23 years. Time felt like it passed normally for me, so you must have experienced time more slowly than usual. Compared to my clock, your clock was running slowly. "
- Stella would reply, "No, time felt like it passed normally for me. You must have experienced time faster than normal. Compared to my clock, your clock was running faster."
-They both can't be right.
- Terra would be correct in this situation, because her frame of reference is the one that must be used. This is because she was the inertial observer, as she was on Earth. To be an inertial observer, you must move at a constant velocity and in a constant direction. Stella changed direction when she started her journey back home. She can't be an inertial observer, hence her observations can't be used as the basis, or point of reference, when trying to measure how much time has passed.
- This means that Terra's observations are the correct point of reference for measuring things like time and distance.
Hallelujah! Someone explained this+!!
omg thank you!
Yes..Yes..YESSS! This is it. Thank you.
Omg this video could have been simplified like how you did here 👍 👍👍
Just want to clarify, the biological processes slows down as well for Stella because of velocity?
Me: I got everything.
My brain: Are you sure about that?
Came to feel smarter....went away feeling like the cat they talk about at the start...😂😂😂😂
Underrated comment
i swear i actually restarted this to see the cat
Ikrrr
Same lol
😂😂
1:18 god that animation is top notch it gave me chillz
I feel like I missed a predecessor video that tells me everything I'd need to know to understand anything from this
Yes. First, you need to be familiar with inertial and non-inertial reference frames. An inertial frame of reference is the perspective of an observer, whose motion is such that other objects with no net forces acting on them appear to not accelerate. In other words, a perspective from which Newton's first law is valid. When someone is in a non-inertial frame of reference, fictitious forces need to be introduced to account for the accelerations of other things from their perspective.
Now, imagine you are in deep space and your twin goes past you in a spacecraft at some high speed. From the perspective of the spacecraft, you go past the spacecraft at the same speed. Now the only way for both of you to meet up again is if either you or your twin (or both) reverses your initial direction. In other words, relative to your original frame of reference, you need to acquire a velocity in the direction of the spacecraft (i.e accelerate till you are moving fast enough so you can catch up with the spacecraft), or else your twin has to accelerate relative to his original reference frame so he can catch up with you. If we assume that you remain in the same inertial reference frame throughout the journey of the spacecraft whereas your twin in the spacecraft is the only one who experiences acceleration at some point between his first encounter with you and his second encounter with you, then your twin will have aged much less than you. From your perspective, the spacecraft goes past you in one direction, then when the spacecraft is some distance away, it decelerates and then accelerates towards you, and finally, he goes past you a second time in the opposite direction. From the perspective of the spacecraft's original inertial reference frame, the spacecraft simply accelerates towards you and thus ends up shifting from one inertial frame to another inertial frame in which you are moving towards the spacecraft instead of away.
From the perspective of a third observer who is stationary with respect to the spacecraft's original inertial reference frame, you go past the spacecraft first and then keep going in the same direction forever. After you have gained some distance, the stationary spacecraft starts to accelerate towards you, and then the spacecraft is traveling at a constant speed, greater than your speed, and the spacecraft will overtake you eventually. There is no inertial frame in which you change direction or speed at any point. Your twin in the spacecraft is in a non-inertial reference frame during the period that he experiences acceleration and he will observe you slowing down and moving towards him. However, the spacecraft's acceleration is of a different nature to yours. You do not feel any of the effects of acceleration whereas your twin does. There is a physical phenomenon associated with the spacecraft's acceleration; rocket thrusters have to fire in order for the spacecraft to accelerate towards you.
From the perspective of a fourth observer who is stationary with respect to the spacecraft's final inertial frame, both you and the spacecraft move towards this observer at constant velocities. First, the spacecraft overtakes you since it's moving faster toward this observer. Afterward, the spacecraft decelerates to a stop. Eventually, you go past the stationary spacecraft. You maintain the same velocity always.
The magnitude and direction of acceleration of any body is relative. However, the nature of the acceleration of a body that accelerates with respect to a single inertial frame is different from the nature of the acceleration of a body that only accelerates with respect to a non-inertial frame. It's the difference in the nature of the two accelerations that breaks the symmetry between the twins. Instruments carried by both can record a difference.
Associated with any pair of events that are 'causally connected' (i.e. there exists a cause and effect relationship between the pair of events), there is an inertial reference frame in which the time experienced between the pair of events is a maximum among all the reference frames in which the time interval between both events can be measured locally with a clock that is situated at both events while they are occurring. Since you remain in the same inertial reference frame throughout the journey of the spacecraft and you are obviously present locally during both twin encounters, then you are in this special frame in which the time experienced between the two encounters with your twin is a maximum. Any reference frame whose state of motion deviates from yours will experience less time than you, between the two encounters. The greater the deviation from your state of motion, the greater the difference in time experienced. If your twin travels very fast and very far then he will age a lot less compared to if he travels slow and nearby (from your point of view); even if both these journeys take the same amount of time for you. The difference in time experienced is not due to acceleration per se, instead, it depends on the extent to which your twin's state of motion differs from yours.
@@MrAlRats oh my freaking god.
@@Fmcela What?
@@MrAlRats that’s some commitment for a comment that long
@@Fmcela I started reading up on Relativity theory when I was a teenager. Over the course of several years, I picked up many aspects of the theory. However, it's only a couple of years ago that I understood the resolution of the twin paradox. I worked it out by considering each of the different perspectives that I mentioned. When I finally understood it, I felt euphoric. I hope more people to be able to experience that rare delight, so I consider my efforts worthwhile.
Absolutely loved the quote at the start
fun fact:
Terra and Stella means, in Italian, "Earth" and "Star".
A genial easter egg
Fun fact:
That’s also what they mean in English
@@J.M.. Fun fact: because both come from the Latin root language.
It also comes from Ancient Greek :)
Mostly because Italian is heavily based on Latin
in Brazilian's portuguese "Terra" don't change
"your fish died :("
*top 10 saddest anime deaths*
@Rylan Otter timecop want to know your location
I understood: "There are twins name Stella and Tara, one is going to space one is staying on earth...." after that everything started sounding like the teacher in a Charlie Brown movie.
I only understood that and the doctor who quote at the end
Even that you understood wrong, it's Stella and Terra, for star and earth ahah
This just makes me believe even more that I have already lived this life, but only now I am experiencing it in Earth time.
Is no one going to mention the brilliant pun at the end of the video? "And as twins who are eleven years apart in age, they are a perfect example of a special relativity." This is so clever, because it both references the topic of the video, and the fact that Stella and Terra are twins, and thus, relatives. They're also special, because all twins are the same age, but they are not, making them one of a kind! That's why they are a special relativity! Omg this is so clever!
Go take an iq test or something damn
Ok, the video is better...
The.. what now???...
You caught a pun they didn't pitch.
Seriously, it blew my mind that it’s not only incredibly difficult to follow but then it’s also clever at the same time - yes, very cool and so cool of you to get that inference 👍
Meanwhile 23 years have passed and i still haven't understood this
First, you need to be familiar with inertial reference frames. An inertial frame of reference is the perspective of an observer, whose motion is such that other objects with no net forces acting on them appear to not accelerate. In other words, a perspective from which Newton's first law is valid. When someone is in a non-inertial frame of reference, fictitious forces need to be introduced to account for the accelerations of other things from their perspective.
Now, imagine you are in deep space and your twin goes past you in a spacecraft at some high speed. From the perspective of the spacecraft, you go past the spacecraft at the same speed. Now the only way for both of you to meet up again is if either you or your twin (or both) reverses your initial direction. In other words, relative to your original frame of reference, you need to acquire a velocity in the direction of the spacecraft (i.e accelerate till you are moving fast enough so you can catch up with the spacecraft) or else your twin has to accelerate relative to his original reference frame so he can catch up with you. If we assume that you remain in the same inertial reference frame throughout the journey of the spacecraft whereas your twin in the spacecraft is the only one who experiences acceleration at some point between his first encounter with you and his second encounter with you, then your twin will have aged much less than you. From your perspective, the spacecraft goes past you in one direction, then when the spacecraft is some distance away, it decelerates and then accelerates towards you and finally he goes past you a second time in the opposite direction. From the perspective of the spacecraft's original inertial reference frame, the spacecraft simply accelerates towards you and thus end up shifting from one inertial frame to another inertial frame in which you are moving towards the spacecraft instead of away.
From the perspective of a third observer who is stationary with respect to the spacecraft's original inertial reference frame, you go past the spacecraft first and then keep going in the same direction forever. After you have gained some distance, the stationary spacecraft starts to accelerate towards you and then the spacecraft is travelling at a constant speed, greater than your speed, and the spacecraft will overtake you eventually. There is no inertial frame in which you change direction or speed at any point. Your twin in the spacecraft is in a non-inertial reference frame during the period that he experiences acceleration and he will observe you slowing down and moving towards him. However, the spacecraft's acceleration is of a different nature to yours. You do not feel any of the effects of acceleration whereas your twin does. There is a physical phenomena associated with the spacecraft's acceleration; rocket thrusters have to fire in order for the spacecraft to accelerate towards you.
From the perspective of a fourth observer who is stationary with respect to the spacecraft's final inertial frame, both you and the spacecraft moves towards this observer at constant velocities. First, the spacecraft overtakes you since it's moving faster towards this observer. Afterwards the spacecraft decelerates to a stop. Eventually you go past the stationary spacecraft. You maintain the same velocity always.
The magnitude and direction of acceleration of any body is relative. However, the nature of the acceleration of a body that accelerates with respect to a single inertial frame is different from the nature of the acceleration of a body that only accelerates with respect to a non-inertial frame. It's the difference in the nature of the two accelerations that breaks the symmetry between the twins. Instruments carried by both can record a difference.
Associated with any pair of events which are 'causally connected' (i.e. there exists a cause and effect relationship between the pair of events), there is an inertial reference frame in which the time experienced between the pair of events is a maximum among all the reference frames in which the time interval between both events can be measured with a clock that is situated at both events while they are occurring. Since you remain in the same inertial reference frame throughout the journey of the spacecraft, then you are in this inertial frame in which the time experienced between the two encounters with your twin is a maximum. Any reference frame whose state of motion deviates from yours will experience less time than you, between the two encounters. The greater the deviation from your state of motion, the greater the difference in time experienced. If your twin travels very fast and very far then he will age a lot less compared to if he travels slow and nearby (from your point of view); even if both these journeys take the same amount of time for you. The difference in time experienced is not due to acceleration per se, instead it depends on the extent to which your twin's state of motion differs from yours.
@@MrAlRats You did do your research.
Okay big boi
@Strine ah yes, some of us are just born knowing relativity, lmao.
“Terra and Stella both have a better understanding on how time works”
Me: okay great, now explain to me
Lol HAHHAHAHAHAHHA
Ok ok I got it. Now explain to me like I was a 5 year old
Loved this! Thanks Amber for the amazing video
Who else straight up forgot who's name was who's?, I just assumed stellar was space girl and Terra was earth
You assumed correctly. That may be why they chose those names in the first place.
Terra is earth in portuguese ,so if someone brazilian had that name it would be like :" Hi earth! How are you? How is moon going?" ;-;
Clara 1707Blox exactly and Stella = star, as she’s the twin in space
Terra is earth and Stella is star in italian lol
Yeah because of latin
"Terra" and "Stella"? I see what you did there, TED-Ed.
That's the name I'll use if I have twins
Interstellar the movie..lmao..i love the movie
My mom asked me why I'm watching cartoons ..
hahaha underated comment
At first look, eveyone will think these are cartoons, coz they ARE cartoons, just more informative ones.
I feel bad for you
Tell her its complex cartoons.
Your mom needs to be less close-minded
For people who do not understand, basically the twin paradox is where the saying that time goes slower in space is challenged, when in reality it goes extremely slow in the beggining and extremely fast at the end, equalling it out.
thank you so much, so does that mean they are gonna be the same age biologically?? and those years lasted the same amount of time for both of them?]
@@juliaannabobrek No. As the video explained, they are biologically going to be 11 years apart, when stella returns from her journey.
@ezmeeplays2125 is wrong in saying that it all 'equals out'
@@juliaannabobrek no. only the perception equals out. the biological truth bears the difference, since the one on the ship would age slowly because time itself is moving slower on the ship. when i say time, i mean physical time, not just theoretical time.
think about it this way. Stella on the ship would have her cells divide more slowly. Terra on earth would have her cells dividing faster, which is why she is going to age more while Stella will be younger.
Why would stella still be younger by 11 years at end tho?
It doesn't equal out. Stella is more than 10 years younger than Terra because she flew at 86% of the speed of light. If Stella flew slower they'd be closer in age, except it would take so long that they would both die of old age before seeing each other again. The human lifespan is too short for space travel. If we can live longer then it can be possible but this doesn't refute the fact that faeter travel means slower motion. That's what it comes down to. Slower motion means slower cell turnover which means others will die before you because their cells moved more than yours. Less motion means less aging.
“Since light takes a year to travel one light year...”
Ummm， yes
This is the only thing I knew for certain.
Some people dont know what a light year means
Lolol
How does Einstein begin his stories?
Once upon a space time.....
Was it really Einstein who came up with this story?
In xyz Light year..........
I thought it was with a damn headache
Light years ago...
cunning
Step 1 anti aging skincare routine: be in outer space 🤯
Screw botox! I’m calling Jeffrey Bezos
you have to return to another frame of reference to be younger.
Your skin will only look younger to someone still on Earth. To you it will look the same as normal.
@@Uppernorwood976 What the heck, I'm so confused
The way I thought this was gonna be about why twins have telepathy lmfao
Who else feels like their mind is exploding and enjoying at the same time? 😀
I started to enjoy, then it exploded, then I continued to enjoy.
🤯😀
Others : *confused by the science
Me: confused by the names
By the way, please stop liking me after 420 likes
Ok, at least stop at 690
Exactly😅😅
Don't be... I didn't catch it at first but the one who was on space was "Stella" ( Stellar, star ) and the one who stayed on earth was Terra ( Land, Earth )
😁
I was confused by both
True.
For those that need a little assistance, I'll do my best to Feynman the situation:
Part of Relativity says when something observes something else moving, time passes more slowly for the Mover. Stella thought the universe 'moved' around her as she would observe that happening during flight, so the universe would have less time passed. Terra thought the spaceship would move more slowly in time because she would see the spaceship moving.
Terra's idea was proved because their Lightspeed Texts traveled a tiny bit faster than the ship moves. So when Stella was going away, the yearly texts reached earth years apart. When coming back the texts reached earth all at once because she was traveling in the same direction almost as fast as the texts could move.
This let Terra count the years, 5 texts in 21 years going out, then another 5 texts in 2 years on her way back.
The point of the video (and the paradox) is to fix the misunderstanding that the observer is always the one who sees time move slower. It's about more about what direction they move compared to you.
(The physicists will know this is heavily simplified and leaves out the movement of earth compared to the ship, but Concept, Toddler, Gaps, Simplify.)
Yo you did it. I actually understand what the video is trying to say now.
I assume you actually know what you talking about so i have another question for you.
Shoot, it's been a minute since I posted that, but I'll do my best to deconflict.
I get what you’re saying (i think), i just don’t get why they are “11 years apart” ? and how when she returns home the other twin is older ???
@@abbeyvergata because 23 earth years pass but on the ship only 11.5 earth years pass
Awesome, now my brain won't buffer about this again lol
What a great way to explain. Now my all confussions gone.
Me in my bed at 2:40am half asleep: “ah, yes.”
Good soup
Going to have to watch this several times I think!
im responding to the most recent comments
hi.
Yeahm as usual
so in summary: for the one that went to space (Stella): length contracted by a factor of two, and (inside the spaceship) time seemingly passed normally. Therefore she was able to Make the journey in 11.5 (spaceship) years. For the one on earth (terra), the journey would take 23 years, but if she could see Stella she would witness time inside the ship passing at half the rate time passed on earth. Thus when the twin returns to earth, 23 earth years would have passed but Stella would have only experienced 11.5 and would be biologically 11.5 years younger than her twin. This is true because to be in an inertial frame of reference you must move at constant velocity, the earth is therefore an inertial Frame of reference but the ship is not as changing direction requires acceleration and deceleration.
When you say: ''23 earth years would have passed but Stella would have only experienced 11.5'', I think you are wrong. Considering that 1 ''earth year'' means 1 ''year'' (there is o such thing as earth year), It is not that 23 years have passed but Stella only experienced 11.5, in reality, it depends on who you ask this question to (depends on the observer). It is not that Stella only experienced 11.5 out of the 23 that have passed, for Stella, only 11.5 years HAVE PASSED (and for Terra, 23 years have passed, this is relativity (I believe (yes, I just put a parentesis inside a parentesis inside a parentesis)))
@@Artzera824 Anyway, Stella and Terra (=Langevin's twins) are just a thought experiment, it's not a real experience, it's an *imaginary prediction,* you can make it say whatever you want.
_To know more: __ruclips.net/video/vruCJAUxI0M_/видео.html_ (English subtitles available)_
huh?
So in summary, meow
I don't understand what happened in this video but I'm glad those twins are happy and learning things :)