2:40 - Picture yourself on a train in a station With plasticine porters with looking glass ties Suddenly someone is there at the turnstile The girl with the kaleidoscope eyes
@fletchro789
4 жыл бұрын
LUCY IN THE SKY WITH DIAMONDS!!!
@raymondj8768
4 жыл бұрын
our age is showing lol
@carlton7015
4 жыл бұрын
and shes gone
@flashbazbo694
4 жыл бұрын
Halfway through the first sentence I found myself smiling and singing the rest in my head. Thank you !
@johnx9318
4 жыл бұрын
Now that made sense!
@ScienceAsylum
7 жыл бұрын
I loved the example of viewing the train from space. Very nice! I never thought of that.
@upandatom
7 жыл бұрын
+The Science Asylum thanks! I can't take credit for it though. I got this paradox from a book by Jim Al-Khalili and he used it in his explanation. I saw your video about this topic by the way, very nice n_n
@ScienceAsylum
7 жыл бұрын
Up and Atom Ah yes... My video was just before I finally figured out color correction, so it's the last video of mine that looks terrible. Anyway, I love solving paradoxes. This one is especially fun because there are so many variants that all need solving.
@phs125
6 жыл бұрын
Nice to see you both at same place :)
@DMSG1981
6 жыл бұрын
I loved your video on this paradox a couple years ago and am now curious about Jade's take on this :)
@DMSG1981
6 жыл бұрын
The Science Asylum, when you say "terrible" you're very harsh on yourself.
@dijojohn38
7 жыл бұрын
Interesting to see the beginnings of a channel that is going to blow up in the future. Great work!
@upandatom
7 жыл бұрын
+Dijo John Thank you! Hopefully your prophecy is true :)
@reduser3731
4 жыл бұрын
@@upandatom It is!
@fletchro789
4 жыл бұрын
Excellent prediction. Person from the future here. Jade has gotten better and better! She's awesome!
@dijojohn38
4 жыл бұрын
@@fletchro789 Haha the potential was obvious. The video is so polished for being one of her first KZitem videos.
@Orax1701
4 жыл бұрын
@@yotodine Insulting on so many levels.
@braincandytv
7 жыл бұрын
Hi Jade, great video. That relativity stuff sure gets weird, but Einstein was wonderful at coming up with these thought experiments to help us visualize what's going on! It was really nice to meet and chat with you at VidCon last week. Cheers, Michael
@upandatom
7 жыл бұрын
Thank you Michael! It was great to meet you too :) It's funny, there was actually an experiment that proved that the speed of light was constant long before Einstein, but nobody knew how to infer the results. Einstein actually came up with the result without ever having known about the experiment!
@rmsgrey
6 жыл бұрын
+Martin Popplewell That's actually one of the issues that led to Einstein's theory of Special Relativity. Using Newtonian mechanics, time is universal, but all motion is relative - there's no such thing as an absolute speed, only how fast something is moving relative to the ground, or to the Sun, or to the Milky Way, or to a river barge, or... Then Maxwell's equations explained electromagnetism, but predicted that electromagnetic waves would have a specific speed - not a speed relative to anything, but a fixed, absolute speed. The obvious conclusion was that light's fixed speed is relative to the aether - the medium that transmits light waves - and that could provide a fixed reference frame to measure absolute speeds against. So the Michelson-Morley experiments used incredibly sensitive apparatus to try to measure the Earth's speed relative to the aether, by measuring the difference in the speed of light relative to the Earth in different directions and at different times. The result of the Michelson-Morley experiments was that, to the limit of the accuracy of their measurements, Earth wasn't moving relative to the aether. Of course, it was possible that Earth is actually stationary, and the whole of the rest of the universe is rotating around it, and orbiting it in various strange paths. Or that the aether isn't static, but moves with nearby objects, so the speed of light varies from place to place as the aether's motion changes. Or that motion through the aether changes lengths and masses in particular ways. Einstein wasn't the only person who could have come up with the answer - he was just the person who published first - but his solution was almost frighteningly elegant: take the Maxwell equations at face value, assume that the speed of light will always be the same relative to any object in motion, so wherever you are, however you're moving (provided you're not accelerating), you'll measure the speed of light relative to yourself to be the same fixed value. Following through on the consequences of that, you quickly get that your measurements of the elapsed time between two events will depend on your own motion - time is no longer universal. So for anything traveling slower than light-speed, the speeds of other objects are always relative, but the speed of light (in a vacuum) is constant. And the universe is weirder than we imagined.
@randomgrinn
3 жыл бұрын
And you don't care that Einstein randomly became female for no reason? Umm..... sure.....
@Ryan_Thompson
3 жыл бұрын
@@randomgrinn I thought Alberta was quite charming, unlike your comment. Did you get your pole stuck in a barn as a small child or something?
@waltertanner7982
Ай бұрын
@@upandatomWhat exeriment, by whom, please?
@EvilSSP
4 жыл бұрын
I've got news for ya, Alberta is going straight through that damn door if she's going nearly the speed of light.
@clive7394
4 жыл бұрын
The doors are moving faster
@raho2005
4 жыл бұрын
yeah, imagine ~60kg going c in 1atm, that Barn is the least of her problems, poor Alberta.
@roleeyou
4 жыл бұрын
Damn you, Evil D, you made me laugh out loud at 5:30 in the morning when other people were sleeping.
@Stangil1
4 жыл бұрын
@@clive7394 Not possible.
@zsoltbakos685
4 жыл бұрын
best answer congratulation my kind of physics
@MandleRoss
4 жыл бұрын
I shared this on facebook with this blurb: "An Aussie lady who has an excellent series explaining physics concepts. Aimed mostly at young people, this is a great series for confused parents to watch with their kids when these topics come up at school, so that the kid can understand them quicker and explain them to the still-struggling parent. This is a great one in the series:"
@OMGclueless
4 жыл бұрын
Ahh yes this would have been great when I was in fourth grade and my teacher was teaching us special relativity.
@MandleRoss
4 жыл бұрын
@@OMGclueless I was thinking more in the middle-school range.
@KatanaBart
4 жыл бұрын
Note: the doors also have to move at near light speed. Therefore they are shorter... just stay away from the hinges and squeeze in the space at the other end. Also keep running since the pressure wave will destroy most of the continent.
@Sehon13Ultd
Жыл бұрын
What if we replace the thin pole with a moving rectangular brick so vertically tall that it can’t squeeze below the shortened doors?
@AdrianColley
5 жыл бұрын
Thank you! I found this concept so hard to visualize for so long, and this video makes it simple and intuitive.
@haroerhaktak2613
4 жыл бұрын
"Told ya it was juicy."
@Saanichian
4 жыл бұрын
Haroer Haktak I had to rewind and watch that part about a dozen times.
@dmounce5513
3 жыл бұрын
Just for that I'm subscribing 🤣
@adamthestimator
3 жыл бұрын
My new text tone...
@jessaustin1122
3 жыл бұрын
Lol
@phy_dude
2 жыл бұрын
" That's what she said "
@pyral514
6 жыл бұрын
I know about this paradox for such a long time but it surprises me every time.
@Lehmann108
4 жыл бұрын
That's because in our daily experience space and time are absolute.
@pyral514
4 жыл бұрын
@@Lehmann108 Yeah, pretty much.
@lowhanlindsey
4 жыл бұрын
That's right ladies! I'm not short I'm just moving near the speed of light!
@asterix811
4 жыл бұрын
I'll have to remember that line.
@hanskloss7726
4 жыл бұрын
Thought it was all about the technique that counted? Damned, misunderstood that again.
@RupertFoulmouth
4 жыл бұрын
Based on the animation shown in the video the comprehension happened parallel to the direction of movement so it would make you thin rather than short. 😜
@lowhanlindsey
4 жыл бұрын
@@RupertFoulmouth yeah, it was a dick joke.
@csmith1696
4 жыл бұрын
But sadly they closed their barn door before you arrived.
@MacLethal
6 жыл бұрын
This video is AMAZING.
@x666x34b
4 жыл бұрын
Einstein's "pole in the barn" is the most suggestive thumbnail I have ever seen. It casts the great physicist in a whole other light, so to speak.
@CommieBastard-dj9ot
4 жыл бұрын
Would love to have heard more about WHY things contact at the speed of light and HOW we know this. Also, wouldn't the device emitting the signal also be traveling towards alberta at the same speed as the two doors? And for that matter, wouldn't the signal itself also be traveling towards alberta at the same speed as everything else? I feel like a lot was left out.
@Volleyball_Chess_and_Geoguessr
Жыл бұрын
it's all theoretical, no? Or maybe the earth is just flat and stationary and this is all bs.
@alexbowman7582
3 жыл бұрын
I seen this guy in a tracksuit carrying a long stick. I asked are you a pole vaulter? He replied Nein, I’m a German, how did you know my name is Walter?
@BDRmongoose
3 жыл бұрын
nice
@alexbowman7582
3 жыл бұрын
@@BDRmongoose a joke by Glasgow surreal comedian Chic Murray.
@KatorNia
3 жыл бұрын
Let's assume that the doors don't open again. - What if she stops as soon as she reaches the middle of the burn? We'll see the pole expand & hit the already closed doors, but she'll see the pole hitting the rear door before it closes. How's that possible? - Now assume that the barn is round, with a diameter a bit bigger than the pole's contracted length, but smaller than it's normal length. Also assume that as soon as she enters, she starts running around (still at SoL). We see her fit in the barn & running around, but what is she seeing?
@DrDeuteron
3 жыл бұрын
If the stop signal travels at "c", the max it can, the front of the pole leaves the barn before it gets the "stop" info. The rear of the ladder enters the barn before it finds out. To understand acceleration and Lorentz contraction, you need to master Bell's Spaceship Paradox. The result is that no object can be perfectly rigid, and under uniform acceleration, there are mandatory stresses caused solely by relativity.
@hcilliers
5 жыл бұрын
I'm a complete novice... But what happens if the doors close and don't open again? From the observer's point of view, Alberta would still be stuck in the barn, but from Alberta's point of view?
@sharathkumar8422
5 жыл бұрын
Door B would close first and before Alberta could stop and get out, Door A would close too. Then she'd have to stop running cause she'd be stuck. Remember that all this is happening at near light speed so most of it would really be simultaneous.
@spookyfbi8
5 жыл бұрын
Henk Cilliers as soon as the door in front of Alberta closed and didn’t open again, she would have to stop running and because she would no longer be moving the speed of light, the pole would no longer be shorter than the barn from the observer’s point of view.
@w0ttheh3ll
5 жыл бұрын
great question - there would certainly be an explosion (as gacekky1 mentioned), but the details are a bit tricky. your example includes acceleration, because Alberta slows down rapidly either when she realizes that the door is closing or when she crashes into the door. now einstein's "special theory of relativity", on which the thought experiment in the video is based, doesn't describe accelerations. for that, the far more complex "general theory of relativity" is needed.
@ioannisk.7637
5 жыл бұрын
Everything you say doesnt make really sense when you think of what would the other observer see. For sure Alberta has to stop at some moment and when she stops she cant fit in the barn, and as long she moves in one direction it means that the back end of the pole never will enter the barn. But the doors will close when Alberta is in the barn (from the outside observator#), so the front end of the pole has to enter the barn. so whats happening from the different point of views, when it has to come to the same situation when she stops? Here the solution, again the key is time: From Albertas view: Because of the length contraction the barn is smaller than a half of its static size, so it doesnt seem Alberta will even get inside, but before the front pole reaches door B, the door closes and alberta has to stop. As she is stopping the barn, expands to its original size and Alberta will fit inside, but not the back of the pole, so door a will not close because of the pole. From the outside: Alberta is contracted and runs in the barn, but she starts stopping before she fully is inside the barn (way before, because remember, the back of the pole, at the end will be outside the farm and if you look just at the back of the pole, it has to make a trajectory only in the forward direction.). So Alberta starts expanding and before the front side of the pole reaches door B, both doors close simultaneously, but door A wont close, because of the pole.
@CrazyBeardedGamer
5 жыл бұрын
The barn would explode, and the atmosphere would be burned away.
@richardjones1224
4 жыл бұрын
If there were another person running from the opposite direction at the same time, wouldn't the doors close farthest then closest relative to that runner also? what would the runners see for what the other is going through? or can you only have 2 points of reference at a time?
@docfreeman3028
4 жыл бұрын
Not sure but I suspect the nature of the paradox is that because each opposing vaulter has a different perspective the only time they are running at the 'same time ' is at the exact moment they pass and that moment THE door that they are travelling towards are , relative to them ,open , thus paradoxically both are open and yet closed at the same time... I think?
@geoffdavids7647
4 жыл бұрын
The order of events can change based on the relative speed of observers. The outside observer would see both runners run past each other and fit into the barn with both doors closed around them as they would be equally squished. From each runner's perspective they see the doors closing in the order 'further one then nearer one' - which would be opposite for each runner. Finally, as taken from runner A's perspective, runner A would see runner B as even more squished than the barn (as to runner A, runner B would be be moving even faster than the barn) , and so A would see B fit easily even inside a squished barn just before the far-side door closed behind them, then the near-side door would close behind A, but B would still be inside and fit inside the barn due to their super-squishedness. Then the door would open and both runners would be on their way. Obviously the same set of events would be observed if you just switched the letters A and B in the above explanation - even though they don't agree on the order of events. When things move that close to the speed of light, order of events doesn't have to be consistent for all observers. Thank you for listening to my Ted Talk.
@Lehmann108
4 жыл бұрын
@@docfreeman3028 Yes, you are correct. The barn and its relationship to the pole is actually physically different for different observers. There are as many physical realities of the barn as there are observers when these observers or the barn/pole are traveling at a percentage of the speed of light. It is hard to understand this because relative to the barn/pole we are not traveling very fast at all and therefore experience the "same" barn/pole. If we had refined enough measuring tools we could quantify the infinitesimal difference between observers even at relatively slow speeds.
@danieljensen2626
4 жыл бұрын
Yeah, but Alberta would already be inside and her pole would be even shorter than the barn reference frame.
@RomainVanAelst
4 жыл бұрын
This is actually the whole point of the paradox. Every point in space is it's own point of reference. The paradox exists only when you use 1 point of reference to explain both points of references. The paradox cease to exist the moment you look at each point seperately.
@davidaldi2742
4 жыл бұрын
Jade, you are so wonderful! I totally enjoy all of your videos! My favorite is the one on the "impossible to solve" problems where you talked about rerouting roads etc. The ideas similar to the traveling salesman problem etc. You have a fantastic way that you present yourself and you emanate such warmth and positive energy! I absolutely love your animations! I live half a world away from you so I have to thank the presence of KZitem that allows me the opportunity to connect to such an intelligent, nice, gorgeous young woman! Have you every looked into the concepts of the electric universe model? Wal Thornhill and David Talbott. I find their theories very interesting. The crux of the idea is that electricity is the primary driving force of the universe, not gravity. Wal Thornhill postulates that gravity is just a special case of electrical attraction. This could be "fodder" for many many more videos that describe an alternate point of view of the forces of nature! Thank you for being you! Keep up the great work!
@declanz5067
2 жыл бұрын
Possibly my favourite KZitem video ever, that blew my mind!
@qc1okay
4 жыл бұрын
"This is where things start to get a bit crazy" (1:20 in the video). Dunno, but seems to me that a female pole-vaulter running through a barn in which a mad scientist is opening the front and back doors simultaneously is ALREADY a bit crazy.
@shufukillah6772
4 жыл бұрын
*Krazy
@torestrand2663
4 жыл бұрын
This Brainiac is AWESOME! Gotta love her, how she explains things, makes intricate stuff "easy" to understand and makes it so it's interesting. I really enjoy every video. Trying to learn something new every day :-) Thanks!
@antonnym214
4 жыл бұрын
Hyper-interesting, nicely-researched, and expertly presented. Jade is very good on camera. All good wishes!
@qwazy01
4 жыл бұрын
@3:50 Twist: The juicy part of the solution is the doors have windows ...and they're always open. Great video btw!!
@JoshKaufmanstuff
6 жыл бұрын
Here from Answers with Joe. I've discovered I love paradoxes too!
@upandatom
6 жыл бұрын
haha they're the greatest aren't they
@commonmogoreanu7135
5 жыл бұрын
It isn't just cold outside, but I also ran at nearly the speed of light!
@richfrazier8756
4 жыл бұрын
Yeah....thats it!
@zoahibahmad3480
6 жыл бұрын
please do a video on the spin of fermions and bosons, and explain physically that why and how these particles have half spin and integer spin
@samhands275
5 жыл бұрын
Isn’t it more of an analogy than a physical explanation?
@michaelsommers2356
5 жыл бұрын
Spin arises from the depths of quantum mechanics and electromagnetism, and can't be fully explained in a KZitem comment, but (very) briefly: particles, such as electrons, have magnetic dipole moments, which can be measured. This moment can be explained by ascribing to the particle an intrinsic angular momentum, which is called 'spin' for brevity, although nothing is literally spinning. This intrinsic angular momentum is distinct from the so-called "orbital" angular momentum (although nothing is actually orbiting, either).
@adithibhat7277
4 жыл бұрын
Dear Jade, I have a question for you. When the barn is moving towards Alberta from her reference frame, shouldn't the signalling instrument also move, and have to cover the same distance along with the barn, towards Alberta? (Assuming the signal is passed from inside the barn as depicted in the video) Thank you
@rudyc79
4 жыл бұрын
Sooooo. I think the real question now is, Did Alberta make it over the bar with her shortened pole?
@Dawnstar1350
4 жыл бұрын
if she's traveling at close to the speed of light and jams the pole into the pocket for the jump... there's going to be a HUGH explosion. and going back to non-close to light speed Alberta, the poles are made to bend and flex so the pole, when trapped by the doors coming back down, would have just bent and arched into the space of the barn depending on the strength of the closing mechanism.
@jjwalter5897
3 жыл бұрын
Yes, as the pole turns vertical its angle of speed changes. It becomes longer and thinner.
@jimmeade2976
4 жыл бұрын
Good explanation. "Length contraction" describes the pole getting shorter, and Door A opening after Door B is "time dilation".
@astrolillo
2 жыл бұрын
So the lesson here is dont run at high speeds or your pole will look shorter to other observers
@Holobrine
4 жыл бұрын
Why is this 3 year old video in my feed right now? I mean, I’m glad it is, but why?
@richbaker8211
4 жыл бұрын
There's a distinct problem with this, it's based on a perfect scenario. If Alberta was able to travel at near light speed, then for her to be trapped inside the barn, she would have to come to a complete halt, thus increasing the length of the pole back to it's regular dimensions and preventing the doors from shutting. Also, given that she is travelling at near lightspeed, both doors would have to close at the same speed or faster than her, closing at the precise moment she and the pole entered the barn AND were contracted to trap her. Since both she and the doors are moving at near equivalent speeds, surely she would perceive them to either be closing very slowly, or not closing at all.
@liquidminds
6 жыл бұрын
So she fit's in there relatively easy, but absolutely not. I get it now. xD
@iamTheSnark
4 жыл бұрын
*fits*
@SpydersByte
4 жыл бұрын
lel.
@Smeggit7
4 жыл бұрын
I'm curious how this would work if you added a light that turns on only if the doors are both closed. From our perspective the doors are closed simultaneously so the light would turn on but from the pole vaulters perspective the doors are not closed at the same time so the light stays off. Schrodinger's light?
@BobfromSydney
4 жыл бұрын
There are two ways to implement your proposed light. The most straightforward method is to have the light attached to the controller that switches both the doors open and shut, the other is to have one or more sensors located at various locations that then send a signal to activate the light. I think you can see how various issues can occur once Alberta begins travelling towards, through and past either type of set up at relativelistic velocities.
@rvirzi
4 жыл бұрын
That's a very interesting "what if" question. I think the answer lies in trying to measure the condition "at the same time". It requires a clock at both doors which reads the local time when the door closes, then sends those times to a "sensor" at a central point (say in between) once the measurement is made. The sensor cannot not decide to light up until both measurements arrive. From the stationary point you would expect everything to happen normally and sensor lights up. What about from Alberta's viewpoint? Well, the barn is moving away from her to the left, so when B closes, it will take much longer for the time measurement to reach the light sensor, and when A closes later, the measurement will get to the sensor faster. Since the relative speed is the same, the delay between measurement arrivals exactly matches the delay between door closings, so they are guaranteed to arrive at the same time in the moving frame. So far so good - but will the clock measurements also match? The answer is yes, but that is even harder to see. In relativity, the idea of simultaneity kind of goes away. You can only tell what a clock will say by extrapolation. In Alberta's frame, A is closer to the sensor than B, and yet the light signal reaches them at the same time. If light always travels at the same speed, that would be impossible unless the clocks were ticking differently at both locations. By extrapolation, the local time of closing MUST be identical for A and B, even though Alberta would not see them close together by the time the signal reaches her (which is measured in a much different location!). This was always another inherent paradox of relativity - that something could look simultaneous when measured from one place and not simultaneous when measured from another. But in short, the light would turn on in both reference frames. I love how special relativity problems always work out like that.
@hulkrae
4 жыл бұрын
The more I read/watch about relativity, the more I don't get it. 😂
@markrobbins2441
3 жыл бұрын
Redo so that she is carrying a flashlight, and the doors close as she enters, and remain closed for as long as it takes for light to traverse the barn. From other perspectives... How fast is the light if she is at light speed, and does the beam always hit the other side.
@truecrimeraw4545
3 жыл бұрын
"length contraction" happens to me in swimming pools.
@oldtimer5111
3 жыл бұрын
Boy you must be able to swim really, really fast.
@BDRmongoose
3 жыл бұрын
@@oldtimer5111 😊
@vincenzodevito6999
Жыл бұрын
Conway you are a genius!! You are a great teacher and are able to explain abstruse physics concept with very illustrative videos. I plan to watch every physics video that you will post. So far I have seen about a dozen but I won't stop until I will be able to see them all!!
@justsittinhere72
4 жыл бұрын
All I know about Albert is, he plays cards with Isaac, Steven and Data and they're not relatives.
@randomgrinn
3 жыл бұрын
I also know he was born male, stayed male, did not have a blonde ponytail, and was not a millennial.
@ehmaree
Жыл бұрын
Every time I think I understand Einsteinian relativity, something like this comes up, and I'm confused once again. Great video!
@OleTange
4 жыл бұрын
Imagine a guillotine. It is 1 light second long and the height difference between one side of the blade and the other is 1 m. Now bend the blade, so it is an arc. This way you can stand in the center exactly the same distance from every point of the blade - just like if you stood in an arena of a circus. Now the blade moves down at a steady pace of 0.9c. All along the blade there are pins that are cut whenever the the blade meets the straight edge in the guillotine. At what speed does the information of what pin is cut travel from one end of the arc to the other end, and at what speed does this information travel to the center of the arc? When the blade has moved 1 m down, the point where pins are cut has moved 1 light second. So when the blade moves down 0.9c how fast is this point moving? Does the point contain information (well if it is not pins, but your neck it is an important information whether your head is chopped off or not).
@mysteryhombre81
4 жыл бұрын
You need to explain that more clearly bro.
@danieljensen2626
4 жыл бұрын
You can't have a circular blade 1 light second in diameter/circumference and have the highest edges of it be 1m above the cutting block unless it has already cut almost all the way through your pins... For more practical numbers let's say the blade is a semi-circle 10 meters in diameter. If the highest edges are 1 meter above the cutting block then you've got 4 meters of blade already sticking through the block. But either way, no, you cannot transmit information based on where the edge of the blade is. There is a more famous example of this with a pair of scissors a light year long, where the point the blades cross is allowed to move faster than light because it doesn't transmit information. For a much clearer example, you can shine a laser at the moon. If you flick the laser across the moon really fast the laser dot may appear to move faster than the speed of light across the moon's surface, but there's no information being transferred between the different points you shine the laser at so that doesn't violate relativity.
@OleTange
4 жыл бұрын
@@danieljensen2626 It is not a circular blade. It is a flat blade, that is bent. Another way to explain the setup is: Imagine a knife. Stretch the blade so it is 1 light second long. Stretch the blade so that it is 2 m tall. Now cut a triangle from the blade: The triangle is 1 m tall and 1 light second long. This leaves a 1 light second long blade that is 1m tall at one end and 2 m tall at the other. This is the guillotine. Now bend the blade (just like you would could do with a long knife) into a circle.
@danieljensen2626
4 жыл бұрын
@@OleTange Ah, I see, the bend is in the horizontal direction while the blade is falling vertically? That makes a lot more sense. In that case, yes, the point where the blade meets the cutting block (which I assume is also circular) would move much faster than the speed of light, but that doesn't violate relativity because the point doesn't have mass and doesn't transmit information. The information about when each pin would be cut would arrive to you at the same rate the pins were cut, but with a constant delay. For ease of calculation let's say 1 light second is the radius of the semi circle rather than the half circumference, then the delay would be exactly 1 second. Physically you're going to have a lot of trouble getting a blade that long to move all at the same speed though. If you take a knife and swing it the force of your swing is only transmitted from your hand to the tip of the blade at about the speed of sound within the metal. That's also why you can't cheat by using a light year long stick to push a button in order to transmit information. It would take much more than a year for the far end of the stick to move after you started pushing your end.
@HenningStrandin
4 жыл бұрын
This is the best explanation of time dilation _and_ length contraction I've seen so far. (My first exposure was in Nigel Calder's _Einsteins Universe_ in secondary school.)
@jaydawg7820
4 жыл бұрын
When are we going to Stop the confusion of 'light physics' (perception) and 'physical physics' (actuals) ... ? Contraction is just our perception ....
@yotodine
4 жыл бұрын
when you realize that without the physical light has nothing to bounce off of! duh
@Lehmann108
4 жыл бұрын
Actually no. At a percentage of the speed of light the pole really is shorter. To understand this "paradox", because it really is not a paradox, you have to understand special relativity. In short, special relativity reveals that time and space are variables that change with the speed of the object being measured. Time and space are not constant for all observers. If and when you truly "grok" this it will blow your mind. If you really want to get this, read the slim volume that explains this and offers a brilliant geometric proof, "The Universe and Dr. Einstein."
@danieljensen2626
4 жыл бұрын
It is NOT just perception, time and space do actually change depending on the relative velocities between the objects in question. The perfect proof of this is muons. They are formed in the upper atmosphere by cosmic rays colliding with air molecules. We know how long muons last before they decay, and in that time it should be impossible for them to reach the ground from the atmosphere even traveling at the speed of light. But they DO reach the ground before decaying. This is possible because in our reference frame time moves slower for the muons, and in the muon reference frame the distance from the upper atmosphere to the ground is shorter. Here is a video explaining this. kzitem.info/news/bejne/04ywqoRujH-Zg6Q
@Graeme_Lastname
4 жыл бұрын
Time changes to space and space changes to time. As simple as I can put it. ;)
@warrenhls3083301
4 жыл бұрын
Yes its a dilation effect like the doppler effect, the pole doesn't get shorter, also if she is traveling near the speed of light the doors couldn't close faster than she could run through the barn
@rancol23
Жыл бұрын
Fascinating special relativity weirdness that I had never heard before. Thanks!!!
@bagelstruth9313
7 жыл бұрын
I have wanted to know the answer to this since I hit puberty.
@upandatom
7 жыл бұрын
+Bagels Truth well hopefully now you know!
@adityakhanna113
7 жыл бұрын
+Bagels Truth You didn't!
@eternalnaught
4 жыл бұрын
I love your videos. You break the complex down into juicy, bite sized pieces and I love the animations not to mention your personality and genuine passion for the subjects! Perhaps it is just me, and to be clear I am not a mathematician but it seems most paradoxes are rooted in the contradictory nature of communication. Even math or the game of numeration seems to forget the fundamental role of the "counter" (the observer). I mean in Einstein's pole in the barn paradox, the definition of the terms used to pose the idea change in the middle. The doors close and open at the "same time" but time is relative and each door closes and opens differently dependent on the speed and position of the relative observer (the pole). Also, the pole length is clearly defined as longer than the width of the barn but then those terms become fuzzy when dealing once again with the relative pole. I can see the front of the pole is shorter when moving quickly but doesn't that contradict the earlier claim the pole was longer than the barn? The terms are fluid and the role of the observer is key. The same with the idea of the continuum vs the discreet in math. It's and easy thing to say something is discreet but a much harder thing to define. Pairing up oranges and apples to denote equivalency numeracy is just as hard. How do we distinguish an apple from an orange. We can agree but that is not quite good enough for math (or is it). Where is the edge of an orange? If size is relative and speed is relative then defining a thing as "bigger" or "smaller", "inside" or "outside" becomes much more difficult and so the questions using those terms are not very clear. Perhaps some wacky "external" perspective "moving" at some wacky rate through wacky "positions" may conclude the pole entered the barn but never exited or it entered it and exited at the same "time" or nothing is moving at all and the relative sizes simply change. It seems to me paradox is rooted in perspective and reflects the contradiction of being (terms require definitions which require terms). Classic chicken and the egg. Perhaps the discreet and continuum are the same "thing" but viewed from different perspectives. Anyway, after such long wind I want to end by thanking you for your work! It's so much fun and very informative! Thank you! Thank you! Thank you!
@ChrisNostalgic
7 жыл бұрын
Your drawings are soo cool :)
@upandatom
7 жыл бұрын
+Chris Nostalgic thanks! I just checked out your channel it's hilarious. "PhD in little shits" haha
@ChrisNostalgic
7 жыл бұрын
Haha thanks for watching :))
@Tony_Regime
4 жыл бұрын
if the barn can be treated as moving due to its relative position to the observer then by that logic the stars are moving around the Earth at many times the speed of light. given that the closest star to the solar system is roughly 4 light years away it appears to travel approx 25 light years in a 24 hour period, or just over 1 light year per hour.
@danieljensen2626
4 жыл бұрын
It only works for constant motion without acceleration. Rotation requires constant acceleration (acceleration is a "change" in velocity, changing direction at a constant speed counts) so it breaks the symmetry.
@spencercase5370
4 жыл бұрын
I’ve always been curious about this
@poorplayer9249
7 жыл бұрын
The fastest any of us have traveled? Wouldn't that be 108,000 kph (70,000 mph)? :D Another good video. Thanks.
@upandatom
7 жыл бұрын
+Karl Kiefer haha well yes I guess technically it would be... Thank you I appreciate it :)
@mykobe981
6 жыл бұрын
about the speed earth revolves around the sun, 'eh? nice one. if we're going there, might as well throw in the orbital speed of the sun around the galaxy core.. and the speed the galaxy orbits the local groups center of mass.. then.. wait a minute.. at some point we lose sight of what we are moving relative to! :P
@TbirdMan
4 жыл бұрын
Cool and very easy for anyone to understand. Good teachers are a rare breed.
@TheRealUnknown01
4 жыл бұрын
i read this as "Epsteins pole in the barn paradox" lmao it was so much more interesting before i realized it was einstein lol
@miguelhernandez72
3 жыл бұрын
Great video! Good hook at the beginning and delivery at the end. I was at the edge of my seat the whole time, at least from my frame of reference.
@vikingslayer34
4 жыл бұрын
You saying juicy like you do makes me think bad things...
@PedroHernandez-uy3pi
3 жыл бұрын
Jade i think might be my new fav educational channel
@3d1e00
6 жыл бұрын
So you can claim your questionable manhood magnitude is actually due to the near light speed velocity you have achieved.
@metricdeep8856
4 жыл бұрын
I can't get an erection as fast as can explain the "shortage"
@jaimeduncan6167
7 жыл бұрын
Hi, very good explanation. There is a detail: The effects are evident in two ways: 1. Like you say relative velocity is close to the speed of light. 2) you stay in the movement for a long, long time. An example of the later will be a satellite or space prove. 3) You have a super sensitive equipment, but this one does not count for the evident part.
@ericsu4667
7 жыл бұрын
Special Relativity is consistent only in mathematics. It does not describe physics. Therefore it works only in virtual world. In reality, object does not become shorter. You will be become flatter if you run faster. vixra.org/abs/1703.0169
@Cruz8R
5 жыл бұрын
I think Alberta is a distant relative of Albert Einstein.
@jdanielcramer
5 жыл бұрын
Ok, hold on a sec. since Alberta is the one in motion, is it true to say that the barn would actually contract from her viewpoint? And, wouldn’t the timer that generates the signal also be moving with the barn (relative to Alberta) and thus negate any alteration in the timing signal? I’m confused🙀
@jdanielcramer
3 жыл бұрын
And two years later 🤔 having forgotten I ever saw the video, would I still be confused? 🙃
@xXCrossGamingXx
7 жыл бұрын
why does she say juicy so seductively...and why is the title a sexual innuendo
@jaimeduncan6167
7 жыл бұрын
Seek therapy before you hurt someone.
@Edgard422
7 жыл бұрын
HOW TF is that tittle a sexual innuendo?
@leahhobart4322
6 жыл бұрын
Bowzin cuz it sells.uf it takes INNUENDNO to learn this is just get views its win win formula WHY NOT? STILL I LEARNT SOMETHING..IM A STRAITGRL.
@Jadinandrews
6 жыл бұрын
Leah Hovart, the current title is fine, and I don't think it is sexual at all. The previous title was "How To Fit Something Long Inside Something Short", which judging from Jade's other videos was probably an innocent mistake.
@EmmaHopman
6 жыл бұрын
Don't worry everyone, he is a 12y/o
@prestonrodenkirch8412
3 жыл бұрын
The doppler effect in a spacial frame of reference instead of an audio frame of reference. Makes perfect sense
@Athrun000
6 жыл бұрын
Nice video. But with all due respect, I think the traditional version using the train and the tunnel is easier to understand.
@sammylane21
3 жыл бұрын
I wish Jade was my HS Science Teacher. My actual Science Teacher was an old guy. Jade is a Teacher I'd have paid more attention to in class.
@randomgrinn
3 жыл бұрын
Einstein was an old guy. But wait! Let's pretend he was a transsexual millennial with a blonde ponytail! Totally reasonable!!
@adityachk2002
3 жыл бұрын
I always had this question, glad I found it
@GlynWilliams1950
4 жыл бұрын
Very well explained. Can I humbly suggest that SI metric units are used. They are internationally used and accepted but imperial are only used by 3 countries and some of the units are not even agreed upon.
@Tletna
4 жыл бұрын
The US is one of those nations and represents a large fraction of the viewers on KZitem. It would be good to use both though.
@christophertatro2352
4 жыл бұрын
So quick question. If you were on an object and applied force to the object to get it to the speed of light and you were looking at another object. Could you technically say the other object is moving at the speed of light away from you even though no force was applied to it? Also, does this mean protons are larger then they appear? Like, if you froze a proton, It would be larger than when it's moving?
@briancherry8088
4 жыл бұрын
I think this paradox is a good example of science trying to make their hypothesis fit the universe. Sometime in the future people will look back at us and say "remember when people used to think that they shrunk when approaching the speed of light", and laugh.
@PotentiallyAndy
3 жыл бұрын
I was completely ok with physics .... now I realize I’m a total noob. I love this :)
@Pandaemoni
4 жыл бұрын
So what if you don't open the doors again after she is safely inside? Assuming she can't turn around and escape through Door A before it, in her frame of reference, closes after Door B (her turning around to run back out Door A would involve her accelerating, which changes everything). From your frame of reference both A and B close simultaneously with her fully inside. From the pole vaulter's frame of reference, B closes first, then A and her pole if too long to fit inside the barn. So does she see Door A close on and hit her pole?
@lymantryon5538
4 жыл бұрын
The problem is that the clock is in the barn, and it also experiences the lengthening/shortening issue, so the signal will have the same distance to each door. Relativity is all perspective-based. i.e.: if the rocket gains mass as it approaches light speed, so does the fuel, and everything that deals with that fuel. At light speed, concepts like time, distance, volume, and mass all take on different meanings. Does compression of an object moving at that speed reduce it to a singularity on the part of some observer somewhere, or does the object gain the properties of a wave form? Nice thought experiment, all in all.
@Nosirrbro
4 жыл бұрын
It should also be noted that when traveling at these speeds, if you were to look at the pole-holder she would not be contracted, but rather rotated to the side. This isn’t a consequence of any actual physical process, but rather the fact that when you are moving at a speed near the speed of light, the way the light would reach your eyes is impacted beyond the actual physical change to the object
@truetothefaith6610
4 жыл бұрын
This is an interesting concept, and being the kind of person that loves to think about things (especially when it comes to physics), something like this appeals to me. I had questions but after some thought, I was able to work them out.
@johnny_medicot927
4 жыл бұрын
The fun thing about these "paradoxes" is that they are not really paradoxical if you realize how Einstein showed us that time and space are stitched together neatly so that when one is tugged on the other "gives" to maintain an overall theme of invariance.
@gevmage
4 жыл бұрын
This is a fantastic explanation of the paradox. This is at least as or more cogent than the explanation I got in physics class (I went on to get a physics degree). I've never heard the part that the "signal" propagating forwards and backwards is why the non-simultaneous doors work in Alberta's reference frame, but that makes a lot of sense. I like this. Great video. Cool!
@johntiloshvilli
4 жыл бұрын
A few of my favorite paradoxes in physics are the Tolman Lever Paradox and the Gravitating Charge Paradox. The Tolman Lever paradox has had some very questionable explanations but Tolman himself came up with a reasonable explanation. The gravitating charge paradox deals with General Relativity: If an accelerating charge radiates shouldn't we be able to distinguish an accelerating frame of reference from a non-accelerating frame with a gravitational field by observing charges at rest relative to each frame. In the non-accelerating frame, we should see no radiation but in the accelerating frame we would, so it breaks the equivalence between gravitation and acceleration. Richard Feynman gave a resolution to this paradox but some physicists are not happy with his solution.
@danieljensen2626
4 жыл бұрын
I always forget that simultaneity is also relative, somehow that's even harder to wrap my brain around than length contractions and time dilation. I suppose the the fact that we don't get many homework problems on simultaneity doesn't help.
@royceparkjr5559
4 жыл бұрын
Nice explanation & graphics, but what was the pole jump height & did she make it? 🤔 Traveling that fast would be hard to hit the correct spot & bend the pole, etc. Now I'm worried about her... Please give update on outcome... 🤗
@Ashlynn.HudsonWelburn
2 жыл бұрын
One of my favourite physics paradoxes
@clickster1883
4 жыл бұрын
I learn something new every time I watch another of Jade’s videos. In this one I learned that Einstein was a blonde! Mind. Blown.
@rick4electric
4 жыл бұрын
When things contract in length, it is known as length contraction! That's really good, which is also known as good reality!
@kingbeauregard
3 жыл бұрын
There's a version of this they had in my physics text ages ago (Kenneth Crane, "Modern Physics" I think). It involved an incident report filed to the Intergalactic Federation about one ship taking hostile action against the other. The report read: "As the Zyrglion ship approached us -- and it was a much shorter ship -- first it fired at us with its aft lasers and nearly hit the front of our ship; and then, when it passed the back of our ship, it fired its forward laser and nearly hit the back of our ship. Dude wanted to start an intergalactic incident." The Zyrglion captain filed a report in response, that read: "That Cyrliod captain must be on space LSD. First of all, our ship was a tiny bit longer than theirs. Secondly, as we were passing their ship, we fired our forward and aft lasers at the same time, as that is the intergalactically understood greeting of friendship. Leave it to a Cyrliod to misinterpret a greeting."
@NVME57
3 жыл бұрын
I'm genuinely curious about this. Does your explanation of the order in which the barn doors close mean that the timing of the doors beings closed is dependant on the direction in which the girl is running? What if she was running from right of the barn and passing from B to A? Would A close first then door B? The part that is confusing me is that the signal to close the doors is started at the same time but for some reason reaches a different door depending on which direction a person is running. What if there were town people running with poles from both directions but they don't collide because the barn door is big enough for them to both pass through. Do both doors then open at the time each runner arrives or are they both closed because of the signal being delayed by the direction the opposite runner is running. Basically why is the signal slower or faster in either direction? Why is the signal not in tune with the barn itself?
@davidg81815
4 жыл бұрын
I always see this paradox explained with the doors closing on a timer. But what happens if instead of a timer, a solid cage is lowered around the barn--for a split second. Does the paradox still hold up? Can the pole vaulter fit instead the cage that is half the size of the pole?
@paulschirf9259
3 жыл бұрын
It is even more fun when Bob is running in the opposite direction with a pole of the same length and he sees the doors open and close in the opposite order!
@yigalhakak2330
4 жыл бұрын
This is the question: from Alberta`s reference, everything is moving, accept herself. "everything" includes the contraption itself, that from her reference is fixed to the barn. This means, that door A is not "running away from the signal" and door B is not running toward the signal - they are all fixed to each other and stay in the same distance between them . The explanation you gave is correct only if the contraption is fixed to Alberta, and that is not so.
@ericlondon5731
4 жыл бұрын
Relatively speaking, Einstein's special theory is mostly incomprehensible, even when explained very well by a beautiful intelligent lady.
@robertbutcher222
6 жыл бұрын
The way I see it, there’s some missing information, how fast do the doors open and close, how long in between each action? If she’s traveling at light speed, it seems as if she wouldn’t have to wait for the doors, just go in and out in one swoop, canceling out the paradox. Or am I the one whose missing something?
@KamalaLovingMan
5 жыл бұрын
robert Butcher she's not traveling at the speed of light she's traveling near the speed of light, huge difference
@davidtipton514
Жыл бұрын
Great video, and a good look at what Einstein proposed. (Your background music had me searching for a ringing phone, though!)
@johnmcclain5972
4 жыл бұрын
Question The doors swinging. The fixed end is not moving but the other would be moving at the speed of light. How would this show in the problem?
@NM-pi6ve
5 жыл бұрын
What happens if the runner stops suddenly in the barn with both doors closed? What would each observer see?
@NM-pi6ve
5 жыл бұрын
@Matthew Morycinski suddenly is relative, but from the point of view of someone standing outside of the barn, they can see Alberta in the barn with both doors closed. All of Albertas momentum (which includes the pole) is transferred or disipated at this instant and now she has zero forward movement relative to the barn, so she has stopped moving relative to the barn with both doors closed as seen by the observers point of view when standing outside of the barn. I hope that defines "suddenly."
@scudder991
5 жыл бұрын
Truly enlightening and entertaining description of that Special Relativity Paradox. Well done!
@armus550b
4 жыл бұрын
Thank you. My physics teacher got me with this 28 years ago (kid on skateboard approaching crack exact length of board, does he fall) and she never answered it. So I've been waiting for the answer all this time. This isn't quite right but it's close.
@pramienjager2103
4 жыл бұрын
I'm going to go out on a pole and say no. The movement doesn't affect the signal. As Alberta runs into the barn with it's doors open the barn behind her stretches out by double what it contracted in the first place. Meaning her pole (giggety) easily fits. Both doors close and open and she runs out the back.
@dcterr1
3 жыл бұрын
Speaking of paradoxes, how about the EPR paradox? Have you done a video on that?
@mischatal
6 жыл бұрын
Thank you. I could not understand it until you mentioned the time in frames part when it actually made sense.
@romanus2312
Жыл бұрын
After following your channel for a good amount of time, I stumbled upon this vid, and just wanted to say hi to the old amazing you.
@PeterBoardman1
5 жыл бұрын
Hey. Love your channel. I understand what your trying to say but there's two huge flaws in the paradox. Flaw #1: The speed of light is constant. It would travel the same speed from the clock in both directions (forwards and backwards). It doesn't matter if the barn is traveling at the speed of light towards Albert. Flaw #2: Who's to say there's only one clock that controls both doors? Theoretically, you could have 2 timers, independently controlling the doors. Even if you disagree with flaw #1, you could include a delay function to counteract the timing - forcing both doors to truly be closed at the EXACT SAME TIME. So, if the doors are truly capable of being closed at the same time, then the two relative perspectives contradict and the paradox is impossible. The truth is: nothing with mass can reach the speed of light - so it's an invalid paradox.
@arnavnaidu8883
5 жыл бұрын
Yes,indeed the speed of light is constant but from the reference frame of the moving person,the barn is also moving. Thus,the total time it takes for the signal to reach the doors will be different(because of the direction). Talking about the second flaw u told about,what do you mean by exact time?...exact time in whose frame? If u do fit 2 clocks and have some sort of computer that could calculate the delay and compensate for that,then in the earth’s frame the doors would not close at the same time.
@arnavnaidu8883
5 жыл бұрын
The paradox does not talk about the person moving at light speed.It is moving at velocity CLOSE to speed of light.The closer u are ,the more pronounced these effects would be (I’m talking length contraction and the time delay)
@PeterBoardman1
5 жыл бұрын
@@arnavnaidu8883 right. So, assuming we have a contraption that does manage to close both doors at the same time (from Alberta's perspective) then the whole thing breaks - as Alberta's pole is twice the length of the barn. If it's at all possible for the barn doors to be closed at the same time (from any perspective) this whole paradox breaks. My point is: it's not really a paradox. It's an impossible scenario. I don't believe that anything with with mass can travel with a high enough velocity to be effected by length contraction.
@arnavnaidu8883
5 жыл бұрын
@@PeterBoardman1 If the experiment breaks in alberta's point of view. It would also surely break in earth's frame.And well, we dont really see objects moving at speeds close to light. But it is pretty common to see such speeds at space.As of now,we have only been able to move protons at 99% of c. Who knows,we might also get to move macro sized objects at those speeds in the future. Btw, i remember now, u dont really have to move at speeds close to light to feel dominant effects of length contraction. Magnetic field can be explained as a consequence of length contraction and electric field. isnt it amazing? It is happening at all speeds, just that the effect is so small at slow speeds,that we cant notice it just by seeing. But we can definitely feel its effects.
@aaroncurtis8545
5 жыл бұрын
@@PeterBoardman1 maybe a point that's being missed here is that if you fix it so it's simultaneous for Alberta, it will then not be simultaneous from the earth perspective. And naidu is right about the clock signal. Yes, it (light) moves the same for all observers... But does take Time. And the measure of time passed is going to be different for the different observers.
@MacShrike
5 жыл бұрын
Sooo… but if she is in the center of the barn, from Alberta'r view, the barn is contracted but the pole still the same size. So there is a moment that, from her point of view, the pole would be sticking through one of the closed doors right? And what about if she instantaniously stops the second on of the doors is shut? right?
@richardschofield2201
4 жыл бұрын
The doors just confuse matters. Take the same problem but with a bar with openings instead of doors. You still have a paradox because from your frame of reference the pole fits. From Alberta's reference the pole is sticking out from both ends. There's still a paradox to solve there.
@paulpresto673
4 жыл бұрын
Love science and love your channel, Jade! Maybe some stuff regarding quantum reality?
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