(Recommended)Popular Videos : [Veritasium] Does a Falling Slinky Defy Gravity?
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(Recommended)Popular Videos : [Veritasium] Does a Falling Slinky Defy Gravity?
https://www.youtube.com/watch?v=uiyMuHuCFo4
Summary Comments : [Veritasium] Does a Falling Slinky Defy Gravity?
ma***************:
1. show this to primitive, backwards desert people 2. ??? 3. profit!!! ahlulululu
Playtime Comments : [Veritasium] Does a Falling Slinky Defy Gravity?
So******:
At 0:40 I thought Sherlock's theme song was going to play.
Lu*******:
0:14 so satisfying the slinky falling on beat
Va*******:
I love how at 0:40 you start getting both a longitudinal and traversal wave. also seems that traversal one is propagating faster, interesting.
Lu*********:
At 0:00 you're nothing short of a model. Your pose, your gestures and gaze, your classy clothes, the image quality, the slow motion and the slinky's motion, make it a fine clip. Companies would pay a fortune for such videos.
Sp*************:
@4:20 that sweat
Co************:
I noticed that although the bottom of the slinky doesn't fall, it does spin at 1:20, so there are some forces that make there way to the bottom before it starts falling.
DS***********:
4:15
Top Comments : [Veritasium] Does a Falling Slinky Defy Gravity?
Ro***********:
My explanation: There is tension in the slinky - The top pulls the bottom up and the bottom pulls the top down. When the slinky is released, gravity has a downward force on both the top and the bottom, but the tension has an upward force on the bottom equal to gravitational pull, keeping it at rest. The opposite happens with the top - The force pulling it down is double gravitational force. At least this is my hypothesis - If someone can possibly determine the acceleration of the top part, it would prove/disprove this.
AS*******:
Great to have met you in San Fran!
Sa*:
"Awesome HD Slinky Slow-Mo."
Ru**************:
What happens if you drop the bottom first, will the slinky fully extend and the top won't move? @Veritasium
Ra***:
I saw this video featured in an episode of QI
In***********:
Don't worry, this physics glitch will be patched out in the next version of the universe.
ed**********:
Ok so here is what I think. If i am wrong (witch probably) feel free to comment. The reason why the bottom doesn't touch the floor before the top is because the bottom is being pull by the top. Why? because is a spring, even if its coming down still have gravity or force to pull it up. I'm sure there is an equation somewhere for that. Now lets go a little far here, hover-boards, how do they work? or better question how do we think they work? So far the only hover-boards that we had made are with metal, magnetic and cooling system if i'm not mistaking. if the bottom of the spring by doing this action doesn't touch the floor, then is it the bottom hovering the floor? now imagine you can expand this Slinky for miles up, the bottom's not going to touch the floor till the top collapses or comes down right? maybe, here is the solution for hover-boards. Don't ask me to explain the science i'm not that smart.
Bu********************:
So I take it that gravity pulls it down but the equal tension upward keeps parts of it static?
Gu*********:
It's like reverse Loony Toons. There, their heads would always be the last part to fall down, and here it's the bottom that's the last part to fall down.
Na***********:
what happens with a slinky in space held at different ends and released at the same time? Does it pull toward its centre? And is it at the same speed as 1G on earth?
Gl********************:
An interesting second experiment: drop a ball next to and simultaneously with the slinky. The following questions are left as exercise for the reader. Comparing the 'top end' speed to the ball, which would fall faster? Comparing 'center of mass of slinky' and ball, which would fall faster? At what point would the ball (if ever) would the ball pass the end of the slinky?
Et******:
Amazing, the very first anti-gravity device, and it costs 1$ for 2 at the dollar store...
ti******:
This is nothing new. Any medium (material) has a propagation speed related to its tension and density. It takes a certain amount of time for the information (slinky being released) to propagate to the bottom of the slinky. It takes a certain amount of time for a compression wave of air molecules (sound) to travel through air. The speed of light is telling that space has something analogous to tension and density.
Sg*****:
So.. a slinky of infinite length.. could hover?
Ma***********:
What would happen if you were to hold a slinky up from the middle so that the the slinky is in the shape of a horseshoe, and then drop it?
Ta****:
I think the graphs with the center of mass are somewhat good for the understanding, however the talk of "information" likely isn't. I'd also point out that really any object acts the same when we hold it at the top and then let go. The effect is just not visible.
We***********:
the channel never gets old
cu*********:
When the slinky is held from the height it has tension on both the ends. On the top there is more tension than at the bottom end which is gravitational pull. When it is released, the top end cancels out the tension faster also acceralated by gravitational pull and the bottom is already at a neutral level. So the top end goes down first followed by the bottom.
Da******:
So in theory, if I strap two slinkies to my feet that reached higher than world trade center and I was hanging a few feet of the ground. I would float for a few seconds before slaming my face to the floor?
Za********:
Can you have a quantum slinky where the two ends are entangled? :P
Ha********:
I can't help but look at the fact that the other end of the slinky stays statonary
Be**********:
I don't think it's a "signal". It seems like it is the design and the tension of it being stretched. Just because you let go of the top doesn't mean all the tension holding it in that position will just disappear. Like if you stretch a river and and let go of both ends at the same time, the tension is stronger than the gravitational pull on it, so it has to react before it can fall
Da**************:
suddenly i feel that the loony toons were on point
Ch***************:
OK, with only under grad knowledge of physics (core curriculum at that) I'm thinking this has more to do with gravity and spring torsion than "signaling." Basically, when you're holding the spring, gravity is pulling down on it, stretching it out as your hand is pulling up on it's top end. When you release the top, gravity and the reclamation of the torsion are in equilibrium until the spring fully compresses. The small amount of slacking toward the end is from imperfections in the experiment (including the inevitable loss of torsion every time a spring is flexed).
xE*********:
WHY IS GRAVITY NOT PULLING THE BOTTOM OF THE SLINKY TOAWRDS THE GROUND? D:<
Sh*********:
I love this physicist. "This looks to me much more realistic." "Well, it is. That's why I did it." And then "A lot of people on the internet get uncomfortable with the term information" You can almost feel the urge to say "A lot of people on the internet are stupid."
Mi******:
Interesting demo but it is not because the information has not flowed to the bottom of the spring, that happens almost as soon as the spring is released. The bottom of the spring is moving up towards its centre of mass as it’s centre of mass is falling under gravity minus the residual tension of the upper part of the spring. I did these calculations while studying springs in engineering. It was flight of fancy stuff as we were looking at the action of large valve springs where effectively you can discount gravity but it is still an element in the formula. The same is true for a solid bar which stretches when suspended vertically and then contracts on release.
Su********:
So when you stretch the slinky out with gravity and then let go, it's already in balance between spring tension to contract, and gravities pull right? Then when you let go of the top end the spring force pulling up equals the gravity force pulling down and that's why the bottom doesn't move?
Kr*********:
I love physics. <3
SI*********:
Note that these demonstrations start with the Slinky held stationary, so it is as a coil spring extended by gravity toward the bottom. In this mode, the spring starts in tension that's equal to the pull of gravity throughout the spring. When the Slinky is released, that tension is applied against the center of mass that falls only slightly slower than the collapsing top while maintaining equilibrium against gravity toward and at the bottom. The Slinky's contraction starts and is maintained from the top which is freed and collapsing under tension also against the center of mass (below it) while also falling with the force of gravity, accelerating at a rate near 2 G's. The resulting standing wave cannot propagate faster than the falling center of mass while the length of the released Slinky contracts when its bottom is maintained in equilibrium between gravity & contraction. A much stiffer and/or shorter spring wouldn't likely behave this way because the natural frequency of the spring would be too high for the C.G. to catch it in its descent. Rotation of the bottom coils results from the way all contracting extension springs are made in which a twist of the wire (around the wire's axis) is accompanied by helically coiling the spring so that it maintains a fully compressed form until extending forces are applied; the wire-twist stores and releases spring energy, twirling the coil around its helical axis in a screw-like manner and increasing the coil diameter slightly as it contracts in length.
Ja**********:
Watch the little white dot move across the screen starting by his feet as the slinky hits the ground in the first drop of the silver slinky. This is something I see all the time especially when filming myself and others hitting golf balls. I used to think it was a piece of light material being blown around by the wind or something deflecting off of the club, but it kept happening and sometimes it seemed to defy the laws of physics, so I kept searching for an explanation. I think it is because, as objects, especially metal objects with strong reflective properties that can also expand, contract, bend etc. as they store and release some kind of kinetic energy (golf club and slinky are perfect examples).. their centers of gravity shift and wobble and rotate constantly with respect to the camera lens, and the white spot is essentially the representation of the objects center of gravity returning to a fixed position as it approaches its resting state. This could be something else but it is the EXACT kind of thing I have spent many hours learning and coming to understand to the point that I am able to capture the phenomenon at will, and even control it's starting point and the movement across the screen that it exhibits. For example when I swing a golf club, the club is moving on an arch, and I swing the club back and up with pressure exclusively in my right hand, so the club is anchored and hinged with my conscious feeling being that it is several inches shorter than when I apply pressure and hinge the club at impact with my left hand. When I do this, for those of you who have some piano playing experience, I do so the same way you play notes "legato" on the piano... meaning I release the right hand and grip with the left with one conscious command, as though the action is not two seperate but one simultaneous. It feels very much like the club is getting shorter on the way back, and immediately becoming longer when the hinge/anchor point changes. This happens in an insanely short amount of time and in conjunction with the club impacting the back of the ball as well as the ground, releasing the clubs stored energy... it is also precisely when the white dot appears and moves "impossibly" across the screen. It is easiest to anticipate in terms of where to put the camera and where to position myself relative to it, and most apparent on the recorded video when the sun is between 30 and 45 degrees, do mid morning or mid to late afternoon, when the sun is still very bright but the shadows are elongated noticeably more so than the actual length of the club. My hypothesis is - the center of gravity is rotating and moving up and down during the swing, and the club is bending and twisting with enough force and it is changing from a horizontal plane to a vertical impact plane, so the stored energy is actually being released through impact at exactly the same time as the club is being tilted and rotated in to the upright position. I believe this causes it to create an overlapping event in which the clubs center of gravity is undefined, for a tin tiny tiny fraction of a second. You can clearly see that there are, in some cases, as many as 12 extremely bright halos of white light that simultaneously flash on the shaft at the moment the energy is released, and in the very next frame, the image and position of everything, including the ball and club and me and EVERYTHING else is in the exact same position (which is weird, given what happens next) and the only change is that the shaft of the club is no longer metallic with bright dots up and down it, instead it is a dim, slightly shorter, transparent shadow. This is with a high definition, 1000 frame per second, slow motion setting. In the following frame the club is not visible because it appears to have somehow, in the course of 1/1000th of a second, managed to cover about 3 feet worth of arch, and in the opposite direction of the path it took through impact. After that, aside from an insanely amazing feeling, it basically behaves normally to the average observer. I can tell that it is doing something subtle and interesting because I know what it feels like as it shoot s up in to the followthrough, but no one else can gain anything from it. The notable thing is that, during the frames when the club goes from bright spotty light halos to compressed transparent shadowy thingy... the bright spot pops up and traces a seemingly impossible path across the screen, jumping and bouncing around like it is a UFO from a bad fake home video in the 70s. Sometimes, if I do it without actually hitting a ball, I can clip the ground just right and get the spot to trace a smooth slightly curved path before disappearing, like it does in the first slinky drop in this video. I am working on a video right now showing exactly what I mean, and explaining how I go about capturing it personally. I will also explain exactly what the logic of my hypothesis was/is, and how I went about discounting every other seemingly more likely reason for the repeated appearance of the spot. The idea being, any one who has survived reading this up to this point, and is actually interested in seeing what I mean.... can determine with confidence that I am not crazy... or that I am. Either way it will allow such a person to make an educated decision on the matter. I'm pretty confident.... actually scratch that I am absolutely positive that the inquiring mind of any viewer who takes the time and pays attention to what is happening will be more than intrigued.. and will probably be driven to the driving range just like they were driven to Wal Mart for a slinky upon seeing this video. Thanks for reading and I apologize if this sounds like an attempt to push traffic my way. It is not. I have no YouTube channel and my ultimate goal if any would be to capture the interest of the creator of this video. Ideally to persuade them to take what I have posted and explain it in more depth, because I am tapped out as far as my ability to further identify the underlying principles of the phenomenon.
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