Damn it! I'm starting to get more convinced by your theory!! Is it the start of losing my 10000 cents?! We shall see! But this video was quite clear and understandable. Thanks!
Nice, and I love the surgical empiricism here - dividing this problem up into pieces has not always been easy - I like what you did here - for me, the simulation where the bottom of the pot is removed is the killer moment I think (and that the simulation can provide force data). Nice work!
I think the de-looping effect is also an important part that needs to be better understood. Why does it give an upward force when the loops are pulled straight?
Where Neil and Bill cannot be, Derek can. Nice to see so much good and prolific scientific debate out for a general audience who are genuinely interested in the questions, the answers, and of course the methods.
7:50 Not only can you see the fountain rising up on the left but you can actually see the pile being pushed down as well. So there is a clear force being applied there.
this comment fully proved the theory for me, i don’t see how it could be anything else besides the moving chain having it’s own “push” affect on the stationary one
@@Unsensitive Yea I was just thinking this is literally the same thing in a different format. Hell, we could be witnessing history being written right now as this ... feud(?) might be in the history books of the future (or ... if books are phased out, then whatever format history is taught in the future...)
You have won back my vote of confidence. I think the real phenomenon is how each of us can have our minds and perception changed with a good argument and it's important to avoid a "one and done" approach to evidence and arguments. I am team Mould again... pending further evidence.
You've changed my mind; was agreeing with Mehdi's explanation after your initial videos. Your new demonstrations are great. Good job! And kudos to Mehdi for not letting you throw in the towel, we need more of this!
I used to watch the anchor chain do this whenever we dropped anchor on boats, when I asked about it the experienced sailors told me it was my imagination or not to worry about it. Glad to see someone finally proved what I observed as a kid was actually real. It isn’t just bead chains, works with bigger chain too.
I'm glad that someone other than myself used to find the properties of such stiff chains interesting as a child! I was quite fascinated by them... well, regular bead chains of various sizes, not anchor chains. :P If you tie them into certain knots in just the right way, you can get them to retain their shape, and thus produce neat little sculptures made out of chain loops. It's been too long for me to remember exactly how it's done though. ;_;
Thing about old-school mentality is that they don't care for deeper thinking, just that something works, and that's it. I will say though, that when you do run into those gems that are just as deep thinkers as others, because they have the wisdom of an old person, with the creative mind of a kid.
I vaguely recall this phenomenon depicted in a Saturday morning cartoon...it might be better called the "Wile E. Coyote effect" ...or is that the act of running off a cliff and remaining suspended in the air until you realize you're in midair?
Man I love this new trend of science youtubers doing "live science" and trying to proof each other wrong! Always restores a bit of my faith in humanity ;)
It is possible for reasonable people to disagree. And what do reasonable people do? They talk, and use facts and logic. The premise of all good science is 'I don't know'. So they try to demonstrate how they think it happens, and are open to scrutiny and demonstrations of more likely theories. It's not a shame to be proven wrong, if your theory is the reason that other people come up with different theories that may or may not be more valid. In fact, you just helped further your common field of interest. And that's the beauty of it.
I've been an admirer of both of your channels for a long time, and I must say, you both have a wonderfully pedagogical approach. I really appreciate your content and your commitment to the scientific method.
I just want to say that I love this back and forth “UA-cam science drama” and it would be awesome to see more creators challenge each other with different hypothesis. I suppose it might be hard to find a surplus of topics to argue, but if it’s possible I’d love to see more of this!
As others have pointed out, at 7:00 with the horizontal chain, he says it "the fountain doesn't grow" when clearly it does grow from the point of acceleration to the arc (equivalent to vertical fountain height) at 7:40 he makes the same claim yet you clearly see it increasing. Also notice at 7:00 the chain rapidly spiraling at the point of acceleration. In almost all videos you see this spiraling yet no one makes mention of it. Think about a football(American) when spun on its side it will stand up and spin. ua-cam.com/video/Lo3Sltktifo/v-deo.html
This whole bit is easily one of my favorite internet moments. The simulation made a real difference to me. You ought to just put the beaker on a load cell and record the down-force directly. How long until we get a Medhi/Mould channel? Call it, like, "Mouldhi"
I have to admit that I was convinced when I saw the horizontal demonstration. After you reframed it and explained it I realised how two very different things can have the same perceived effect
Wasnt that hard to see if you looked carefully, people called that out already in the comments on Mehdis original video, but if you just watch it on the side you get swayed by eloquence more than reason
Perception is everything. You see two things and think they are completely different even though the are not. But if you only ever saw one view you'd think that view is correct by default and think the other view is wrong even though the are the same. This is true for almost all of life. Example. Someone says if a dog barks at nothing there's a ghost.. well they are perceiving that the dogs barking at nothing. Because the dogs senses are magnitudes more sensitive than a person's.. they might have senses something. You as a person go and look and see nothing and think the dogs barking at nothing. If you had the perception of the dog as well that might not be the case. In both cases your seeing the dog bark. They are both the same. But you don't see the other information and there for say it doesn't exist and there's no explanation. Life is chaotic. Another one example is high tensity situations. You can have 3 people in an area witness the same event but have completely different explanations because of their perception. News media uses this as a deception tool for profits. They lie by ommission. If they only wrote " there's nothing there the dog was barking at nothing this proves it" and that's all they focus on the consumer only does as well. They leave out " dogs have highten senses and might have senses something like a mouse or another animal next door or outside the window you can't see or didn't notice". If that's included the consumer now isn't set that the first point is the only truth. Now there nuance. Or they leave out information from an event for whatever reasons. So the perception of the viewer is X happened.. the perception of the people involved say " no all this happened too so maybe it was this" the news viewer perceive the outlet as authoritative so they disregard the witness statement that they sent report as false or un verified. Even though the outlet never verified what they stated. Perception is everything. Example. You see a dude haul off and shoot someone in the head. Immediately you think evil person murdered this guy. Later on it's revealed the person he shot raped and tortured his daughter and got off. Now if you only witnessed it and never got any information your perception is this person just blasted this guy for no reason and you spread that as facts when it's wrong
Or, you know, both can contribute to the same effect, be it additively, multiplicatively, etc. Doesn't have to be just one. The validity of one cause doesn't necessarily invalidate another
Could be wrong, but what if the chain isn’t rising because it doesn’t have to go up to start. Medhi’s hypothesis was that the momentum of the chain going up was creating a force that made the chain rise, but if there is no rising to begin with, how will it rise at all. All the momentum is going horizontally.
I LOVE this back and fourth feeling where I have been "pretty sure" both parties were right respectively after each video. The realisation that I was wrong is humbling.
After the first video I was certain I was right that it was simply the chain construction that caused the rising fountain and no kickback force. After this video I feel partially correct, but got there by accident and sheer luck. The thought process that Steve and Medi followed was much more rigorous than my guess process. I appreciate the entire process they've gone through more than the end result of who is "right."
From the very beginning (when I started watching these videos, that is), I intuitively guessed that the lower flexibility of the bead chains was key to understanding the effect. As a child, I loved to play with such chains because of how interesting it was to twist them into different shapes. If you tie them into certain knots, you can actually get them to retain their shape in surprising ways.
I love how this is the best """""drama""""" between two youtubers, but instead of insulting each other you're fighting hypothesis after hypothesis, admitting mistakes and challenging each other to disprove the other person better than last time. Yay for the scientific method!
It's similar to Veritasium's recent wager with a physicist over the wind-propelled car that could exceed the speed of the wind. Very respectful, everyone learns more than when they started including the one who was right; good stuff.
@@hesperhurt as a former amazon worker, we've seen worse lol
3 роки тому+30
I just watched the previous video like 5 minutes ago. UA-cam recommendations are now so advanced that relevant videos are not only recommended but made when I would watch them
Wouldn't the chain itself negate the usefulness of putting something soft at the bottom? If the beads are metal wouldn't they be hitting off each other and still creating the effect? I guess it might dampen the initial fountain, but with a long chain I don't think it would change anything.
@@sromnorba Couldn't you in theory test different materials lining the bottom that would potentially provide a measurable difference if the kick-back is the force responsible for creating the fountain? (Even if the difference is small due to the beads hitting off each other, that'd be uniform among the test I think?)
14:11 "Having this disagreement has been fairly enjoyable" This is what I love about science and more specifically science on UA-cam. Its so great to see people completely disagree on things and enjoy themselves while doing it. Just like Veritasium's recent video's on the vehicle that travels into the wind. Keep up the good work!
This explained the theory of the kickback force for me as well. After that it all clicked into place exactly how this appears to be caused. The wave generated during the stiffer chain unraveling creates a downwards force which flings the chain upwards due to it rebounding off the bottom of the jar, or in the horizontal case rebounding off the pile.
Oh come on, 1) The amount of movement is nothing compared to the motion required to yank the thing out of the pot 2) Once it gets yanked it wants to keep on going, so there has to be some kind of bulge, otherwise there would be an infinite acceleration involved 3) You can't just assume gravity has nothing to do with it.
@@DinoDiniProductions The simulation removed the downward force of gravity in the pot, so what you are seeing is probably a wave of force that would normally push against the rigid surface beneath it. After it leaves the pot gravity is in effect again, and is what is causing the chain to pull out from the pot. So it is not being ignored, and it's effect on acceleration is maintained. The only difference is that the simulation was an attempt to remove any forces originating inside the pot to show that the chain fountain came from those.
@@Caelinus Oh OK, but in any case those small forces are insignificant compared to the huge force that keeps being overlooked: the force applied by the chain vertically, which is automatically present and unavoidable due to the fact that the container has depth.
@@DinoDiniProductions which keeps the chain following through its path - like Medi showed, that force is enough to fight gravity (decaying slightly due to friction). That's "the first half" Steve is talking about. The tiny kickback forces just need to be a tiny bit greater than friction, that causes the "wave" to decay - that slight force pushes it up. Not much, the culmination of all the kickback force, minus the friction forces, only slowly "grows" the fountain. It's not much force - but it's acting on a system near equilibrium. The equilibrium is caused by the much greater force you are talking about - but that's well understood.
5:15 the beads have to be horizontally constrained and stacked vertically. He’s losing a ton of energy from the chain whiplash. The chain wants to move side to side but if it can’t it must go up. Unless the energy is great enough.
This video finally made me understand the Mould effect. In order for the chain to be pulled up from the base, it needs to change the angle of the connecting rod between the two beads which has just enough resistance to push the bead into the base harder, causing it to have a higher kinetic reaction.
My favorite part is how you selectively break the rules of physics in the simulation to reaffirm your hypothesis in an intuitive & visual way, amazing work!
@SaltyBrains this was my first reaction to the use of simulations as well, that they are probably not the best for unknown physics problems because they were by definition programmed without an understanding of the mechanics at hand, but in combination with the other evidence I do find it convincing in this case.
LOL so true. As others have pointed out, at 7:00 with the horizontal chain, he says it "the fountain doesn't grow" when clearly it does grow from the point of acceleration to the arc (equivalent to vertical fountain height) at 7:40 he makes the same claim yet you clearly see it increasing. Also notice at 7:00 the chain rapidly spiraling at the point of acceleration. In almost all videos you see this spiraling yet no one makes mention of it. Think about a football(American) when spun on its side it will stand up and spin. ua-cam.com/video/Lo3Sltktifo/v-deo.html (read description)
Great video! I might have another interesting idea: The falling end of the chain speeds up because it is nearly performing a free-fall accelleration. As we've seen, a chain wants to maintain its shape, so every part of the chain also wants to keep up with the increasing speed. At the beginning, the rising part of the chain inside the glass is so short that gravity forces and inertia only have a small effect. So what if we look at the top of the fountain as being a half circle? Objects moving along a circular path are pulled outwards by the (imaginary) centrifugal force. Because the lower half of the circle is missing, the sum of all centrifugal forces points straight upwards. I think this might be the reason why the top of the fountain is rising. The centrifugal force at the top of the fountain is pulling the rising part of the chain higher out of the glass. The fountain is growing until the gravity force of the rising part (which becomes longer and heavier as the fountain rises) matches the pulling force of the fountains top. Having reached that "point of equal forces", the fountain will remain a stable hight until the end of the chain. Does that make sense?
thats another way to explain it, the same forces are still present just in a different order, it shows somewhat how a chain preserves its weight. However, I dont think the centripetal force alone would be stronger than gravity in this scenario, partly because gravity is what powers it in the first place, and partly because the experiment on a flat surface doesn't show this behavior. I think its closer that the tension and centripetal forces are canceling each other, and gravity is still uncountered, hence the sinking without the kickback. great idea though!
"The centrifugal force at the top of the fountain is pulling the rising part of the chain higher out of the glass" Centrifugal force is fictional, it does not exist and therefore has no effect. If you want to know why the chain jumps into the air just watch a video of a skateboarder doing an ollie.
If you hold the Motorized Spool™ on a higher level than the beaker, thus pulling the chain up rather than down, will there be a peak/fountain that rises above the spool too?
Yes, just like it did in the video, it's due to the rotational forces and inertia. There is much more mass coming from the original container to the spool than is pulling on the spool itself, since the spool is rotating, thereby imparting an angular acceleration on the chain, the conservation of momentum will sling the chain out from the axis of the spool.
@@ruaine83 Might be, I wish to see it though. I'm guessing it might depend on the diameter of the spool too, if it's too wide it might not be "bendy" enough for the chain to peak upwards.
@@Tomapon its anomalous to the shapes sizes and material used. There is a proper diameter and speed that will nullify backlash, but the equation eludes me . E=mc2 but the speed of light being replaced by the relative gravity to its most predominant magnetic or gravitational influence .. here would be what we deem gravity.
And what proves this is it would not happen if the little spheres were magnetic because it would dampen or cancel out the K energy build up in the chain.
I'm glad I pointed it out to him in his last video. I had been binge watching a lot of those videos a few hours before Steve's last video on this topic came out so the scene was fresh in my mind. HNTH is such a great resource for climbers.
I think the interesting point is at 9:49 when the gravity is removed in the simulation. The chain line being pulled out drops below the level of the base line, without gravity this can only mean it was pushed down. If the bottom was still there then that push would result in a reactive force from the bottom of the pot, proving Steve correct in saying there is a "kick" from the pot.
There's an easy explanation as to why it decreases (5:20 mark). The chain used up around the end is further back than the fountain origin. As such, gravity + friction cause the lag to a much greater degree than at the start. More force is required to maintain the shape but more force is not being applied to do so. Check the equation and see that the force required increases in a linear fashion.
I found your channel when the yt algorithm recommended your bead chain fountain video to me. I stayed there for the other simulations as well, they are really interesting!
9:46 I had an aha moment. That simulation really helped me understand your view on the kickback force and why the rigidity is so crucial to the kick back happening in the first place.
@@craigfjay yep, i made a comment that its backwards wave propagation, essentially the force of the bead chain falling sends small waves backwards along the chain, which without a pot sends the beads below the level of the loops of chain, but with a pot, they cant travel any further down, so the pot exerts a force upwards, giving that wave a bit of energy back into the chain. Ultimately, the force is technically from gravity. Gravity on the chain, gravity on the pot, resistance to gravity, resistance to the backwards wave propagation. The simulations did for me something that a million beads in jars couldnt do, they showed a simplified version that performed according to obvious parameter. i could never actually tell where the force was being introduced before those simulations were shown.
@@craigfjay 8:00 was my initial moment as well, for the overall explanation to fit, but it wasn't until 9:46 that the local mechanics of the phenomenon became apparent.
I first watched yours, and I was convinced. Then I watched Medhi's, and I thought yours was debunked and I was convinced of his. Now I see your rebuttal, and I think his is debunked and am convinced of yours again. What this teaches me is that I almost always believe the last person I talked to, and I should just shut up and wait for the community consensus to establish.
@@nathanb011 I was more convinced by everybody else being convinced, but I was still skeptical. I also laughed at Medhi when he said "see? no mould effect!" while it's actively producing the mould effect....
This is truer than it seems for everyone learning about nearly anything. It's why it's important to be skeptical and have critical thinking. To have an open mind, but not so open that your head-jelly falls out.
It's good to recognize that you tend to believe the last person's argument, but you must realize that the community consensus must not convince you as easily all the same
One thing about the horizontal simulation, is that the movement “down” isn’t immaterial. You would need to compare that to a a chain actually falling down, but lower the beaker as you do it.
That's what I was thinking as well. In the spaced-out example, the top of the beads is going down much faster than it is in the clumped example (or in the actual pot), so you'd need to account for that
@@kriscpg You could perhaps design a cup that rests the chain on a poorly supported paper floor. Something that would not provide a strong restoring force to any "kicks", but that would otherwise hold the chain if it is stationary. I think with a "soft" floor like that you could simulate the lack of beaker floor, but still support the chain for the experiment without imparting any additional velocity to the chain.
@@meateaw even better. Calculate out how much force is being imparted to raise the chain on the floor and build the support just to support the weight. Then if there is the kickback force it should break through the paper. Although this would actually probably pretty hard to engineer accounting for all factors
Dang, Steve, I'm really glad you made this follow up. I was one of those that felt there were a lot of unanswered questions. In a perfect display of the scientific method, you've strengthened your arguments substantially. As you say, it's not about winning, but about finding the truth and adjusting our positions based on new stronger evidence.
I would be interested to see some experiments on a surface that would absorb some of the peaks in the normal force (foam, rubber, a pillow?) instead of reacting with a kickback force, and see how it makes a difference vs a hard surface.
That would eliminate kickback from the jar. Normally there's also kick back from the chain stacked on top of each other. I wonder how much the foam would dampen that. You could try to space things carefully so the chain doesn't stack. I'd be interested in seeing this because I think the spring effect of the turning radius provides more of the force than the "lever" force of the beads.
@@zunuf Cover the chain itself with something. But all of these change other properties also, not just the kickback force. Like rigidity, friction, etc
I absolutely loved this video! It feels so real, you guys are haveing an actual public debate, to test your theories and continue to learn. One thing that annoys me is when the modern scientist show "it works in the computer model!" But no real debates or tests.
@Timothy Lim it's not just the spaced out pile, it's that in combination with the pile that's *not* spaced out right next to it that makes it convincing. Specifically the part at 7:52
Crowdsourcing science - freaking love it. You have 2 guys debating and others essentially peer reviewing. This is how you get to answers _really_ fast. Love it, love it, love it!! This is brilliant.
It brings together the people that have the energy to try out any experiments and ideas, with the people that can find genuine flaws or weaknesses in just about anything. So you can rapidly get to the strongest possible answers.
Between Mehdi and Lewin a similar approach led to destroying the correct lession and made an old teacher/scientist apologize for something that he never made just to escape alive from the emotional trap Mahdi have set.
It’s very interesting and fun to see the increasing precision and detail in the descriptions of the phenomenon under study. You can really tell that both Steve and Mehdi are learning and gaining more understanding as this goes on. Good work, both of you!
Interesting points, I used to be industrial abseiler and found that I also had the Fountain effect when throwing my rope off tall builds. I used to have the rope tied in daisy chain and rope was 11mm thickness. I agree with your kick back resistance. Thanks for the video. All the best. Phil
Start a fountain from a high place, then after it starts to fountain drop the pot into freefall. If the pot then accelerates faster than a dropped pot with no fountain then there is a kickback. The said kickback would push on the fountain forcing the pot downward faster. This would also exaggerate the fountain length as well. Might answer some of the questions to try this experiment.
However by having a fountain, mass would be leaving the pot, thus slowing it down, which would have a more pronounced effect than the kick back described. Right?
@@haydenhagemeier4458 the mass leaving the pot should have no effect, I think, as the object will accelerate downwards the same regardless of the weight. If it falls faster than 9.8m/s², it will be due to the additional downward force created by the tension in the chain. What will likely happen though is that once the pot is dropped, the whole assembly will almost immediately be in freefall, which is indistinguishable from a weightless state. It will all fall together and appear motionless relative to each other (chain versus fountain versus pot). Interesting question, and I'd like to see the results of trying it out..
The fountain would collapse rapidly as the pot accelerate, but I think with a high speed camera we could measure the initial acceleration of the pot. That is a tremendous idea, I was thinking about using scales, but the bead leaving the pot really complicated thing. With your idea the mass of the beads in the pot is irrelevant, since they are free falling and are not applying force on their own.
@@donalbaine Yes it would require a high speed camera and the important information we are looking for would be in the initial second or two. The idea was to remove as many variables as possible such that we are left with the usable data we need to answer the question.
The simulation was crucial for my understanding. Once I could see the loop first dipping downward when the bottom of the container was removed, I immediately grasped what you were saying about a "kickback force". Really well done all around.
Ok Steve, you've won me back. I did not notice the falling arc in Mehdi's 2D experiment, or how dramatically he imparted the arc in his beaded fishing line. Both valid points. Your 2D comparison of the ball chain spaced out versus bunched together specifically shows the need for the kick-off effect to increase the height of the arc. I'm convinced...again. Are we done yet?
Absolutely. we need a lot more judges. a high speed camera to prove/disprove my theory. ua-cam.com/video/Lo3Sltktifo/v-deo.html (you have to read the descriptions in the videos)
@@PongoDaMan but is it really banter if only you and I hear it? While thousands are convinced by this "Proof". I know Atomic Shrimp saw it, but he prefers Steve's "Proof" video because of the rigorous scientific methods he used (hand held drill, denying that it rises at 7:00, rock solid simulations) confirmation bias is a bitch these days. This is not science!
These were exactly my thoughts on Medhi's video, with regards to his experiments not actually showing the Mould effect. Glad to see them addressed, and with a proper explanation of the wave dynamics!
Yes I was nearly convinced then I noticed the "fountain" always decayed, (the floor one never goes "up", and he imparted the chain one with his initial movements). The hoover hose was interesting though.
I want to see waves in an extra dimension in space - you only get a Y wave on earth but imagine the wave going on the X as well, like a spiral! And yes, the "pull rope and observe feedback" is delicious, even more so as a child. MAGICAL
I loved it too, my friends and I would have battles where you each hold one side of the rope and take turns sending waves at each other. Because sending waves at the same time just cancelled each other.
Have you seen the chain whips they use as tourist attractions in China. There are videos on UA-cam une of them. They get the chain to break the speed of sound using simple conservation of momentum.
Great job. Kickback maybe not the most intuitive word to describe it for me but this certainly makes sense. The inertia tries to bend the chain when it pulls away and the chain presses against the ground when it bends. Awesome video.
As a mechanical engineer, this debate has been a real treat. Shows how difficult classical mechanics can get. Medhis did an awesome job, but I'd declare Steve the winner. Simulations always have to be analysed carefully, however I think in this case the core of whats going on mechanically is represented and the consequences we learn from them unlock the physicis of whats going on.
The thing is that there were 2 things going on, and the simulations and slightly different experiments show them: 1) wave propagation in a chain; 2) force of a pile over the links of a chain falling. Of course the force applied is not that big all the time or consistent all the time, but that doesn't matter for the effect since we just need the chain speed to increase in 1 side relative to the other. You can probably suppress the effect in many ways, some shown here too.
Like the veritasium video on moving faster than the wind. It all comes down to forces at the end of the day, and it was very deceptive in working out how they balanced.
This is very interesting. Indeed I agree, it should be tested with an energy absorbing bottom layer in the container (elastic vs. non-elastic deformation). I too think that this should have an impact if Mould is correct
Ok Mould. You've convinced me that the height is due to both the resistance to bending and the fact there's a base to push off of. Well demonstrated. The simulation was what pushed me over the fence when it depicted the spike in downward force right before the bead came up.
I'm really glad he used simulations. You should try the Mould effect on ropes and should have the beaker set on a sensitive force gauge to look for the force spikes.
Exactly. All Mehdi showed was (as stated here) that the chain will follow the existing chain's path and curvature. He never showed it increasing in "height", if anything is was always decreasing.
Great job Steve! You really earned the right to give the Mould effect your name! I was convinced by Mehdi's explanation as much as now I'm convinced by yours. Science is great.
It was interesting to see the chain in the simulation with gravity suspended. The chain clearly travels below the missing bottom of the pot. If the bottom of the pot wasn't missing, this would produce the upward reaction force the chain would feel to produce the fountain.
PLEASE READ: Using the spaced beads in that way is wrong in my opinion. if you just let the beads off the edge of the board, there is no upwards force acting upon the chain. its only being pulled to the side and down. But in a beaker/cup. the chain is forced to move UP out of the cup. therefore it initially creates and upwards force that then increases as the momentum of the falling side increases.
What's also not shown in that test, of the chain going off the edge sideways, is a camera recording the chain from the side. I am more than certain the chain makes a sideways loop, away from the board, that grows in lateral distance, as the chain falls and gains speed. Very bad example, not showing all the angles of the test. That's hiding information.
@@shotguntornado I think the reason why the effect is not happening is because the length of one side gets longer and longer. and the drill is stationary. The reason it works on the left is because one side is always longer than the other, therefore more momentum. Another reason this could be happening is the drill is exceeding the force of gravity if it was vertical. The effect works vertically because the only main forces in play are gravity and momentum. if the side inside the cup took longer to get over the lip, then the effect would be smaller or nonexistent. I still believe the effect happens because the momentum of the falling side exceeds the threshold for the other side to slow down and start to fall.
I think you need to do one more computer simulation of low and high flexibility bead chains without the container walls as a control to really complete the explanation!
The spiky nature of the chain-fountain ground-force plot seems like it may be connected to the side-to-side movement of the top of the chain coil as it unwinds. So I guess we'd expect a wider container to impart energy to the fountain either more quickly or less quickly than a narrower one? Probably less quickly, since a wider container would make chain stiffness less of a limiting factor in how smoothly it can uncoil?
I want to see an annular container, of significant diameter, such that it's only as wide as the ball chain is, and curl it around in a perfect helix. Reducing any tangling, or sharp corners/bends. I think this would produce less of a mould effect because it seems to be the restriction in the minimum radius the chain can bend/pinch, that is pushing against it, which would explain why the rods don't work.
The natural chain fountain you see is the result of throwing a ball in the air, several times and seeing the energy difference between them. The energy is causing the balls to rise because of the chain connecting them. They are similar in weight and mass, so gravitational potential energy is getting converted to kinetic energy when you move it. You are seeing the fountain rise because an object in motion continues in motion unless a force is acted on it. The chain balances the gravitational pull of the start of the chain, directs it upwards later down the chain, and gains and looses height based on the balance between gravitational potential, and kinetic energy. The fountain grows due to gravity pulling in the falling part of the chain, which due to inertia, causes the chain to be thrown in the air at the lip of the beaker. Depending on how much heat energy is lost, the fountain will eventually loose enough energy to not pull the chain over the lip, as no energy is being added to the chain once started, only converted.
If your explanation was correct then this effect would be observed with other types of chain (like 'normal' chain made from linked metal circles), but normal chain does not create a fountain, only this specific type of ball-chain does. Thus, your explanation is wrong.
Here is the thing. If the chain has any "stiffness" at all, the bottom of the chain thats leaving the pot can be seen as a part of the chain (of arbitrary lenght) that feels a force (being pulled up by the 'previous' part of chain) on only one of its sides. Since that part of the chain has non-zero stiffness/rigidity it will start turning around its centre of mass. But its either on top of other chain, or the bottom of the pot. So it will be 'pushing' (levering around its center of mass) on the bottom of the pot. Since the pot isnt moving down, it must be excerting an equal force up. That is the kick that the bottom of the pot gives the bottom of the chain. Or how the bottom of the chain pushes itself off and 'jumps' after itself. It would be really interesting to see how friction (like, chain to chain friction) would affect the height or stability of the 'jump curve'. Im thinking the levers might work even better if they cant slide across one-another as easily This is still such a rich topic for utterly pointless but nevertheless interesting research. How would weight, shape, etc etc of both pot and chain affect things? Would the jump be higher or lower on mars?
If there is a lever action effect created by the tiny balls, it could be measured by a calibrated scale / along with an accumulator to get a mass effect. I doubt there's a fraction of a gram produced, and even if so, the overall effect would be negligible. There's not much going on when 'next ball' is yanked from it's stationary position, that change of state is practically instantaneous.
I'm an ecologist, I took applied maths so I love these but I'm no expert on the physics. All I can say for sure is: Steve does a mean Clint Eastwood impression during his spaced bead test.
Thanks for emphasizing that science moves understanding forward when disagreeing theories emerge. This is in contrast with dogma which just stands in the way of knowledge.
In the simulation without gravity you can clearly witness the “kick” by looking at the loops that constantly push below where the floor used to be. That shows that when the floor is there, those loops are pushing against it.
This is fascinating! I'm genuinely curious how the size of the beads affects this phenomenon. Like if the beads were individual atoms, would the same thing happen?
Quick, everyone! Start liking! We need to get this to the top of the comment section in case a bored physicist with access to an electron microscope decides to watch this video
As far as I can tell the beads themselves are negligible. It's the degrees of freedom of each chain link that matters. The beads provide some resistance if they're close enough but you could get the same effect with a bunch of stiff, stick-shaped links. Iirc Steve mentioned this in his first video? So I think even if the beads were tiny, with enough restriction you'd still see the effect!
@@KalebPeters99 each bead is a metal sphere with rotational momentum, and intertia. To curve the force applied by gravity has not only to accelerate each bead linearly, but also rotationaly. Some linear force is changed to rotational motion.
@@billtoo4694 Rope experiences this same force. (he showed a rope based example in this video). The kickback force that causes the fountain is caused entirely by the "chain" (or rope) having a limited bend radius. I think the bead-chains are particularly good at showing it because of their behaviour under tension compared to when slack. When slack they don't tangle very much because they have a very small bend radius, but when under tension the bend radius shallows out, and the shallower the bend radius the higher the kickback. The bead chains are just really good for showing it in relatively short runs.
I still think you're both partially correct. It still feels like there's something missing. I would like to see a graph of the effect chain rigidity has on the height of the fountain over time.
I just love this Dialog between scientists! My offering is to Steve , to ask someone on the ISS to perform the experiment. It would be interesting to observe what happens when gravity is taken out of the equation. Chain on!
Or at least get in a fast downward-moving elevator (lift, hah!) and see what effect it has. I guess elevators probably won’t be fast enough, but who knows?
You could probably get sufficient results testing this effect out on the vomit comet for significantly less cost than getting an experiment up to the ISS.
Two things to help. 1.) When the chain is not moving, it has friction with the surface it's resting on. When you pull it, you break that force of each successive bead, which releases a tiny bit of energy to kick up the bead. 2. The loop gets higher because of the accumulation of successive beads breaking their friction bond with the surface. If you want to see that in action, look at the END of the chain as it leaves the surface. One more thing: The chain follows the path of least resistance as it leaves the surface while accumulating energy from the friction bonds breaking, which is like a very weak rubber band snapping. Try this experiment in some way where there is no friction and see what happens. Weightless still had friction where the beads met. I suspect if there is no friction, there will be no snap back.
I watched the video on the Spring Paradox because it was randomly recommended to me and instantly got hooked These are so well explained and entertaining! Can’t wait to finish watching the vid
After watching both of the previous videos of you two, I felt that Boom reconfirmed your suspicions. And after this one, I'm even more convinced you're right.
This is the first I've heard of this phenomena, but my immediate intuition was: it's due to lag in the chain at rest rotating into alignment with the direction of the chain pull. In the case of a traditional link chain this would be from a combination of angular inertia and friction between links. If the chain is travelling faster than the time it takes for the 'picked up' chain link to rotate into alignment, the non-aligned link rises up, I.e. a 'kink' travels up the chain. If the same happens with the next link behind and so on, it results in a series of kinks that, if they don't straighten in time, create a rising wave. The misalignment might be small between each link, but combined they form a curve. It would be interesting to do duplicate drops with a link chain, first dry, then lubed, to see if there is a difference in wave height. I suspect the lubed one would create a lower wave, despite the potentially reduced friction over jar lip allowing a faster initial chain speed. I also suspect the layout of chain in a pot might effect things. I.e. I wonder if a chain laid out circles around radially around the circumference of a pot would create a different /more consistent height standing wave than one lapped back and forth into a pot, due the different angular change their links experience from at rest vs. direction of pull. I'll caveat all this by saying dynamics is not my area!
Maybe more like this? ua-cam.com/video/Lo3Sltktifo/v-deo.html You have to read the descriptions I don't make good videos but check other vids of fountains too
Simulations work on the rules we give them. If the simulation doesn't have realistic rules concerning the chain fountain effect (as we don't truly understand how it works), then the result won't be realistic either.
@@Renee_R343 Normally you only put in rules that you know of, and then see whats happening on a specific setup. Mass, gravity, chain length, chain "bendability", friction. I guess he has done exactly that.
If you use a loop, things get interesting. If you put that rotating loop in zero g it would maintain its circle, O or even a 8 shape, if you were able to touch it without slowing it down you would see standing flow waves that slowly smooth out itself back to a basic shape. Checkout my Magic Inertia Videos :)
Oh, we made the same experiment with a drill in 2012 (see our video 2016 in Russian, with English subtitles). // If you want to know historical details about the discovery of this phenomenon, read here: en.wikipedia.org/wiki/Chain_fountain
During the simulations around the 10min mark you can also see the chain that has more tension exhibits a small fountain effect with the gravity turned off, but only when it is able to make contact with the edges of the pot, and therefore able to transfer the energy to launch itself into the fountain shape
@@Justin73791 Facts: There's a gravity affected chain with an embryo inside a gravity less zone. The chain has equally spread mass in each joint. There are two parallel walls, both fixed in space unaffected by any force, both have unknown mass, therefore we do not know if the have any at all, can't make assumptions so it can only be the boundary. There is no wall underneath the chain. The chain lays flat in an overlapped position after being put there manually. The chain has only its own mass to attract to but the outside gravity is stronger, thus making the stress affected parts of the chain's gravity null. The parts not affected by the stress are pulled to the center of mass in the gravity less zone, thus getting further from the side walls nulling their being. Conclusion of facts based theory: When the chain will bundle up in the gravity less zone, it'll actually create an opposite force at the end of the overlaps edges, being supported by the centerly gravitating part of the chain, generating an environment which encourages the effect..
Those are fed from a reel inside, and drop straight down outside though: Any suspended loop would jam the drop. Plus they're really heavy, even without the massive anchor on the end. That said, it would be interesting to repeat this experiment with bigger/heavier chains.
@@robinhodson9890 Dont know. I do know I took a tour on a navy ship in the San Diego harbor. Navy guy pointed to the anchor reel on the deck of the ship with huge links that looked like they would weigh about 300 pounds each. And he said when they drop the anchor, the links whip up 7 feet in the air as the anchor drops.
What do you think? Have I convinced you? You can also discuss this video on REDDIT: stvmld.com/8asj3e4u
Yes
Quite,interesting but not convincing yet! Keep going
@@Regularsshorts you havent even watched the video yet lol
what if you drop the pot while it happens
I dunno, but I think you ate spaghetti before shooting this video, just look on the corners of your mouth 😂
Damn it! I'm starting to get more convinced by your theory!! Is it the start of losing my 10000 cents?! We shall see! But this video was quite clear and understandable. Thanks!
Only one option left, you have to go into space and perform the experiment without influence of gravity or friction.
Yes!
I believe in you, mehdi
That debate is simply so exciting to follow, thanks a lot for you both
Or in Zero-G plane, the closest thing we have on earth for no gravity.
Nice, and I love the surgical empiricism here - dividing this problem up into pieces has not always been easy - I like what you did here - for me, the simulation where the bottom of the pot is removed is the killer moment I think (and that the simulation can provide force data). Nice work!
I am sad Steve didn't use a wobble dog and settled for a drill :(
I think the de-looping effect is also an important part that needs to be better understood. Why does it give an upward force when the loops are pulled straight?
You should do a follow-up video in light of the new info! Some of the things in your video could use updating
Oo never thought I'd see you here shrimpy, love u
@@fwiffo Did you not watch the video? There are at least 3 examples of falsifying in this video alone.
I’m convinced! Give the man 10,000 pennies.
Damn I love you folks
Where Neil and Bill cannot be, Derek can. Nice to see so much good and prolific scientific debate out for a general audience who are genuinely interested in the questions, the answers, and of course the methods.
But first, ask NileRed to cover them with gold ua-cam.com/video/HafE177cV_o/v-deo.html
UA-camrs testing weird things and discovering effects should be a thing, and I'm glad the trend has started x)
I saw this comment at 42 likes, as it should have been seen.
7:50 Not only can you see the fountain rising up on the left but you can actually see the pile being pushed down as well. So there is a clear force being applied there.
Oh yeah good call, that's pretty pronounced.
this comment fully proved the theory for me, i don’t see how it could be anything else besides the moving chain having it’s own “push” affect on the stationary one
That's a really good point.
I actually came down into the comment section to mention this, glad other people agree!
This is literally spot on. Thank you
This feels like that stuff we read in history books about mathematicians, and scientists in general, throwing challenges at each other; it's awesome!
10,000 cents says you're wrong!
Not just feels like. It's just like that, but with videos, not letters.
@@Unsensitive Yea I was just thinking this is literally the same thing in a different format. Hell, we could be witnessing history being written right now as this ... feud(?) might be in the history books of the future (or ... if books are phased out, then whatever format history is taught in the future...)
Man i love it when scientists and mathematicians throw duel at each other.
I know just like we did it for fun and Knowledge
I am not saying knowledge isn’t fun
Einstein Bohr debates!!!! I feel you!
You have won back my vote of confidence. I think the real phenomenon is how each of us can have our minds and perception changed with a good argument and it's important to avoid a "one and done" approach to evidence and arguments. I am team Mould again... pending further evidence.
It's shocking how convinced I was Mehdi was right, and how convinced I am Steve is now. It really makes you question your confidence
@@303elliott wait until Medhi releases the video on a zero G plane
@@303elliott i know right! It really illustrates the importance of having an open mind and allowing change when new evidence is presented.
Good observation...
Nice way of saying you were wrong.
You've changed my mind; was agreeing with Mehdi's explanation after your initial videos. Your new demonstrations are great. Good job!
And kudos to Mehdi for not letting you throw in the towel, we need more of this!
18 HOURS AGO? HOW?
@@aashsyed1277 Patreon supporters have early access.
@@timongutleb8940 ;0
me too
Chain-ged?
I used to watch the anchor chain do this whenever we dropped anchor on boats, when I asked about it the experienced sailors told me it was my imagination or not to worry about it. Glad to see someone finally proved what I observed as a kid was actually real.
It isn’t just bead chains, works with bigger chain too.
I'm glad that someone other than myself used to find the properties of such stiff chains interesting as a child! I was quite fascinated by them... well, regular bead chains of various sizes, not anchor chains. :P
If you tie them into certain knots in just the right way, you can get them to retain their shape, and thus produce neat little sculptures made out of chain loops. It's been too long for me to remember exactly how it's done though. ;_;
Fascinating
I was wondering just this now, thanks for sharing.
Thing about old-school mentality is that they don't care for deeper thinking, just that something works, and that's it. I will say though, that when you do run into those gems that are just as deep thinkers as others, because they have the wisdom of an old person, with the creative mind of a kid.
I vaguely recall this phenomenon depicted in a Saturday morning cartoon...it might be better called the "Wile E. Coyote effect"
...or is that the act of running off a cliff and remaining suspended in the air until you realize you're in midair?
Man I love this new trend of science youtubers doing "live science" and trying to proof each other wrong! Always restores a bit of my faith in humanity ;)
da this is some of my favorite Y.T. content
Whats cool is this is how it's always been its just in journals and not in the public eye this is just peer reviewed science it is great to see tho.
It is possible for reasonable people to disagree. And what do reasonable people do? They talk, and use facts and logic. The premise of all good science is 'I don't know'. So they try to demonstrate how they think it happens, and are open to scrutiny and demonstrations of more likely theories. It's not a shame to be proven wrong, if your theory is the reason that other people come up with different theories that may or may not be more valid. In fact, you just helped further your common field of interest. And that's the beauty of it.
Prove*
This is how science is supposed to be.
I've been an admirer of both of your channels for a long time, and I must say, you both have a wonderfully pedagogical approach. I really appreciate your content and your commitment to the scientific method.
Dude, you said exactly what I was going to say, you just said it better, so I'll just agree! Ditto.
@The mRNA jab Is the mark of the beast As soon as your Bitcoin payment hits my wallet, the lesson will start.
The scientific method, and also entertainment. That's all you need.
I just want to say that I love this back and forth “UA-cam science drama” and it would be awesome to see more creators challenge each other with different hypothesis. I suppose it might be hard to find a surplus of topics to argue, but if it’s possible I’d love to see more of this!
The only kinda drama I care to watch!
It doesn't deserve to be called drama
Debate, not Drama
UA-cam drama but like not cringe
As others have pointed out, at 7:00 with the horizontal chain, he says it "the fountain doesn't grow" when clearly it does grow from the point of acceleration to the arc (equivalent to vertical fountain height) at 7:40 he makes the same claim yet you clearly see it increasing.
Also notice at 7:00 the chain rapidly spiraling at the point of acceleration. In almost all videos you see this spiraling yet no one makes mention of it. Think about a football(American) when spun on its side it will stand up and spin.
ua-cam.com/video/Lo3Sltktifo/v-deo.html
This whole bit is easily one of my favorite internet moments.
The simulation made a real difference to me. You ought to just put the beaker on a load cell and record the down-force directly.
How long until we get a Medhi/Mould channel?
Call it, like, "Mouldhi"
ElectroSTEVE
MouldyBOOM
SteevoBOOM
I have to admit that I was convinced when I saw the horizontal demonstration. After you reframed it and explained it I realised how two very different things can have the same perceived effect
Wasnt that hard to see if you looked carefully, people called that out already in the comments on Mehdis original video, but if you just watch it on the side you get swayed by eloquence more than reason
Perception is everything. You see two things and think they are completely different even though the are not. But if you only ever saw one view you'd think that view is correct by default and think the other view is wrong even though the are the same. This is true for almost all of life.
Example. Someone says if a dog barks at nothing there's a ghost.. well they are perceiving that the dogs barking at nothing. Because the dogs senses are magnitudes more sensitive than a person's.. they might have senses something. You as a person go and look and see nothing and think the dogs barking at nothing. If you had the perception of the dog as well that might not be the case. In both cases your seeing the dog bark. They are both the same. But you don't see the other information and there for say it doesn't exist and there's no explanation. Life is chaotic.
Another one example is high tensity situations. You can have 3 people in an area witness the same event but have completely different explanations because of their perception. News media uses this as a deception tool for profits. They lie by ommission. If they only wrote " there's nothing there the dog was barking at nothing this proves it" and that's all they focus on the consumer only does as well. They leave out " dogs have highten senses and might have senses something like a mouse or another animal next door or outside the window you can't see or didn't notice". If that's included the consumer now isn't set that the first point is the only truth. Now there nuance. Or they leave out information from an event for whatever reasons. So the perception of the viewer is X happened.. the perception of the people involved say " no all this happened too so maybe it was this" the news viewer perceive the outlet as authoritative so they disregard the witness statement that they sent report as false or un verified. Even though the outlet never verified what they stated. Perception is everything.
Example. You see a dude haul off and shoot someone in the head. Immediately you think evil person murdered this guy. Later on it's revealed the person he shot raped and tortured his daughter and got off. Now if you only witnessed it and never got any information your perception is this person just blasted this guy for no reason and you spread that as facts when it's wrong
Or, you know, both can contribute to the same effect, be it additively, multiplicatively, etc. Doesn't have to be just one. The validity of one cause doesn't necessarily invalidate another
Could be wrong, but what if the chain isn’t rising because it doesn’t have to go up to start. Medhi’s hypothesis was that the momentum of the chain going up was creating a force that made the chain rise, but if there is no rising to begin with, how will it rise at all. All the momentum is going horizontally.
@@saltysoyman6908 In all the videos the chain or rope Always Spirals. A spiral has angular momentum
ua-cam.com/video/Lo3Sltktifo/v-deo.html
I LOVE this back and fourth feeling where I have been "pretty sure" both parties were right respectively after each video. The realisation that I was wrong is humbling.
I had thought Steve was right the whole time, but I respected mehdi and could still see his side but was more inclined to Steve's
After the first video I was certain I was right that it was simply the chain construction that caused the rising fountain and no kickback force. After this video I feel partially correct, but got there by accident and sheer luck. The thought process that Steve and Medi followed was much more rigorous than my guess process. I appreciate the entire process they've gone through more than the end result of who is "right."
The simulators did a great job tbh, they deserve the credit
From the very beginning (when I started watching these videos, that is), I intuitively guessed that the lower flexibility of the bead chains was key to understanding the effect. As a child, I loved to play with such chains because of how interesting it was to twist them into different shapes. If you tie them into certain knots, you can actually get them to retain their shape in surprising ways.
I love how this is the best """""drama""""" between two youtubers, but instead of insulting each other you're fighting hypothesis after hypothesis, admitting mistakes and challenging each other to disprove the other person better than last time.
Yay for the scientific method!
Based comrade
So it seems the antonym for a pissing contest is a chain fountain contest.
Thats why I love this so much
They’re both wrong. In all the videos the chain or rope ALWAYS Spirals. A spiral has angular momentum
ua-cam.com/video/Lo3Sltktifo/v-deo.html
It's similar to Veritasium's recent wager with a physicist over the wind-propelled car that could exceed the speed of the wind. Very respectful, everyone learns more than when they started including the one who was right; good stuff.
I’d love to see Steve’s Amazon account for the last few months, just loads and loads of chains
Warehouse picker thinking either;
A. Seriously obsessed with 1970s style door obstructions.
B. Prolific kidnapper.
C. Just another day at the office.
that or ali-express
history:
chains
chains
chains
long chains
long chains
silly orangutan picture
long chains
In all seriousness though... surprised he hasn't encountered supply"chain" issues with Brexit.
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... sorry😞
@@hesperhurt as a former amazon worker, we've seen worse lol
I just watched the previous video like 5 minutes ago. UA-cam recommendations are now so advanced that relevant videos are not only recommended but made when I would watch them
Perhaps youtube knew when this was set to release, so it recommended the previous one to watch first quickly before this one ;)
Nice steve, maybe you could use cotton down the pot to cushion the chain and check if the fountain still happens.
that's a very good idea
I was thinking a layer of neoprene or rubber would be interesting
But how much force can the cotton absorb?
Wouldn't the chain itself negate the usefulness of putting something soft at the bottom? If the beads are metal wouldn't they be hitting off each other and still creating the effect? I guess it might dampen the initial fountain, but with a long chain I don't think it would change anything.
@@sromnorba Couldn't you in theory test different materials lining the bottom that would potentially provide a measurable difference if the kick-back is the force responsible for creating the fountain? (Even if the difference is small due to the beads hitting off each other, that'd be uniform among the test I think?)
14:11 "Having this disagreement has been fairly enjoyable" This is what I love about science and more specifically science on UA-cam. Its so great to see people completely disagree on things and enjoy themselves while doing it. Just like Veritasium's recent video's on the vehicle that travels into the wind. Keep up the good work!
This is getting out of hands, I see a global chain shortage emerging
you could say they caused a chain reaction
Reminds me of an old joke the punch line was "where is all the chain coming from"
Someone will have to start a chain store to sell these.
You had me in the first half of your comment , not gonna lie...
They're going to have to improve the supply chain.
Seeing the chain try to kick through the bottom of the pot when you removed the floor in the simulation was what really convinced me
This explained the theory of the kickback force for me as well. After that it all clicked into place exactly how this appears to be caused. The wave generated during the stiffer chain unraveling creates a downwards force which flings the chain upwards due to it rebounding off the bottom of the jar, or in the horizontal case rebounding off the pile.
Oh come on, 1) The amount of movement is nothing compared to the motion required to yank the thing out of the pot 2) Once it gets yanked it wants to keep on going, so there has to be some kind of bulge, otherwise there would be an infinite acceleration involved 3) You can't just assume gravity has nothing to do with it.
@@DinoDiniProductions The simulation removed the downward force of gravity in the pot, so what you are seeing is probably a wave of force that would normally push against the rigid surface beneath it.
After it leaves the pot gravity is in effect again, and is what is causing the chain to pull out from the pot. So it is not being ignored, and it's effect on acceleration is maintained. The only difference is that the simulation was an attempt to remove any forces originating inside the pot to show that the chain fountain came from those.
@@Caelinus Oh OK, but in any case those small forces are insignificant compared to the huge force that keeps being overlooked: the force applied by the chain vertically, which is automatically present and unavoidable due to the fact that the container has depth.
@@DinoDiniProductions which keeps the chain following through its path - like Medi showed, that force is enough to fight gravity (decaying slightly due to friction). That's "the first half" Steve is talking about.
The tiny kickback forces just need to be a tiny bit greater than friction, that causes the "wave" to decay - that slight force pushes it up. Not much, the culmination of all the kickback force, minus the friction forces, only slowly "grows" the fountain. It's not much force - but it's acting on a system near equilibrium. The equilibrium is caused by the much greater force you are talking about - but that's well understood.
5:15 the beads have to be horizontally constrained and stacked vertically. He’s losing a ton of energy from the chain whiplash. The chain wants to move side to side but if it can’t it must go up. Unless the energy is great enough.
I agree. I wished he show the original ball chain and see if it would grow in height.
This video finally made me understand the Mould effect. In order for the chain to be pulled up from the base, it needs to change the angle of the connecting rod between the two beads which has just enough resistance to push the bead into the base harder, causing it to have a higher kinetic reaction.
Mould-Effect surely caused a very pleasant "Chain-reaction". Love to watch your guys intellectual discussions.
Under-rated comment. I wish I could award you like on reddit.
That's a good one.
My favorite part is how you selectively break the rules of physics in the simulation to reaffirm your hypothesis in an intuitive & visual way, amazing work!
@SaltyBrains this was my first reaction to the use of simulations as well, that they are probably not the best for unknown physics problems because they were by definition programmed without an understanding of the mechanics at hand, but in combination with the other evidence I do find it convincing in this case.
LOL so true.
As others have pointed out, at 7:00 with the horizontal chain, he says it "the fountain doesn't grow" when clearly it does grow from the point of acceleration to the arc (equivalent to vertical fountain height) at 7:40 he makes the same claim yet you clearly see it increasing.
Also notice at 7:00 the chain rapidly spiraling at the point of acceleration. In almost all videos you see this spiraling yet no one makes mention of it. Think about a football(American) when spun on its side it will stand up and spin.
ua-cam.com/video/Lo3Sltktifo/v-deo.html (read description)
Great video! I might have another interesting idea: The falling end of the chain speeds up because it is nearly performing a free-fall accelleration. As we've seen, a chain wants to maintain its shape, so every part of the chain also wants to keep up with the increasing speed. At the beginning, the rising part of the chain inside the glass is so short that gravity forces and inertia only have a small effect. So what if we look at the top of the fountain as being a half circle? Objects moving along a circular path are pulled outwards by the (imaginary) centrifugal force. Because the lower half of the circle is missing, the sum of all centrifugal forces points straight upwards. I think this might be the reason why the top of the fountain is rising. The centrifugal force at the top of the fountain is pulling the rising part of the chain higher out of the glass. The fountain is growing until the gravity force of the rising part (which becomes longer and heavier as the fountain rises) matches the pulling force of the fountains top. Having reached that "point of equal forces", the fountain will remain a stable hight until the end of the chain. Does that make sense?
thats another way to explain it, the same forces are still present just in a different order, it shows somewhat how a chain preserves its weight. However, I dont think the centripetal force alone would be stronger than gravity in this scenario, partly because gravity is what powers it in the first place, and partly because the experiment on a flat surface doesn't show this behavior. I think its closer that the tension and centripetal forces are canceling each other, and gravity is still uncountered, hence the sinking without the kickback. great idea though!
"The centrifugal force at the top of the fountain is pulling the rising part of the chain higher out of the glass"
Centrifugal force is fictional, it does not exist and therefore has no effect. If you want to know why the chain jumps into the air just watch a video of a skateboarder doing an ollie.
If you hold the Motorized Spool™ on a higher level than the beaker, thus pulling the chain up rather than down, will there be a peak/fountain that rises above the spool too?
Yes, just like it did in the video, it's due to the rotational forces and inertia. There is much more mass coming from the original container to the spool than is pulling on the spool itself, since the spool is rotating, thereby imparting an angular acceleration on the chain, the conservation of momentum will sling the chain out from the axis of the spool.
@@ruaine83 Might be, I wish to see it though.
I'm guessing it might depend on the diameter of the spool too, if it's too wide it might not be "bendy" enough for the chain to peak upwards.
@@Tomapon its anomalous to the shapes sizes and material used. There is a proper diameter and speed that will nullify backlash, but the equation eludes me . E=mc2 but the speed of light being replaced by the relative gravity to its most predominant magnetic or gravitational influence .. here would be what we deem gravity.
And what proves this is it would not happen if the little spheres were magnetic because it would dampen or cancel out the K energy build up in the chain.
@@thundernuts8308 Perhaps the fountain might move to be near the Motorized Spool™ instead of the beaker :o
Oh man, that howNotToHighLine plug! As a rock climber myself, that guy is seriously helpful in showing what gear can handle.
I'm glad I pointed it out to him in his last video. I had been binge watching a lot of those videos a few hours before Steve's last video on this topic came out so the scene was fresh in my mind. HNTH is such a great resource for climbers.
How not to highline is amazing. Don't know how they can afford to break so much stuff!
Yep, excellent channel. Really useful, and pretty fun to watch too. Someone compared it to watching that hydraulic press channel...
I think the interesting point is at 9:49 when the gravity is removed in the simulation. The chain line being pulled out drops below the level of the base line, without gravity this can only mean it was pushed down. If the bottom was still there then that push would result in a reactive force from the bottom of the pot, proving Steve correct in saying there is a "kick" from the pot.
That also happens at 8:01 in the horizontal dirll pull
Gravity always plays a part. In all the videos the chain or rope Always Spirals. A spiral has angular momentum
ua-cam.com/video/Lo3Sltktifo/v-deo.html
@@zaphodbeeblebrox2817 Gravity also plays a part when it's switched off...?
@@HenryLoenwind it’s impossible to switch off gravity
@@zaphodbeeblebrox2817 wdym? it is possible, either in a well made simulation or more realistically in space where its almost negligible
There's an easy explanation as to why it decreases (5:20 mark). The chain used up around the end is further back than the fountain origin. As such, gravity + friction cause the lag to a much greater degree than at the start. More force is required to maintain the shape but more force is not being applied to do so. Check the equation and see that the force required increases in a linear fashion.
In the pot there is also a distance change though
Thank you for featuring my simulations.
I found your channel when the yt algorithm recommended your bead chain fountain video to me. I stayed there for the other simulations as well, they are really interesting!
@@krampusz Thanks!
9:46 I had an aha moment. That simulation really helped me understand your view on the kickback force and why the rigidity is so crucial to the kick back happening in the first place.
My moment was at 8:00, you can see the stack of beads being pushed downwards
@@craigfjay yep, i made a comment that its backwards wave propagation, essentially the force of the bead chain falling sends small waves backwards along the chain, which without a pot sends the beads below the level of the loops of chain, but with a pot, they cant travel any further down, so the pot exerts a force upwards, giving that wave a bit of energy back into the chain.
Ultimately, the force is technically from gravity. Gravity on the chain, gravity on the pot, resistance to gravity, resistance to the backwards wave propagation.
The simulations did for me something that a million beads in jars couldnt do, they showed a simplified version that performed according to obvious parameter. i could never actually tell where the force was being introduced before those simulations were shown.
@@craigfjay
8:00 was my initial moment as well, for the overall explanation to fit, but it wasn't until 9:46 that the local mechanics of the phenomenon became apparent.
I first watched yours, and I was convinced. Then I watched Medhi's, and I thought yours was debunked and I was convinced of his. Now I see your rebuttal, and I think his is debunked and am convinced of yours again. What this teaches me is that I almost always believe the last person I talked to, and I should just shut up and wait for the community consensus to establish.
Personally I was never convinced by Medhi for the reasons shown in this video: he never actually showed the Mould Effect with loose chain.
You're a hero, Matt, and I applaud you 👏.
Well, at least until someone comes up with a better reply lol
@@nathanb011
I was more convinced by everybody else being convinced, but I was still skeptical. I also laughed at Medhi when he said "see? no mould effect!" while it's actively producing the mould effect....
This is truer than it seems for everyone learning about nearly anything. It's why it's important to be skeptical and have critical thinking. To have an open mind, but not so open that your head-jelly falls out.
It's good to recognize that you tend to believe the last person's argument, but you must realize that the community consensus must not convince you as easily all the same
7:56 this convinced me. Also, splitting into two parts and narrowing down what the Mould effect precisely is was a very good idea.
One thing about the horizontal simulation, is that the movement “down” isn’t immaterial. You would need to compare that to a a chain actually falling down, but lower the beaker as you do it.
there is one problem with that. as you lower the beaker, you wouldn't only be removing the bottom of the pot, but also "pulling" the chain down.
That's what I was thinking as well. In the spaced-out example, the top of the beads is going down much faster than it is in the clumped example (or in the actual pot), so you'd need to account for that
@@kriscpg You could perhaps design a cup that rests the chain on a poorly supported paper floor.
Something that would not provide a strong restoring force to any "kicks", but that would otherwise hold the chain if it is stationary.
I think with a "soft" floor like that you could simulate the lack of beaker floor, but still support the chain for the experiment without imparting any additional velocity to the chain.
@@meateaw even better. Calculate out how much force is being imparted to raise the chain on the floor and build the support just to support the weight. Then if there is the kickback force it should break through the paper. Although this would actually probably pretty hard to engineer accounting for all factors
Dang, Steve, I'm really glad you made this follow up. I was one of those that felt there were a lot of unanswered questions. In a perfect display of the scientific method, you've strengthened your arguments substantially. As you say, it's not about winning, but about finding the truth and adjusting our positions based on new stronger evidence.
I would be interested to see some experiments on a surface that would absorb some of the peaks in the normal force (foam, rubber, a pillow?) instead of reacting with a kickback force, and see how it makes a difference vs a hard surface.
It would be interesting to use hollow chains that would float on water and try it.
Shouldn't be too hard to do a quick test on some memory foam.
@@martinshoosterman I think they would have to be neutrally buoyant
That would eliminate kickback from the jar. Normally there's also kick back from the chain stacked on top of each other. I wonder how much the foam would dampen that. You could try to space things carefully so the chain doesn't stack. I'd be interested in seeing this because I think the spring effect of the turning radius provides more of the force than the "lever" force of the beads.
@@zunuf Cover the chain itself with something. But all of these change other properties also, not just the kickback force. Like rigidity, friction, etc
I absolutely loved this video! It feels so real, you guys are haveing an actual public debate, to test your theories and continue to learn. One thing that annoys me is when the modern scientist show "it works in the computer model!" But no real debates or tests.
Or how claimed experiments can't be replicated.
Are they testing theories or hypotheses?
The horizontal experiment with the drill, where the beads were spaced out versus not, was quite convincing. Nice video.
Yes, around the 8:00 mark you see the stacked beads being pushed down. That convinced me.
@@iamdave84 that part was indeed very convincing. Though I would have loved to see the experiment with the pile at the “bottom”, closer to the spool.
@Timothy Lim it's not just the spaced out pile, it's that in combination with the pile that's *not* spaced out right next to it that makes it convincing. Specifically the part at 7:52
Crowdsourcing science - freaking love it. You have 2 guys debating and others essentially peer reviewing. This is how you get to answers _really_ fast.
Love it, love it, love it!! This is brilliant.
What's more, through youtube and patreon, it's effectively being funded by the interest of the peers.
It brings together the people that have the energy to try out any experiments and ideas, with the people that can find genuine flaws or weaknesses in just about anything. So you can rapidly get to the strongest possible answers.
Between Mehdi and Lewin a similar approach led to destroying the correct lession and made an old teacher/scientist apologize for something that he never made just to escape alive from the emotional trap Mahdi have set.
It’s very interesting and fun to see the increasing precision and detail in the descriptions of the phenomenon under study. You can really tell that both Steve and Mehdi are learning and gaining more understanding as this goes on. Good work, both of you!
Interesting points, I used to be industrial abseiler and found that I also had the Fountain effect when throwing my rope off tall builds. I used to have the rope tied in daisy chain and rope was 11mm thickness. I agree with your kick back resistance. Thanks for the video. All the best. Phil
Start a fountain from a high place, then after it starts to fountain drop the pot into freefall. If the pot then accelerates faster than a dropped pot with no fountain then there is a kickback. The said kickback would push on the fountain forcing the pot downward faster. This would also exaggerate the fountain length as well. Might answer some of the questions to try this experiment.
However by having a fountain, mass would be leaving the pot, thus slowing it down, which would have a more pronounced effect than the kick back described. Right?
@@haydenhagemeier4458 the mass leaving the pot should have no effect, I think, as the object will accelerate downwards the same regardless of the weight. If it falls faster than 9.8m/s², it will be due to the additional downward force created by the tension in the chain. What will likely happen though is that once the pot is dropped, the whole assembly will almost immediately be in freefall, which is indistinguishable from a weightless state. It will all fall together and appear motionless relative to each other (chain versus fountain versus pot). Interesting question, and I'd like to see the results of trying it out..
@@donalbaine awesome thanks for explaining👍
The fountain would collapse rapidly as the pot accelerate, but I think with a high speed camera we could measure the initial acceleration of the pot.
That is a tremendous idea, I was thinking about using scales, but the bead leaving the pot really complicated thing.
With your idea the mass of the beads in the pot is irrelevant, since they are free falling and are not applying force on their own.
@@donalbaine Yes it would require a high speed camera and the important information we are looking for would be in the initial second or two. The idea was to remove as many variables as possible such that we are left with the usable data we need to answer the question.
The simulation was crucial for my understanding. Once I could see the loop first dipping downward when the bottom of the container was removed, I immediately grasped what you were saying about a "kickback force". Really well done all around.
yes
Yeah I thought when he was holding the pot he would absorb the kick back.
I love a kickback, force
Ok Steve, you've won me back. I did not notice the falling arc in Mehdi's 2D experiment, or how dramatically he imparted the arc in his beaded fishing line. Both valid points. Your 2D comparison of the ball chain spaced out versus bunched together specifically shows the need for the kick-off effect to increase the height of the arc. I'm convinced...again. Are we done yet?
Wait, we need Destin from Smarter Every Day as a judge as well.
Yes that
72
Absolutely. we need a lot more judges. a high speed camera to prove/disprove my theory. ua-cam.com/video/Lo3Sltktifo/v-deo.html (you have to read the descriptions in the videos)
@@zaphodbeeblebrox2817 oh banter! I love it!
@@PongoDaMan but is it really banter if only you and I hear it? While thousands are convinced by this "Proof". I know Atomic Shrimp saw it, but he prefers Steve's "Proof" video because of the rigorous scientific methods he used (hand held drill, denying that it rises at 7:00, rock solid simulations) confirmation bias is a bitch these days. This is not science!
This explanation really made me see how in Medhi's video every time there was an initial wave imparted, but no fountain grown from no arc
These were exactly my thoughts on Medhi's video, with regards to his experiments not actually showing the Mould effect. Glad to see them addressed, and with a proper explanation of the wave dynamics!
Yes I was nearly convinced then I noticed the "fountain" always decayed, (the floor one never goes "up", and he imparted the chain one with his initial movements). The hoover hose was interesting though.
Really? Sounds lame. No pics--it didn't happen.
@@noahway13 you can go see my comment on Medhi's video if you don't believe me lol
@@isaacjackiw9711 Didn't check, but I believe you. Your reply was to nice to troll you.
That's incredible. I love that you both go after this very seriously.
As a kid the "wave whip" with ropes and the like always blew my mind. I would do it with bigger and bigger ropes to see how far it could go.
I want to see waves in an extra dimension in space - you only get a Y wave on earth but imagine the wave going on the X as well, like a spiral! And yes, the "pull rope and observe feedback" is delicious, even more so as a child. MAGICAL
I loved it too, my friends and I would have battles where you each hold one side of the rope and take turns sending waves at each other. Because sending waves at the same time just cancelled each other.
And then you discover the mechanics of a whip, with decreasing thickness
Have you seen the chain whips they use as tourist attractions in China. There are videos on UA-cam une of them. They get the chain to break the speed of sound using simple conservation of momentum.
You should put the bead container on a weight measurer to confirm the kickback force
He explained in a previous video that doing that is very difficult because the mass of the chain in the pot is constantly changing.
@Tame Rome This problem has already been solved, the solution is in a paper linked in Steve's first video on this "dispute"
@Jun Yan Yap just because it’s a paper doesn’t mean it’s correct.
@@KP3droflxp Yes, but in my humble opinion what’s published there, or at least their key conclusions, are correct.
Richter has measured the force felt by the base of the pot.
10:12 onwards 👍🏽
You flipping genius Steve. Loved the horizontal spaced and non-spaced with mould effect esp when you added the lip of beaker simulation. Spot on!
Great job. Kickback maybe not the most intuitive word to describe it for me but this certainly makes sense. The inertia tries to bend the chain when it pulls away and the chain presses against the ground when it bends. Awesome video.
Trying to find the 'right' answer, vs. just 'winning'. What a concept. :-)
But they ignore the obvious. In ALL the videos the chain or rope ALWAYS Spirals. A spiral has angular momentum
ua-cam.com/video/Lo3Sltktifo/v-deo.html
I love UA-cam scientists making the new modern “drama” videos debating science.
That simulation is amazing! Impressed that you were able to recreate your findings in real life in the simulation by removing gravity
We need the gods of UA-cam physics to come in a finish this for once and all. I call upon Veritasium, MinutePhysics and Smarter Every Day to join in
We do need the gods. But we have one! Veritasium joined
Pbs space time
Pretty sure one of them have released it already
Cody’s Lab and ScienceAsylum joined the fray!
@@TheCosmokramer1 what about V SAUCE everyone forgot about it
As a mechanical engineer, this debate has been a real treat. Shows how difficult classical mechanics can get. Medhis did an awesome job, but I'd declare Steve the winner. Simulations always have to be analysed carefully, however I think in this case the core of whats going on mechanically is represented and the consequences we learn from them unlock the physicis of whats going on.
The thing is that there were 2 things going on, and the simulations and slightly different experiments show them:
1) wave propagation in a chain;
2) force of a pile over the links of a chain falling.
Of course the force applied is not that big all the time or consistent all the time, but that doesn't matter for the effect since we just need the chain speed to increase in 1 side relative to the other.
You can probably suppress the effect in many ways, some shown here too.
Yes, they over simplify it. In all the videos the chain or rope Always Spirals. A spiral has angular momentum
ua-cam.com/video/Lo3Sltktifo/v-deo.html
Like the veritasium video on moving faster than the wind. It all comes down to forces at the end of the day, and it was very deceptive in working out how they balanced.
So, from your theory, should you place a soft bottom to the pot (like a sponge), the chain shouldn't raise as much?
I would be interested to see it ^^
This is very interesting. Indeed I agree, it should be tested with an energy absorbing bottom layer in the container (elastic vs. non-elastic deformation). I too think that this should have an impact if Mould is correct
@@FanaticTentacle so plastic?
@@PBMS123 more like cotton balls
No see the better solution would be a preassure pad at the base of the jar, if the preassure increases steve is correct but i doubt he is
@@SkELAo7 Usually the way the science proves something is right is by proving the other teories are wrong, isn't it?
This is the UA-cam drama I'm actually interested in. I get to learn along with it.
Ok Mould. You've convinced me that the height is due to both the resistance to bending and the fact there's a base to push off of. Well demonstrated. The simulation was what pushed me over the fence when it depicted the spike in downward force right before the bead came up.
I'm really glad he used simulations. You should try the Mould effect on ropes and should have the beaker set on a sensitive force gauge to look for the force spikes.
Nailed it. I think I commented it on Mehdi's video, that while momentum kan keep the arch up, leverage is needed to grow it.
Physics is interesting.
Exactly. All Mehdi showed was (as stated here) that the chain will follow the existing chain's path and curvature. He never showed it increasing in "height", if anything is was always decreasing.
Dude that is so fucking cool how that works. Mind blown
Very glad the chain stiffness was mentioned especially when under tension. This was my thinking and I'm pleased to be thought to be correct.
this debate inspires me to study physics more precisely and get all the pieces together. i have a hand wavy understanding now. Thanks steve and mehdi!
Great job Steve! You really earned the right to give the Mould effect your name! I was convinced by Mehdi's explanation as much as now I'm convinced by yours. Science is great.
It was interesting to see the chain in the simulation with gravity suspended. The chain clearly travels below the missing bottom of the pot. If the bottom of the pot wasn't missing, this would produce the upward reaction force the chain would feel to produce the fountain.
Can me take a moment to admire the faces these two do when they are in a slow-mo.
I cant stop watching the faces now.
Very epic indeed.
Your name should be Salmon boi
PLEASE READ: Using the spaced beads in that way is wrong in my opinion. if you just let the beads off the edge of the board, there is no upwards force acting upon the chain. its only being pulled to the side and down. But in a beaker/cup. the chain is forced to move UP out of the cup. therefore it initially creates and upwards force that then increases as the momentum of the falling side increases.
What's also not shown in that test, of the chain going off the edge sideways, is a camera recording the chain from the side.
I am more than certain the chain makes a sideways loop, away from the board, that grows in lateral distance, as the chain falls and gains speed.
Very bad example, not showing all the angles of the test. That's hiding information.
@@gdxd7956 yes i was thinking that too but didnt mention it. I believe if you showed another angle. You would see the same effect but sideways
7:51
@@shotguntornado I think the reason why the effect is not happening is because the length of one side gets longer and longer. and the drill is stationary. The reason it works on the left is because one side is always longer than the other, therefore more momentum. Another reason this could be happening is the drill is exceeding the force of gravity if it was vertical. The effect works vertically because the only main forces in play are gravity and momentum. if the side inside the cup took longer to get over the lip, then the effect would be smaller or nonexistent. I still believe the effect happens because the momentum of the falling side exceeds the threshold for the other side to slow down and start to fall.
I think you need to do one more computer simulation of low and high flexibility bead chains without the container walls as a control to really complete the explanation!
You're right Steve. Your evidence is totally convincing IMO. Enjoy those sweet, sweet 10,000 Canadian cents.
What Is IMO?
@@aashsyed1277 in my opinion
The spiky nature of the chain-fountain ground-force plot seems like it may be connected to the side-to-side movement of the top of the chain coil as it unwinds. So I guess we'd expect a wider container to impart energy to the fountain either more quickly or less quickly than a narrower one? Probably less quickly, since a wider container would make chain stiffness less of a limiting factor in how smoothly it can uncoil?
I want to see an annular container, of significant diameter, such that it's only as wide as the ball chain is, and curl it around in a perfect helix. Reducing any tangling, or sharp corners/bends. I think this would produce less of a mould effect because it seems to be the restriction in the minimum radius the chain can bend/pinch, that is pushing against it, which would explain why the rods don't work.
The natural chain fountain you see is the result of throwing a ball in the air, several times and seeing the energy difference between them.
The energy is causing the balls to rise because of the chain connecting them. They are similar in weight and mass, so gravitational potential energy is getting converted to kinetic energy when you move it.
You are seeing the fountain rise because an object in motion continues in motion unless a force is acted on it. The chain balances the gravitational pull of the start of the chain, directs it upwards later down the chain, and gains and looses height based on the balance between gravitational potential, and kinetic energy.
The fountain grows due to gravity pulling in the falling part of the chain, which due to inertia, causes the chain to be thrown in the air at the lip of the beaker. Depending on how much heat energy is lost, the fountain will eventually loose enough energy to not pull the chain over the lip, as no energy is being added to the chain once started, only converted.
If your explanation was correct then this effect would be observed with other types of chain (like 'normal' chain made from linked metal circles), but normal chain does not create a fountain, only this specific type of ball-chain does. Thus, your explanation is wrong.
This is a fresh era of integrating science into videos on YT
I love this! Keep discovering new things!
The force on the beaker in the simulation seems key. It'd be great if that could be verified experimentally.
It has been proven experimentally. Check out the video starting at 8:00. You can see the chain that's still "in the pot" being pushed downward!
"Seeing as to how this thing is already made, I might as well try to simulate a gory chainsaw accident"
Here is the thing. If the chain has any "stiffness" at all, the bottom of the chain thats leaving the pot can be seen as a part of the chain (of arbitrary lenght) that feels a force (being pulled up by the 'previous' part of chain) on only one of its sides. Since that part of the chain has non-zero stiffness/rigidity it will start turning around its centre of mass. But its either on top of other chain, or the bottom of the pot. So it will be 'pushing' (levering around its center of mass) on the bottom of the pot. Since the pot isnt moving down, it must be excerting an equal force up. That is the kick that the bottom of the pot gives the bottom of the chain. Or how the bottom of the chain pushes itself off and 'jumps' after itself.
It would be really interesting to see how friction (like, chain to chain friction) would affect the height or stability of the 'jump curve'. Im thinking the levers might work even better if they cant slide across one-another as easily
This is still such a rich topic for utterly pointless but nevertheless interesting research. How would weight, shape, etc etc of both pot and chain affect things?
Would the jump be higher or lower on mars?
If there is a lever action effect created by the tiny balls, it could be measured by a calibrated scale / along with an accumulator to get a mass effect. I doubt there's a fraction of a gram produced, and even if so, the overall effect would be negligible. There's not much going on when 'next ball' is yanked from it's stationary position, that change of state is practically instantaneous.
Your regular bead chain actually also starts out with the 'pre defined shape of the bead chain'. it starts out above the lip of the container.
I'm an ecologist, I took applied maths so I love these but I'm no expert on the physics.
All I can say for sure is: Steve does a mean Clint Eastwood impression during his spaced bead test.
"Clint Eastwood impression "
So true haha!😄
Thanks for emphasizing that science moves understanding forward when disagreeing theories emerge. This is in contrast with dogma which just stands in the way of knowledge.
Dogma is associated with religion even more than science. Tho they both have dogma.
To be realistic, it takes more convincing to undo a currently held belief. It is not just dogma.
In the simulation without gravity you can clearly witness the “kick” by looking at the loops that constantly push below where the floor used to be. That shows that when the floor is there, those loops are pushing against it.
This is fascinating! I'm genuinely curious how the size of the beads affects this phenomenon. Like if the beads were individual atoms, would the same thing happen?
Quick, everyone! Start liking! We need to get this to the top of the comment section in case a bored physicist with access to an electron microscope decides to watch this video
As far as I can tell the beads themselves are negligible. It's the degrees of freedom of each chain link that matters. The beads provide some resistance if they're close enough but you could get the same effect with a bunch of stiff, stick-shaped links. Iirc Steve mentioned this in his first video?
So I think even if the beads were tiny, with enough restriction you'd still see the effect!
@@KalebPeters99 each bead is a metal sphere with rotational momentum, and intertia. To curve the force applied by gravity has not only to accelerate each bead linearly, but also rotationaly. Some linear force is changed to rotational motion.
@@billtoo4694 Rope experiences this same force. (he showed a rope based example in this video).
The kickback force that causes the fountain is caused entirely by the "chain" (or rope) having a limited bend radius.
I think the bead-chains are particularly good at showing it because of their behaviour under tension compared to when slack.
When slack they don't tangle very much because they have a very small bend radius, but when under tension the bend radius shallows out, and the shallower the bend radius the higher the kickback. The bead chains are just really good for showing it in relatively short runs.
@@marshallsober graphene strands used in vax
I still think you're both partially correct. It still feels like there's something missing. I would like to see a graph of the effect chain rigidity has on the height of the fountain over time.
I just love this Dialog between scientists! My offering is to Steve , to ask someone on the ISS to perform the experiment. It would be interesting to observe what happens when gravity is taken out of the equation. Chain on!
Or at least get in a fast downward-moving elevator (lift, hah!) and see what effect it has. I guess elevators probably won’t be fast enough, but who knows?
You could probably get sufficient results testing this effect out on the vomit comet for significantly less cost than getting an experiment up to the ISS.
The horizontal experiments on the floor are essentially removing gravity and showing us a 2D version of the experiment
@@TomHarrisP not realy there are forces that would not be in microgravity(which is where ISS is)
Two things to help. 1.) When the chain is not moving, it has friction with the surface it's resting on. When you pull it, you break that force of each successive bead, which releases a tiny bit of energy to kick up the bead. 2. The loop gets higher because of the accumulation of successive beads breaking their friction bond with the surface. If you want to see that in action, look at the END of the chain as it leaves the surface. One more thing: The chain follows the path of least resistance as it leaves the surface while accumulating energy from the friction bonds breaking, which is like a very weak rubber band snapping.
Try this experiment in some way where there is no friction and see what happens. Weightless still had friction where the beads met. I suspect if there is no friction, there will be no snap back.
I watched the video on the Spring Paradox because it was randomly recommended to me and instantly got hooked
These are so well explained and entertaining!
Can’t wait to finish watching the vid
Hehe Hooke-d
@@ShinySwalot I see what you did there😂
@@randaranatunga7259 I mean you made the joke I just "explained" it xDDD
Hope atomic shrimp gets more viewers from this! His channel is great, he does all kinds of random interesting stuff.
Yes hopefully this will help. I love everything on his channel. I was happy when Steve Mould mentioned his name in the video !
i love the dudes content, he embodies discovery and sharing down to the bone and i hope to carry a bit of that with me
After watching both of the previous videos of you two, I felt that Boom reconfirmed your suspicions.
And after this one, I'm even more convinced you're right.
This is the first I've heard of this phenomena, but my immediate intuition was: it's due to lag in the chain at rest rotating into alignment with the direction of the chain pull. In the case of a traditional link chain this would be from a combination of angular inertia and friction between links. If the chain is travelling faster than the time it takes for the 'picked up' chain link to rotate into alignment, the non-aligned link rises up, I.e. a 'kink' travels up the chain. If the same happens with the next link behind and so on, it results in a series of kinks that, if they don't straighten in time, create a rising wave. The misalignment might be small between each link, but combined they form a curve. It would be interesting to do duplicate drops with a link chain, first dry, then lubed, to see if there is a difference in wave height. I suspect the lubed one would create a lower wave, despite the potentially reduced friction over jar lip allowing a faster initial chain speed. I also suspect the layout of chain in a pot might effect things. I.e. I wonder if a chain laid out circles around radially around the circumference of a pot would create a different /more consistent height standing wave than one lapped back and forth into a pot, due the different angular change their links experience from at rest vs. direction of pull.
I'll caveat all this by saying dynamics is not my area!
Maybe more like this? ua-cam.com/video/Lo3Sltktifo/v-deo.html You have to read the descriptions I don't make good videos but check other vids of fountains too
This back and forth of real science is some of the best content your channels have made so far.
Gaston!
Medhi getting rectified. That was pretty convincing i have to say.The simulation by Maarten Baert was the cherry top, pretty nice one my dude.
Sorry dude. It's the other way round.
Simulations work on the rules we give them. If the simulation doesn't have realistic rules concerning the chain fountain effect (as we don't truly understand how it works), then the result won't be realistic either.
@@Renee_R343 Normally you only put in rules that you know of, and then see whats happening on a specific setup. Mass, gravity, chain length, chain "bendability", friction. I guess he has done exactly that.
next: have someone at the international space station do this experiment!
If you use a loop,
things get interesting. If you put that rotating loop in zero g it would maintain its circle, O or even a 8 shape, if you were able to touch it without slowing it down you would see standing flow waves that slowly smooth out itself back to a basic shape. Checkout my Magic Inertia Videos :)
Every curved part of the chain acts like a live segment of a flywheel/gyro
@@aaa69200or in zero g airplane?
@@sonnenklang6925 zero g is too short to gather usable data
@@krotchlickmeugh627 at least something to start with,
it will have limited observation time anyway by the Friction it has. So 30sec is a lot :)
I love how two guys on UA-cam are currently doing a better job of furthering scientific knowledge than most established academic journals.
It's two guys, not UA-cam.
The chain fountain was explained in established journals years ago. Everyone on youtube is ignoring that.
@@jenks4879 edited
wow, talk about an exaggeration
@@PhysicsUnsimplified 🤣
Oh, we made the same experiment with a drill in 2012 (see our video 2016 in Russian, with English subtitles). // If you want to know historical details about the discovery of this phenomenon, read here: en.wikipedia.org/wiki/Chain_fountain
Yup. Good job!
+
Cool
of course there is some asian that has already done it...
@@ToMeK3001pro Asian ? tf ?
During the simulations around the 10min mark you can also see the chain that has more tension exhibits a small fountain effect with the gravity turned off, but only when it is able to make contact with the edges of the pot, and therefore able to transfer the energy to launch itself into the fountain shape
Entropy mate... Entropy.
@@prob_io7299 How is this entropy?
@@Justin73791 Facts:
There's a gravity affected chain with an embryo inside a gravity less zone.
The chain has equally spread mass in each joint.
There are two parallel walls, both fixed in space unaffected by any force, both have unknown mass, therefore we do not know if the have any at all, can't make assumptions so it can only be the boundary.
There is no wall underneath the chain.
The chain lays flat in an overlapped position after being put there manually.
The chain has only its own mass to attract to but the outside gravity is stronger, thus making the stress affected parts of the chain's gravity null.
The parts not affected by the stress are pulled to the center of mass in the gravity less zone, thus getting further from the side walls nulling their being.
Conclusion of facts based theory:
When the chain will bundle up in the gravity less zone, it'll actually create an opposite force at the end of the overlaps edges, being supported by the centerly gravitating part of the chain, generating an environment which encourages the effect..
@@prob_io7299 I read everything you wrote, but I still don't understand how entropy is involved in your conclusion.
@@Justin73791 Well, the walls are furthest from it. It goes where ever's effortless , in this case it's bound to bundle up...
I love it when two channels I really like and respect do projects together.
I had heard this happens on huge military ship anchor chains, and it looks pretty damn impressive.
Those are fed from a reel inside, and drop straight down outside though: Any suspended loop would jam the drop. Plus they're really heavy, even without the massive anchor on the end. That said, it would be interesting to repeat this experiment with bigger/heavier chains.
@@robinhodson9890 Dont know. I do know I took a tour on a navy ship in the San Diego harbor. Navy guy pointed to the anchor reel on the deck of the ship with huge links that looked like they would weigh about 300 pounds each. And he said when they drop the anchor, the links whip up 7 feet in the air as the anchor drops.