Continuing the debate of the chain fountain with Steve Mould, I shall not hand over the bet of 100 Canadian Cents so easily! Especially since I still have proof. Let me know what you think about the new evidence.
My First Chain Video:
Steve’s First Video:
Steve’s Second Video:
Paper on Cascade of Hanging Chains:

Thanks for your support @
Checkout my merch:
Post your submissions to:
My Facebook:
My Twitter:
My other articles:
Thanks to and for proving my essential lab tools and giveaways.
Checkout my Amazon picks (my affiliate link):
Below are my Super Patrons with support to the extreme!
Nicholas Moller at
Sam Lutfi
EIM Technology:
Peter Membrey
Marius Hoel
Enter your school for tools:
My sponsors and top patrons:
By: Mehdi Sadaghdar

Hi so steve mold released a new video explaining the chain fountain again, if you don't know steve and i released a video each at the same time, link in the description disagreeing on why the effect happens. I had everyone in my pocket with my reasoning. Even derek of veritasium was almost convinced by me, but then steve's new video link in the description made me lose everyone even derek of veritasium. I watched steve's video and i thought damn.

I was wrong about this, but then i quickly realized i was just mesmerized with his blue eyes and soothing voice. He was just so convincing in his video and he would have won our bit of ten thousand canadian sense if he hadn't shot himself in the foot throughout his video left and right. Sorry, steve, i'm just hyping up the drama throughout the video for science. You know left and right.

What i like about this debate, though, is that it got many of you involved and we received a ton of great thoughts and experiments, so it's a win for science and hopefully eventually for me. Okay, let me give you a quick history for more details. You can watch our earlier videos, but this is a chain fountain or mold effect. The chain rising above the lip of the container before falling to be on the same page with steve.

The effect must be able to start growing on its own pair my view, because acceleration and force can't be infinite. A time period is needed for the chain to start from stationary to a certain speed and another time period. For that speed to change from positive to negative as the chain is speeding up falling in a certain period of time, the chain would have to travel higher and higher. One note, though, that becomes important later the chain will shoot out in a direction that it can, in average, consistently escape from.

For example, in my previous video, you saw in my 2d floor test that the chain shoots away from the pile against the direction i'm pulling, and here i place the pile sideways and you see the chain only shoots sideways steve. On the other hand, reasons based on the cambridge university paper that it is not enough for the chain to rise without an additional force that comes from the surface. The chain is sitting on based on steve and the paper a chain or a string in general. That has a limited bend radius exhibits a lever-like behavior where the chain pulls up on one side, the other side pushes against the surface, and so the surface pushes back, which is the force needed to help raise the chain.

Now, there's a common ground between both of us, like steve, mentioned in his video a chain will flow through the shape that you give it well not always, and that shape would be maintained in the absence of gravity, not exactly true in the presence of gravity the Shape that you give the chain collapses over time, i don't agree with that. Yet sounds like a hypothesis as i pull the chain around it moves through the shape that i give it. Actually, the shape does collapse a little bit, presumably because of friction in this case. As opposed to gravity yeah, i agree with that.
This textbook, from 1860 talks about chains maintaining their shape when flowing in steady state. Oh yeah, as if you read the book and understood all of it, have you ok? The way i understand steve's argument is a chain. Tends to travel through the same path in 3d, space in steady state as in traveling, in constant speed and not losing energy due to things like friction or gaining energy. By some pulling force in the presence of uniform forces like gravity, the chain still holds its shape.

It would just travel as one big body in a certain direction, so is the chain fountain system in such a steady state? No at the beginning, it is accelerating and that's when the fountain is growing and even when it reaches a constant speed. It is constantly being pulled by gravity on one side and is speeding up from zero. Although the chain still tries to travel through the same path where it can also, i've mentioned it before and mention it again, why does the chain even reach a constant speed if you're thinking terminal velocity is the cause? That's not the case terminal velocity happens when the force of gravity on an object traveling through a fluid, becomes equal to the force of friction from that fluid against the motion of the object and the speed becomes constant for that. A dense object like a chain must go very fast, dropping from very high for the human body.

It is around 200 kilometers an hour. The chain reaches a puny, slow, constant velocity in just a meter. So it's not terminal velocity like i said there is clearly a force opposing the force of gravity, and i argue that force is the sum of forces opposing the acceleration of the chain from zero to speed and another one opposing the change of speed from positive to Negative steep hasn't provided any other reason for this constant speed like it's nothing but, in my opinion, that's the whole point. Existence of such force indicates a limited acceleration and so a finite time period needed for the chain to loop around but never mind these.

Let's do some experiments, or rather re-watch some experiments since steve already did enough in his video and i'll tell you why he's shooting his own foot left and right? He argues that my very convincing test of pulling the chain over ground creating the effect is not convincing. At all, i did this test to specifically show that the chain doesn't need to push against the surface, to create the effect to eliminate factors like gravity and the supposed lever effect. I spaced out the chain in the pile on the ground and pulled the chain from one side to create the effect, but he said the fountain doesn't actually grow. It does appear to grow in height, but that's just because the top of the pile is receding in this direction.

If you look at the peak of the fountain, it doesn't get any higher. It actually moves down slightly, probably due to friction. Oh really so for the mold effect. The chain has to rise and stay in the same height, so you're, claiming if we have say a two meter pile and the chain drops there as the chain goes and the top of the pile recedes.
The top of the chain stays in the same height really so why in the world, did you drop your chain from 45 meters high in your first video to get a world record of one and a half meters? You could have just made this two meter. High pile and the chain would eventually go above 2 meters. Is that too much drama? Yeah it's for science, even steve's, fountain peak goes down as the top of his pile goes down, even if the chain was going at a constant speed throughout. You can clearly see it here before after before, after so the peak dropping down over time is not an excuse.

Steve made a motorized spool to pull the chain at a constant speed and did two 2d tests on the floor. One with the chains bunched up together and one like mine with chains spaced apart, he says in the tightly bunched up pile the chain, fountain rises and stays high, because the chain pushes against the pile to rise, unlike in the spaced out test where the peak is Dropping no steve your bunched up pile fountain is also dropping, but at the smaller rate, because the chains are much closer and the pile is receding at a much smaller rate. And what did i say, the fountain starts from stationary to go around. So, let's align the two tests where the stationary chain just starts going.

Look at this in my spaced out method. The loop gets even taller, perhaps because there is less banging and tangling in the pile and it indicates no lever push against the pile is needed for the loop to get tall. Thank you steve for doing this competitive test, because it's pretty much confirming my idea. Sorry steve, like i said, the drama is just to get people invested in science and then he does another test, creating a lip for the chain to go around showing in my method.

The chain never rises above the lip really steve. If, at a constant speed a certain peak height is achieved, you can't put the lip above it and expect a chain to go beyond that. Here's the bunched up pile but far away from the lip see you get the same result as steve's spaced out version, because the lip is too far away from the pile another thing in my video i provided a chain with string and spaced out balls to eliminate The lever effect, but still create the mold effect, and i argued my peak is going down because clearly the chain is slowing down due to the backward forces. Steve did the same test from a higher drop and although his chain was still speeding up, his peak dropped.

So he argued i'm full of well. He didn't say that he's too nice, but he said due to the lack of the lever effect, the fountain collapses under gravity. Well, i don't buy that, although, on my side, the slowing chain helped lower the peak, there were other factors that contributed see in our test. The chain is spaced out in the pile sitting on a surface like this and is falling from the edge, but as the chain unwinds for the chain to travel the same distance through the loop.
The peak has to drop. Another thing i mentioned earlier was the chain wants to shoot toward the direction it can consistently escape from which, in this case, is that way. So this peak was momentary to start with, because i whipped the chain and not the steady state, and not only that when the chain is being pulled sideways, it drags across the surface and the friction eats away its energy, which means considering all these, even with the Proper ball chain. In that specific setup, we can't really maintain the fountain, so we can't really convince ourselves one way or the other, but if there was one thing, the test on my side confirmed was that the chain slowed down in the presence of opposing forces due to accelerations, like I talked about so paint me unconvinced by steve's arguments, although i can't 100 deny that level force.

Maybe a tiny bit of level force exists that puts just enough energy into the system over time to help raise the chain, but just based on the 2d floor test. Steve kindly provided no leverage is required to help the chain rise higher and maybe the lever effect actually makes it worse. The problem is, it is very hard to come up with a good test setup to confirm things, one way or the other. But let me introduce you to a magnificent test done by peter steinkamp, a medical researcher at oregon health and science university, which further indicates that mechanical engineering degree is a joke.

Sorry, just that in my previous job it was me against, like 20 other mechanical engineers, lest you forget, he has a plastic ball chain with strings connecting the ball, so no limited bend as steve showed, and he puts them on a rod back and forth. Like a curtain - and he drops the chain - isn't that beautiful the chain is super flexible, so no lever effect and it is not pushing against any surface, and yet it rises upwards as the chain can consistently escape. That way, let's see if i can repeat it with my chain here, so why in the world is the chain rising now steve argued in one of his emails that it is a force from the surface of the pipe pushing the chain up. Sure the chain is pushing against the pipe, and so the pipe is pushing back, but this force is perpendicular to the motion of the chain and it's not like it's pulling it up and the chain is rising even before it reaches the surface.

In my mind, this is a very definitive test, and yet i can't confirm or deny things beyond the shadow of doubt. Frankly, as you might have also noticed, i saw the effect of this backward push against the pile or the surface here and there, but then again it didn't seem necessary for the fountain effect based on some other tests. Anyway, i love these kind of challenging puzzles and had tons of fun arguing with steve on this make sure to subscribe to his channel, because he may come back with an even more convincing report. All.

10 thoughts on “This Video of a Motorized Spool Proves Me Right”
  1. Avataaar/Circle Created with python_avatars Axe Murderer says:

    I've seen these fountains now for a few months. And something I've noticed that has yet to be addressed is the "twisting" motion of the chain. All the analysis to this point seems to be presuming that the balls in the chain do not spin at all. However, if you observe the chain right at the point where the fountain starts lifting from the surface (near the bulk of the portion which is not in motion), there is always what appears to be a twisting force causing the chain to follow a sort of vortex path going up and into the lifting fountain portion. In fact, to me anyway, it appears as though the falling part of the chain is imparting a spin on the stationary balls as they are set into motion. And that the spinning increases as the falling chain gets faster and faster implying that an increasing twisting force is being applied to the chain as it accelerates. As a result you see the vortex pattern forming, and then growing in both length and breadth, as the chain accelerates. As the fountain begins to form, this vortex shape rotates, starting in a horizontal orientation perpendicular to gravity, and tending towards a vertical orientation parallel to gravity as the fountain proceeds to grow. I'm thinking it even looks sometimes as though it is the vortex which raises the fountain when it rotates rather than it becoming vertical in response to the forming of the fountain.

    It seems to me that if one ball in the chain starts to spin, the friction between the balls and the links which connect them would cause a twisting force to occur and then be propagated along the chain, potentially invoking an upward force component sufficient to raise the fountain. I believe there is a torque force being applied that is not being accounted for due to this spinning. If you know the trick where you spin an American football on the ground sideways, it will pick itself up so it can stand on one of its pointy ends and spin along its more stable axis through the ends of the ball parallel to gravity like a top. It's kinda like that force I think, which may be lifting the balls up using a rotational force (angular momentum) so they can spin more stable along an axis parallel to gravity. It's a sort of gyroscopic force. A force which tends to place the links between the balls (i.e. the pointy ends of the football) along an axis parallel to gravity, placing the balls themselves one on top of the next. And while I am pretty confident that it is affecting the chain's motion significantly and is the cause of the vortex shape, I am not so sure that it is the source of the mysterious fountain force. The reason for this doubt is due to the fact that it is based on a rotation which is cyclical. So while it may impart an upward force, it may only be doing that half the time and the other half it imparts a downward force. I believe it more probable that any forces generated from torque may only be acting within the plane that is perpendicular to the force of gravity, or to the line of the chain when it is horizontal. So it might cause a vortex without necessarily causing any upward or downward forces at all, only sideways forces. However, it must be a contributing factor…just maybe insignificant. In any event, it ought to be considered in my opinion as it is most certainly an overlooked portion of the force equation.

    Have you guys considered you might both be wrong?

  2. Avataaar/Circle Created with python_avatars Dismythed & JWA says:

    Mehdi, I hope you have the strength of character to admit that Steve is right after Steve's latest video. He saw exactly what I saw in the chain on the bar (which I posted in a comment below). His science is better. Please be a mensch. It's just $100 Canadian and a little pride.

  3. Avataaar/Circle Created with python_avatars What is says:

    I think you both correct. Specifically you are correct for general and he is correct for special. Actually all chain drop from high got this effect and you explain the reason correctly.But for chain with metal ball this effect show alot stronger and chain jump alot higher he explained correctly where did this extra energy come from. So you both correct and this should be two theory. Special theory of chain fountain effect and General theory of chain fountain effect.

  4. Avataaar/Circle Created with python_avatars Jacob Crosby says:

    I am sorry Medhi, but you are very, VERY CLEARLY incorrect! It blows my mind that you are completely ignoring the clear movement and push from the 'tight' 2d test. I genuinely do not have any kind of clue as to why you are still arguing this.

    In EVERY single video he has released, you can slearly and abundantly see the push down on the bunch of chain in the container… It really frustrates me how you are actively avoiding any mention of the SEVERAL INCHES that the chain is pushed down!

    You are obviously a smart guy, but you're not doing yourself any favors here…

    Maybe stick to elections!

  5. Avataaar/Circle Created with python_avatars piwi2005 says:

    I fully agree this reaction thing is pure BS.

    Here are a few points:
    1/ The reaction force of a fix support is by essence a non working force.
    2/ if you put a rigid beam on a table and lift one extremety, there is everything that you stated in your videos : a rotation, a couple, a reaction force. Does the table send the beam into the air ? Of course not, because this is not how normal reaction forces work. The normal force is equal with opposite sign to the force applied originally, and the consequence is that the point of contact stays still. Let me repeat: stays still. if the contact point leaves the surface, the reaction force is instantaneously 0, which is why normal reaction forces from fix supports do not provide work. That reaction force can have any value, as long as it does not break the support, and it will not be a force providing a movement. By definition its value cancels with the one applied in the first place.
    3/There is a reaction force with or without torque, with spherical bean or rod-like beans, with small or larges beans, and with blue or red beams.
    4/At best, you could use shocks. Shocks are treated with conservation of momentum and energy, rarely with forces. And in that case the correct concept would be impulses.
    5/ The "reaction force" you speak in the end is even more a fuzzy concept. The beans continue up because they have inertia, not because there is a force from the rod.
    6/ If you take the reaction force out, then the entire set of beans fall, under gravity. The fact that there would be no fountain without a reaction force is fantastically obvious. There would be no string falling neither, just a packed bunch of beans.
    7/ In reality, each bean is a small spring, with very high stifness coefficient and also with its own torsion. Every bean on the table gets an initial impulse, with its speed changing from 0 to the speed of the chain in a very small amount of time, and every bean can store energy in the form of torsion or of stiffness. Such energy can be stored and released.

    And finally
    a/ If the string has constant speed v, then the tensionT in the string must increase linearly in time, being equal to the weight of a mass lambda*v*t falling down: T=lambda*v*t*g.
    b/ With a constant path, longitundinal speed is constant along the string, which then makes the tension the same everywhere in the string moving. That's because if not constant, a moving section of string would be accelerating, longitundinally, and the speed would change. So T=lambda*v*t*g everywhere in a moving string with constant speed.
    c/Thus the impulse T dt applied to the bean at rest becomes bigger and bigger, increasing proportionally to time. This is just not physical, and mechanical energy must be loss, either as heat or deformation.
    d/ In a string with beans, deformation can happen, but in a string with small rods, it can't, or much less. This increased tension can be absorbed into the elasticity of the rods up to a certain point, but the only way to make it decrease is to make a longer path. If the path gets longer, then the speed can increase smoothly, and the tension can decrease.
    e/How do you make a longer path ?

  6. Avataaar/Circle Created with python_avatars GhostFish50 says:

    i have another suggestion that puts a twist on what mould did to prove you right i just dont know how to draw it out but if you take the beads and basely change them so there is no "lever" witch is not what creates that little "fountin" ive been doing that effect for years sense i was a kid i was doing it with plain sting when messing around. but if you take the bead cut it in half put a pin in the middle and use a chain like connecter for all of them it would create the same effect but would have no limitation the chain could spin 360 around the bead. i will work on explaining it better but this would work and remove the already nonexistant "lever"

  7. Avataaar/Circle Created with python_avatars Anthony McCue says:

    @ElectroBOOM it caused by its own momentum force accelerating and decelerating that causes it to act that way. the force travel backwards against the direction of momentum. like when you jam on the brakes on a bike after a fast ride the front stops but the back wants to follow the path but cant. but the force has to go somewhere until dissipated. so it creates lift.

  8. Avataaar/Circle Created with python_avatars BleedingRaindrops says:

    you raise a query about the constant speed, but we do notice when Steve does his world record drop that the speed does increase further. I believe you are assuming that because the chain is free flowing while the beads are airborne, and that because gravity continually applies a force to the falling beads, that there must be an increase in energy in the system, which would prevent a constant speed.

    Consider that the collective kinetic energy of the system exists individually within each individual section of the chain, and that once that section of chain reaches the ground, that energy has left the system. the beads inside the cup and the beads in the air are the only ones that count. so when the rate of energy entering the system due to gravity equals the rate of energy leaving the system due to beads hitting the ground, there is your terminal velocity.

    I do recognize your point that the lever effect is not the primary force raising the chain fountain, however, I am curious if that is your only point, or if you have your own idea as to what is causing it. So far all I gather is that you believe Steve is wrong; I would like to know what theory you believe is the right one.

  9. Avataaar/Circle Created with python_avatars AndrianTimeswift says:

    So, I'm new to this debate, and am catching up from Steve's latest video (and then I went back to watch the rest). I think the most convincing real-world experimental evidence I've seen from this whole debate was actually provided by you in this video…. but it made Steve's case. That is that when you pulled the chain sideways along the floor, it rose up and fell back to the floor, then slid flat across the floor. On your explanation, the chain should only travel along the floor, but it's not. The chain is chaotically bouncing around just enough that it's pushing off from the floor and creating a fountain. It's hard to tell for sure if this has been happening in the other tests, but I think it has. Still, on your explanation, we shouldn't see that fountain effect happening when you're pulling the chain across the floor – it should stay on the plane of the floor.

    This confirms the simulations Steve has shown in his videos, where if you remove the force of gravity and the bottom of the container, the chain will sometimes loop below where the container's bottom was – if the chain has stiffness to it.

    All that said, physics isn't really my strongest subject, so I fully accept I could be wrong on this point.

  10. Avataaar/Circle Created with python_avatars Hola! Edward Bagumian says:

    Very interesting and insightful thanks Mehdi and Steve. I kind of lean more on Mehdi's explanation. Perhaps, a constant motorized ejection at the edge of a plane with nothing to push against or even in a chain loop will allow friction-less stream and provide more insight I think. Thanks guys.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.