Chain Fountain Dispute
Why does Mould Effect happen? It might be exactly how you think it happens!
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Watch Steve's side of argument:

Original Mould Effect Video:
Cambridge Video on Mould Effect:
Cambridge paper on Chain Fountain:
Paper on Falling Chain Speed:

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By: Mehdi Sadaghdar

0:00 The Wager
1:15 Mould Effect Dispute
2:29 Chain Fountain Background
3:20 My Analysis of Mould Effect
9:53 My Tests to Confirm My Analysis

  • ElectroBOOM

    Thanks to @SteveMould for battling this out with me! Every time I feel I know something a debate like this shatters some of my thoughts and makes me think harder. Make sure to check Steve's first video: and NOW his second video: that is way more convincing! Does it mean I may lose my 10000 cents?! Eh, it is for science so that's fine. But I haven't given up just yet!

    • Peter Arisz
      Peter Arisz

      "Momentum" isn't that inertia?

    • shashi kumar
      shashi kumar

      Hey @electroBOOM "the coolest guy ever 😁 . We can use a soft base(a cushion) to absorb the force pushing the chain down. And if still rises then it proofs that force is not the the reason for that effect. though that force exist.

    • ꧁𓆩F.B.I ༒ I.G.X𓆪꧂
      ꧁𓆩F.B.I ༒ I.G.X𓆪꧂

      I like how u tried to ping Steve mould as if it's Discord

    • Pontiw

      its all about Centrifugal force that is wh fricttion doesnt mater.

    • SubCoolSuperHeat

      Well, now think harder, because you just got 1 uped big time.


    Who's missing sparks and exploding of electronic components ☹️

  • Gabriel Pangan
    Gabriel Pangan


  • John Grace
    John Grace

    I noticed something, this seems very similar to Whip physics, this occurred to me on the last test shown with the weights and fishing line where the end of “chain” flared out like a whip when it breaks the sound barrier

  • Giuseppe La Spina
    Giuseppe La Spina

    I think the only variable during all tests should be the chain. In every tests, usually the starting point changes, table, different glasses, heights.. we need more constants to really judge the effects.

  • A Drunk Potato
    A Drunk Potato

    I think its a pipe, do the math

  • Zegichiban

    I'm probably more surprised at the vacuum in the wall than the problem itself.

  • Goose Boat
    Goose Boat

    ElectroBOOM I've been developing my own theory and plan on using a bit of your video too, I'll post my explanation in the comments when it's done rendering as well as Steve's. Do I have permission to use some of the video?

  • J Mc
    J Mc

    It looks like centripetal force in action to me

  • Laura Pichon
    Laura Pichon

    doubt anyone will see this but this whole phenomenon is in my opinion, the simple conservation of Velocity within deltaV. All types of chain are subject to pull-forces on the front of each link in directions that cause that link to need to move, while also pulling on the link behind it. Regular link chain even has the force of the links rubbing on each other as they try to turn. Rope (and vacuum hoses lol) also are subject to forces that resist change in direction but chain is more pronounced because of those pivot points.. So basically the loop and its rising is the resistance to change in Direction being higher than the resistance to change in speed. When acted upon by a force while needing to make a 180 turn, the chain will travel faster around a big loop as it is easier than turning hard at a slower speed.. Basically its simple resistance to change in direction

  • Roope T
    Roope T

    explaining somewhat complex kinetic systems with levers only seems a bit, I don't know, dubious

  • Yudo P.
    Yudo P.

    This is what I love about experimental physicists including engineers, they experiment and find out how to test things. If this debate was a tv show it'd be Leonard vs Sheldon.

  • Alkis05

    "It is a mechanical problem, so as an electrical engineer I'm over qualified to deal with it" LMAO. That is exactly the kind cheap shot that you can hear all the time in a maintenance room among technicians.

  • Reelworthy

    @ElectroBOOM You went Full Bridge on Steve. Well done sir. Now sell that glove at auction to raise money for the family of Steve Mould’s Ego, may it rest in peace.

  • Naveen Prashanth
    Naveen Prashanth

    12:21 To avoid lever effect, you can try the regular link chains on the floor, like you did for ball chains 😋

  • Lior

    I think that the height the loop can reach depends on the energy it has, more friction means more "loss" of energy which means smaller loops (less velocity and hence less distance that can traveled) so I believe that technically it would happen in every type of chain.

  • Luis Miguel Zapata Muñoz
    Luis Miguel Zapata Muñoz

    ElectroCute whit the boxes: “A!”

  • gamboge

    Someone with a Phantom needs to get on this

  • PG Guru
    PG Guru

    Wow, we now have proof that a youtuber with no mechanical background has better understanding of the subject than the Cambridge experts. Well done 👏, great technical demonstration. Enjoy the 10dollar meal.

  • Enrique Moran
    Enrique Moran


  • _xNotDragon

    An experiment done in home is understood better than done in videos or theories

  • Ben Hatcher
    Ben Hatcher

    I agree with the momentum theory.

  • 18 18
    18 18

  • green gaming
    green gaming

    Im u r big fan

  • Morris Tran
    Morris Tran

    It is inertia

  • derDere

    Someone has done it with a rope:

  • jonahtang

    Is this just centripetal acceleration? Mv^2/r? As the beads fall, the velocity keeps increasing and for the centripetal force to stay constant (force of gravity) , the radius must increase.

  • C Patterson
    C Patterson

    Have you seen this

  • Christopher Banbury
    Christopher Banbury

    Steve's sister video starts with a polymer climbing out of a beaker. The Mould effect should occur here as well if you could get air started between the polymer and the edge of the glass and show that @electroBOOM is right.

  • Dean G
    Dean G

    Gyroscopic effect. The balls are spinning. Probably alternating CW, CCW, CW... Your both wrong, the 10,000 Canadian pesos are mine.

  • Robyn Linderman
    Robyn Linderman

    Do you not get the same effect from a slinky? I seem to remember the longer ones rising, the kick back effect can probably be seen more easily. Also reminds me of coiled rope off a ship's bow

  • TexasDieselGuy

    It's centrifugal force... The chain moves through an arc, which is the top half of a circle, so it only produces an upward force which lifts the chain. The key to the whole thing is very clear at 15:44, just watch how the tail of the chain whips the last few pieces out. It is this conservation of momentum that provides the force everyone is missing.

  • Jack Franklin
    Jack Franklin

    nice ringtone

    • MAPP Gaming
      MAPP Gaming

      I love it and want it Wait... that sounds sketchy

  • Aaron Walderslade
    Aaron Walderslade

    *Here is the solution.* It's so simple actually. In your analyses, you have both failed to examine how you set the chain off. The chain is telegraphing the information of your initial flick. The answer is in comparing the start and end. It's not different from the effect you get when you suddenly flick a rope up and down, making a little hill travel the length of the rope. The flick is carried the length of the rope, transformed into a hill, which is suppressed as it too tries to recreate the flick, and so on (although this is in reality a smooth transfer of forces), culminating finally in the release of the flick at the end of the rope, which is really a telegraphed version of the flick you gave the rope (or chain) at the beginning. You start with a whip cracking motion and indeed at the end the chain behaves like the end of a whip. You would see this better by using a very short chain of say nine inches (and not letting go). The transfer of force works better in the ball chain because it transfers forces more efficiently.

  • Anirban De
    Anirban De

    👍Yours is better.

  • Gary Ha
    Gary Ha

    Maybe this plays out in a quantum scale somehow

  • Morris Tran
    Morris Tran

    The rectifier looks like a diode

  • kew eyz
    kew eyz

    ElectroBOOM is correct. And 11:20, the chain probably didn't rise because it weighs more than twice that of a ball chain on top of everything ElectroBOOM says. 13:14, watch the chain that is moving closest to the chain that is still stationary, it's visual ASMR lmao.

  • us here
    us here

    ee here, too (love the "overqualified" comment, lol!!) XD i feel like the physics of whips plays in here forces from each link affect the subsequent link. but it's been over 30 years since i've taken mechanics (except quantum, for which you need an angstrom wrench ;) [shrug]. :\

  • huafan1

    The key to this problem is: all the balls dropping must have the same speed

  • Patrick Burns
    Patrick Burns

    The apparent force that is felt by an object moving in a curved path that acts outwardly away from the center of rotation. Reactive Centrifugal Force.

  • Nicholas Carlough
    Nicholas Carlough

    Ould this have some relation to what happens when you whip opes and chains causing a wave to travel down it. the wave in this case is stationary and the chain is moving.

  • codemiesterbeats

    I agree with your interpretation... it seems to me that it is just creating a "whipping" motion as it falls off the edge and it rises to a certain point... the whipping motion just adds to itself like constructive interference in a wave. ( I would guess that that will top out at a certain height, allowing the falling part to reach terminal velocity) Not sure if the business end hitting the ground would change things much... I guess it would have some effect. It is an interesting thought experiment. Edit: upon watching both videos I can't say either are wrong. I am wondering if the distance of the beads spacing has something to do with angular momentum imparting a separate whipping motion in the "pile" It is pretty interesting conversation lol

  • No Reverse
    No Reverse

    The effect happens with normal chain, like 3/8mm BBB anchor chain. That is why the chain coming up the howse from belowdecks jumps the gipsy if you free-fall the anchor. If that happens you may lose the whole anchor+chain. When dropping anchor one releases the brake of the gipsy just enough to let out the chain moderately slow. It is simply the chain accelerated upwards continuing motion upwards You could run a random chain over a pully suspended by fish-scale. When the chain runs the scale will measure less than with the chain at rest.

  • Darian Tolofson
    Darian Tolofson

    You're both 33% accurate Newton's second law of motion. What you 2 are bickering over is how a barrier will guide the chain, and yes the chain can act as a barrier towards it's self! Tension and friction are also very pronounced forces with these chain experiments. Sir N's 2nd law is also why the gyroscope structures in your ears can stabilize you on a bicycle and why at a certain speed threshold you can ride with no hands.

  • cargasm383

    I'm not math guy, or even an engineer. But I picture a pulley in the loop. As gravity pulls down the falling chain, The chain on the opposite side of the "pulley" is pulled upwards. "The pulley" is caused by the turning radius of the chain, the momentum of the chain moving upwards, the time it takes to change direction, and rotational torque of the direction change. as the chain moves faster the centripetal force increases which then increase the "turning radius" of chain.

  • Austin S.
    Austin S.

    I'm sorry but I'm all moulded out... i dont really care anymore.... its just a damn chain

  • SeventhSwell

    Your explanation seems obvious and is the same conclusion I came to (though, without the math. Never had the head for that). Of course, that I came to that conclusion kinda makes me worry I'm wrong, since I couldn't write or solve a physics equation to save my life. Just seems so obvious that the speed of the falling chain pulls upwards on the resting chain with such force that it has to launch into the air, and since it's part of the chain it has to curve over and be pulled down. Doesn't seem mysterious at all. But, I guess I should go watch his video too.

  • swamy sriman
    swamy sriman

    I personally think that no rigid body(i.e; no moving parts) can "push" against a surface. That just doesn't make sense to me.....

  • with my heart upon my sleeve
    with my heart upon my sleeve

    principle of lever effect is being applied to wrong place. this effect is happening not where the chain is leaving the cup but when it is turning.

  • Christoph Beer
    Christoph Beer

    The central vacuum system blew my mind I didnt know this is a thing! I guess this is just possible with western cardboard houses.

  • Tim Lewis
    Tim Lewis

    To be honest I thought it was plain centrifugal inertia: the velocity of the chain restricts how tight a radius of bend it can take - just like a car travelling at 100 mph can't take car park level turns. Having a limited bend radius helps getting it started instead of grinding to a halt dragging on the side of the glass, although provided you can get enough speed, I can't see why you can't achieve this with an ordinary rope.

  • IrvineCascade

    10:45 I'm sitting here, wondering how an orbital literal "chain gun" could be weaponized when I notice the sudden whiplash effect of this chain. Fun. I would say that you're pretty close. Of course, we'd have to see the full mathematic equation for the definitive.

  • Mara caui
    Mara caui

    You are right.

  • Jo Kah
    Jo Kah

    What? Your daughter has grown up to a cute lady

  • Darshan Neupane
    Darshan Neupane

    its all about inertia ... the higher mass of the chain falling towards the ground provides more than enough energy for the part of the chain going upwards towards the rim of the container....the velocity of up moving part is higher than the falling one which provides just enough energy to slowly increase the height of the system so that the system can stay in equilibrium...... an initial force is required for the chain when falling from a flat surface so that the chain starts moving upwards and then down rather than horizontally and then down .

  • Brian Tristam Williams
    Brian Tristam Williams

    Dispute is between him "and ME" not him "and I"

  • Son Goku
    Son Goku

    4:29 chain won

  • Son Goku
    Son Goku

    I read China dispute

  • kjakobsen

    ElectroCUTE has really grown since we saw her last time. :)

  • electroBANG

    i am 10 days past 13 years old i don't understand a single word you are telling but it sounds pretty intelligent you are the 3rd great scientist known to me after nicholas tesla and albert einstien

  • payam ghasemi seproo
    payam ghasemi seproo

    خیلی دوستت داریم ستون 💙💙🤟🤟

  • TheyCalledMeT

    i have a hard time not to see all of it explained by inertia .. barely if not no "leather effect"

  • Velvet Casuat
    Velvet Casuat

    Thank you for showing ME that Cambridge are a bunch of scammers .

  • eaglee_1

    this is just easy, the pulling force created by the chain going down is making this happen, there is no surface force or whatever steve says, sorry steve. its the momentum as mehdi says. so when the end of chain hits the ground, the speed changes to constant because only a part of the chain is pulling down, until it hits the grond, and when it hits the ground it cant pull anymore. you can see that the more u pull the chain down the higher the waterfall will get. u dont have to do any videos. mehdi is the winner(they both deserve credit tbh)

  • Juniorbatista Junior
    Juniorbatista Junior

    Hello, Mehdi. I know it's a bit off topic I was wondering if you could build a Wimshurst static generator. thank you

  • DrR1pper

    The lever arm explanation also helps explain why a falling chain will fall faster than a free-falling object.

  • Gnana Prakash
    Gnana Prakash

    Idk what to say. This is such a simple problem. It's the Centrifugal force that's doing a lot of the weird magic in these weighted rope/chains. It also increases till it balances out with the constant gravitational force, stopping the chain's acceleration. Now, like Mehdi said, he is an electrical engineer so, I think its fine that he didn't arrive at the conclusion straight away (although, his explanation is the closest to the correct mechanism), the other ppl from CAMBRIDGE have no excuses!!

  • shashi kumar
    shashi kumar

    Hey @electroBOOM "the coolest guy ever 😁 . We can use a soft base(a cushion) to absorb the force pushing the chain down. And if still rises then it proofs that force is not the the reason for that effect. though that force is exist.

  • Angel Angelescu
    Angel Angelescu

    Have you ever used a whip?! It's a similar effect.

  • Rasmus Voss
    Rasmus Voss

    Just call it magic. that way no one is right

  • Chris Hulkow
    Chris Hulkow

    You both are for getting about the weight and force of the chain .. you can do the same thing with rope

  • Alexander Christopher
    Alexander Christopher

    Can you PLEASE explain this???

  • GloveSlapnz

    To the death!!

  • Rueben Mikoch
    Rueben Mikoch

    Shouldnt have had the initial loop when testing horizontally

  • Ganesh Karan
    Ganesh Karan

    Whip effect

  • Diesel Life
    Diesel Life

    So it seems to me that gravity just happens to be the force that is pulling on the chain. The part that makes this look confusing is the chain it self. When the chain reaction starts, part of the chain is static and the other is loading inertia and transferring it to the next link in line. Like if you tied a long rope to a car and on the other end attached something like a brick and you drove the car at high speed, when the rope is fully extended the brick will experience all the available inertia from the fast moving car at once and it will have to move in the same direction as the car. first changing direction which is effectively a whipping effect. Back to the chain, as the chain lengths down wards it has more potential energy then the static links that are at the beginning of the curve. So the links build them self upwards at a faster rate then the part of the chain that is straight down. the part of chain that is going straight down is also experiencing constant tugging tension in both way, up and down thus feeding the rising or growing fountain curve.There are other minor forces at play, but i think in my humble opinion this is what is happening. ElectroBoom I love your channel. You definitely make learning fun. I appreciate your efforts.

  • Jemar Catubig
    Jemar Catubig

    wouldnt a highspeed camera solve this by marking three lines of the same distance from each other and measure if the chain is accellerating as it falls during the fountain duration? ask veritasium for one, he loves highspeed camera velocity measurement.

  • Owen Mull
    Owen Mull

    this is a lot more like how I always thought it worked. great explanation too thank you

  • Q.D. White
    Q.D. White

    These Cambridge guys are way off the mark. The "kickback force" they are seeing is just the normal force that appears in any free body diagram of an object in contact with another object due to gravity. It is balanced by the gravitational force. It is the chain tension force that provides the unbalanced accelerating force.

  • Shaikat Sarkar
    Shaikat Sarkar

    Boom effect approved

  • Astarothpool17

    Momentum NUFF SAID

  • Stranger

    person who isn't an expert in the field they claim to know all the answers to rejects actual scientific studies in favor of "well i say it works like this" and everyone claps like seals because trusting actual scientists over youtube e-celebs with invalid credentials is apparently so 2012.

  • Чернобог

    I love the way he says “negligible” so much that I’ve started saying it that way. Feels much better

  • XxXx xXxX
    XxXx xXxX

    I wander if a string shooter can prove anything?

  • bredisfun

    I watched both videos and the only question I really have is why in the 3D experiment with the ball chain in a cup, why do metal ball chains work but plastic ball chains don’t?

    • Nick Dumas
      Nick Dumas

      The metal ball chain does have metal bar linkages to amplify the launch, while the plastic balls have stretchy string between them.

  • Sgn Sgn
    Sgn Sgn

    Could this not be explained as a fluid under pressure with a siphon effect in this case the flexible chain acts like a fluid and the initial downward Force acts like pressure and the links between the chain act like the siphon continuously pulling more chain until it's all gone

  • mbkennels

    First, it’s “between X and me,” not “between X and I.” Second, it’s “better than I,” not “better than me.” We can scarcely apply the rules of science logically if we cannot apply the rules of English usage. Now, this argument is very simple. Mould is clearly wrong. This can be settled very simply by having the free length of chain (the length of chain being pulled up) hang freely under the force of gravity, and not resting of any kind of horizontal surface that could be argued to give it a “kick up force.” The argument is risible on its face. You can’t push on a string. This experiment would require working from a substantial height, simply to provide room for the hanging length, but a balcony 2 or 3 stories up should suffice. In addition, the free length might have to hang with some substantial radial clearance within a guide tube, just to keep it from going pear shaped. But it might not. Easy to try either way. Support the free end of the chain (then end to be dropped) over a freely spinning light weight pulley to start, just to give it support so the delicate chain won’t have to drag over the edge of the tube and perhaps break. Attach a weight to the free end of the chain that weighs significantly more than the free hanging, tube encased length of the chain, so that it will fall as desired. Then, drop the weight. After sufficient kinetic energy is achieved, the arc of the chain will rise up and away from the pulley, which could even be removed. It will rise higher with additional speed of the fall. The sideways banging of the free hanging length of the chain within the vertical tube can not possibly have a components force 90 degrees up and along the chain. There is no kick up force. No part of the chain is engaging any horizontal surface. Case closed. This might also not need the guide tube. The fact that this would work with rope or string as well merely reinforces the point. All real world elongated and flexible materials have some stiffness and so will arc around the bend when whipped. Like a fly rod and line.

  • Jim Brenneman
    Jim Brenneman

    I see the value of this argument, but after seeing both videos, I have to agree with Mould. most of the science in this is sound, but Newton's equal and opposite forces do not both act on the same object (The chain), but rather, they are the forces that objects exert on each other, so the inverse force of gravity would be provided by air resistance and the ground once it hit, but this would not cause the chain to become a fountain. (If I'm incorrect in an assumption or have a simple mistake, feel free to point it out.)

    • Tirdad Kiafar
      Tirdad Kiafar

      The way I see it with my college level physics the friction does not play a big role, specially air resistance cuz these are really heavy for that sake (visual evidence from the videos) , but your point of hitting the ground and quick propagation of force is a good point. Unless you have a really friction heavy, resistant system like the latent in this video. To add to it I see the diameter of the chain on top stays the same if not hit the ground early, which was one of the Steve's main points (indirectly) so that is why a lot of people are trying to approach it from the centrifugal force stance and equations but I also can't see how that relates since it has a lot more forces in and out on the chain before and after the effective "circle" of centrifuge. I am totally at loss :D

  • ixdygames cz
    ixdygames cz

    I would say "Chain effect" was called after something...

  • Pete Micofsky
    Pete Micofsky

    Great job !! loved it !!! always learning from you, thanks

  • Eric Clare
    Eric Clare

    I think that Steve needs to reproduce the chain fountain with the more flexible ball chain the exact same way as the original. Doing it in a different way (the way that he has) it feels like he's hiding something. Whether or not he is. For control purposes he needs to do that from the same beaker not laid out flat. The same test under the same circumstances. Otherwise it's missing a data point.

  • Andrea Rimondi
    Andrea Rimondi

    To me the one single reason that sinks Mould's arguments is that constraint forces never do work, and thus, id does not matter how you decompose the reaction of the bottom of the cup, it will never do work.

  • Rohit Yadav
    Rohit Yadav

    This is a perfect demonstration of stabilization of string in mould effect

  • Woodstock Dz9
    Woodstock Dz9

    Nice, but I think Steve is right. Now I gonna on his channel and say that you are right. XD

  • NerfTuco

    ngl, mehdi's constant, has a certain ring to it, when you discover a new concept or a new formula or something new, please name it mehdi's theorem/mehdi's formula/ mehdi's law

  • NerfTuco

    electocute's bracelet looks like a coil, was this on purpose, or just a happy coincedence?

  • Sudip Tsai
    Sudip Tsai

    I love that we can be a part of the dispute cuz if it was in the old times before the internet we'd just be like. What? Scientists fighting over a chain falling? How stupid. But cuz of the internet and engagement peoples really are genuinely interested well I don't know about others but at least I am.

  • Plactoec

    Is it something to do with how the chain can collapse some?

  • Andrew Boyles
    Andrew Boyles

    I was an idiot and watched Steve's video first and was almost drainwashed into forgetting my electrical training. Thanks for reminding me of the mechanical engineering failure in his argument.