Chain Fountain Dispute

hi today we rectify the rectifier there is this scientific dispute between steve mold the great science youtuber and i around the so-called node effect what is it oh it's steve hi steve hey meddy so yeah something i've learned from youtube recently if you have a scientific disagreement it's not official unless you have a wager wager so i propose that whichever one of us turns out to be wrong gives the other ten thousand ten thousand cents okay canadian yep obviously because you're canadian yeah sure what do you think i think it sounds good especially since i'm gonna win and it's gonna pay for my lunch money now if you can have someone like neil degrasse tyson to settle or dispute it would be nice so you're on the dispute is just simple mechanics but if you struggle to understand it it could have helped you if my sponsor kiriko was around when you were kids but it's never late for your children to start with very fun hands-on projects and learn with cubicle that's why i got a bunch of these crates for my daughter to try here try kiwiko free for the first month using my lingkiriko.com electro boom anyway this is mold effect named after steve where you drop this ball chain it will rise before it falls i couldn't convince steve that the reason for this happening is not what he thinks which is based on a paper published by a professor and his student from cambridge university published in the royal society i think their conclusion is incorrect well it's a mechanical problem so as an electrical engineer i'm overqualified what whatever i'll show you my detailed analysis here and steve also just made a video of his analysis in his channel you should watch after my video link in the card here and in the description but at the end of the day it's my word against his this video won't be funny except maybe for the fact that i'll beat steve but i really hope that you'll stay and listen and understand our reasoning and judge who agrees that i'm right anyway i haven't seen steve's video but i can't imagine he has a better argument than me it's just mechanics and i have more subscribers than him so i must be right subscribe to steve to balance the power let me give you a bit of background i had seen this effect when i was a kid before mold effect was cool and i thought i knew how it worked until the cambridge guys explained how they thought it worked basically they say because these ball chains have a limited band radius look it already looks wrong but they say it acts as a lever like a chain made with solid rods connected with strings if you pull the side up this rod wants to turn around its center of gravity so it pushes the side down against a solid surface it's sitting on but the surface being solid provides a counter force and pushes the side up so basically the cambridge paper and video claims that this counter force from the table helps fling the chain above the surface before it falls back down so it was like cambridge royal society stiff mold then it must be true but it didn't sit well with me and i was like it tastes wrong though this analysis doesn't sound right already wouldn't the force from the table also translate into a downward force on this side resisting against the chain rising never mind that if you see here when i raise the chain from the table there doesn't seem to be any lever function anyway the assumption is that these links are solid so when you raise this ball the opposite ball wants to go down around the center ball but in reality these links are so loose you just raise this side and the balls rise with almost no lever function now i understand there are strange things around chains falling for example a falling chain can drop faster than the acceleration of gravity there is even a paper on that is that paper peer-reviewed let me show you here i have a battery and the end of the chain held together with one hand and i'm gonna let go of them together like this but for mold effect i always thought it was due to the momentum of the chain and their explanation felt wrong but i thought maybe i'm dumb and gave up until i saw something at home and said no at home we have a central vacuum system with the holes inside the wall that you pull out lock and turn on to put it back in you unlock the hose and block the suction and the suction will pull the hose back in doing this i created the hose mold effect i unlock the hose block it with a cardboard box and let go created the effect without the need to push against any surface the hose runs parallel to the wall until the end that it turns 90 degrees to go in as the hose speeds up the momentum of the hose becomes too great and it overshoots before going back into the wall and that's what's happening to the chain too so i started talking back and forth with steve with a lot of analysis and tests and i failed to get into his thick skull which is fine we're just two gentlemen having a civilized scientific disagreement to the death no it's a scientific debate of course and i might have been missing a simple crucial fact and be an absolute fool i have more subscribers though in any case listen to our reasoning carefully and judge the reason the chain falls of course is because the longer portion outside the container is heavier than the smaller portion inside and it keeps pulling it out now listen to the chain falling per my calibrated hearing after the initial acceleration the chain continues falling at a constant speed which is what you can see from all other tests too but the chain is free falling before it hits the ground why wouldn't it constantly speed up it's a chain after all so the speed of all the moving links is the same under tension so this link enters the fall at an initial speed of v and gravity must take over and make it go faster but it doesn't which clearly shows that there is a force equal and opposite the force of gravity pulling the chain back up this is the key i could actually count two of them those forces happen when a change in speed or acceleration happens that requires force one is here where the inertia doesn't want the chain to change speed from zero to some velocity v and the other one is a total force around the loop here that resists against the change of speed from positive v to negative b there's also a tiny force of gravity for the tiny bit of chain rising which is much smaller than the large portion of chain falling let's ignore that and also let's ignore the friction for now now force is equal mass times acceleration and acceleration is equal the change of speed over a period of time this period of time cannot be zero as in the chain cannot change from 0 to some speed or the rising edge cannot change direction instantaneously zero time would mean acceleration is infinite and so the force required which is impossible so this time period is finite and so the two forces i talked about see when this chain just starts going at low speeds these two forces are small because the change of speed is small so this big force of gravity keeps accelerating the chain the length of chain between the top here and ground is limited and so this force is almost constant unless you drop the chain from very high and it never hits the ground in that case this force keeps growing well let's assume the chain hits the ground and this force is constant as the chain speeds up under this force these two forces grow larger and larger until the sum of them becomes equal to the force of gravity at which point the chain goes at a constant speed so as i said a time period is needed here in which the chain curves up allowing for the vertical speed to rise gradually and also another time period is needed to allow the chain to accelerate from positive velocity to negative so you see the chain must curve up above the surface to allow for the gradual change of speed the higher the chain falls the greater the force of gravity and so the opposing forces become stronger now call me crazy but during my testing i may have discovered that the time it takes for the chain to go through the loop is constant no matter how far the chain drops or the speed of the chain given a specific chain i suppose here i painted a link black so we can trace it during slo-mo take a look three drop tests at different heights and see the link goes around during the same period right here let's watch it a bit slower there although the chain rises to larger heights for larger drops the time through the loop seems constant i don't know why that happens or if that's true i suppose i could figure it out but i'll leave it to you i know one thing though if that effect is called mold effect then that time constant is medius constant if that's true it also explains that in higher drops where we have faster speeds in the same time the chain has to travel a longer distance through the loop and that's why the loop is taller now let me show you a bunch of tests to confirm my theory first off the edge of the container is a light you don't need it the chain still rises outside the container so one less factor now if only we could remove the surface the chain is sitting on to show that the chain still jumps up without the need to press against the surface i guess we could test that in space but i still have a way to test it i put the chain on the ground without these lines touching in an imaginary bottomless container have an initial loop here and like i showed we don't need an edge here to have the effect going then i'm gonna grab the end of the chain and run this way do you think we'll have the mold effect let's see [Music] so it seems we still have the mold effect without the need to push against any surface there's only friction that's always against the motion of the chain obvious enough eh this still didn't convince steve that's why we are here he argued that the chains might be pushing against each other that's why i space them and they don't he also argued that this effect only happens with ball chains not the regular link chains he even did a test to show that those chains don't rise all right that's the chain there first time i'm trying it [Music] [Music] very disappointing you know i even chose ones that were like almost like a chain of rods since i believe you should be able to create this effect if the friction is negligible i bought a bunch of this chain to try it and quickly i realized this chain is terrible for mold effect not that it won't happen with this but that it generates a ton of losses that drags on the chain and stops it from rising this chain is especially bad see every link generates a lever here that the gravity has to try 10 times harder to pull the chain up and then bang it hits the edge here that brings it to a complete stop and then it falls here and then another lever so it's bad to make it worse these chains don't freely twist unlike the ball chain that does and these tangle and in general they don't rise because they bang and tangle and lose all their momentum and energy not because the ball chain makes a better lever in fact these guys do make better levers see it has such a hard time to drop so i asked steve to make it easier for his chain to drop by going around the round pipe and that didn't work either got this [Music] it didn't work for me either but let me do my 2d floor trick and see what happens here is this chain let's see if it can do well in its ideal habitat [Music] [Music] so [Music] so even this chain can do it there must be minimal resistance against motion and high speed in fact the cambridge guys did a similar test successfully they argued that a chain made of rigid rods that act like levers should be able to rise nicely so they made a spaghetti chain and see what happens and they also argue that a chain made of metal balls with long strings between them doesn't have the lever function and so won't rise and so we'll drop that and see whether that's true as well and looking at those tests i believe both those tests were rigged see the spaghetti chain test was done in a bowl so that the chain wouldn't hit an edge otherwise it would lose all its energy and wouldn't rise the ball and chain test was done in a deep cup so the balls would hit the edge and lose their energy rigged i can show you both those chains would loop on my 2d floor test so i bought a ton of fishing string and weights and put them like one and a half inch apart on the string and the damn thing is already all tangled well let's do the cambridge test first but look at this it's this thing just bangs against the edge of the glass and has a very hard time to drop let's drop it anyway i'm happy it didn't break the edge of the glass look at this chain so nice and free-flowing compared to this one which looks like it's made of friction i can see so many reasons why this one wouldn't rise none of which has anything to do with leverage nevertheless let's see if it can pass the 2d test despite all the friction [Music] well it worked despite the friction and lack of leverage now if i can make it work dropping it from a height i'll drop it from my balcony launching it from my whiteboard with no edge and hope for the best [Music] well i guess i rest my chase now let me go wash my hands i hate those lead balls if i lose this debate it's because of lead poisoning now before i go watch steve's side of argument and potentially be proven wrong i suggest that you make these concepts easy to understand for your kids using practical projects from my sponsor kirikou kiwiku offers subscription lines each catered to a different age group containing super fun hands-on toys and projects to expose kids to concepts in steam with kiwiko's subscription first month free at kiwico.com electroboom each month you will receive a crate that will keep your child busy with an educational project especially during their lazy summer holidays rather than keeping their brains on standby are you done are you wow look at the headset she made on her own and of course this is her favorite pencil sharpener now and you're not done just finishing the project the book that comes with the project contains a ton of technical information that makes the child excited about the science techniques or skills that goes into the project cubicle started by a mom of three to spark creativity tinkering and learning in kids of all ages same as me they believe if you start small today having fun building and learning you will have the confidence and skills to do big things tomorrow so give this gift to your kids and thanks for watching pay

Channel: ElectroBOOM

Views: 1,188,057

Keywords: educational, electrical, ElectroBOOM, science, electronics, engineering, entertainment, equipment, measurement, experiment, mehdi, mehdi sadaghdar, arc, mishap, physics, Sadaghdar, test, tools, circuit, funny, learn, shock, spark, discharge, mould effect, chain fountain, dispute, debate, Cambridge, royal society, ball chain

Id: hx2LEqTQT4E

Length: 17min 49sec (1069 seconds)

Published: Thu Jul 22 2021

Reddit Comments

[u/boot20]

Having watched both videos, I'm on Mehdi's side, just kind of off the cuff. With that being said, there is a LOT of math here that needs to be worked out for it to make sense.

I'm not sure the pot makes a difference and looking at Mehdi's horizontal experiments seems to prove that out.

[u/mr_rivers1]

https://www.youtube.com/watch?v=fYPqs69_5g4

Is this not the 'mould effect' in action on a very heavy, large chain?

I'm not sure how this contends with either argument, but it might shed some light on it.

[u/MoominSnufkin]

That was pretty interesting (even just skipping through it).

[u/jaap_null]

I'm still stuck on the block-gun-shoot thing. Shooting off center makes the thing go higher, meaning it somehow imparted more energy into it? Found that very interesting and not sure I understand why. The whole rotate-kick-off-table thing sounds very weird.

I guess I never really realized how much energy gets converted into heat. It feels very handwavy to use that to "make up" new ways to impart energy like that.