Elastic knots are really mind bending

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When you make a mathematical knot using elastic material you get jumping loops and challenging puzzles.
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[@SteveMould]

I forgot to say, the puzzle knot by Langer is 9_46 (9 underscore 46). The sponsor is Ground News - give it a try at ground.news/SteveMould. If you sign up through my link you’ll get 40% off the Vantage plan which gives you unlimited access to every Ground News feature. Your subscription directly supports Ground News on their mission to make the media landscape more transparent.

[@jaspyjiindust.9227]

lol your comment was written 18 hours ago according to youtube. but nice video

[@stevendavis3872]

Okay, normally I don't really pay attention to the sponsors, but this one actually has got my attention.

[@miil558]

You are (clearly) not autistic, but your character has a lot of positive aspects that autistic people also have.

[@conorstewart2214]

@@miil558 what do you even mean by this?

[@miil558]

@@conorstewart2214 When you are looking at the qualities of a lot of autistic people you can see we have much attention to detail, methodical approaches of problems, skills in observation and absorbing information. Those are positive things that Steve Mould also has. Did I say something controversial? English isn't my first language so I'm sorry if I did.

[@Joulespersecond]

"But it's not stable, and if I let it go it ends up touching itself again" feeling personally attacked by this

[@amytysoe2292]

we're right back to matt parker's 'you can't just show up and start cranking it'

[@MacroAggressor]

Marvin the Martian strikes again!

[@TazwaarAhmed09]

i was about to comment the same 💀

[@aalhard]

Remember Marvin!

[@v_lad8559]

“Marvin the Marion”

[@SamuelLewis-wf7uf]

"Marvin the Martian" LOL

[@mblend27]

But with 3 feet 😜

[@JackFate76]

That’s what I’m calling it from now on.

[@dr.kraemer]

@@mblend27 "It does still have a Marvin, though." (6:35)

[@dr.kraemer]

@@JackFate76 that's one way to preserve a single lifestyle.

[@fxbear]

It’s a testament to my mind that I saw something else

[@clnrrr]

I was always fascinated by these when trying to pack my "2 seconds" tent at the end of a festival. Turns out, the time you save when it "assembles itself", you really invest at the end, learning how it will go back in its bag

[@Bagpipebrad]

<a href="#" class="seekto" data-time="555">9:15</a> "... but it's knot."

[@pier-lucgaranddion1527]

Look at his eyes. He knew lol.

[@no0ne000]

But are quarks?

[@Propherex]

I wanted to write this!

[@kwhite621]

A non self touching knot is also called a Catholic knot

[@jillianonthehudson1739]

Well played

[@mynt253]

Not to be confused with knots that touch smaller knots

[@stevesmith7839]

Good one.

[@vlvchii]

For some reason I read that as a celtic knot and I was like ok makes sense. But I've never heard of a catholic knot

[@stevesmith7839]

@@vlvchii It's a joke. non Self touching.

[@UncleKennysPlace]

Reminds me of how I unwrap new bandsaw blades, which come in overlapping loops: I remove the ties, and toss is across the shop.

[@VinayVarsani]

The only safe way to unpack it is to yeet it😂

[@Vmarracing]

The fun part is wrapping up the old ones in the same overlapping loops. Pretty terrifying, but ultimately satisfying.

[@merendell]

Thats because if you dont yeet the blade across the shop it will yeet your fingers across the shop.

[@ramonhamm3885]

Spring loaded loops with teeth are scary!

[@j.szelecz2530]

BONZAI ! the shopping cry of the workshop ---- WELL SAID ! ---- from Canada J.

[@cherrypie9566]

<a href="#" class="seekto" data-time="218">3:38</a> no self control 😔

[@CDCI3]

Knots are teenage boys.

[@justinklenk]

Please do knot encourage those of us with naturally knotty minds.

[@Nickakanugboy]

I literally came here to point this out

[@jin_cotl]

@@CDCI3🤨

[@junovzla]

@@Nickakanugboy you did... what? 🤭

[@Mike__B]

The beginning of the video I start feeling the cold sweats, and I'm instantly reminded of those window shades for cars or those quick pop up tents/sunshades that I can never figure out how to rebend to fit in the same size area.

[@estherstreet4582]

I just remembered that nitinol wire is also used in dental braces and my teeth hurt...

[@fluffycritter]

I've gotten pretty good at twisting those things back into shape.

[@alankasjan6488]

I just close my eyes and apply pressure. Just like magic, they fold up as they should.

[@SchoolhouseTechno]

Probably got really satisfied at 8:00

[@djmintyfreshful]

I have one of those shades for my car. I have no idea how I know how to put it back in the bag, but if I question it it will become impossible. 😂

[@fragglet]

Polite request that it would be good if you could put things a bit higher up in the frame so that they don't get covered by the subtitles ❤

[@SteveMould]

Noted!

[@abacabdk3490]

You can also move the subtitles out of the way by dragging them, I just noticed

[@meazle]

@@abacabdk3490Now, that's a handy tip. Thank you

[@fragglet]

@@abacabdk3490 this is what I did, yes

[@magnusmedivh6555]

​@@abacabdk3490not at the mobile app

[@yawnberg]

Lord Kelvin's attempts to make mechanical models of elementary particles is one of the coolest failures in history. Also kinda tragic because he was so convinced that he could apply his engineering genius to the atomic scale that, late in life, he got a bit obsessed with trying to model the aether and refused to accept other theories. Shouldn't overshadow his many MANY other accomplishments though. Biographies of Thompson are always a good read, much recommend.

[@TheAgamemnon911]

Yeah... it's always tragic when being validated becomes more important than being correct.

[@yawnberg]

@@TheAgamemnon911 agree but there's a little more to it in this case. At that point in his life he hardly would have needed validation. Steve pointed out how lovely the idea was, even with the hindsight we're afforded today. I think Thompson was enamored with the idea of demonstrating a unified mechanics of the universe. He wasn't the first to aspire to that and he certainly wasn't the last.

[@dmk_games]

You seem a big fan of the guy. But I've always associated him with absolute zero. 😂

[@peterfitzpatrick7032]

@@dmk_games .... that was cold ... 😏

[@SioxerNikita]

​@@yawnbergThat is more likely than wanting to be validated. Beyond that, during that time there wasn't really a great element understanding in the first place.

[@freescape08]

<a href="#" class="seekto" data-time="198">3:18</a> I found the non-self-touching relaxed knot you mentioned not existing! I call it - the Un-knot! And there's actually an alphanumeric character for it: "°"

[@wteff8586]

Un-knot, or simply: not

[@maynardtrendle820]

I guess you already know that the "Unknot" is the name of the most trivial knot- the circle. If you didn't know, great job picking the exact terminology!😂

[@Dave-rd6sp]

<a href="#" class="seekto" data-time="218">3:38</a> I can relate.

[@RangeGleasry]

😂

[@jackbuff_I]

Beat me to it! 😂

[@parmsib]

Heads up: There's a typo in the title. "is" should be "in"

[@SteveMould]

Thanks! Fixed now

[@NlNTENDOJAPAN]

@@SteveMouldheads up: there’s a type in the title. “In” should be “is”

[@Artaxo]

​@@NlNTENDOJAPAN omg Nintendo, stop trying to confuse Steve Mould

[@baronofclubs]

Heads up: There's a typo in the title. "Behave" should be "Beehive"

[@solanumtuberosa]

​@@NlNTENDOJAPANyuzu did nothing wrong

[@amichai345]

So a non self touching knot is a master of it's own domain?

[@tonyjohnson8929]

Two weeks top.

[@kinexkid]

That windows pipe screensaver just gave me a flashback. About 15 years ago i had a really nasty case of the flu, and had a fever of a little over 104 degrees and i woke up in the middle of the night. I was so out of it, that i was hallucinating that those giant blobs of pipes were coming out of my mouth and floating arou d the room while shape-shifting into different configurations

[@Irondragon1945]

hell yeah pipe related fever dreams relateable

[@TheRip72]

It reminded me of the opening sequence for series 3 of Monty Python's Flying Circus.

[@acherongoon]

With the Arizona (?) Teapot randomly.

[@kinexkid]

The second time I was hallucinating against my will was much more enjoyable, but more painful. A couple years after that I was traveling from Central CA to northern AZ to look at a potential college. I took a flight down to LA, then a flight to Pheonix, followed by a 7000 foot elevation drive. During it all, as soon as we took off on the first flight, my ears wouldn't pop and the pressure in my head was getting excruciating. We got to the city that the college was in and I immediately went to the hospital. I had a double ear infection, sinus infection, and an upper respiratory infection. They gave me some really good meds and some steroids for my asthma. That night, while in the hotel bed, I hallucinated a full orchestra performing a double concerto with violin and clarinet soloists. It was so beautiful and clear and lasted about 15 minutes. I received a $40,000 per semester scholarship there for music and astronomy, basically a full ride, but all that pain and discomfort I experienced was probably the main reason I didn't end up going there

[@m.i.c.h.o]

@@Irondragon1945you could almost call them… pipe dreams.

[@nevinofstedal8679]

That was the smoothest transition to a sponsor I've ever seen. 10/10

[@reiserlein]

Popup tents are working like that puzzle. Love it❤

[@steamer2k319]

Yeah--kinda laughing that people would pay just to experience the frustration of trying to put one of those away. It's all about framing I guess 🤭.

[@octoBadger]

I'm enjoying the idea that in 100 years people will be using the euphemism "Marvin" but no-one can remember why.

[@williamsharkey]

Casual exposition style belies mastery of conveying so many beautiful concepts with ease. Thanks for putting in the effort Steve!

[@KarstenJohansson]

I have a fishing hat with mosquito net that uses one of these configurations. When not worn, it packs flat in an envelope. When you pull it out, it springs to life as a full-size hat.

[@MMTMacroTrader]

Looks like Marvin the Martian you say?

[@ccoder4953]

Definitely a very strong, efficient shape.

[@mme725]

​@@ccoder4953RCE, is that you? 😂

[@faramoftae]

My Marvin looks nothing like that 😔

[@andymouse]

LMFAO!@@faramoftae

[@Rthomas176]

😂😂😂

[@kmill31415]

The observation that the figure eight looks sort of like a tetrahedron is a good one. The topologist Bill Thurston noticed that there's a way to glue together two tetrahedra with all the vertices collapsed to a single vertex, and then edges-to-edges and faces-to-faces, such that if you remove a small neighborhood of the vertex in the resulting topological space, what you get is a space related to the figure eight knot: it's the same topological space as the space consisting of everything *outside* a figure eight knot. (It's very mind-bending to try to perceive this...) He used this to show that the space outside of a figure eight knot can be given a hyperbolic geometry, and it was a key insight that eventually led him to his Geometrization Conjecture, one part of which was Perelman's resolution of the Poincaré Conjecture. Topologists still call it the "Geometrization Conjecture", but it's a theorem as of about ten years ago.

[@richieh2006]

I love your videos, Steve. I'm going through a bit of a hard time in my life at the moment and have felt sad. But your videos always enlighten me and cheer me up.

[@AndrewYarmola]

The tetrahedral symmetry is not too surprising if you know that the complement of the figure-8 knot is the gluing of two truncated tetrahedra. The edge colorings also match.

[@columbus8myhw]

To explain somewhat, for those who are not familiar: take two tetrahedra, and cut off the corners (revealing several new faces, which I'll call truncation faces). If you allow yourself to deform these shapes like play-dough, and glue the non-truncation faces together in a certain way, the result will be essentially a doughnut with a knotted hole. If done correctly, that hole will be the figure-eight knot.

[@scottmasson3336]

Try opening a bandsaw blade when it comes coiled.

[@WillBinge]

Oh Christ that sounds like it would end badly

[@BWWWAAALORDOFDUCKS]

Or closing it back up for disposal.

[@octoBadger]

Safety glasses on 😊

[@GingerGigantus]

Amen, keep your gloves on

[@AnthonyHowellII]

Fire in the hole!

[@Mosenhosen]

Topic suggestion for Steve: Somehow this video reminded me of four bar linkages. One day I had an apparently small hobby engineering problem to solve and ended up deep down in a rabbit hole. Four bar linkages are so easy to describe and have so few parameters and yet such complex kinematics emerge from it... And: they are everywhere!

[@thenatron6136]

Thank you, Steve, I love big knots <a href="#" class="seekto" data-time="146">2:26</a> A knot shaped knot lol

[@orangejuliaa]

interesting

[@intangible9838]

🤨 I know what you are

[@MrCrackbear]

rather peculiar

[@robertschnobert9090]

I don't understand! ​@@intangible9838

[@TheKhalamar]

I was looking for a comment about 2:26. Especially during the self-touching part. Thank you.

[@vlvchii]

I never thought knot theory would be so amazing

[@FourthRoot]

I bet that marvin the martian knot is the hardest knot to prevent self-touching.

[@thetruthexperiment]

There need not be any further comments.

[@michaelnauman6511]

Steve, you should heat set the nitonol into the 'solved' position and see if it will solve itself when dropped into warm water.

[@dennywest1353]

This guy is a awesome and informative teacher ty for your videos bro

[@mrhanlon]

This is uncannily similar to my graduate thesis, except there we were exploring optimization algorithms and applying them to untying knots. In one part of the research we used prime knots as input for our knot modeling software and randomly cut the knots so that they would then be "untie-able". Then we used an optimization algorithm to "shake" the knot until it was untied. I'm not sure if the clips shown starting at <a href="#" class="seekto" data-time="298">4:58</a> are from something the authors provided or something else, but it looks so similar to what we built I gasped!

[@flomoose7315]

Man… you’re really intriguing my senses with your videos. They have just the right amount of breaking the information down so an amateur can understand, but still keeping it to a high standard, so that knowledge is transferable. To keep it short: I love your channel! Jep up the great work😍

[@SharpAssKnittingNeedles]

He really is one of the best science/math communicators out there! We are lucky to have him!

[@mikayla_collie]

*_my top 3 favorite knots:_* 1: Fox 2: Dog 3: Wolf

[@manbearcow]

I got a tent that works off this concept one time, and it took me a week to put it back in the bag the first time.

[@mikkolukas]

<a href="#" class="seekto" data-time="556">9:16</a> "..but it's knot" 😂

[@thactotum]

you reminded me of and obsession with knots I had years ago. and also make me want to know if there's a knot equivalent of platonic solids

[@Siderite]

A video of Marvin the Martian touching itself. Well done, sir!

[@ThePhoenixSlayer]

Hey Steve. A new video by the Action Lab was just published, showing a cup that can be used while in a "zero-G" environment. The first thing I thought of is, "We need a Steve Mould see-through hydrodynamic system for this one"

[@96thelycan]

i can't retain information that well, but mathematical knots sure create a lot of pee pees

[@cookesam6]

<a href="#" class="seekto" data-time="218">3:38</a> I think we all end up touching ourselves if we've ever been let go 💔

[@voodoobram]

Never regretted watching one of your videos, about time i subscribe!

[@professormarvel4229]

I love that idea that atoms are knots. So smart really.

[@YannChemineau]

Rabbit : Tie them together, Piglet! Can you tie a knot? Piglet : I cannot Rabbit : Ah, so you can knot Piglet : No, I cannot knot Rabbit : Not knot? Pooh : Who's there? Rabbit : Pooh! Pooh : Pooh who? Rabbit : No! Pooh... Piglet, you'll need more than two knots Piglet : Not possible Owl : Ah, so it is possible to knot those pieces Piglet : Not these pieces! Pooh : Yes. Knot those pieces Piglet : Why not? Eeyore : 'Cause it's all for naught

[@Dan-vq4pz]

Steve at start of video: Unlike any puzzle *Bandsaw blade has entered the arena*

[@StevenHallOfGaming]

Hey Steve thanks for making me a little smarter, always look forward to your next video

[@d0pomein]

Moooooom! The Nitinol knot is touching itself again!

[@atgosh]

Petition to edit the subtitles to say 'knot' whenever Steve says 'not' I would settle for a k/not counter

[@RicardoScattini]

<a href="#" class="seekto" data-time="203">3:23</a> it is like me. When I am feeling unstable, I end up touching myself...

[@cmel7841]

your videos are fascinating, been a fan for a long time, thanks for educating us

[@brycedaugherty9211]

This was stimulating and fascinating. Thanks!

[@vimalk78]

<a href="#" class="seekto" data-time="71">1:11</a> hey that's "Mould Effect" apparatus at the back

[@zzzaphod8507]

I appreciate this work even if it was knot an exhaustive approach.

[@Vok250]

I've played this puzzle with extension cables many times. I loathe it!

[@simeonspottswood8932]

I love this video, I would love more content on this subject

[@cact0s_ulion405]

That reminds me of the video you made about how pup-up tents work!

[@Dee-Eddy]

Really cool! Dont get your marvin stuck in it though!

[@jackbuff_I]

Ground News is brilliant! 👌🏼

[@user-rv5fp3un5t]

Спасибо большое. Очень нравится ваш контент и ход мыслей.❤

[@mrpid87]

@SteveMould what do you use for your physics simulations? Another great video by the way

[@SteveMould]

Algodoo

[@mrpid87]

Much appreciated, sir! @@SteveMould

[@siv9129]

I sure love how they behave is that way 😂

[@HelloKittyFanMan]

"Part of me wishes it was true... but it's 'KNOT'." Haha, nice pun you made there, Steve!

[@stcorbett]

Great video! I was able to connect concepts and get new understanding about knots!

[@Grayson_Wu]

<a href="#" class="seekto" data-time="462">07:42</a> Oh, Mark Pauly at EPFL again! I think that's the third time I saw his name on this channel. The previous are Self-assembling material and Caustic lenses.

[@tolgayldz1898]

He has really great works on solid/geometric modeling as well.

[@Elyasafshweka]

This reminds me of how you safely (?) fold a Bandsaw blade. Also folding a car sunshade feels similar.

[@rickclayton1806]

You need to keep clear when you release one from the package. I throw them out on the floor.

[@Edwardmadethis]

My first thought was as I watched this, what it would look like to blow some bubbles with those knot structures. Or really to see how the bubble solution forms together on the structure.

[@dirxcec7035]

As soon as it came out of the bag, I was like, I have a tent like that! You just twist it down. Neat to see it explained!

[@johnchessant3012]

<a href="#" class="seekto" data-time="146">2:26</a> Marvin the Martian

[@tipsofsmyth]

<a href="#" class="seekto" data-time="146">02:26</a>, that's a classic

[@RangeGleasry]

Marvin the Martian 😂 whatever you say Steve

[@marcusmessenger3335]

Please keep making me curious. Mould my mind. You're such an inspiration.

[@7sevin7]

God I love it when smart people talk about knots. 🥵

[@lassikinnunen]

"I was eventually able to solve this problem thanks to the hydraulic press channel"

[@miriamrobarts]

<a href="#" class="seekto" data-time="168">2:48</a> Or you could call it a butterfly.

[@mohammadsattar5488]

I saw a thing about knots from veritasium and I was amazed at just how many types of knots there actually are and it in the thousands or tens of

[@lemm9068]

reminds me of a folding tent It's such a puzzle to fold it back into a circle

[@insu_na]

"Part of me wishes for it to be true, but it's knot." Steve M∞ld, 2024

[@Matlauk]

It's so crazy how they behave is that way.

[@melodyshortsmusicgame]

Very nice 🙂

[@jaewok5G]

nitinol?! i had been introduced to nitinol maybe 20 years ago … it's great stuff!!

[@user-wm9qx4km1i]

marvin the martian 👀

[@polyblank73]

I thought of something you might be interested in looking into for your channel. When you aggressively pour a liquid into another liquid, sometimes some liquid will splash up into the air. I've been wondering if that liquid splashing up is the... "analyte" or the "titrant" (didn't know what else to call them lol, but you know what I mean). Is it always only the analyte or the titrant, or is it a mix of both? are the drops pure analyte/titrant, or are they x% of the analyte, and y% of the titrant? I dunno, just a shower thought that I thought you'd find interesting as well.

[@echognomecal6742]

Would watching slo-mo videos of pouring coloured liquids help?

[@polyblank73]

@@echognomecal6742 Yeah, that's what I thought too.

[@chrislewis7811]

I doubt there's a single answer here. Say you're pouring A into B. If A is a solid (eg a marble) and B a liquid, any splash is all B. If A is a liquid and B a solid, it's all A. With both liquids, the situation is somewhere between these two extremes. Factors that will affect the ratio include the rate, height and angle at which A is poured, viscosity, density and surface tension.

[@allisoncooke7405]

This is like the pop up beach tent i bought.

[@CutesyPie]

This is very cool ❤❤❤❤

[@DaffaBun]

<a href="#" class="seekto" data-time="217">3:37</a> Relatable

[@MrMediator24]

Marvin the Martian knot definitely fond of self touching

[@KeithSkates]

<a href="#" class="seekto" data-time="223">3:43</a> these knots have a lot in common with me. 😂

[@countryrose93]

Growing up my dad was a soccer coach and we had those foldable goals… I got like 15 sec in and started getting flashbacks of me almost in tears trying to get them to cooperate and go back in the bag 😭 lmao

[@tahaasabir4090]

Too late people, you missed a rare occasion of a typo by Steve Mould

[@bluenono3821]

to*

[@doctorwhom8881]

is

[@derpnerpwerp]

Thats crazy he knew I was thinking about folding tents.. I was thinking about them before he even brought up tent poles

[@markwilding3828]

I bought a tent that used this principle. I opened it at home after I bought it. I've never been camping in it.

[@gruntopolouski5919]

“Elastic knots behave IS a very bizarre way”? Not “…IN a bizarre way”???

[@fermat131313]

You must live for moments like this.

[@Tann114]

Excellent as usual!

[@steveprice5664]

Interesting! Reminds me of trying to remove a bandsaw blade from it's package and installing it on my saw. My bandsaw takes a blade that's over 18 feet long (about 6 meters)! It comes packaged in a flat box 'folded' into 7 circles. I've never been able to fold a dull one back up into 7 circles to make it manageable to re-box to throw it away.

[@KaleOrton]

👍👍👍 Awesome Steve, as ever! Thank you.

[@stefvdiepen]

I'd like to buy the puzzle knot as shown in the bag!

[@Goatman_Gamer]

I was thinking Marvin The Martian too, glad I wasn’t the only one.

[@tonyb83]

Fasinating..... thanks

[@PM-fs2eg]

Gym teacher here...we had these portable soccer goals that came in a bag. When pulled out they would pop up and be ready...problem was it would take up forever to figure out just how to get them back into the bag 😆