High Performance Double Pendulum / 高性能二重振り子

[palstikup]

i see brucelee practicing his nunchaku

[rmc2357]

well done!

[Galoisification]

He's a Kung-Fu Master

[IrkenRob]

Try solving that Differential equation! Really is chaotic motion. 

[borysczad1125]

freaaaaaks!!! :D 10min and dont stop ;)

[arvydas86]

wanna see tripple pendulum

[dvilardi]

Have you ever considering putting a LED on the bottom of the second bar and making a "light painting" of it? It's kinda cool, I did it here once, and it turned out to be very interesting =D

[FailDrummer]

@dvilardi Great Idea!

[TheGreekMachine]

thats freakin messed up lol!! craziness...

[MattKestrel]

i was watching this whilst listening to pendulum and it was pretty cool :)

[4OTKO]

this is sick

[markinwhite]

It makes me think that a small action like lifting and dropping a pendulum creates a very sophisticated chain reaction without any human interference.

[father042]

lol I was actually lookinf for a band but this is intersting

[father042]

LOL I was actually lookinf for a band but this is intersting

[creditcardnext]

It's like Chuck Norris and the Terminator combined...cool

[Skulletman5300]

AHAHAAHAHHAAHAHAHAHA

[FuckimFamouz]

SO FUCKING BORING !!! i watched 1 min of this and i was gonna fall a sleep FUCKING BORING

[metalhead666697]

I wanna turn this into a theme park ride...

[mison2]

that thing have not reason continue with motion from 1:30. I think, there is some opposite polarity magnet under the desk, or it is just fake.

[super6plx]

@mison2 it's not fake, nor is there a magnet. dual pendulums are known for holding enormous amounts of energy for long periods of time. they just keep on spinning, and I looked at 1:30 and it looked completely normal. at 2:30 something weird seems to happen but on closer inspection it's normal as well

[airsoftjunkie2]

i cant believe i watched that whole video

[busotactico]

nice!

[nakkinalle]

omg, thats awesome !



[OhMijnGaap]

Useful.

[aradosman]

@OhMijnGaap it realy is...

[diedy5]

I wanna see this in vacuum

[McChickenguy]

@diedy5 um its not the air that slows it down its gravity.

[Insomniac535]

@McChickenguy

No, it's the air, and the friction in the bearings... Gravity gives you back just as much energy as you put in, and isn't what's slowing this thing down.

[diedy5]

@McChickenguy Do you think I am stupid ?

I didn't even mention slowing down....

[sup3rt0aster]

@diedy5 wounder how many hours it would take for it to stop then?.......

[vanjastanic]

What camera did you used to record this?

[Thuringen]

it is fascinating, and well built, but the behavior of the pendulum is easily predicted by considering it as a Hamiltonian system. though I appreciate cherry999 posts below, i fail to see how this demonstrates chaotic behavior.

[BlindfoldedPoet]

@Thuringen

I am not completely into physics so i have no clue what a hamiltionian system is but if you read the article on Chaos Theory on wikipedia, it is explained rather well i think. but its very alike what cherry999 said.

Anyways it says that the exact path the double pendulum takes is almost impossible to predict since you would have to know the initial condition with far too much precision. Thats why they call it chaos.

[Thuringen]

@BlindfoldedPoet

but that's just it - it's not unpredictable at all. the differential equations of motion for a double pendulum are actually quite elegant and simple when the problem is set up correctly. the whole calculation, given well measured initial conditions, probably would fill a page or so and would exactly describe the motion. however, it is chaotic in the sense that it displays attractors, and massive variations dependent on initial conditions, so I'll admit my first post was wrong

[BlindfoldedPoet]

@Thuringen

But i think thats the point of chaos, it doesnt mean it is no longer undeterministic it just means that very very slight changes to the initial condition will greatly affect the outcome.

So in theory you can work it out, but in practice you cannot because your calculator is to inprecise or humans are not able to measure the initial conditions to such precision and then the outcome will be very different.

[andsalomoni]

@Thuringen The behaviour cannot be predicted at all. Nonlinear systems cannot be solved analitically, so you can only do numerical simulations, and you have to face the fact that the error in the measurement of the initial conditions, no matter how little it is, diverges exponentially and in little time your prediction becomes completely useless. You should have INFINITE precision, which is impossible in principle.

[Thuringen]

@andsalomoni

depends what kind of precision you're looking for. you could easily pull out a solution accurate to one or two mil from an analytical approach. You could probably get even down to half or tenth mil, if you really wanted to. As long as your analysis minimizes contributing factors in its approach, and takes advantage of conservation laws, you minimize contributing errors. that's the beauty of an energy based approach (legrangian) or a momentum based approach (hamiltonian).

[andsalomoni]

@Thuringen If you think so, try to do it. Write the equations for the double pendulum and do a computer simulation with given initial conditions. Use the maximum precision available on your computer. Then run the program with new initial conditions, differing from the previous only in ONE PART of the maximum precision available, and see what happens.

[jonesds75]

@Thuringen Brilliant vid! But just to add my thoughts to this... I coded this up today using a Langrangian approach. The system is chaotic inasmuch as the slightest variation in initial conditions results in a huge difference further down the line. However, in order to solve the differential equations one has to use the Runge-Kutta (or some similar) technique. This provides a very accurate but still approximate solution and therefore the system cannot be predicted due to the chaotic nature.

[cubanpyroman]

lol just like in iron man 2

[2468satoru]

永久機関みたいだ

[hifumidot]

Excellent!

Watching thｅｓｅ videos, I hope more people like physics.

[flaxmo]

where does the energy come from?

[Milithryus]

@flaxmo The energy is given by the dude at the beginning, there is no other source. This initial energy is split in "gravity" energy (height) and kinetic energy (speed).

[plasticgel]

Ok, but where you can you it? Or it main function is similar to lava lamp?

[Dawid4Real]

i love how it looks like it's slowing down suddenly after a few failure turns it goes back and turns like 5 times fast! like its gaining movement speed again

[anidju]

"We're interested in the chaotic behavior!" There is no chaotic behaviour. It just seems chatotic because the first piece of metal is switching directions acording to the second piece's movement. obviously when the first one catches abit of motion, the second one can roll arround and catch even more momentum.

[chemy999]

@anidju when talking science or mathematics, chaotic simply means that something is *highly* sensitive to even tiny changes in the system, and that causes the system to be very very unpredictable. chaotic does not mean random

[chemy999]

@anidju sorry about the double post, but the sensitivity to tiny changes in the system is also known as the butterfly effect (perhaps you have heard of it?)

also weather is considered to be chaotic

[anidju]

@chemy999 No, I'm unfamiliar with such terms as I am with science. But now that you told me what you ment by "chaotic behaviour", it got easyer to understand :) Cheers and best of luck.

[beebop32]

what da hell is that thing?

[AidenWard165]

@beebop32 Lol, I agree

[vgraki]

何でこんなに動き続けられるんだあ。すごい。

[mailanbr]

Oh my god! I can't stop watching.

[asadd2]

This is just cool :D

[onlyAerik]

You didn't need over 9 minut4es of it, geez.

[BonelessSausage]

@onlyAerik Yeah, wouldn't want to take away from your masturbation time or womanising.

[onlyAerik]

@BonelessSausage WTF?  womanising?

[BonelessSausage]

@onlyAerik My comment was a mistake. Apologies.Ed :)

[empyreandreams]

Please don't use the word chaotic to describe the movement, it is very orderly. Chaotic would mean it goes flying off into space or something not orderly.

[thoreffingham]

I finally understand the golf swing.

[agw118]

Could you put a 'trace' of some sort to follow the path made by the tip and the joint? that would be an interesting graph!

[SirDamned]

You spin me right round baby right round...

[ANTALIFE]

fake

[freaktose]

I can't stop laughing at this.

[JauntyHat]

Why am I getting agitated at how long it continues to move!?

[bp061271]

@JauntyHat I don't know, but I'm having the same reaction. I really want it to stop.

[SkylaFan23541]

Now make a triple pendulum!

[colonelangusisgod]

This would be great for training in quick reaction time with a hand gun.

[undystains]

Clearly you and your father are awesome!

[pacorocks]

yeah this is called a propellant motion device its been done a bunch of times

[pacorocks]

@pacorocks sorry propetual sp?

[ovinophile]

When it really gets going, it's a lot like a tilt-a-whirl. I wonder if the same principle applies to both...

[yuishy2003]

Needs a slow-motion video too.

[robinsoncrucify]

if you watch this whole thing, i think i hate you

[thetornone]

Reminds me of the Zipper.

[hubin8or]

Ok, so we cant attach a generator to it, but what about a chainsaw?

[jerphunter]

Best thing ever! I wish I can replicate this!

[esobucks]

10 minutes is a lot less than infinity

[xRawlins]

Anyone saying "attach a generator to it!" has no idea what they are talking about. Any kind of dynamo would cause resistance(which generates the energy) and would bring it to a stop within seconds.

[jcromartie]

The thing people seem to be missing here (those who say "attach a generator to it!") is that it's just a regular pendulum with a joint in it. It would run just as long without the joint. This behavior depends on very high-quality bearings. Attaching a generator to it would make it stop very quickly.

[ZZPharesZZ]

@jcromartie Why not just make the lower armature a magnet?

[frankensteinmoneymac]

@jcromartie Yeah, but what if you attached a generator to it? Ha! I bet you didnt think of that, huh?

[Sumermagor]

@jcromartie if there is no back emf than it can be useful, check out the orbo motor from steorn

[pnkslp67]

woah who would've thought it actually requires almost about 10 min to finally stop! coolz

[thevanities11]

It is not for energy. It is chaos.

[DizzyPika]

The swirly energy of tomorrow!

[Flamesync]

thats ingenious. nearly perpetual motion

[mikasg]

and if it is triple?

[Flamesync]

probably too heavy

[Kevinskie555]

Put a dynamo on it to get energy, and oh my. If you can make this in big this is the invention of the year! Energy generated without wind or anything! w00t!

[mikasg]

you need a way bigger than this size, to put a dynamo on it.

[JohnnyZoo]

you spin me right round baby right round like a record baby right round round round.....

[Getaro]

i love sience

[FMAlch3mist]

@Getaro Clearly not a fan of English though =\

[Getaro]

@FMAlch3mist Just a silly german dude

[oh357]

これ第一関節を、もう一度、てっぺんまで上げることができたら、­永久に動かすこともできるかもしれませんね。

[Ashanmaril]

raocow favorited this!

[sam6555]

@Ashanmaril I know! =P

[RhayneAedyth]

haha yeah thats why i watched it too =)

[ufee]

Quite mesmerizing. I watched the whole thing.

Time well spent indeed.

[ErmDNB]

FTW PERPETUM MOBILE!!

[webj2000]

何に使うんですか？

ブルース・リーの代役ですか？

[Galakuta]

最初のほう、ブルース・リーがヌンチャクを振り回しているように­見えた。

[hansokuya]

ブランコが漕げず、逆上がりができない息子が不憫になった。

[tribefo]

これはすごい！

永久機関も夢じゃないかもしれませんね。

[Pinkych21]

エネルギーの無駄遣い云々はこの動画の主旨にそぐわないと思うな­。

この動画のすごいところは、振り子を二つ連結しただけという単純­な構造でここまで不規則な動きが実現されること、その不規則な動­きに耐え、10分近くも運動を持続させることができる高性能な関­節を作る技術、の二つだと思う。

[jumpeikawamura]

thats wonderful movement

[Grz]

Cool one!

[mah2mah]

エネルギーを効率よく使ってると言うか単振動

ってやつじゃね。位置エネルギーと運動エネルギーが

互いに往復してる。

[kazegg]

力学的計算できる動きですか？

[MrAliardan]

軸受けはすごく精密のようだけど、

カメラのアングルが適当なのはなんでだろう。

[oh357]

これ動力は何？最初の振り上げた力だけで

これだけ動いているの？

[skyfish8152002]

なんか面白い

[hajimekishi]

beautiful

[panchirunchi]

摩擦を減らすのに何を使っているの？

[area8246]

wow!

[Julynosuke]

らばＱから来ました☆

終わりそうで終わらないから

おもしろい☆

[NEWHORIZON129]

やほーからｗ

中国の舞みたい！すげぇ

[xKZKx0213]

すごい！

エネルギーの使い方を考えさせられますね＾＾

[qr807]

This reminds me of the group consisting of a boss, his leaders and their staffs.

[hikio30]

スタート地点が同じ場所だと3回やって3回同じ動きするの？

[shinoaka]

いかに普段エネルギーを無駄遣いしてるか考えさせられますね

[kuskul9]

こりゃ凄い

これだけエネルギーを効率よく使えるって事は

本体への負荷の軽減にも繋がります

既に2通りの使い道が見えてるってわけです

[masarin1974]

that's great!!

[iwai0119]

これって何の役に立つの？

[Merikenuze]

文化レベルの低い地域の人に、クラシックの名曲を聞かせたり、博­物館の芸術品を見せても同じ答えが返ってくるだろうね。

ただ見てる世界が違うだけなんだ。

[OsakaPoppin]

文化レベルと言うか、ただの興味の違いじゃないかな。別に俺ら理­系の人間でも「これって何の役に立つの？」と思うものなんていく­らでもあるだろう？

じゃあそう聞かれたら嫌味を言わずに答えてあげられるのが、文化­どうのこうの抜きで本当にレベルの高い人間だと思うんだがな。

人の教養を馬鹿にするようじゃあまだまだ教養が足りん！

[OsakaPoppin]

そうだね、一言いいたかったから書いたよ。そのためのコメント欄­では？

俺？別にレベル高くないですよ＾＾

自分のことは一言も言ってませんが。

これぐらいで怒りちらしてるようじゃ、まーだまーだですね。

[Merikenuze]

怒り散らす(笑)まーだまーだ(笑)

お前透けてるよｗ

[NOBURINZ]

すっかり　見入ってしまいました。

先っちょにＬＥＤとか付けて

真っ暗闇の中で撮影したらすごそう(^^♪

[kamapet]

小学校じゃおしえてくれない動きだね。

もっとも、教えてもらっても理解できそうに無いけど。

[lucuha]

二重振り子のカオスは昔から発見されているもので特筆すべきとこ­ろは高性能という所。

[piichan315]

踊ってるみたいだ。

[lyonerfan1]

this is chaos!!!

[465takuya]

すごいことを発見しましたね。

本当に不思議な振り子です。

[akio8649]

何分くらい動き続けるのでしょうか？？

[uchikata]

これは・・・発電装置に使えそうじゃないか・・・

３段、４段と振り子を増やして、重力エネルギーの還元が出来たら­素晴らしい

[yoshiaful]

すごいなあ、鉄棒の選手にみえる！

[watermark073]

I just watched the news in NHK.

very interesting!

[peteryagami]

Super COOOL!!!

[Digeridude]

Very cool! I imagine some kind of pendulum-based transmission for an engine.

Too bad there are a lot of idiots in the comments.

[silent1983]

You see a pendulum, I see energy.

[hpcstore]

U should change title... its "Pendulum FAIL"

[DaszekGT]

UUUUUUNNSTOPPABLE

[1Morka1]

hello troll

do you even know how pendulum works? i thought so...

[dokabakibokan]

ブルースリー

[arcane231]

Is this like a carrier bag on a bike handlebars that makes you wobble?

[callanr]

My friend and I are upset. As if he cut the video off before the pendulum finally stopped. 1/5 stars...

[KakHazhar]

6:25

This is probably the best double pendulum i've seen thus far.

great done!

[fqmanuel]

Un vídeo fantástico.

[ChristopherDone]

This is amazing when you think about how much energy comes out of this thing from such a simple push.

[FTBLN]

when a pendulum comes back from its elongation point, potential energy transfroms into kinetic energy minus friction (which is obviously very small), so actually the total energy stored is never bigger than the potential energy of the initial elongation

[itroll3fun]

WRONG. Thanks for playing.

[FTBLN]

go, get some physics credit points at some university before you troll here. I answered to ChristopherDone who claimed all the kinetic energy that is observed "comes out of the initial push" which is may be correct with linear motion, but not with pendulums where the energy forms constantly convert into each other

[itroll3fun]

No, you idiot.

You said: "so actually the total energy stored is never bigger than the potential energy of the initial elongation"

That's not true. The total (initial) energy is equal to the initial kinetic energy ("of the push," if you will), plus the potential energy stored in the initial configuration.

"get some physics credit points at some university"

Thanks, I've got plenty. And I proofread my comments before I go pontificating. Unlike you.

[skinsuit2000]

No! You're both completely wrong.

This obviously happens because of some kind of magic.

Probably done by a wizard or something.

[FTBLN]

What goes around comes around. Either you don't have any credits or you don't read comments properly. More likely is the first one, I guess that from the way you pathetically try to enforce your "arguments" with personal insults - very academic. Again only for you: I said there is loss of energy due to friction so that in other words the total energy stored in the system is smaller than in the beginning.

[itroll3fun]

No, that's not what you said.

First you said "potential energy of the intial elongation." Now you just say "total energy stored in the system."

Those aren't the same thing. Your failure to either recognize or admit this is why you're an idiot.

Does that make it clear?

[FTBLN]

I never claimed that and I won't feed you anymore. Have a nice christmas

[itroll3fun]

LOL, it's OK to be wrong. Just suck it up and admit it.

Oh, you'd rather pout and walk out? No problem. You could make better use of the time by studying up so you sound less like an idiot anyway.

[OsakaPoppin]

you both fail for not being able to explain things at people's level of understanding.

How's someone that thinks energy appears out of flippin' nowhere supposed to understand initial elongation? Just say:

"Energy cannot appear or disappear to nowhere, it only transforms.

So, the energy of that thing swinging around for a long time, is from the push and the gravity, helped by really small friction on the joints and well balanced arm parts to prevent the loss of energy."

Now THAT is easy.

[salatetis]

cool! Now make it about 20 times bigger!

[dfrancos1]

Funny the comments about the plant xD

[mocaxu]

i think this explains why bruce lee with his nun-chucks can't be beaten.... the bad guys can't read his movements... :D

[seymus]

it's not fake, it's Fisic (look the glass in the back).