Gomboc

December 9, 2007 10:02 AM

The Gömböc is the first known convex, homogeneous shape having just one stable and one unstable point (i.e. altogether two points) of equilibrium. A little like some turtles' shells (or weebles), it's self-righting, but for purely geometric reasons.

You can have your very own personal Gömböc -- for a price. Made in a limited series, numbered 001-2007, the models (manufactured to 0.01mm precision) are variably priced. Gömböc "X" sells for EUR (900 + 200 000/X).

posted by gleuschk (35 comments total)

You can have your very own personal Gömböc -- for a price. Made in a limited series, numbered 001-2007, the models (manufactured to 0.01mm precision) are variably priced. Gömböc "X" sells for EUR (900 + 200 000/X).
Hmm... Feels like the wrong way to drive a limited run - the first person pays €200.900 and the last pays €999... But unless someone stumps the initially huge amount, none of the cheaper ones will sell either. Swapping it around would at least mean some cheaper (and growingly expensive ones) would sell until the maximum price the market was prepared to pay was reached...
posted by benzo8 at 10:28 AM on December 9, 2007 [1 favorite]

benzo: They're selling them out of order.

I think I'll hold off until the local exploratorium starts selling them in the gift shop.
posted by you at 10:35 AM on December 9, 2007 [1 favorite]

For now, I'll just buy a weeble.

By the way, your weeble link fell down.
posted by MrVisible at 10:40 AM on December 9, 2007

Ah, fair enough. In that case, they'll most likely just sell in reverse order until the maximum price the market was preparec... etc.
posted by benzo8 at 10:40 AM on December 9, 2007

I like turtles. (Proceedings of the Royal Society B: Biological Sciences, seven-page .pdf.)
posted by steef at 10:40 AM on December 9, 2007 [2 favorites]

Whoops: weebles. Sorry about that.
posted by gleuschk at 10:41 AM on December 9, 2007

Yay! It's back up!

I love weebles.
posted by MrVisible at 10:46 AM on December 9, 2007

Perhaps they think,
regardless of where they set the price initially,
it will force itself to equilibrium.
posted by dragonsi55 at 10:50 AM on December 9, 2007 [1 favorite]

Q. Are you a Gomboc?
A. You bet your sweet ass I am.
posted by Bighappyfunhouse at 10:56 AM on December 9, 2007 [1 favorite]

Fascinating invention. I want one. Looks a bit like the Microsoft Silverlight image.

Never thought about turtles rolling over before.

Video of the inventors, Várkonyi Péter and Domokos Gábor, presenting Gömböc.
posted by nickyskye at 11:02 AM on December 9, 2007

Guess it's a matter of time before we seeing the Chinese knockoffs at www.cheap-gomboc-deals.cn.
posted by chips ahoy at 11:39 AM on December 9, 2007

How tortoises turn right-side up
posted by homunculus at 11:59 AM on December 9, 2007 [2 favorites]

The New York Times article is worthwhile.

I'll bet the mono-monostatic tag stays mono for some time to come...
posted by Tube at 12:00 PM on December 9, 2007

How long before I can order a Personal Transportation Pod shaped like one of these?
(now with anti catastrophic tipping action!)
posted by Balisong at 12:38 PM on December 9, 2007

You can have your very own personal Gömböc

Do not taunt Gömböc.
posted by Anything at 12:50 PM on December 9, 2007 [1 favorite]

I'm guessing the unstable point of equilibrium is on the top edge. That doesn't mean it can't be balanced on that one, too, not if you're this guy, it doesn't.
posted by StickyCarpet at 12:51 PM on December 9, 2007

Your own... personal... gomboc.
Go ahead and give it a shove, it'll roll back.
Your own... personal... gomboc.
Won't flip -- gomboc!
posted by ROU_Xenophobe at 12:57 PM on December 9, 2007 [1 favorite]

This is exactly the sort of thing Lovecraft dedicated his life to warning us about.
posted by Anything at 1:03 PM on December 9, 2007 [5 favorites]

And at the risk of you labeling me insane for saying it explicitly, I fear that certain unmentionable multidimensional horrors are able to smell the shape.
posted by Anything at 1:16 PM on December 9, 2007 [1 favorite]

I know that the picture on the link that homunculus posted is just a tortoise halfway through righting itself, but it looks to me like it's in the process of doing some sort of kung-fu cartwheel kick. I would not mess with that tortoise.
posted by ErWenn at 2:21 PM on December 9, 2007

That's actually a turtle. Don't call it a tortoise or it'll put a Lee Van Cleef on your bitch ass.
posted by homunculus at 3:00 PM on December 9, 2007 [1 favorite]

Tortoise? What's that?
posted by ROU_Xenophobe at 4:06 PM on December 9, 2007 [1 favorite]

Sounds suspiciously like the Nextahedron invented by Thursday Next's brilliant uncle Mycroft, as described in Jasper Fforde's Something Rotten:

... I turned the grapefruit-sized object over in my hands. Some of the faces were odd-sided and some even-sided--and some, strangely enough, appeared to be both, and my eyes had trouble making sense of it. [...] I placed it on the surface, but the oddly shaped solid, unstable on the face I had placed it upon, tipped onto another. Then, after a moment's pause, it wobbled again and fell onto a third. It carried on in this jerky fashion across the worktop until it fell against a screwdriver, where it stopped.

160;160;160;"I call it a Nextahedron," announced Mycroft, picking up the solid. ... "Most irregular solids are only unstable on one or two faces. The Nextahedron is unstable on all its faces--it will continue to fall and tip until a solid object impedes its progress."

Naturally, the Nextahedron has a practical application as an infinite source of free power.
posted by Creosote at 4:12 PM on December 9, 2007

Anything mathematical that also sports dual umlauts has to be good.
posted by stavrosthewonderchicken at 5:06 PM on December 9, 2007 [1 favorite]

...just like Mötörhead.
posted by stavrosthewonderchicken at 6:40 PM on December 9, 2007 [1 favorite]

Tortoise? What's that?

You know what a turtle is, ROU_Xenophobe?

Same thing.
posted by rokusan at 7:26 PM on December 9, 2007 [2 favorites]

Finally ... the one-sided die.
posted by elmwood at 7:48 PM on December 9, 2007 [6 favorites]

This is exactly the sort of thing Lovecraft dedicated his life to warning us about
Yes, beware of the Gömböc
posted by raygirvan at 8:26 PM on December 9, 2007

I thought of the one sided die, but my girlfriend was like "Why?" So I said "Fine, we can write "20" on top of yours, and 1-19 around the other faces.
posted by agentofselection at 9:36 PM on December 9, 2007

That gomboc.eu page doesn't load for me.
posted by pravit at 12:11 AM on December 10, 2007

I'd be more entertained by this if it weren't for the fact that they're looking for a bloody fortune in exchange for one.
posted by JHarris at 12:45 AM on December 10, 2007

Would an egg or egg-like shape not also satisfy these requirements?

I saw the diagrams in the paper of the shape and they seem overly complex; why aren't the surfaces smooth? (They seem to have bulges in them, hard to tell if they're regular or not and I'm a bit tired to look at the math.) I can understand why the turtle's shell is irregular -- by being irregular, and avoiding having a blow land normal to the shell, it effectively increases the shell's thickness (much like angled armor plate on the front of a tank) -- but the self-righting properties of the overall shape are hindered, not helped, by the irregularities. A smooth surface would self-right better, or just as well.
posted by Kadin2048 at 2:48 AM on December 10, 2007

An egg won't naturally rest on one point. (OK, I think a factor here is consistent density - if you were to put all the weight in the larger end of an egg, it probably would.) It will have a circle around the shell along which is would roll until inertia allowed it to come to rest - the point would not be fixed and singular.
posted by benzo8 at 6:13 AM on December 10, 2007

In case anyone is wondering, it's pronounced more or less like "gumbutts", but with more umlautiness, and the accent on the second syllable.
posted by oats at 12:32 PM on December 10, 2007

Yep: "gəmbəts". Although if the pronunication in the folktale vid is typical, the emphasis is about equal.
posted by raygirvan at 1:20 PM on December 10, 2007