What Do You Call This Object?

I’m thinking of an object that I saw when I was younger, but I don’t recall its name.

It was a rubber cylinder, filled with liquid. Its shape was sort of a cross between a cylinder and an elongated torus, such that the I.D and the O.D were indistinct, similar to a Möbius strip but cylindrical.

When you tryed to hold this object, the inside spilled out to the outside, similar to what happens with rectal prolapse, and it usually ended up falling right out of your hand.

What was it?


I’ve seen them called either ‘water snake’ or ‘water willy’ (really).

Klein bottle? (I know people actually make them … most of the ones I’ve seen for sale have been glass, though.)

They’re usually called 'water snake’s around here too, Mangetout. Fun thing to bobble about with your hands while on the phone or watching TV, but sorta disturbing when you notice what motion you’re repeating.

Also known as “Water Weenie.” Here’s a Picture:

Disturbingly, I’ve also seen these things sold in “adult novelty” stores… although you’d need to be hung like a cricket to use one…

No, no, no. The object in question (I’ve heard them referred to as “can’t-hold-ems”) is most certainly and definitely a torus, not a Möbius band or a Klein bottle. The two sides are not the same: You have the wet side, which you can never touch, and the dry side, which you can.

What the heck are klein bottles?

Ok, I can google: www.kleinbottle.com

They look like lab glass, but what are they for?

Nevermind, from my own link: what’s a klein bottle.

Sorry I got ahead of myself and missed that first time 'round.

They’re just the three-dimensional (heh-heh) equivalent of Moebius strips. If you start anywhere on the surface of a Klein bottle, you can travel to any other part of the surface. Big deal, you might think, since an ant on a standard beer bottle could do thae same, and have a good time while he’s at it, but that would be overlooking the subtle mysteries of topology and mark you clearly as an ignoramus unworthy of the great knowledge grasped by those more geeky than yourself.

So to answer your question, I have no idea.


I think those guys are, um, loopy…

But fun.

Mangetout has the names right, JRR has the right picture. You can find them at the Discovery Channel Store, usually in the inexpensive toy bins in the middle of the store (if you feel like playing with one again). Unfortunately, they do not sell Klein bottles.

They’re not really for anything, but they are a fun curiosity of topology. Like a moebius strip, a Klein bottle has only one side, and therefore, zero volume, despite the fact that it can hold liquid.

Klein bottles are fun.

Ah, they’re Klein Bottles.

Not quite: A Klein bottle is still only two dimensional. What distingushes a Klein bottle from a Moebius strip is that a Klein bottle has no edge, whereas a Moebius strip has one edge. However, like the Moebius strip, the Klein bottle is non-orientable, which leads to the weird properties like one-sidedness.

As for the volume, an ordinary tumbler or cup has zero volume, as well, since it doesn’t have a well-defined inside or outside (you can get to any point in the vicinity of a cup without passing through the surface of the cup). But again, it’s the edge thing which makes the difference: A cup also has one edge.

NB: the 3d models of Kelin bottles are not actually Klein bottles, but are the best we can do given the limited spatial dimensions in whcih we live.

I think I’m right in saying that the neck of a Klein bottle should loop around, turn inside out and join back onto itself, but that it should do this without punching through itself - this isn’t possible in three dimensions.

Wasn’t my (heh-heh) clear enough?

I’ve heard them called “Water Wigglers.”