Why is it that Weebles wobble but do not fall down? Can anyone name something else which shares this same characteristic?
Because they have a lead weight in the bottom, lowering the center of gravity below the center of balance.
Any object with this property will not fall over.
I think what Chas was trying to say is that the high density weight near the bottom makes it impossible to tip the object so it keeps tipping. As an experiment you could slice off the top third of a ball. Unless the ball is placed flat side down it will roll flat side up. Place a paper cone on the ball so it covers the flat side. There is no position nit can be rotated to so it won’t right itself.
Sure it could, Chas; imagine a cube with lead on the bottom. Tip it over, it stays tipped. The second trick for Weebles is the gently-rounded bottom. Since it has no flat surface on which to settle, it keeps on wobblin’ until its weight is evenly balanced over its tiny base.
Because they don’t fall down!
Well, you are right, but so am I. In the case you cited, the tipped cube’s center of gravity is equal to the center of balance, so it doesn’t quite fit my description. Once you tip over the cube, the center of gravity changes. This prevents the weeble effect from working.
BTW, there is a great performance art film called “The Way Things Go” that uses this effect. The film is basically one continuous unbroken sequence, showing the operations of a bizzarre Rube Goldberg-ish apparatus made from discarded tires, barrels, cans, pots and pans, etc. My favorite part is where he gets a series of old tires to roll uphill with clever placement of weights.
Is that what the film was? I saw a small part of it very, very late one night (or early one morning, depending on perspective) and couldn’t figure out what the point was of all these objects falling over and going up and down . . . I wonder if it’s rentable?
Yeah, the first time I saw it, it was on exhibit in the LA Museum of Contemporary Art, I sat down and before I realized it, I had watched it loop 3 times. I bought the tape, it was only $20 at Chicago MOCA, but if you want the identifying data:
The Way Things Go (Der Lauf der Dinge)
by Peter Fischili and David Weiss
released 1987, 30 minutes
First Run Features
It’s also listed in the IMDB:
This is a bizzare, mystical artwork. Watch it and don’t think Rube Goldberg, think “fire, water, air, earth.”
Many years ago I was at some frat party with my friend Bill. As usual he got himself drunk & started stumbling around the room. Somehow, even in his state of mind, he managed to come up with the following chuckle:
We Bills wobble but we don’t fall down.
It was funniest the first 1,259 times he said it.
Despite the weighted bottom of the Weeble, it wouldn’t wobble if its bottom wasn’t wwound.
What I was trying to say was, “WTF is a Weeble?”
Another way to think about it: A Weeble in the upright position has already fallen down. Put it any other way, it “falls” to that position.
For the benefit of those who weren’t little kids in the early 80s, Weebles are little egg-shaped toys, usually decorated with human faces, etc., with a weight in the bottom that gives them the afore-mentioned properties.
There a special shape based on a parabola squared, that looks like a tin can with a very-nearly but not-exactly flat bottom. This shape is enormously stable, despite resting on a sing point, and will always right itself. There’s a name for it that escapes me now, but perhaps a math student can think of it.