This makes my head hurt

[andrewducker]

Because it's having the same effect on my brain as one of those optical illusions that's both a rabbit and a duck.

Comments

[andrewducker]

Oh, wait, someone did:

[drjon]

Someone's been dividing by zero again!!!

[drdoug]

Don't have a video, but have just replicated it with a metal ruler, claw hammer, and a loop of string. Takes a little bit of fiddling to get it balanced just right, but it works for me. One key thing to get right is that the heavy bit of the hammer is well beyond the edge of the ruler.

I think one's physics intuitions are led astray by seeing it as three separate components. Imagine it's solid, and it doesn't seem particularly bizarre.

[andrewducker]

Yeah, I ended up thinking of it as a curved object, and that worked for me.

[drdoug]

Once you've done it, you can lift it off the table/shelf and balance it on an outstretched finger held horizontally, perpendicular to the ruler as seen from above (making a T-shape). Assuming, of course, that your outstretched finger is strong enough to hold up the hammer.

I can't decide whether that looks more mind-bending or not. Possibly more spooky to the audience, but less to the person holding it, because you can really feel that the CoG is directly under your finger by rolling your finger a little bit either way.

[skreidle]

And while it really is three separate components, the forces on each part hold them in place.

As for the whole assembly, it acts like a bent pendulum; it'll sit statically with gravity acting on a straight line through the supporting point and the center of mass (in or near the head of the hammer). So long as that arrangement has the supporting ruler sitting level or tipped up a bit, it won't fall. :)

[channelpenguin]

seen as a "one object" it looks to me a lot like a handheld steadicam... (we have 2 in the house though not this one)

http://www.tiffen.com/handheldmerlin.html

[danieldwilliam]

This is going to impress the heck out of my 14 year old daughter.

[avatar]

If you want to impress a teenager with this kind of stuff, here's another one:

Make a small paper box/container, and put some water in it.

Then light the paper on fire from the bottom. It won't light up.

[original_aj]

I remember constructing a parrot at school that was similar - it was a silhouette cut out of cardboard with a plasticine weighted tail and it would balance on a finger. This is a similar idea

[drdoug]

Ah! I *knew* I'd seen something similar before. Thank you.

[original_aj]

No problem! ;)