Reply to: Good party trick

[TimberWolf]

About which axis?

Can we use quaternions? I don't want to end up suffering from gimbal lock

Good analogy. If you can't do it in n dimensions, try in n+1 dimensions.

[TimberWolf]

I can do it an infinite number of times.

It is the old 'tray of glasses on the flat of the hand' waiter's trick. By rotating the hand about the wrist, the plate can be rotated through 360°; conversely, one can hold one's hand still and rotate one's body around the hand, the only hard bit being keeping the tray steady on the vertical axis.

You can do it without rotating your body.

[TheFaQQer]

Head and foot both "work" in that they go spazzy when I try it.

MrsF thinks it's incredibly funny to watch, as she can write her name whilst rotating her foot with no problem. So, which of us is abnormal?

[RichardCranium]

Place a notepad or something on the palm of your hand. Now rotate the hand, without rotating your trunk (cue elephant joke). Can you rotate it through 360 degrees? 720? Even more?

I can do it an infinite number of times.

It is the old 'tray of glasses on the flat of the hand' waiter's trick. By rotating the hand about the wrist, the plate can be rotated through 360°; conversely, one can hold one's hand still and rotate one's body around the hand, the only hard bit being keeping the tray steady on the vertical axis.

[NickFitz]

Place a notepad or something on the palm of your hand. Now rotate the hand, without rotating your trunk (cue elephant joke). Can you rotate it through 360 degrees? 720? Even more?

About which axis?

Can we use quaternions? I don't want to end up suffering from gimbal lock

[TimberWolf]

No can't seem to get beyond about 90 degrees with the head either, but that is each way, unlike this dude inky linky

you guys must do a lot of yoga?

Can you do this one then?

Place a notepad or something on the palm of your hand. Now rotate the hand, without rotating your trunk (cue elephant joke). Can you rotate it through 360 degrees? 720? Even more?

[hyperD]

It probably explains why ballerinas are unable to write an autograph for you during a performance of Swan Lake.

[Halcyon]

Nope. Rotating the head instead appears to reproduce the effect though.

No can't seem to get beyond about 90 degrees with the head either, but that is each way, unlike this dude inky linky

you guys must do a lot of yoga?

[mudskipper]

Nope. Rotating the head instead appears to reproduce the effect though.

If you don't mind looking 'special'...

[Doggy Styles]

I thought I'd give this a go. I've just been doing it for an hour up the pub but I can't quite get it right.

My friends seem to have wandered off to chat up the barmaids. In fact, I've just looked and they've gone home.

[TimberWolf]

My feet don't rotate )c:

does waggling them count?

.

Nope. Rotating the head instead appears to reproduce the effect though.

[Halcyon]

My feet don't rotate )c:

does waggling them count?

.

[TimberWolf]

Your parties sound like a riot.

Hey, it might work better when drunk. Is there anyone who can try? I'm too poor to buy alcohol.

[mudskipper]

• Sit down
• Rotate one foot, either clockwise or anti clockwise in a small circle. Keep rotating it in the same direction
• Easy eh
• Grab a pen and some paper. You are permitted to stop rotating your foot while doing this
• Now sit down and start rotating your foot again. When you think you have got the hang of rotating your foot like that, write your name on the piece of paper
• What's the matter with your foot, keep it rotating in one direction, are you a [censored] or something?

Your parties sound like a riot.

[TimberWolf]

Jeez, I thought I was in good health. Need to see the doctor about my foot tomorrow - Its not working right.

Apparently the same part of the brain controls the same movement, so it has to switch between the two rather than process in parallel. So much for the parallel processing ability of the brain, though I expect their are good evolutionary reasons why foot and hand movements are connected.