gee, I waste time...

[miriam_e]

Stayed up late last night making a funny little tensegrity octahedron out of sticks, pins stuck into their ends, shirt buttons on the pins, and elastic threat looped through the buttons. It is cute, but took me much longer than I thought it would. I originally made one out of just sticks with rubber bands looped over them, but the other day one of rubber bands finally died and it popped apart. Took me a while to find suitable replacement materials, fossicking thru all my junk. Yeah, as well as wasting time I also accumulate junk.

The little guy is about a foot (30cm) tall.

OK. Just took a better pic with my camera instead of crappy webcam. Here it is.

Just realised I didn't mention why I made the damn thing.

Tensegrity is a fascinating concept: shapes formed by the balance between tension and compression. It seems to be what gives our body's cells shape, and probably accounts for the way proteins fold up too. I love that in that cute little octahedron the 3 sticks are not securely fixed -- they are just sitting there, under tension. You can squash the shape and it pops back. Imagine if we built our homes this way... or our cars. How cool would that be?

Comments

[annie-lyne.livejournal.com]

I'm a packrat too. Cute picture :)

[miriam-e.livejournal.com]

:)
Just added a better pic.

Read a little while back in... Scientific American?... that damage to a part of the brain can cause obsessive collecting. Seems we are pre-wired to collect stuff. Remove, or weaken, the brake on that and we really start to accumulate stuff. I've had people (mostly old girlfriends) throw up their hands in despair at me because I hate to throw stuff out (I have New Scientist magazines going back to the '50s). And they are mostly right. But I have been brow-beaten into discarding stuff at times, and, you know?.... every time I do, that old warning that you never need anything until the day after you throw it away seems to be so damn true.

And where would we be if we didn't have obsessive collectors? No libraries, no museums, no statistics, no second-hand shops...

[annie-lyne.livejournal.com]

Right!

Have you tried doing models for other Platonic solids?

ps. I'll still try and get another tutorial entry going soon :) been rather unmotivated...

[miriam-e.livejournal.com]

I was thinking about that this morning. An icosahedron might be fairly straightforward, but I can't see how I could make the simplest platonic solid: the tetrahedron without it degenerating to just a compression-only system. A cube might be possible, however because of the square sides it might be unstable... I need to think more on that.

I'm finding myself starting to wonder more about hybrid structures where the faces are mixtures of triangles, squares, pentagons, and hexagons. But maybe I shouldn't be wasting that much time.

There is no great urgency for the maths stuff. I probably need more reasons to do my work than reasons to do other things anyway. :)