"Spirit Arrow" : Black Bamboo with a Mission

"Spirit Arrow" stands twenty-one inches high, fifteen inches wide, and twenty-two inches long. It's made from black bamboo and black Kevlar thread. The three struts do not touch each other, but are kept aligned by the tendons:

They say that having a child is like shooting an arrow into the future. Very apt.

But where is the future?

"Spirit Arrow" will try to nail that down. The mission of this little arrow is to be shot into the future, and spear it.

As a launcher for such an awesome trip, a tensegrity structure would be ideal. And the simple construction above does have tensegrity.

"Tensegrity" is short for "tensional integrity", the quality of having all the tensile forces in a structure be continuous. (This word was invented by Buckminster Fuller, one of my principal heros.) The tense "outside" can be a skin, like in a soap bubble or an inflated tent, which are both tensegrity structures, or just a continuous path of tendons, like "Spirit Arrow", with his tendons pulling in and his struts pushing out.

A tensegrity figure is inherently balanced so it dosn't depend on gravity for stability. This means that "Spirit Arrow" works as a wall piece or a hanging piece just as well as a table piece. Just be sure to mount it where no one can walk into it and stab themselves or, even worse, damage "Spirit Arrow".

I would usually use stainless steel wires for tendons in a structure this size, but metal seemed too hard and wrong for such a spiritual mission. I needed some kind of fibrish thing. Kevlar fibre is the very strongest one, so I gave some yellow Kevlar an India ink bath to make the lashings. I particularly liked combining a very modern material with one of the most ancient, because it crosses lots of categories, which I always try to flout.

(Also, a really stuffy purist might say, "..sure, that crazy thing has tensegrity in outer space, but not here in a gravity field. With gravity, the parts sticking out past the fastenings will cause little bending moments. These will raise tensile forces, which are not permitted in struts."

What a nitpicker. What a nerd. I wouldn't even try to convince such a person that the little bending forces will be easily absorbed by all the big compressive forces.)

"Spirit Arrow". . . . . . . . . . .$ 400