I’m heading to the parking lot with my grandmother after a family picnic by the ocean, making small talk about the weather. The tide. The corn.
“What is on top of that car?”
“I think… it’s… hay.”
“…I think there’s a ball of hay on top of that car.”
It’s the weirdest thing. In the middle of a state park by the ocean, close to sundown, almost no one around except for this car with an enormous BALL OF HAY tied to the roof pulls into the parking lot.
The passengers of Car Hayball get out. We’re staring, or maybe gaping, it’s hard not to.
My dad breaks the silence: “So, I have to ask. What is that on your car?”
A ball of hay. I was right!
I stop staring for a moment, but all I can manage to ask is “…Why?…”
It turns out the owner of the ball of hay is an artist, and this is part of his work. He makes sculpture, and his medium is hay. For some reason everything suddenly makes sense.
His story goes that at one point he needed to move a ball of hay, and he did it by strapping it to his car and driving it where it needed to go. But he realized transporting the hay ball was a work of art in it’s own right. People everywhere would stop to take pictures, or to ask him about it. It calls a lot of attention to itself, and now he drives it around sometimes for kicks. It brings people together.
Being the math major that I am, I don’t stop myself before saying,
“Have you heard of the Hairy Ball theorem? Your hay ball totally reminds me of that!”
The Hairy Ball Theorem says that given a ball covered with hairs, think perhaps of a Pom Pom or something similar, there is no way to smoothly comb down every single hair. At some spot you will be forced to leave some hairs sticking straight up (see a short video on it by MinutePhysics here).
I find myself explaining the basics of the theorem to the artist, telling him that not only can he make an artistic statement with his hay, but also a mathematical one! How exciting is that?!
Even if the “mathematical statement” is just an excuse to leave the hay a little bit messy, think: since the Hairy Ball Theorem says it is not possible to comb the strands of hay in a way that they all lay flat, why bother to try combing them at all?
Also interesting on the subject of the Hairy Ball Theorem:
- a NPR article with a “real-life” application using the Hairy Ball theorem in computer graphic animation
- a post by Vi Hart on spherical camera angle and the Hairy Ball Theorem