We start with a pool of oil. We turn on a magnet. The oil travels up a superstructure and blossoms into a tree. Turn off the magnet, the branches, the needles, the tree melt away. It's a puddle again.
The perfect tree for an oil billionaire, no?
It's the creation of Japanese artist Sachiko Kodama, and I'm not sure she had Christmas or Texas in mind when she made it (though I hear more than a hint of "Come All Ye Faithful" in her video soundtrack).
You should watch her tree self-generate first, then I'll try to figure out how she did it.
OK. Let's talk about the oil. It's not exactly oil, it's ferrofluid, which is oil laced with bits of iron oxide. When the magnets are turned on, the little bits of iron (and the oil with them) are pulled by a magnetic field into columns and shapes that produce the "tree."
The oil and iron, steered by the magnets, become "branches." Surface tension in the oil causes those branches to pull in on themselves, forming the sharp "tips." The "towers" Sachiko built create the spiral effect. There's nothing that sophisticated about this scientifically. Ms. Kodama just knows how to create beautiful things using electromagnetism as her paintbrush.
I imagine Neiman Marcus, the big Dallas-based department store, might want to try a Texas-sized version, suitable for oil barons with big living rooms. You could start Christmas dinner beside a pleasant pool of familiar looking oil, press a button, and up pops the tree. Just another example of petroleum at work.
On The Other Hand ...
The problem is, where do you put the gifts? Not under the tree — too messy. Also, you don't want your 7-year-old, sock deep in oil, trying to pry her new bike off a magnetized tree. Plus there are pets. I'm thinking of a packaging label: "Caution! Dogs Ingesting Ferrofluid May Suddenly Attach."
Nah, this isn't my best idea. But it's still nice to notice that artists can play with nature, even the invisible rules of electromagnetism. Rembrandt used a paintbrush. Sachiko Kodama makes her marks with magnetic fields. The options keep increasing. That's one of the dividends of science; the more we know, the more ways we can play.
Robert Krulwich is co-host of Radiolab, WNYC's Peabody Award-winning program that examines big questions in science, philosophy and the human experience through compelling storytelling. Today, Radiolab is one of public radio's most popular shows. Its podcasts are downloaded over 4 million times each month and the program is carried on 437 stations across the nation. In addition to Radiolab, Krulwich reports for National Public Radio. “Krulwich Wonders” is his NPR blog featuring drawings, cartoons and videos that illustrate hard-to-see concepts in science.