Power of analogies in science

If you know how a basketball spins on each of its axes, then it turns out that you also know how a classical methane molecule spins. Such analogical pairings are useful because they allow you to better understand the less familiar of the pair through what you know of the other. The trouble, of course, is that analogies are often imperfect. Not every property is directly connected between the pair. So you have to be careful to assign which are mappable. For example, you certainly won't be able to play basketball with methane despite the analogy with respect to rotations.

Meanwhile, mapping a problem to one that is even more difficult to solve sounds like a bad idea. But if the more difficult problem solves itself them you just might win out after all. Toshiyuki Nakagaki and his colleagues at Hokkaido University did just this, twice. First, they showed that they could map simple mazes onto a board in which mold could grow. It turns out that after a while, the mold grows best along the shortest path between the ends. It would be very difficult to simulate the mold growth, and yet the analogy allows the mold to solve a complicated optimization problem for us. It turns out that you can replace the maze with a real problem related to finding the best possible train network connecting some number of cities over a selected terrain. Now the mold can be used to find the optimal rail network. For each of these two analogies, Toshiyuki Nakagakii received ig Nobel awards. I mention him, in particular, because I got a chance to meet him while I was in Japan. And now, I wonder if I might be able to map the solution of a chemical reaction pathway to his mold growths?!

In detail, the dates and prizes of the teams recognized by ig Nobels for mold growths mentioned above are:

2008 ig nobel in Cognitive science: Toshiyuki Nakagaki, Hiroyasu Yamada, Ryo Kobayashi, Atsushi Tero, Akio Ishiguro, and Ágota Tóth, for discovering that slime molds can solve puzzles.

2010 ig nobel in Transportation Planning: Toshiyuki Nakagaki, Atsushi Tero, Seiji Takagi, Tetsu Saigusa, Kentaro Ito, Kenji Yumiki, Ryo Kobayashi of Japan, and Dan Bebber, Mark Fricker of the UK, for using slime mold to determine the optimal routes for railroad tracks.