IF YOUR central heating thermostat breaks down this winter, don鈥檛 call an engineer. Just take a few tips from skunk cabbages, non-linear forecasting and Zazen attractors.
The smelly skunk cabbage (Symplocarpus foetidus) 鈥� a member of the arum family rather than a true cabbage 鈥� can tell us a thing or two about staying warm. It is one of the few complex plants that controls its tissue temperature, maintaining a comfortable 16 to 24 掳C in all weathers. It can even melt snow as it warms itself to protect its delicate flowers. The plant generates heat by burning starch in special cells, but until now no one understood exactly how it controls its internal thermostat.
Now two researchers say its temperature follows a kind of mathematical pattern called a strange attractor. Takanori Ito and Kikukatsu Ito of Iwate University in Japan monitored several skunk cabbages in the wild, recording their temperatures every minute. At first, the temperature fluctuation appeared to be random. But using a statistical technique called non-linear forecasting, they found it varies in a way specified by a unique mathematical algorithm. They have called the algorithm a Zazen attractor after the plant鈥檚 Japanese name, Zazen-sou, meaning Zen meditation plant (Physical Review E, vol 72, 051909).
Advertisement
And the thermostat is surprisingly robust, despite its apparent jitteriness. 鈥淲hen a stable state is catastrophically damaged by drastic changes of environment, it is hard to regulate the system,鈥� says Takanori Ito. But the skunk cabbage鈥檚 thermostat can cope even under extreme conditions. 鈥淚t can be regulated even when the ambient temperature drops below freezing.鈥�
Roger Seymour, an expert on temperature control in plants at the University of Adelaide in Australia, is not convinced. He thinks the self-heating weed might use simpler mathematics. 鈥淲hether it relies on a straightforward feedback mechanism or something more complicated having to do with strange attractors remains to be seen.鈥� The biochemistry that enables the skunk cabbage to regulate its temperature is also obscure. 鈥淲e really do not know how the plants regulate heat production on a cellular level.鈥�
Even so, the researchers are keen to put their work to use. They are testing a prototype temperature control unit that uses the algorithm, and within a year or so they hope to know whether the cabbage brain can take control of home heating systems.
