ABSTRACT
All physical systems store their past experiences. Rocks retain the heat of the sun after it has set. The magnetism and crystal structure of minerals reveal the conditions under which they were formed, and machines wear out or rust. Inanimate objects rarely benefit from the information they store; the reverse is more likely to be true. The cumulative effect of all those revolutions finally lands an internal combustion engine on the scrap heap. Animals, however, have evolved methods of benefiting from the effects of their experiences.
