Book Review

ASTROCHICKEN AND ENERGY TREES

Penrose, Roger, Roger Penrose is the Rouse Ball Professor of Mathematics at the University of Oxford

1988

Overview

Mr. [Freeman J. Dyson]'s main case for ''diversity'' comes from biology, which, by its very nature, is more diversified than physics. Only Darwin's theory of natural selection, or perhaps the discovery of the genetic code as revealed primarily through the work of Francis Crick, can qualify as profoundly unifying. Among other things, Mr. Dyson cites the theory of ''genetic drift'' of the Japanese geneticist Motoo Kimura, who believes that random statistical fluctuations in evolution have been more important than Darwinian selection. Mr. Dyson addresses a question I have always found puzzling: Why is life so complicated? If simple elegant solutions to problems are the best, then why does nature need go to the lengths she does in order to produce viable living structures such as ourselves? Mr. Dyson's answer lies in ''homeostatic systems'' - systems that maintain a constant local environment despite changing external conditions. He argues that homeostatic systems are a necessary prerequisite for life and that such systems are necessarily complicated, relying on diversity to maintain their equilibrium. He applies this belief particularly to space research, arguing that the scientific values of missions in space have been more or less inversely proportional to their cost. He believes that it will be possible, in the dim but not too distant future, to use genetic engineering to design creatures that can exist and be self-supporting in space. Unabashed by the science fiction nature of such suggestions, he presents his ''scavenger turtle'' (with diamond-tipped teeth), ''energy tree'' and ''mining worm.'' His centerpiece is a one-kilogram spacecraft ''astrochicken,'' which will be ready to launch in 2016. It will not be built but grown by the use of genetic engineering, and it will depend on artificial intelligence and solar-electric propulsion for its operation. Accompanying it will be a ''Martian potato,'' a ''comet creeper'' and a ''space butterfly.'' He has a great faith in the value of artificial intelligence, but believes that human intelligence will ''remain far ahead . . . as far into the future as I can imagine.''

• Publisher: New York Times Company
• Subject: Dyson, Freeman / DYSON, FREEMAN J (PROF) / PENROSE, ROGER