Engines of Our Ingenuity

No. 2672
SELF REPLICATING MACHINES

by Andrew Boyd

Today, remaking yourself. The University of Houstonís College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them.

The ideaís been around for a long time. The technology already exists. And the potential applications are mind-bending.

The idea is to build self replicating machines — machines that make copies of themselves. Imagine building a machine capable of two things: making copies of itself and collecting solar power. If we send just one such machine to the moon, it could eventually cover the moonís surface with copies of itself. Then each copy could act as a solar collector and send the energy back to earth.

self replicating machines image

And the job wouldnít take long. First, one machine makes one machine. But then there are two machines to make two more. And so on. If the solar panelís about a square meter and it takes the machine a day to make a copy of itself, it could cover the entire lunar surface in just thirty-five days. Not a bad return for building just one machine.

Of course, the machine would need to fashion parts for itself with raw materials found in the moonís soil. Thatís not impossible. But itís the big engineering challenge.

All sorts of ideas have been proposed for self replicating machines. Garbage collectors that produce garbage collectors from recycled garbage. Spaceships that build spaceships to explore the universe. Self replicating nanobots that destroy cancer cells. The possibilities are an engineerís dream come true.

If it sounds like an impossible dream, itís not. We have countless examples all around us in nature. Bacteria. Wildflowers. Rabbits. Raw materials and energy from the surrounding environment are used to create offspring; to self replicate. The copies arenít identical, but remarkably close.

A frequent concern is the thought of self replicating machines run amok. In his 1986 book Engines of Creation, technologist Eric Drexler coined the term grey goo for a scenario in which unstoppable self replicating machines consume everything in sight. Itís a wonderful plot device for science fiction writers. But could it happen? None of the self-replicating life forms all around us has yet managed to turn the earth into grey goo. But biological self replication constantly creates havoc. The boll weevil decimated U.S. cotton crops early in the twentieth century. Flu viruses kill an estimated quarter to half million people each year.

H1N1 flu virus picture

The fact that we, as humans, exist to ponder our universe demonstrates the good that can come from self replication. But as with anything, we must use care as we seek to engineer self replicating devices.

family portrait

Iím Andy Boyd at the University of Houston, where weíre interested in the way inventive minds work.

(Theme music)


Notes and references:

E. Drexler. Engines of Creation: The Coming Era of Nanotechnology. New York: Anchor (Random House), 1987. The book can also be found online at the E-Drexler.com Web site: http://e-drexler.com/p/06/00/EOC_Cover.html. Accessed January 4, 2011.

All pictures are from Wikimedia Commons.



The Engines of Our Ingenuity is Copyright © 1988-2011 by John H. Lienhard.