Humans will be marrying robots within 50 years, according to David Levy, winner of the 2009 Loebner Prize for artificial intelligence.
"People will have fewer problems with robots," declares Mr. Levy, who cites advances in intelligence simulation that will enable people to carry on long-term relationships with artificial human companions. "Robots will be programmed to be sensitive sex therapists and help them to get over their sexual problems."
Although such machines won't initially be cheap, Mr. Levy says he hopes that, as with other electronic products, demand eventually will drive prices down.
Frederic Kaplan, the robotics researcher who co-programmed the brain of Sony's robot dog Aibo, is skeptical of claims like Mr. Levy's. He agrees that highly sophisticated sex robots will be available soon but says he doesn't think they will ever successfully pass as humans.
"It is not impossible that some of these robots will actually be 'sexy' in one way or another, but they will not be clones of human beings," Mr. Kaplan says. "Human-machine interactions will be interesting in their own right, but not as a simulation of human relationships."
Sophisticated sex dolls are already on the market, however, including the Japanese Honey Doll and American Real Doll. German inventor and aircraft mechanic Michael Harriman even has invented a doll with a "heartbeat" that purportedly speeds up during sex.
But sex isn't the same thing as love. While some people claim to have rewarding relationships with their Real Dolls, what Mr. Levy envisions is a robot capable of having a conversation, not simply a mute object of desire.
The obsession with creating artificial human companions goes back a lot further than the electronic era. Mechanical beings are mentioned in ancient Chinese texts and in Homer's "The Iliad." Jewish folklore describes a creature called the golem, which is created from inanimate matter but has the semblance of being alive.
Golems, like robots, take instructions literally when commanded to carry out a task. This legend was the basis for Gustav Meyrink's novel "The Golem," set in Prague. The Czech capital also was the home of Karel Capek, who popularized the term robot in his play "R.U.R." ("Rossum's Universal Robots").
The development of robots began in earnest only with the advent of computing and cybernetics in the second half of the 20th century. In 1950, English computer pioneer Alan Turing developed a measurement criterion known as the Turing test. A human and a machine, neither visible to the referee, both answer a series of written questions. If the referee can't distinguish which answers are the human's, the machine is deemed to have passed the test.
This doesn't mean the computer is self-aware, however. Some thinkers have speculated that computers will never be sentient in the same way a human being is. Roger Penrose's book "The Emperor's New Mind," for instance, maintains that quantum processes inside the neurons of the brain give humans a unique way of processing data that machines will never be able to replicate.
Futurologist Ray Hammond says he thinks Mr. Penrose's speculations are wrong and that machine consciousness will happen toward the middle of the current century - the same time frame in which Mr. Levy has said robot marriage will occur.
"There will certainly be emotional attachment between humans and machines," Mr. Hammond says, "although I don't think 'marriage' is anything other than a word for headline writers. People already form weak emotional bonds with inanimate objects, and as objects become increasingly intelligent, these bonds will strengthen."
Mr. Levy, however, says he thinks sentience is not the real issue. He points out that it isn't the algorithm people fall in love with, but the convincing simulation. "If a robot appears in every way to possess consciousness, then in my opinion, we should accept that it does," he says.
The problem of exactly what constitutes consciousness is a tricky one, Mr. Kaplan agrees. "For a long time, playing chess was a definite sign of intelligent behavior," he says. "But when a machine was able to beat the chess world champion, it was soon suggested that human intelligence had other distinct characteristics. The same kind of redefinition is currently happening around consciousness. New robots will force us to define exactly what is meant by 'being conscious.' "
Here's another one: If Tiger Woods' wife were a robot, would he have to apologize to her?