Dangerous Thoughts

It's always cheering to clear up a troublesome literary and scientific mystery. The late great Isaac Asimov's long-running chronicles of our future have posed one such problem, and now at last the answer can at last be revealed ... thanks to analysis based on robotic hardware specifications.

In its early days the difficulty wasn't recognized. Dr Asimov simply appeared to be recording two separate, incompatible histories of things to come. One ran from the near future to a time when human colonies are established in several distant solar systems, and revolved around the uses and abuses of intelligent humanoid robots who devoted their vast computational powers to finding and exploiting loopholes in their programming (I, Robot, 1950, and sequels). The second covered a much later period of galaxy-wide human hegemony, and was characterized by a total absence of any robots or artificial intelligences whatever (the Foundation trilogy, 1951-3).

Students tended to assume that either these future histories occurred on alternate time-lines -- a conjecture easily sliced apart with Occam's Razor -- or that one, very probably the first, was fictional.

Dr Asimov dropped his bombshell with the further posthistorical study Foundation's Edge (1982), in which the two historical sequences were declared to be one. Several more dismayingly bulky volumes have expanded on and confirmed this change of paradigm.

We can now state the problem. How was the technology of intelligent "positronic robots" so completely lost before the time of the Galactic Empire, and never rediscovered in centuries if not millennia of scientific advance? Here Asimov could only offer a somewhat discreditable theory of galaxy-wide conspiracy and mind control, scarcely more convincing than blaming it all on the Rosicrucians, the Templars or the World SF Society.

An alternative and far more compelling explanation is that robots were banned -- made universally taboo -- at some time between the two historical sequences, simply because they were a major health hazard. This hazard can be demonstrated through a straightforward thought experiment, even though the inviolable First Law of Robotics (Asimov, passim) provides that no robot may harm a human being or through inaction allow a human being to come to harm.

Consider the workings of the robot brain. Asimov himself records that this complex device operates by the creation and annihilation of positrons. Of course the only plausible mechanism for the latter process is mutual annihilation with the positron's antiparticle, the electron. Each has an energy mass of some 0.511 MeV; the annihilation reaction has the characteristic energy 1.022 MeV, resulting in varying numbers of hard gamma rays.

At once we see that inside one of these positronic supercomputers, such reactions must be happening billions and billions of times per second, with gammas and X-rays spraying out like nuclear halitosis. Obviously it's extremely hazardous to stand anywhere near a robot ... especially when it's thinking. Positronic robots endanger health.

Asimov himself provides confirming evidence with the test case of the colony world Solaria discussed in his The Naked Sun (1956), where it is shown that a large robot population results in a tiny and shrinking human remnant, and in Foundation and Earth (1986), where genetic wreckage has left the very few remaining Solarians with funny lumps on their heads.

One serious objection to our analysis remains. To students of these chronicles it is a notorious fact that hard radiation causes Asimovian robot brains to seize up so rapidly as to leave no time even for a traditional chorus of "Daisy, Daisy". If robots already spew out gamma rays, how can this possibly be?

With a little thought, the answer is obvious. High-energy gamma radiation from an external source will produce random electron-positron pairs by interaction with heavy nuclei (copiously available, as the substrate of the positronic brain is stated to be platinum). These extraneous positron showers must appear to the robot mind as wrong and illogical thoughts imposed from outside, such as an irrational desire to write a trilogy containing more than three volumes.

We can argue that the robot itself will detect this malfunction and intelligently deduce the whole scenario just outlined, intelligently realize it's been leaking harmful rays in defiance of the First Law all its life, and thus intelligently suffer what Dr Asimov insisted was the inevitable result of First Law violation: immediate brain death.

Such an unwelcome demonstration that intelligence has little survival value might well explain why the highly intelligent Asimov should have unconsciously blinded himself to this entire line of reasoning. Or would the many future additions planned for his series have taken it into account? Would the astonishing plot revelation of some later book have been that the unlikely mechanism which very slowly makes the whole Earth radioactive (between the times of the 1985 Robots and Empire and the 1950 Pebble in the Sky) was all a bluff, the true cause being large numbers of robots all thinking hard and radiating furiously? We will never know.

Meanwhile, don't hang around in the vicinity of any robot that seems to have something on its mind. HM Government warns you that most doctors don't own robots. The Surgeon General has determined ...