Free Planet of the Damned and Other Stories: A Science Fiction Anthology (Five Books in One Volume!) by Harry Harrison Page A

seven years ago, to give me a general idea of the field. I've worked with survey teams since then, but I have only the vaguest idea of the application of the information we got. Could you cover the ground again—only a bit slower?"
    Neel controlled his anger successfully and started again, in his best classroom manner.
    "Well, I'm sure you realize that a good survey is half the problem. It must be impartial and exact. If it is accurately done, application of the k-factor equations is almost mechanical."
    "You've lost me again. Everyone always talks about the k-factor, but no one has ever explained just what it is."
    Neel was warming to his topic now. "It's a term borrowed from nucleonics, and best understood in that context. Look, you know how an atomic pile works—essentially just like an atomic bomb. The difference is just a matter of degree and control. In both of them you have neutrons tearing around, some of them hitting nuclei and starting new neutrons going. These in turn hit and start others. This goes on faster and faster and bam , a few milliseconds later you have an atomic bomb. This is what happens if you don't attempt to control the reaction.
    "However, if you have something like heavy water or graphite that will slow down neutrons and an absorber like cadmium, you can alter the speed of the reaction. Too much damping material will absorb too many neutrons and the reaction will stop. Not enough and the reaction will build up to an explosion. Neither of these extremes is wanted in an atomic pile. What is needed is a happy balance where you are soaking up just as many neutrons as are being generated all the time. This will give you a constant temperature inside the reactor. The net neutron reproduction constant is then 1. This balance of neutron generation and absorption is the k-factor of the reactor. Ideally 1.0000000.
    "That's the ideal, though, the impossible to attain in a dynamic system like a reactor. All you need is a few more neutrons around, giving you a k-factor of 1.00000001 and you are headed for trouble. Each extra neutron produces two and your production rate soars geometrically towards bang. On the other hand, a k-factor of 0.999999999 is just as bad. Your reaction is spiraling down in the other direction. To control a pile you watch your k-factor and make constant adjustments."
    "All this I follow," Costa said, "but where's the connection with Societics?"
    "We'll get to that—just as soon as you realize and admit that a minute difference of degree can produce a marked difference of kind. You might say that a single, impossibly tiny, neutron is the difference between an atom bomb and a slowly cooling pile of inert uranium isotopes. Does that make sense?"
    "I'm staggering, but still with you."
    "Good. Then try to go along with the analogy that a human society is like an atomic pile. At one extreme you will have a dying, decadent culture—the remains of a highly mechanized society—living off its capital, using up resources it can't replace because of a lost technology. When the last machine breaks and the final food synthesizer collapses the people will die. This is the cooled down atomic pile. At the other extreme is complete and violent anarchy. Every man thinking only of himself, killing and destroying anything that gets in his way—the atomic explosion. Midway between the two is a vital, active, producing society.
    "This is a generalization—and you must look at it that way. In reality society is infinitely complex, and the ramifications and possibilities are endless. It can do a lot more things than fizzle or go boom. Pressure of population, war or persecution patterns can cause waves of immigration. Plant and animal species can be wiped out by momentary needs or fashions. Remember the fate of the passenger pigeon and the American bison.
    "All the pressures, cross-relationships, hungers, needs, hatreds, desires of people are reflected in their interrelationships. One man standing by