"Very fine work, son, very fine indeed," Haynes congratulated the younger man at the conclusion of his report. "We shall begin at once, and be ready to rush things through when the technicians bring back the necessary data from Medon. But there's one more thing I want to ask you. How did you come to place those spotting-screens so exactly? The beam practically dead-centered them. You said that it was surmise and suspicion before it happened, but I thought then and still think that you had a much firmer foundation than any kind of a mere hunch. What was it?" "Deduction, based upon an unproved, but logical, cosmogonic theory--but you probably know more about that stuff than I do." "Highly improbable. I read just a smattering now and then of the doings of the astronomers and astrophysicists. I didn't know that that was one of your specialties, either." "It isn't, but I had to do a little cramming. We'll have to go back quite a while to make it clear. You know, of course, that a long time ago, before even interplanetary ships were developed, the belief was general that not more than about four planetary solar systems could be in existence at any one time in the whole Galaxy?" "Yes, I am familiar with that belief--a consequence of the binary-dynamic-encounter theory in a too-limited application. The theory itself is still good, isn't it?" "Eminently so--every other theory is wrecked by its failure to account for the quantity and above all, the distribution, of angular momentum of planetary systems. But you know what I'm going to say--that 'limited application' proves it!" "No, just let's say that a bit of light is beginning to dawn. Go ahead."