"The trouble with uranium is that it doesn't make a big enough bang," said MacPherson. "People aren't impressed by it any more. The same goes for plutonium, even for lithium, at least for any size bomb we can make. The idea is to show the world something so convincing that they'll never even think of a war again. When they see every island in the Waaku chain wiped off the map, they'll get the point."
Avery creased another card and cleared his throat. "Did you check the inverted twelve-by-twelve, Rothman?"
"I suppose you think I forgot to. Have you checked it?"
"Yes, I have. I may not know much math, but I did check it."
"Even after the Columbia boys said it was nonsense? Well, does it come out right?"
"No, it doesn't! You multiply the inverted matrix by the original and you not only don't get zeros for all elements outside the diagonal, you get a haphazard assortment of ones and twos. Worse still, every element in the diagonal comes out equal to zero. The product of the two matrices is about as different from the identity matrix as anything could be. You're one of our most brilliant mathematicians—how could you manage to make so many mistakes in one set of calculations?"
"Did I tell you that was an inverted matrix? Maybe, for this problem, you need something a little more advanced than algebra. Anyhow, if my math is all wrong, why did your first report okay it?"
"What do you mean, my first report?"
"The one you sent to Prexy. The one you later called in and burned. Except Prexy showed it to me and I photostated it. Here." Rothman reached into the pile of papers on his desk and drew out a little envelope. It contained photographic prints. He held one before Avery's glasses. "Does that look familiar?"