Heinlein, Robert A – Expanded Universe

brains had thought up, asked for, and been given. Canada supplied us with all the

uranium we asked for-tons of the treacherous stuff-from Great Bear Lake, up near the

Yukon, and the fractional-residues technique of separating uranium isotope 235 from

the commoner isotope 238 had already been worked out, by the same team from Chicago

that had worked up the earlier expensive mass spectograph method.

Someone in the United States government had realized the terrific

potentialities of uranium 235 quite early and, as far back as the summer of 1940,

had rounded up every atomic research man in the country and had sworn them to

silence. Atomic power, if ever developed, was planned to be a government monopoly,

at least till the war was over. It might turn out to be the most incredibly powerful

explosive ever dreamed of, and it might be the source of equally incredible power.

In any case, with Hitler talking about secret weapons and shouting hoarse insults at

democracies, the government planned to keep any new discoveries very close to the

vest.

Hitler had lost the advantage of a first crack at the secret of uranium

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through not taking precautions. Dr. Hahn, the first man to break open the uranium

atom, was a German. But one of his laboratory assistants

had fled Germany to escape a pogrom. She came to this country, and told us about it.

We were searching, there in the laboratory in Maryland, for a way to use U235 in a

controlled explosion. We had a vision of a one-ton bomb that would be a whole air

raid in itself, a single explosion that would flatten out an entire industrial

center. Dr. Ridpath, of Continental Tech, claimed that he could build such a bomb,

but that he could not guarantee that it would not explode as soon as it was loaded

and as for the force of the explosion-well, he did not believe his own figures; they

ran out to too many ciphers.

The problem was, strangely enough, to find an explosive which would be weak

enough to blow up only one county at a time, and stable enough to blow up only on

request. If we could devise a really practical rocket fuel at the same time, one

capable of driving a war rocket at a thousand miles an hour, or more, then we would

be in a position to make most anybody say “uncle” to Uncle Sam.

We fiddled around with it all the rest of 1943 and well into 1944. The war

in Europe and the troubles in Asia dragged on. After Italy folded up, England was

able to release enough ships from her Mediterranean fleet to ease the blockade of

the British Isles. With the help of the planes we could now send her regularly and

with the additional over-age destroyers we let her have, England hung on somehow,

digging in and taking more and more of her essential defense industries underground.

Russia shifted her weight from side to side as usual, apparently with the policy of

preventing either side from getting a sufficient advantage to bring the war to a

successful conclusion. People were beginning to speak of “permanent war.”

I was killing time in the administrative office, trying to improve my

typing-a lot of Manning’s reports had to be typed by me personally-when the orderly

on duty stepped in and announced Dr. Karst. I flipped the interoffice communicator.

“Dr. Karst is here, chief. Can you see her?”

“Yes,” he answered, through his end. I told the orderly to show her in.

Estelle Karst was quite a remarkable old girl and, I suppose, the first woman ever

to hold a commission in the Corps of Engineers. She was an M.D. as well as an Sc.D.

and reminded me of the teacher I had had in fourth grade. I guess that was why I

always stood up instinctively when she came into the room-I was afraid she might

look at me and sniff. It couldn’t have been her rank; we didn’t bother much with

rank.

She was dressed in white coveralls and a shop apron and had simply thrown a

hooded cape over herself to come through the snow. I said, “Good morning, ma’am,”