“I’m sort of following you here, Joe … but what does it mean? What does it all add up to?”
Janis Bell tucked her legs up. Wilderness had long ago concluded she was part cat.
“Let me begin with a tangent.”
“If you must.”
“Do you remember the Tsar Bomba the Russians set off over Novaya Zemlya in ’61?”
“Do I? I went on a demo in protest in my last year at Cambridge!”
“Cambridge? OK. Here … they were somewhat closer to it. The bomb broke windows even in Sweden. It was five hundred megatons, and utterly impractical … can’t fit it onto a missile, few planes are big enough to carry it and even then you’re sending the crew on a suicide mission. It may just be the most pointless big bang in history. Five years later the Russians haven’t attempted anything else on that scale and no one is copying them.”
With a cheek he admired rather than resented, Janis Bell took herself off to the kitchen and returned with wine and glasses.
“I get the feeling it’s going to be a long night.”
“So … if big bombs have proved their uselessness, what is a country to do?”
“I dunno … join CND?”
“Think about it, Janis.”
She knocked back a big gulp of red, did her best to assume the expression of someone drinking and thinking. Then another. “Mini,” she said at last.
“Eh?”
“You make the Morris Mini of bombs. Put the engine on sideways or summat like that. It’s a metaphor, you will understand.”
“I will?”
“Make something smaller and better.”
“By George, I think she’s got it.”
“So … how do you make a smaller atom bomb as effective as a big one.”
“Sorry, Professor ’Iggins. I shot my bolt with the Mini.”
“You make the outer casing out of cobalt-59.”
“In what way does that differ from cobalt?”
“It is cobalt. Cobalt-59 is the atomic mass of cobalt’s most stable isotope.”
“I hear a ‘but’ coming.”
“But cobalt-59 is turned into cobalt-60 by the thermonuclear explosion that sets off a chain reaction and beta decay. Cobalt-60 is not a stable isotope. It’s a law of nature, in a manner of speaking, that matter is always in search of stability. Imagine a sinking ship jettisoning cargo until it’s buoyant again. Unstable isotopes throw out stuff until the atom is stable. The stuff-thrown-out, for want of a better term, is what makes for radioactivity. It stops when the atom is stable again—the eventual stable atomic isotope from cobalt-60 is nickel-60. Meanwhile cobalt-60 is highly radioactive. It has a half-life of 5.27 years.”
Janis Bell shook her head like a wet dog on the threshold.
“Hmmm … Sort of leaves me breathless. Dumb admitted here. What does that mean?”
“It means that its radioactivity diminishes by half every 5.27 years. Anywhere the fall-out from a cobalt bomb lands will be radioactive and uninhabitable.”
“For … 5.27 years.”
“No … halving the radiation every 5.27 years still leaves you with a toxic level a hundred odd years later. It can’t be outlasted. You can’t live in a fallout shelter for three generations.”
“So our American cousins digging big holes in the ground are wasting their time?”
“Yep.”
“And how many of these … er …”
“They’re known as dirty bombs.”
“How apt. How many dirty bombs would it take to wipe out life on Earth?”
“Not many … trade winds would do the work the bomb couldn’t do for itself.”
They’d reached a natural break. Wilderness poured himself a drink and listened to the wheels of cognition engage in Janis’s mind.
“OK. Dumb again. So I shall ask the silly question. What’s all this got to do with your pal Kostya?”
Wilderness was still wondering whether to answer. He had an answer. He’d been kicking an answer around for two days now and still was not convinced of it. It made sense. It did not make sense. It added up. It did not add up.
“He’s not spying, he’s buying.”