• It was equally imperative that this chain of reactions should always tend to dampen, to die out. It must not build up, or the uranium mass would explode within a time interval too short to be measured by any means whatsoever. Nor would there be anyone left to measure it.

    Robert A. Heinlein (2013). “The Man Who Sold the Moon and Orphans of the Sky”, p.101, Baen Publishing Enterprises