
Book Review: The Precipice - tosh
https://slatestarcodex.com/2020/04/01/book-review-the-precipice/
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tosh
""" And even when people seem to care about distant risks, it can feel like a
half-hearted effort. During a Berkeley meeting of the Manhattan Project,
Edward Teller brought up the basic idea behind the hydrogen bomb. You would
use a nuclear bomb to ignite a self-sustaining fusion reaction in some other
substance, which would produce a bigger explosion than the nuke itself. The
scientists got to work figuring out what substances could support such
reactions, and found that they couldn’t rule out nitrogen-14. The air is 79%
nitrogen-14. If a nuclear bomb produced nitrogen-14 fusion, it would ignite
the atmosphere and turn the Earth into a miniature sun, killing everyone. They
hurriedly convened a task force to work on the problem, and it reported back
that neither nitrogen-14 nor a second candidate isotope, lithium-7, could
support a self-sustaining fusion reaction.

They seem to have been moderately confident in these calculations. But there
was enough uncertainty that, when the Trinity test produced a brighter
fireball than expected, Manhattan Project administrator James Conant was
“overcome with dread”, believing that atmospheric ignition had happened after
all and the Earth had only seconds left. And later, the US detonated a bomb
whose fuel was contaminated with lithium-7, the explosion was much bigger than
expected, and some bystanders were killed. It turned out atomic bombs could
initiate lithium-7 fusion after all! As Ord puts it, “of the two major
thermonuclear calculations made that summer at Berkeley, they got one right
and one wrong”. This doesn’t really seem like the kind of crazy anecdote you
could tell in a civilization that was taking existential risk seriously
enough. """

