
Cleansing thermonuclear fire - danso
http://blog.nuclearsecrecy.com/2018/06/29/cleansing-thermonuclear-fire/
======
yesenadam
From Hamming's paper _Mathematics on a Distant Planet_ (1998):

...before going farther I need to mention a few things in my life that have
shaped my opinions. The first occurred at Los Alamos during WWII when we were
designing atomic bombs. Shortly before the first field test (you realize that
no small scale experiment can be done - either you have a critical mass or you
do not), a man asked me to check some arithmetic he had done, and I agreed,
thinking to fob it off on some subordinate. When I asked what it was, he said,
"It is the probability that the test bomb will ignite the whole atmosphere." I
decided I would check it myself! The next day when he came for the answers I
remarked to him, "The arithmetic was apparently correct but I do not know
about the formulas for the capture cross sections for oxygen and nitrogen-
after all, there could be no experiments at the needed energy levels." He
replied, like a physicist talking to a mathematician, that he wanted me to
check the arithmetic not the physics, and left. I said to myself, "What have
you done, Hamming, you are involved in risking all of life that is known in
the Universe, and you do not know much of an essential part?" I was pacing up
and down the corridor when a friend asked me what was bothering me. I told
him. His reply was, "Never mind, Hamming, no one will ever blame you." Yes, we
risked all the life we knew of in the known universe on some mathematics.
Mathematics is not merely an idle art form, it is an essential part of our
society.

[http://libgen.io/scimag/get.php?doi=10.2307/2589247&download...](http://libgen.io/scimag/get.php?doi=10.2307/2589247&downloadname=&key=3WSYZDNDCNT7FUD3)

~~~
mirimir
Maybe Hamming didn't "know about the formulas for the capture cross sections
for oxygen and nitrogen". But "after all, there could be no experiments at the
needed energy levels" seems like a valid point.

However, perhaps "knowing" physics includes coming up with likely values for
currently unmeasurable parameters.

> I was pacing up and down the corridor when a friend asked me what was
> bothering me. I told him. His reply was, "Never mind, Hamming, no one will
> ever blame you."

Right. If there was any blaming to be done, nobody left alive would know what
Hamming's role had been.

~~~
enkid
I think that last part is a joke.

~~~
mirimir
Yeah, but that's the thing about jokes. They tell the truth, but in a deniable
way.

------
maxander
> The answer they found: if the Earth’s oceans had twenty times more deuterium
> than they actually contain, they could be ignited by a 20 million megaton
> bomb (which is to say, a bomb with the yield equivalent to 200 teratons of
> TNT, or a bomb 2 million times more powerful than the Tsar Bomba’s full
> yield).

A factor of twenty in the elemental composition of hydrogen, and a factor of a
million in the fission efficiency of uranium. We’ve been lucky with regard to
untested physical constants so far, but there’s no promise that that will hold
going forward!

~~~
p1mrx
That reminds me of Three Worlds Collide, chapter 5:

[https://www.lesswrong.com/posts/HawFh7RvDM4RyoJ2d/three-
worl...](https://www.lesswrong.com/posts/HawFh7RvDM4RyoJ2d/three-worlds-
collide-0-8)

Humans are comparing notes with a new alien species, and find a _huge_
discrepancy in one of the physical constants. It turns out that scientists had
published a fake value, because the information would've allowed anyone to
build a superweapon.

------
grkvlt
Initially I assumed this was going to be about how nuclear tests were 'self-
declassifying' since all the bomb components, test fixtures and equipment, the
tower it was mounted on etc. would be completely vaporized in the explosion,
so there was nothing left to classify as secret. Except for that one
embarassing time when the UCRL device in test Upshot-Knothole Ruth[0] fizzled
and failed to destroy the steel tower it was detonated on...

0\.
[https://en.wikipedia.org/wiki/Operation_Upshot%E2%80%93Knoth...](https://en.wikipedia.org/wiki/Operation_Upshot%E2%80%93Knothole)

------
nine_k
It's worth noting that the makers of Tsar Bomba [1] also considered the
possibilities of igniting the atmosphere, though it had "mere" 50 Mt of yield.

1:
[https://en.wikipedia.org/wiki/Tsar_Bomba](https://en.wikipedia.org/wiki/Tsar_Bomba)

------
labster
TL;DR: the atmosphere will never ignite in nuclear fire, but if you add enough
deuterium to the oceans you can get runaway fusion in the oceans with an
absurdly large nuke.

~~~
ianai
How far from realistic is the amount needed?

~~~
wtracy
Twenty times the total amount of deuterium currently present in the world's
oceans.

Basically, you'd have to completely change the chemistry of the oceans on a
global scale.

Also, AFAIK there is no realistic way to synthesize deuterium artificially
(please let me know if I'm wrong!) so to get started you'd need to go out and
find something like an order of magnitude more deuterium than exists on planet
Earth. You'd have to scour a big chunk of the solar system.

So, not something an apocalyptic cult is going to pull off in the forseable
future.

~~~
helpfulTroll

      You'd have to scour a big chunk of the solar system.
    

No, bombarding regular water with neutrons from fission reactions will produce
heavy water.

[https://en.wikipedia.org/wiki/Heavy_water#Production](https://en.wikipedia.org/wiki/Heavy_water#Production)

~~~
wtracy
I stand corrected.

------
yosefzeev
A Greater Hand than math was involved.

