Where Kimchi Comes From

Kimchi reactor during the Choson Dynasty

Every nation has its iconic food -- one that defines its people as a culture. For Scotsmen, that food is haggis, of which the less said the better. English relish their fish and chips while Frenchmen eat snails. The Italians have pasta in all of its manifold varieties, here in America, we have MacDonald’s, which may be almost as terrifying as haggis if you stop to wonder what might go into those burgers.

And In Korea... they have... kimchi...

Kimchi (Km) is a trans-uranic element with an atomic weight between 233 and 241. Its most common isotope, Km-238, is comparatively stable, with a half-life of several billion years. This isotope occurs naturally in the Earth’s crust and in vegetables such as cabbage. A lighter isotope, Km-235, has the interesting property that it can be split by neutron bombardment to produce a variety of lighter elements along with more neutrons. If these secondary neutrons are slowed by a moderator, such as graphite, heavy water, or saliva, they will split more atoms of Km-235 to create a ‘chain reaction’ that releases enormous amounts of energy. This chain reaction is the basis for kimchi’s use in food and weaponry.

Due to its short half life, Km-235 does not occur in nature in any signficant quantity. But during the early decades of Choson Dynasty (1393-1910), Korean scientists learned how to create this isotope artificially. By concentrating cabbage in pellets, and loading these into a reactor along with an appropriate neutron source, a moderator, and an arrangement of damper rods to keep the reaction under control, they could produce the unstable heavy isotope Km-239, which decays by the emission of an alpha particle and two electrons to yield Km-235. The Km-235 could then be extracted using gaseous diffusion or high-speed centrifuges to produce food- or weapons-grade material. As a byproduct, Kimchi reactors also produced heat and electricity, which could be used to run the extraction process, light homes, and power the wheels of industry.

Kimchi is credited with turning back the Japanese invasion of 1592-1598. As they viewed the resulting devastation, the people of Korea decided that kimchi was too terrible to ever use again in war, and the manufacture and use of kimchi-based weapons was abandoned forever. This left them unable to defend their country when Japan invaded again during the Sino-Japanese War at the end of the 19th century. But in view of the enormous humanitarian disaster that might have accompanied the use of kimchi on a modern battlefield, we can only applaud their decision.

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Last modified: 25 September 2009