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Today, and just because I’m reading (better late than never …) Kurt Vonnegut’s Cat’s Cradle and it’s hot around here these days, we are gonna cover one of these do-it-yourself experiments that never seem to work for me, yet there they are …

One of the leading threads in this (awesome) novel is Ice-Nine, the hidden, most lethal creation of the nuclear bomb father Dr. Felix Hoenikker. I’m not going into further detail on the plot, in case someone has not read it and wants to. The idea behind Ice-Nine is to help troops move around swamps and muddy landscapes by dropping a tiny fragment of the substance inside them. Automatically, all water in contact with the fragment would become Ice-Nine as well and soldiers could move easier. 

In the book, Ice-nine is a polymorph of water more stable than common ice that melts at 45.8 °C. As soon as a chirp becomes in contact with any liquid water below that temperature, it acts a a seed and solidifies the entire body of water. Ice-Nine obviously doesn’t exist -one hopes- but this idea is based on a very real phenomenon known as supercooling. Indeed, Vonnegut gives credit for the idea to General Electrics scientist Irving Langmuir, who reportedly invented the trick to entertain H.G. Wells during a visit to GE. 

Impressed? Here’s a tutorial on how to do it yourself, although it might take some practice to get your water at the precise correct temperature. The key idea is to bring your bottled water down to a temperature where it’s about to freeze … just not there yet. This process is called supercooling (or undecooling). At this point, homogeneous nucleation (which leads to crystallization) has not ocurred yet, and the water is an amorphous solid. To avoid homogeneous nucleation, the water must be as pure as possible.

At this point, the supercooled water is ready to freeze as soon as it touches a seed, i.e. a piece of ice, and … voila, instant ice.

 

subcooling water

 

So differences with Ice-Nine? Fortunately, there are many. For starts, the supercooled thing would need to be the large body of water we want to freeze, not the chirp of ice in our pocket. Total pureness is not likely to be a property in any body of water outside a lab too. Most important of all, supercooling works at 0ºC, not at 45.8ºC (a temperature threshold that grants that we could freeze almost all the world on a whim).

In fact, a Ice-IX does indeed exist, but has none of Vonnegut’s Ice-9 properties. The closest call would be the so called disappearing polymorphs, a type of crystals that, introduced in an environment, replace local crystals with their own form. 

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