ooblick

A mixture of corn starch and water. It can behave as a liquid or solid, depending on how much force you apply. Roll it around in your hands, and it forms a ball. Let it sit, and it melts into a puddle. Great fun.

To make it, start out with some corn starch and add water little by little, stirring constantly. Stop when the water and corn starch are completely mixed, but before it's too easy to stir. Add green food coloring for the complete experience.

Ooblick (or ubleck, or any of the other myriad spellings) is not necessarily based on corn starch, though I believe it must be an organic. The point is that its state diagrams lie in such a way that it acts as a non-newtonian fluid. In its normal resting state, it is a gel suspension, which thermodynamically favors the solid suspension state, but overpoweringly kinetically favors the amorphous state. The kinetic energy of the rest state, when driven upwards by something such as being shot or hit by a hammer, will push it over the entropic energy barrier, and drive it to its ordered state. Thusly, the process is approximately...:

• Initial Impulse
• Ordered barrier diffuses pressure wave through the mass at the speed of sound in itself
• Kinetic overpressure overuns tensile strength (being a non-crystalline solid) and the mass shatters
• Shards are pulled back along the entropic curve and revert to a gel suspension, exothermically

For the purposes of armor (which is what many world military forces are using this for now) it can absorb the impact, and diffuse its kinetic energy as heat. The M1-A1 is a perfect example of this, in being able to withstand the depleted uranium rounds from an A-10 Warthog's main gun, with almost negligable damage, where most other structures would be cut in half.

one-liner wars = O = op

ooblick /oo'blik/ n.

[from the Dr. Seuss title "Bartholomew and the Oobleck"; the spelling `oobleck' is still current in the mainstream] A bizarre semi-liquid sludge made from cornstarch and water. Enjoyed among hackers who make batches during playtime at parties for its amusing and extremely non-Newtonian behavior; it pours and splatters, but resists rapid motion like a solid and will even crack when hit by a hammer. Often found near lasers.

Here is a field-tested ooblick recipe contributed by GLS:

1 cup cornstarch

1 cup baking soda

3/4 cup water

N drops of food coloring

This recipe isn't quite as non-Newtonian as a pure cornstarch ooblick, but has an appropriately slimy feel.

Some, however, insist that the notion of an ooblick recipe is far too mechanical, and that it is best to add the water in small increments so that the various mixed states the cornstarch goes through as it becomes ooblick can be grokked in fullness by many hands. For optional ingredients of this experience, see the "Ceremonial Chemicals" section of Appendix B.

--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.