Ceramic armor development against shaped charges

The shaped charge is basically a liquid metal jet of copper that eats right through the steel at near the speed of sound. If you put ceramic in there, the copper doesn't react with the ceramic, and so it doesn't destroy it. Now there's all kinds of different armors — it's proliferating, it's gotten very complex, and they're using supercomputers to model these things. One of the things they developed: depleted uranium, basically a half-inch diameter rod 36 inches long, fired at a target. When it hit the armor, the stresses in it would get to 300, 400 thousand psi, and most materials would fracture.