"From there, we decided to conduct an experiment to demonstrate the shadow of a laser beam." To do this, the researchers directed a high-power green laser through a cube made of standard ruby ...

In the illustration: A tesseract (a four-dimensional cube) and the "shadow" it casts on a plane—the quasicrystal discovered by Shechtman. According to Prof. Bartal, "The fact that a quasicrystal ...