J. McClintock et al. A drop of water or prism of glass can spread out visible sunlight into a rainbow of colors . In order of increasing energy, the well known spectrum of colors in a rainbow runs red, orange, yellow, green, blue, indigo, violet. Unlike the familiar appearance of a prism's visible light rainbow , the energies here are ordered along radial lines with the highest energy x-rays near the center and lowest energies near the upper left and lower right edges of the image. The central spiky region itself is created by x-rays from the source which are not spread out by the array of gratings.
Specific rights apply .