What color are radio waves or x-rays anyway? With computers, astronomers can make them any color they want, and even liven up images at just one radio wavelength or photon energy making the different brightness levels different colors. Without doing this, astronomers would not be able to show us how things "look" outside the narrow visible spectral range. These artificial colors are called "false colors" and are used in a lot of the images we show in this course.

cartoon, scientists looking at picture, "Of course these are false colors. The reds are really greens, the greens are reds, the blues are oranges, and tyhe oranges are blues." other scientist: "Makes sense."(From Sidney Harris)