Physics, Astronomy & Cosmology / If you shine orange light through a prism, will it split into other colours?« on: 23/02/2009 15:08:15 »
That's technology for you. I remember being shown a hologram in 1966 and almost no one at Uni really knew how it worked. They could only make them photographically. As you say, diffraction gratings used to cost a fortune.and now they're available on ebay for a couple of pounds. Cheap enough that I can be relaxed about my kids playing about with them without worrying about them breaking them.