The order in which colors are named worldwide appears to be due to how eyes work. Researchers have found that colors familiar to one culture might not even have names in another, suggesting that different cultures indeed have different ways of seeing--and understanding--the world.
Color names always seem to appear in a specific order of importance across cultures: black, white, red, green, yellow and blue. In LiveScience, Charles Choi quotes physicist Francesca Tria as saying, "If a population has a name for red, it also has a name for black and for white--or, if it has a name for green, it also has a name for red." But if a population has a name for black and white, that doesn't necessarily mean they have a name for red.
Confused? You need to find the colors you like in smart paint! Engineers have long dreamed of a paint that could FIND and REPAIR cracks and other damage to bridges and wind turbines. Well, that future is here.
It's made up of the old fashioned mixed with the modern: fly-ash (a fine-grained waste product from coal-fired power plants) and carbon nanotubes (cylindrical molecules made of elemental carbon). The material like cement in texture--in fact, it's so cheap that whole structures could be built using it instead of cement.
When it dries, the fly-ash acts as a coating (like paint), able to withstand the elements in places where it's exposed, while the carbon nanotubes conduct electricity.
The tubes' conductivity is affected by cracks in, or corrosion of, the painted surface. When they're under stress, the nanotubes bend and become less conductive. If they detect chloride ions, (the result of corrosion by salt water), their conductivity increases, making it possible to determine WHAT KIND OF damage is there.