Real and unreal get thrown around a lot, in pop culture and also in science. Most of us first encountered these notions in high school math when forced to learn about imaginary numbers. In real life, there’s no such thing as the square root of -1. But engineers use v-1 for actual applications like circuit design and fluid dynamics. Does that make it sort of real?
Bob Berman’s Strange Universe: Facing reality
July 2009: What's real becomes blurry when scientists question familiar concepts.