What is the X in X-mas?
"to seek for hollows underground by ramming the ground and observing the vibrations," 1929, ultimately from Scottish word boss "hollow, empty" (1510s), earlier a noun meaning "small cask, wine flask" (late 14c.).
Indian physicist who derived the quantum statistics of photons by assuming that photons with the same energy were indistinguishable particles. His idea inspired Albert Einstein to apply the same concept to other particles, including atoms, predicting the possibility of Bose-Einstein condensates. Particles behaving in accordance with Bose's statistics are today called bosons.