4: - The four elements of alchemy are earth, water, air and fire. - In Buddhism there are Four Foundations of Mindfulness – contemplation of the body, contemplation of feelings, contemplation of mind, contemplation of mental objects. - In Judeo-Christian symbolism the Tetragrammaton is the four-letter name of God. - In Islam the Four Arch Angels are: Jibraeel (Gabriel), Mikaeel (Michael), Izraeel (Azrael), and Israfil (Raphael) - The Chinese, Vietnamese, the Korean and the Japanese are superstitious about the number four because it is a homonym for "Death" in their languages - There are four basic states of matter: solid, liquid, gas, and plasma. - The four color process (CMYK) is used for printing. - In Astrology, Cancer is the 4th astrological sign of the Zodiac. - In Tetris, a game named for the Greek word for 4, every shape in the game is formed of 4 blocks each. - 4 is one of The Numbers – 4, 8, 15, 16, 23, and 42 – featured in Lost.