Bentonite, the name given to a group of industrially useful clays containing the mineral montmorillonite. Bentonite clays are primarily aluminum silicates, mixed with varying amounts of sodium, calcium, or magnesium. A major use of bentonite clays is in oil-well drilling mud, a mixture of water, bentonite, and chemicals used to cool the drilling bit and carry away cuttings from the well. Certain types of bentonite expand to several times their original volume when mixed with water; they are used as sealants in dams and concrete-lined canals.
He is famous for a phrase he never said, for wearing turtlenecks and for hosting the original 'Cosmos' TV series. As enthusiastic about the stars as he was about marijuana, Carl Sagan led a very surprising life. Here are 10 cool facts.
Space collisions are the universe's car wrecks. Only in outer space, it's stars, asteroids and even galaxies doing the smashing.