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's ventured to the abyss of black holes, wagered on the information paradox and floated around in zero gravity. Meet the man, the legend, the super scientist: Stephen Hawking.
So much about galaxies remains a mystery. We know what they're made of and that we live in one (the Milky Way), but we're not sure how they form and evolve.