Glass

Glass is an amorphous solid formed by cooling molten silica, usually mixed with soda ash and lime, fast enough that the atoms never settle into the ordered lattice of a crystal. The earliest known glass objects, small beads and inlays, date to around 3500 BCE in Mesopotamia and ancient Egypt, and glassblowing, invented on the Syro-Palestinian coast around the first century BCE, made hollow vessels cheap enough for ordinary households for the first time. Modern flat glass is made by the float process, patented by Alastair Pilkington in 1959, which floats molten glass on a bed of liquid tin to produce a perfectly flat sheet without grinding or polishing, and remains the standard method for window and architectural glass worldwide. Its transparency, chemical inertness and capacity to carry light with very little loss also make it the medium of optical lenses and, drawn into hair-thin strands, of the fiber-optic cable that carries most of the world long-distance data traffic.