Year of Invention: 100 B.C.
What Is It? A transparent, rigid liquid made by fusing (with heat) sand, soda
ash, and lime combined with a variety of trace components.
Who Invented It? Syrian glassmakers (in Syria)
Windows, windshields, eyeglasses, magnifying glasses, mirrors, and lenses for telescopes, microscopes, and periscopes are all made of glass. So are the glasses we drink from and the beakers and other lab-ware scientists use to conduct laboratory experiments. We have designed houses, schools, and offices around glass.
Glass is one of the truly unique substances on Earth. Glass is technically a liquid because its molecules don’t align into regular patterns, as do the molecules of all solids. Glass flows—albeit very slowly—so that every window eventually grows thicker at the bottom than at the top. Glass is the only liquid that can cut you. It is the only liquid that can break.
Glass occurs naturally. Obsidian is black glass created in the fiery heat of a volcano. When lightning strikes sand it can fuse silica sand into flowing sculptures of glass. Roman historian Pliny reported that Phoenician sailors accidentally discovered the formula for making glass around 3500 B.C. While boiling fish stews on the beach, they balanced cook pots over the fire on blocks of saltpeter because the beach had no suitable rocks. After the embers died, those sailors discovered that the saltpeter and sand had fused into lumpy rings of crude glass.
Buildings had few windows. Light streamed inside when doors were left open. Those windows that existed were simply small open spaces in a wall that were often covered with a blanket to block out the cold and rain.