is glass a liquid or a solid?

[Bally]

my dad tells me that glass is actually a liquid. is this true? thnx!

[Pavouk]

Yes glass is a liquid even at room temperatures but it is very viscous. The viscosity is how thick the liquid is. So water is not very viscous and pours easily. Oil is thicker and pours more slowly. The black tar on roads is another high viscosity liquid. In winter it feels solid but as the weather warms up it starts to become softer.

One test is how the stuff turns into a thin liquid as it is warmed. Solid ice turns directly into liquid water at a certain temperature. Tar and glass simply get softer and softer until they pour like water.

(Metals get softer as they get warmer but they are solid - soft solids but still solid - until they reach melting point and they suddenly collapse into liquid. It is the suddenness that matters.)

Glass is so viscous that it takes centuries for it to pour. They have noticed that some of the ancient stained glass windows in medieval cathedrals in England is slipping. The panes of glass are now slightly thinner at the top than the bottom.

[T-Ho]

ok... you have to understand everything on this planet can be in the state of liquid solid or gas, and its physical state depends on ambient temperature and pressure

Glass when strongly heated, melts into a liquid. When the liquid is cooled sufficiently it turns to a solid AT ROOM TEMPERATURE

so normally the glass we see is in the state of solid.

[sunshine ?]

Most glass right now is in a solid form. What's interesting about glass is that it keeps on getting harder and harder if you leave it at a specific temperature. Glass is also a liquid- it has a high viscosity. Some liquids have a very high viscosity and flow so slowly that by the time a can of liquid falls over there is time to pick it up before it spills! The ultimate example of a high viscosity liquid is glass. The viscosity of glass is so high that even though it's a liquid it looks like a solid. Believe it or not, but if you put pieces of smashed glass into a cup and left it there, and came back in a million years, you'd find the glass had flowed and taken a form like ice frozen from liquid water.