Is glass a solid or a liquid?

Question

Seriously...I think window panes get larger at the bottom as they age. is the glass then "flowing" towards gravity?

Answer 1

The glass is a supercooled liquid, that's why the windows panes get larget at the botom.

Answer 2

There is no "solid" answer to this question. :-)
The simple labels solid and liquid don't work with glass.

Glass flows very very (lots of verys) slowly. The story about glass windows getting thicker is a myth, based partly on old windows which just are of uneven thickness. It has been calculated that to get a window measurably thicker at the bottom would require much more time than the universe has been around, much less the window.

Lots more about that:

http://www.cmog.org/index.asp?pageId=745

Glass has some properties of a liquid, some of a solid. There are good scientific reasons for calling it either one, although most find the solid label a better description and the liquid label a stretch. Scientists avoid this choice by using terms like "crystalline solid" and "glass" to distinguish glass from either solids or liquids.

Lots more about that:

http://www.weburbia.com/physics/glass.html

"In terms of molecular dynamics and thermodynamics it is possible to justify various different views that it is a highly viscous liquid, an amorphous solid or simply that glass is another state of matter which is neither liquid or solid. "

Answer 3

It is most certainly is a solid, since no one has been able to absolutely prove the theory that there is "flow" or "creep" in manufactured glass.

Good examples to disprove it are numerous, such as telescope glass(over a hundred years old), old stained church glass, and Roman blown glass(thousands of years old), stone-age arrowheads(made of obsidian, an naturally-occuring glass).

Most old buildings have windows that were made of liquid silica/lime, rolled into shape, then allowed to cool. These windows almost always have "flow marks" which are imperfections occuring during the manufacturing process.

You may also see this on the top of a pane, as well as the bottom, and in some cases, as with blown glass and leaded glass, in many areas of the glass.

Some people think that the reason for recaulking an old window every year is because of thickening of the window pane. But the real reason the caulk comes off is because of temperature and moisture variations on the window sash itself, and/or deterioration of the caulking material.

It is not a super-cooled liquid. A glacier is a super-cooled liquid. If a glacier is heated just above it's surface temperature, it will begin to melt and creep. Glass will not, as evidenced in our Chicago homes every summer.

Answer 4

The term for substances like glass is "amorphous solid." By most tests it acts as a solid. It has a specific volume, will hold a shape, is rigid and will shatter. However, over long periods of time it will flow like a liquid, although it flows very slowly. If you take a tour of old buildings you can see that the windows are wavy. This is because the glass is very slowly flowing out of the frame. If you were to never replace the windows in your house, in about a hundred years the same thing would happen to them.

A similar type of substance is a "non-Newtonian fluid." These have some similar properties in that if you treat them one way they will act like a solid, but if you treat them in another way, they will act like a liquid. Two examples of this are Silly Putty and oobleck.

If you stretch silly putty slowly, it will stretch into a long skinny thread. This is its more liquid behavior. If you stretch it too quickly it will cleanly break into two parts. This is its more solid behavior.

Oobleck is a mixture of cornstarch and water. It is messy, but easy to make and clean up. If you treat it violently it will act like a solid, but if you treat it more gently, it will flow like a liquid.

Answer 5

Glass is a solid. A solid is a state of matter, characterized by a definite volume and a definite shape (i.e. it resists deformation). Within a solid, atoms/molecules are relatively close together, or "rigid"; however, this does not prevent the solid from becoming deformed or compressed. In the solid phase of matter, atoms have a fixed spatial ordering; because all matter has some kinetic energy, the atoms in even the most rigid solid move slightly, but this movement is "invisible".

Answer 6

Both, glass is known as an amorphous solid meaning that the atoms are not crystalline in structure so it is not a true solid but the atoms are not freely moving about as in a liquid so it is not a true liquid, therefore glass is both known as an amorphous solid

Answer 7

there's arguments for both, as glass does get thicker at the bottom of a pane over time. i think they used to hold it was a very thick liquid, but i think now reason has triumphed and its considered a solid.

Answer 8

Glass is actually a liquid.
It flows so slowly that it may take centuries to see the difference.

Answer 9

It is a liquid that flows over time. Medieval glass is thicker at the bottom than the top. Glass has no crystals it is amorphous.

Answer 10

all matter can be solids, liquids, and gas. it depends on the temp.
glass is however, solid at room temp. it still does creep, not flow, to the nearest source of gravity until the kinetic energy is completely used up