🪞Read more of Quanta’s archival coverage on glass and mirrors: www.quantamagazine.org?s=glass

11/11

In recent years, LIGO’s researchers have made advancements towards a more precise instrument by switching to new, more stable glass mirrors. LIGO is now sensitive enough to detect one black hole merger about every three days.

10/11

The Laser Interferometer Gravitational-Wave Observatory (LIGO) bounces lasers between a system of mirrors to detect gravitational waves. The machine’s extreme sensitivity is limited by those tiny atomic motions in the mirrors’ surface.

9/11

While still imperfect, ancient glass like this 110 million year old piece of amber is helping scientists understand how atoms in glass stabilize over time.

8/11

Is it possible to perfectly stabilize glass? “Ideal glass” is a hypothetical phase of matter that packs atoms together in the densest possible arrangement. Inconveniently, it would take so long to form that it may not have done so in all of cosmic history.

7/11

But a strange form of noise is baked into glass’s molecular structure. Small clusters of atoms constantly switch back and forth between two different configurations, shifting by as much as an atom’s width.

6/11

At the molecular level, glass looks like a liquid in suspended animation, with molecules that curiously cannot flow.

5/11

When glass cools, its disordered molecules contract slightly, crowding closer together, which makes the substance increasingly viscous. Eventually, the molecules stop reorganizing.

4/11

When you cool a liquid, it will either crystallize or harden into glass. Which of the two happens depends on the substance and on the subtleties of the process, as glassblowers have learned through trial and error over thousands of years.

3/11

Windows, mirrors, plastic, and even hard candy are technically glass materials, because glass is anything that’s solid and rigid despite being made of disordered molecules like those in a liquid.

2/11