Monday, February 7, 2011

Glass, Hypothetical Not-Quite-Helium, and Strange Physics

"Not only is the universe stranger than we imagine, it is stranger than we can imagine."
Sir Arthur Eddington English astronomer (1882 - 1944)

The Lemming's quoted Eddington before. (March 23, 2010) Strangeness isn't always something in a faraway galaxy. Sometimes it's something you look at every day. Or, in this case, look through:
"Quantum Fluctuations May Melt Ultracold Glass"
Dave Mosher, Wired Science, Wired (February 7, 2011)

"Just above absolute zero, the coldest temperature possible in the universe, quantum fluctuations can melt some forms of glass into goo.

"At the subatomic scale, particles like protons, neutrons and electrons behave like waves, not just infinitesimal points. As a result, particles have jittery positions and can “tunnel” through other particles, among their other abilities.

"At everyday temperatures and in ordinary silicate glass, those fluctuations are drowned out. But at ultracold temperatures, in simple glasses made of tiny particles — including hydrogen, helium and even electrons — the chaos of quantum fluctuations may liquefy glass.

" 'We had a pencil-and-paper result a few years ago, but we didn't believe it. It seemed like a ridiculous prediction,' said chemist David Reichman of Columbia University, co-author of a study published Jan. 9 in Nature Physics. 'But two quantum simulation experts said they could make large-scale computer simulations to verify it, and they did.'..."

There's more, including a short video clip of a simulated sample of supercooled glassy stuff - that's none-too-well edited, in the Lemming's opinion. But that's being picky.

The video shows what happens to a tiny sample of hypothetical stuff that's sort of like helium atoms, except they act like glass - sounds goofy, but the Lemming suspects that really was the best way to test this decidedly odd idea.

Anyway - at just above absolute zero, the (heliumoid?) atoms 'melt,' and at slightly warmer temperatures the quantum effects seem to strengthen the glass-like virtual substance.

That's just one more oddity in the list for glass. Back to the article:

"...Debates about the essential nature of glass have raged for a century. At room temperature, it acts like a solid. Its molecular structure, however, resembles that of a liquid, and at high temperatures it turns molten. The Nobel Prize-winning physicist Philip Anderson has described the nature of glass and its transitions as 'the deepest and most interesting unsolved problem in solid state theory.'

"There's agreement on a few crucial points, though. Glasses have no hint of a crystal structure, and their particles have no order or simple pattern. As temperatures drop, glasses become more brittle...."

So, glass is a solid at room temperatures, except it's like a liquid at the molecular level. And some physicists think it'll be easier to study glass if they take quantum effects into account. Others think that'll make things more complicated.

From the Lemming's point of view, this new speculation about glass is just one more example of how the universe is fascinating - just pick a direction to look, and how big a sample you want, and start studying what you find.

It sometimes seems there's no end to the wonder.

Sort-of-related posts:

No comments:

Unique, innovative candles

Visit us online:
Spiral Light CandleFind a Retailer
Spiral Light Candle online store

Pinterest: From the Man Behind the Lemming

Top 10 Most-Viewed Posts

Today's News! Some of it, anyway

Actually, some of yesterday's news may be here. Or maybe last week's.
The software and science stuff might still be interesting, though. Or not.
The Lemming thinks it's interesting: Your experience may vary.
("Following" list moved here, after Blogger changed formats)

Who Follows the Lemming?


Family Blogs - Blog Catalog Blog Directory