Posted on 07/22/2002 2:01:00 PM PDT by vannrox
Random Samples
In December 1932, scientists surveying the southern Egyptian desert came upon pieces of a translucent, pale yellow-green, glassy substance, from tiny fragments to football-sized chunks, scattered over a huge area at the Libyan border. Known as Libyan desert glass, this almost pure silica contained isotopes showing it to be of extraterrestrial origin. But scientists haven't been able to figure out where it came from. Now Farouk El-Baz, director of the Boston University Center for Remote Sensing, believes the mystery has been solved. This month, poring over satellite images of the Sahara Desert, he found a gigantic impact crater in the area. At a diameter of 30 kilometers, it's "the largest crater yet found in the Sahara," El-Baz says, and big enough to be the source of the glass, which covers a 60- by 100-kilometer area. He believes the crater hadn't been recognized before because it is so big; also, parts of its rims were eroded by two ancient river systems. El-Baz has named the crater, located on the Gilf Kebir plateau, the Kebira. "This is a large crater and well worth scientific investigation," says Friedrich Horz, a crater expert at the Johnson Space Center in Houston, Texas.
CREDIT: LANDSAT
I imagine you know about this recent discovery...
and this is my personal favourite - desert glass embedded with little spherules, ain't it pretty?
Thanks for the ping, I will now continue reading this fascinating post.
Libyan Desert Glass.
http://www.fjexpeditions.com/frameset/waunamus.htm
Your urban legend is about to be trumped by the Cornell Museum of Glass
No, it isn't. Nothing in your link states that glass is a liquid. It only says that it has *disordered molecules* like most liquids do, but that's not the same as saying that it *is* a liquid. Having disordered molecules is not what makes something a liquid -- having *mobile* molecules in contact with each other is.
L
Maybe they liked it because it's shiny and they found out that other primitive tribes liked shiny things as well. It could have been used in trade, like the mother of pearl that was traded by the early Native Americans.
L
The Cornell Museum of Glass provided the information that glass had some of the same attributes as liquids.
The answer provided by the University of California Riverside Physics department (interesting read) is:
There is no clear answer to the question "Is glass solid or liquid?". 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 nor solid. The difference is semantic. In terms of its material properties we can do little better. There is no clear definition of the distinction between solids and highly viscous liquids. All such phases or states of matter are idealisations of real material properties. Nevertheless, from a more common sense point of view, glass should be considered a solid since it is rigid according to every day experience. The use of the term "supercooled liquid" to describe glass still persists, but is considered by many to be an unfortunate misnomer that should be avoided. In any case, claims that glass panes in old windows have deformed due to glass flow have never been substantiated. Examples of Roman glassware and calculations based on measurements of glass visco-properties indicate that these claims cannot be true. The observed features are more easily explained as a result of the imperfect methods used to make glass window panes before the float glass process was invented.
That trumps the "urban legend" claim... as did the Cornell Museum. And that was my point. To simply dismiss a question such as this as an "urban legend" is not at all accurate.
Green glass could just be from extreme temperatures of many kinds.
A comet or meteor hitting ground might do that, right?
Oh man! Ivan Sanderson! I remember listening to him on the old Barry Farber radio show when I was a kid! Always had something interesting.
A chunk of old glass... it has been delivered to you at the closest empty lot to your house...
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IN 2101 B.C....
...WAR WAS BEGINNING.
Terrestrial Evidence of a Nuclear Catastrophe in Paleoindian Times
Mammoth Trumpet | March 2001 | Firestone/Topping
Posted on 07/24/2006 3:03:03 AM EDT by ForGod’sSake
http://www.freerepublic.com/focus/f-news/1671134/posts
The Cycle of Cosmic Catastrophes:
Flood, Fire, and Famine
in the History of Civilization
by Richard Firestone, Allen West, and Simon Warwick-Smith
ping for later read...
It is believed in some circles that Sodom and Gomorrah were destroyed by nuclear bombs. Lot’s wife turned into a certain mineral salt that is only possible due to nuclear exposure.
there was the war in the heavens... maybe these vitrified remains are the remnants of such a conflict.
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