glass melts at absolute zero

[melter skelter]

crazy talk...

http://www.newscientist.com/blogs/sh...lute-zero.html

[Greymatter Glass]

beat ya to it :P

http://www.talkglass.com/forum/showthread.php?t=36823

At Absolute Zero, in theory, all quantum movement ceases. NOTHING happens at absolute zero.

Slightly above absolute zero, glass destabilizes and starts to move around as a liquid.

[Kevin Bumble]

leave it to doug....
























NERD!!!!! wait do you guys get the same mail? source?....


and how come i'm out of the loop?

[l33t:weasel]

liquid helium is the closest we get to absolute zero and it don't melt glass.
so them partikal phyzicists can say what they like but ain't nobody getting glass cold enough to melt.

[Dazza]

The first thing to happen is always a crazy idea.
Then the solution appears next.
Just cause it aint been done yet don't mean it wont ever happen.

[Uriel]

Glass isnt ever sollid anyway.. so @ almost absolute zero its more liquid than @ room temperature or 500c.

[Bo Diddles]

^ Where did you get that from? Your ass?

[Greymatter Glass]

Uriel, despite what some kids shows and old wives tales would have you believe, glass is solid at STP (Standard Temperature and Pressure, similar to room temp on a nice day near a beach)

Science/physics defines a point at which something goes from being liquid to solid, called the solidus, and glass passes that point around its lower strain point.

As a solid it is an amorphous crystalline solid. Glass is virtually unique in that it has no rigid molecular structure, but that doesn't mean it's a liquid. Concrete has a similar property, but it too is solid.


the stuff mentioned above about absolute zero is all theoretical, done in computers and on paper... with our current understanding of physics and limits of technology we cannot conduct an experiment to prove or disprove the theory - but math is pretty solid.

Check out the KOBE experiment for proof that math works.

[akmewon]

Uriel, despite what some kids shows and old wives tales would have you believe, glass is solid at STP (Standard Temperature and Pressure, similar to room temp on a nice day near a beach)

Science/physics defines a point at which something goes from being liquid to solid, called the solidus, and glass passes that point around its lower strain point.

As a solid it is an amorphous crystalline solid. Glass is virtually unique in that it has no rigid molecular structure, but that doesn't mean it's a liquid. Concrete has a similar property, but it too is solid.


the stuff mentioned above about absolute zero is all theoretical, done in computers and on paper... with our current understanding of physics and limits of technology we cannot conduct an experiment to prove or disprove the theory - but math is pretty solid.


Check out the KOBE experiment for proof that math works.

i was under the impression that glass was a liquid too .just cause in old houses the windows get thicker at the bottom over hella years..but i sure as hell can be wrong but how else would they get thicker other than flowing downward....

[Greymatter Glass]

i was under the impression that glass was a liquid too .just cause in old houses the windows get thicker at the bottom over hella years..but i sure as hell can be wrong but how else would they get thicker other than flowing downward....

ugh. no. Old style glass was blown and cut open and flattened. The panes would start off as uneven thickness. it was common practice to put the thicker side near the bottom, but not always.

The math behind glass flowing at room temperature says it would take hundreds of billions, with a B, of years at room temperature for glass to move enough to be detectable, let alone obviously visible. FWIW, stone moves faster than that.

[Alfred]

http://www.nytimes.com/2008/07/29/sc...ewanted=1&_r=1 Stole this link from one of Doug's posts he linked to above.

[gotglass?]

i've replaced Window panes in a 1700's stone house and the thickness issues were not from manufacture.... where the glass was held in place by the mullions on the window, the glass stayed original thickness. at the bottom of the pane it pooled along the inner edge of the mullion. this wasn't apparent until i removed the mullion to replace a broken pane. i wish i had saved a piece as evidence to this question...

[hashmasta-kut]

yeah i just read somewhere recently that they put them thick edge down. you sure it wasnt a thick edge?

[Alfred]

i've replaced Window panes in a 1700's stone house and the thickness issues were not from manufacture.... where the glass was held in place by the mullions on the window, the glass stayed original thickness. at the bottom of the pane it pooled along the inner edge of the mullion. this wasn't apparent until i removed the mullion to replace a broken pane. i wish i had saved a piece as evidence to this question...

Behavior of antique glass

The observation that old windows are sometimes found to be thicker at the bottom than at the top is often offered as supporting evidence for the view that glass flows over a timescale of centuries. The assumption being that the glass was once uniform, but has flowed to its new shape, which is a property of liquid.[36] However, this assumption is incorrect; glass does not flow. The reason for the observation is that in the past, when panes of glass were commonly made by glassblowers, the technique used was to spin molten glass so as to create a round, mostly flat and even plate (the crown glass process, described above). This plate was then cut to fit a window. The pieces were not, however, absolutely flat; the edges of the disk became thicker as the glass spun. When installed in a window frame, the glass would be placed thicker side down both for the sake of stability and to prevent water accumulating in the lead cames at the bottom of the window.[37] Occasionally such glass has been found thinner side down or thicker on either side of the window's edge, the result of carelessness during installation.[38]

Mass production of glass window panes in the early twentieth century caused a similar effect. In glass factories, molten glass was poured onto a large cooling table and allowed to spread. The resulting glass is thicker at the location of the pour, located at the center of the large sheet. These sheets were cut into smaller window panes with nonuniform thickness, typically with the location of the pour centred in one of the panes (known as "bull's-eyes") for decorative effect. Modern glass intended for windows is produced as float glass and is very uniform in thickness.

Several other points can be considered which contradict the "cathedral glass flow" theory:

* Writing in the American Journal of Physics, physicist Edgar D. Zanotto states "...the predicted relaxation time for GeO2 at room temperature is 10^32 *years. Hence, the relaxation period (characteristic flow time) of cathedral glasses would be even longer."[39] (10^32*years is many times longer than the estimated age of the Universe.)
* If medieval glass has flowed perceptibly, then ancient Roman and Egyptian objects should have flowed proportionately more — but this is not observed. Similarly, prehistoric obsidian blades should have lost their edge; this is not observed either (although obsidian may have a different viscosity from window glass).[30]
* If glass flows at a rate that allows changes to be seen with the naked eye after centuries, then the effect should be noticeable in antique telescopes. Any slight deformation in the antique telescopic lenses would lead to a dramatic decrease in optical performance, a phenomenon that is not observed.[30]
* There are many examples of centuries-old glass shelving which has not bent, even though it is under much higher stress from gravitational loads than vertical window glass.

*This forum does not recognize scientific notation,10^32 years =1,000,000,000,000,000,000,000,000,000,000,000yrs

It is well known that panes of stained glass in old European churches are thicker at the bottom because glass is a slow-moving liquid that flows downward over centuries.Well known, but wrong. Medieval stained glass makers were simply unable to make perfectly flat panes, and the windows were just as unevenly thick when new.

If you want to see glass flow at room temperature, you have to wait at least 10,000 million million million times the age of the universe! It's enough to make your eyes glaze over.

I could go on,and on, but you can do further research yourself by examining the citations in the links already provided (the quotes are click-able links to their sources).

[Pogo]

Doug, i could hump your big beautiful brain.

Great references, Alfred.

[senz1]

yeh man glass is fluid always ! old glass is always thicker at da bottom ! dont u guys know ? its fact! if u hold glass for 30 years in your hand it will leave an imprint ! FACT ! look it it up! u ever heard of google? u also probably think we have climate change!! wow.. sorry had to comment to the nay sayers..http://www.youtube.com/watch?v=nBOJj...eature=related

[Shiny]

ugh. no. Old style glass was blown and cut open and flattened. The panes would start off as uneven thickness. it was common practice to put the thicker side near the bottom, but not always.

The math behind glass flowing at room temperature says it would take hundreds of billions, with a B, of years at room temperature for glass to move enough to be detectable, let alone obviously visible. FWIW, stone moves faster than that.

^^
I like this guy. Good info. No references, though. Tisk.