These little doodads were invented by Rupert, Count Palatine of the Rhine, Duke of Bavaria. With a rich and varied career as a soldier and a scientist, the glass drops that share his name were but one of his many achievements.
Tempered glass also shares some of the vulnerabilities of the Ruperts drops.
In brief, the tempered glass in the window is just like the glass in a Prince Rupert's Drop, the center is under tension and the outside is under compression. When you impact the glass with a sharp point, like that of a porcelain shard, it nicks the glass. Stresses in the local area pull or push on that nick, and cracks can now propagate from that area, spiderwebbing accross the entire pane of glass. The front windscreen of a car is laminated to prevent this.
(It should be noted that I copy/pasted the above explanation from a Metafilter thread. I is not that smarts.)
-
0 remarks:
Post a Comment