How to Determine if a Glass was Broken from Inside or Outside

[vabamyyr]

I saw CSI today and a glass was broken on the crime scene and furensics took one sample fracture from there and did one experiment in the laboratory also. (experimentor broke a window (glass) with baseball bat). And then they analysed those 2 fractures(one from scene and one from lab) and determined that the glass broken on the crime scene was done from the inside not from outside which would refer to burglary. But i couldn't figure out how. They talked about some Haeckel marks? and i typed it into google search and found nothing. Anyway can someone tell me the method determing whether normal window (glass) is broken from inside or outside, or is my question too confusing?

 

[faust9]

http://www.stanford.edu/~zhongj/SGKBweb/def/joiSurMor.html

http://members.aol.com/JRD203/csi-episode-010.htm

Enjoy.

 

[quetzalcoatl9]

i also have a question about glass: is it a liquid or a solid?

because i read something that claimed it is now considered a liquid with high viscosity, since old stain-glass windows appear to "run".

 

[brewnog]

The thing about glass flowing in churches is untrue. The reason that such glass is thicker at the bottom is due to the manufacturing process. This glass was generally blown, flattened, and then spun, meaning that the glass was thicker on the outside of these big discs. The glass was then cut up into sheets, and when installed, common sense led to the glass being installed with the thick (heavy!) side at the bottom.


The answer to the question "is glass liquid or solid" is not a clear one, and if you use the search facility you will see some rather long debates presenting both sides of the argument. For engineering purposes, I like to class glass as an amorphous solid, although there are arguments for it being a highly viscous liquid, and some class a "glass" as being a separate category altogether.

 

[quetzalcoatl9]

brewnog, thanks for the clarification.

i can remember when there were just 3 forms of matter, solid/liquid/gas..those days are long gone.

 

[brewnog]

brewnog, thanks for the clarification.

i can remember when there were just 3 forms of matter, solid/liquid/gas..those days are long gone.

For most practical purposes, it's still prudent to make a distinction between those three states. I'd always treat glass as a "solid" (unless it were molten :smike:)