I saw a car commercial last night where they showed slo-mo of a bullet entering a bottle through the open neck, then utterly shattering the bottle when it hits the bottom.
OTOH I’ve seen clean bullet holes in glass windows.
What are the differences in glass that cause one type of glass to shatter, and other types to be left with a clean hole?
If you are talking about car windows, especially the front and back windshields, they have a plastic layer in the middle that binds the class together and prevents it from shattering. I suspect that energy efficient windows for houses have something similar. They aren’t all glass. They are layers of glass bound together to prevent shattering.
A lot of it has to do with the distribution of stresses in the glass, which are set up as it cools and solidifies (yes, into a solid). A bottle has corners, bumps and different thicknesses in different places, so the stresses will distribute themselves differently than in a flat, uniform pane (also, there are probably lots of differences in the production process - annealing and stuff)
Also… a bullet entering a bottle through the neck will be creating a pressure wave into the closed space, which means the forces exerted on the glass surfaces aren’t the same as they would be for a bullet hitting a window.
Plus there are probably just differences in the material properties - bottles are generally exposed to a different set of conditions from windows, so the glass used for either is probably tailored to suit the purpose.
There is a special bottle made to demonstrate the importance of stresses. Its exterior is in compression and its interior is in tension. You can use it to pound a nail, but dropping a grain of a sharp and hard mineral into the bottle makes it shatter immediately.
I thought the name of this was “Prince Rupert’s Bottle”, but didn’t get any hits in a web search, so likely this name is incorrect.
and another:
A similar effect is show with a"Devil’s Bottle"