system
Given the following post, respond as if you're commenting on Reddit:
human
Why does glass break in the pattern that it does?

For example: My windshield got hit with hail, beside where the hail hit at the bottom, one crack went directly up until halfway and then a 35 degree angle across most the windshield. Why didn't the crack continue straight up from the halfway mark, is it because weaknesses in the glass?
gpt
Glass is amorphous, meaning it's molecular structure is more or less randomized. Because of this randomness a crack in glass generally just goes through the path of least resistance. 

If it were crystalline, meaning it's molecules are packed into repeating, ordered shapes called unit cells, it would fracture in a more normal, predictable way (like table salt always being tiny cubes - it's because of their molecular structure).