system
Given the following post, respond as if you're commenting on Reddit:
human
If you drop your a phone or something else with a glass screen and the screen doesn't crack, does it have a higher chance of shattering the next time you drop it?

If you drop glass and it doesn't crack, are there invisible changes to the glass that make it weaker?
gpt
TL;DR: Yes.

Materials Engineer here...Your brand new phone screen has billions of cracks in it.  They're just really really really small.  Now, anytime you do something to the phone (drop it, sit on it, bump your keys against it, whatever) you're putting stress on those cracks.  

If the stress is over a certain threshold, it can cause the crack to grow.  The longer the crack, the less stress needed for it to grow.  So every time you drop your phone, you're effectively lowering what's called the critical stress - the amount of force it can take before catastrophic failure - aka a shattered screen.