Hello all, I have perused this forum for a while now. I've never signed up because I have nothing to offer you folks. I'm not evan an amateur, I'm just interested in physics. I'm a critical care / flight medic, so my understanding of physics is really, really, really limited. Although, I'm highly interested and constantly read and study, and observe. Gas laws area actually something I think about on a pretty regular basis (02 / CO2 diffusion, gas expansion at altitude etc.) However, I observed something today that no amount of googling has given me the answer to. So here it goes.... I am visiting my grandmother who hoards food like no one else I know. She puts everything in the freezer, including her potato chips. In this case it is specifically Ruffles Original potato chips. She placed a NEW unopened bag in the freezer. The bag was normal volume (she lives at about 500 ft elevation) when she put the bag in the freezer. When I went to take it out today the bag looks as if you took it up to 15,000 ft. I have wracked my meager mind about what little I know of gas laws to try and figure this out, but I can't. Everything I know says that gas volume compresses at lower temperature, not expand. What's even more perplexing to me is that it's a PERMANENT change. Meaning, hours after having the unopened bag out of the freezer, it still looks like it's about to burst. I also wondered if it was something more to do with the bag, however, I don't have an unfrozen bag to compare to. I know, this is probably really elementary but I didn't know where else to turn to. Take it easy on me :) Thanks!