Magic Forums

I'm a little confused. We always tell people what magical energy can't do and with good reason. You can't use magic to levitate yourself or other things, control the wind, hurt someone instantly, light something on fire, etc. Note I'm leaving out obvious physically impossible things like creating fire/lightning/ice from nothing or teleportation. According to the recent topic about glass braking during a spell though, it was suggested that a spell can in fact have enough energy to somehow break glass under certain circumstances. I don't understand how this is physically possible if some other things are not. I know of the many mundane ways glass can break, but what would allow magical energy which is a subtle energy to break glass? It just seems odd. Or is this just something that's not currently understood?