Home › Forums › setting the stage › solids as quantum systems › Definition of a Solid This topic has 0 replies, 1 voice, and was last updated 1 week, 4 days ago by Jesse. Viewing 1 post (of 1 total) Author Posts July 21, 2025 at 8:48 pm #12713 JesseParticipant I think of a solid as a state of matter. Unlike gas and liquid, a solid must be able to go back to exactly the same formation of atoms as it was a second ago. The orientation of the matter seems like the most defining factor. Author Posts Viewing 1 post (of 1 total) You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In