Someone had to ask the question that threw me into infinite loops back in school: What would happen if I dug straight down, at a speed of 1 foot per second? What would kill me first?
Well not that question in particular threw me into brain disharmony, but what happens to air pressure at the center of the earth. Not just me either -- from Scientific American circa 1920:
My best guess is that enlightenment may be down the path of analyzing the forces that at on a molecule of gas at the center of the earth, then on a molecule 50 feet "up" then one 50 feet further... all the way to the surface.
But it's all too much for right now, I have a tax extension to get in the mail.
Question, what forces are acting on that envelope? The pressure question is pulling it away from the mailbox even though the question has no mass or gravity.