The Physics of Gas

• A gas resists squeezing. It pushes out with pressure .
• If you squeeze a gas while not allowing any thermal energy in or out, it gets warmer as it is compressed.
  • Warmer = the molecules move faster.
  • That's why air gets warmer when it flows from a mountain top to a valley.
  • The same applies when gravity compresses a gas.
• As a gas gets warmer while not allowing any thermal energy in or out, its pressure goes up, resisting further compression.
• But if some energy gets out eventually, the gas begins to cool.
• Cooling lowers the pressure and allows more compression from the squeezing force.