Capt. Ally Bergman, 47th Operations Support Squadron the aerospace physiology flight commander, gives a lecture about air pressure to a class on Nov. 23, 2020, Laughlin Air Force Base, Texas, for their flight certification. She’s discussing Boyle’s law: a relation concerning the compression and expansion of a gas at constant temperature. (U.S. Air Force photo by Airman 1st Class David Phaff)