Heavy Bubble: this vial contains xenon gas and liquid alcohol at very high pressure (approximately 65 atm) and hence encased in resin for safety. At this extreme pressure the xenon gas becomes more dense than liquid alcohol! The Xe bubble sinks to the bottom in the liquid. In this pressure regime Xe is near a supercritical fluid in its phase diagram, very compressible like a gas, but dense like a liquid. Until I saw this demonstration I did not know it was possible to make a high density bubble