Students at Manchester University undertook an experiment to determine the identity of a fluid in a container through the use of a mass spectrometer*. When vaporising the liquid using a vacuum pump, the students managed to find its “triple point”, which is when a pressure change causes a substance to exist as a solid, liquid and gas all at the same time. (The liquid, according to the students, was cyclohexane.)

*A mass spectrometer is a scientific instrument that can measure the masses and concentrations of atoms and molecules. It uses magnetic force on a moving charged particle. Credit: Youtube/Tom Enstone