Mysterious Fluid Appears to Freeze and Boil at the Same Time

YouTube user Tom Enstone has posted an interesting video where an unknown fluid in the process of being evacuated, or having all the air and other contents that aren’t said fluid removed, in order to then vaporize for mass spectrometry appears to alternate between solid and liquid, boiling and freezing. This is apparently due to the fluid reaching it triple point, a specific temperature and pressure that causes the substance to coexist in multiple phases like solid and liquid.