What if you have a need for liquid nitrogen, but you do not wish to simply order it from a local supplier? In that case you can build your very own pulse tube cryocooler, as [Hyperspace Pirate] is ...

Nitrogen makes up about 78% of the Earth's atmosphere. Liquid nitrogen is very cold, so it is often used to freeze food. The boiling point of nitrogen is −196 °C, so liquid nitrogen is very ...