Now, while that can be fun to play with, it's pretty dangerous if you are not expecting it.
That's kind of an understatement when it comes to liquid oxygen.
I look forward to seeing the equivalent of sparkfun for homebrew cryogenics.
Compress some dry air.
This will heat it up, so cool it down.
Return it to atmospheric pressure.
While expanding, it, of course, gets even colder still, and condenses. Liquid nitrogen is old tech, older than you might think.This could come in handy for the insane overclocking crowd and the arguably insaner DIYBio crowd. The advantages of being able to store cell/other cultures in LN should not be underestimated. Countdown to Homeland Security/FBI overreaction in 3, 2...