
my original theory that space time
was like a super-cooled LIQUID,
The Big Bang Theory Season 9, Episode 18

I'm not seeing anyone
using LIQUID helium vortices like this.
The Big Bang Theory Season 9, Episode 16

How about a LIQUID cooler?
A little aquarium pump here.
The Big Bang Theory Season 1, Episode 2

Floating in a warm pool
of LIQUID
The Big Bang Theory Season 12, Episode 19

Careful, Leonard. Liquid nitrogen,
320 degrees below zero.
The Big Bang Theory Season 1, Episode 5