There's no such thing.
Physics encompasses the entire universe.
The Big Bang Theory Season 3, Episode 10
Homespun stories,
knowledge of PHYSICS
The Big Bang Theory Season 5, Episode 5
...to succeed in theoretical PHYSICS.
The Big Bang Theory Season 2, Episode 6
...I probably would have gone
into PHYSICS or ice dancing.
The Big Bang Theory Season 3, Episode 10
Well, my work in PHYSICS,
her work in neurobiology...
The Big Bang Theory Season 4, Episode 1