
Ah, GRAVITY--
thou art a heartless bitch.
The Big Bang Theory Season 12, Episode 24

- I wonder what he's doing this very second.
- Conducting experiments in zero GRAVITY.
The Big Bang Theory Season 6, Episode 1

No, there isn't. Only loop quantum GRAVITY
calculates the entropy of black holes.
The Big Bang Theory Season 2, Episode 2

And, of course, it's Gravity Probe B.
The Big Bang Theory Season 1, Episode 13

...for this university's
six-loop quantum GRAVITY calculations.
The Big Bang Theory Season 6, Episode 9