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

I got to experience
zero GRAVITY.
The Big Bang Theory Season 5, Episode 18

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

I really miss GRAVITY.
The Big Bang Theory Season 6, Episode 3

The idea that you might be able
to incorporate GRAVITY...
The Big Bang Theory Season 2, Episode 6