
And how you threw up
in zero GRAVITY,
The Big Bang Theory Season 7, Episode 16

...she's unjustifiably arrogant
about loop quantum GRAVITY...
The Big Bang Theory Season 2, Episode 2

It uses powerful electromagnets to create
a force strong enough to overcome GRAVITY.
The Big Bang Theory Season 6, Episode 5

GRAVITY wave discovery,
the more excited I get.
The Big Bang Theory Season 7, Episode 20

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