...on its center AXIS
until the lights turn green.
The Big Bang Theory Season 8, Episode 22
...by an inclined plane
wrapped helically around an AXIS.
The Big Bang Theory Season 4, Episode 5
at which the Earth
rotates on its AXIS,
The Big Bang Theory Season 7, Episode 2
The rate of spinning
for the central AXIS centrifuge
The Big Bang Theory Season 10, Episode 20
...by an inclined plane
wrapped helically around an AXIS?
The Big Bang Theory Season 4, Episode 5