Then a laser will map
the reflective SURFACE...
The Big Bang Theory Season 6, Episode 5
or under the icy SURFACE
of Europa?
The Big Bang Theory Season 11, Episode 10
If there is life beneath
the SURFACE of these planets,
The Big Bang Theory Season 11, Episode 10
...as the SURFACE of
an n-dimensional superfluid.
The Big Bang Theory Season 8, Episode 23
that's just a doodle of
a hyperelliptic Riemann SURFACE.
The Big Bang Theory Season 7, Episode 20