
You mean where they were advanced
enough to invent an INTERSTELLAR warp drive...
The Big Bang Theory Season 6, Episode 18

Or that the-- Hey, you worked
on the movie Interstellar?
The Big Bang Theory Season 12, Episode 18

...for INTERSTELLAR flight on a surfboard
when part of my brain...
The Big Bang Theory Season 3, Episode 16

So the ideal INTERSTELLAR lingua franca
would be haptic.
The Big Bang Theory Season 8, Episode 21