2001:A Space Odyssey
From The Big Bang Theory Wiki
"2001:A Space Odyssey" is a classic science fiction movie directed by Stanley Kubrick.
One of the most famous themes from the soundtrack is the opening sequence ("Sunrise") from "Also sprach Zarathustra" (German for "Thus Spake Zarathustra") by composer Richard Strauss.
The beginning of this theme is heard in the opening scene of "The Cooper-Hofstadter Polarization".
