
I'm sorry, but you're obviously stuck
in a pre-Zero Hour DC Universe.
The Big Bang Theory Season 2, Episode 20

...that could serve as a portal
to a parallel UNIVERSE.
The Big Bang Theory Season 6, Episode 8

♪ Our whole UNIVERSE
was in a hot, dense state ♪
The Big Bang Theory Season 12, Episode 14

♪ Our whole UNIVERSE
was in a hot, dense state ♪
The Big Bang Theory Season 7, Episode 12

Is our UNIVERSE the only UNIVERSE?
The Big Bang Theory Season 4, Episode 20