
You know how I know
we're not in the Matrix?
The Big Bang Theory Season 2, Episode 2

Multiplied by a MATRIX
of negative I comma zero...
The Big Bang Theory Season 5, Episode 7

the calculation
of nuclear MATRIX elements.
The Big Bang Theory Season 7, Episode 20

You can see the MATRIX, can't you?
The Big Bang Theory Season 1, Episode 12