Penny has no interest
in subatomic PARTICLE research.
The Big Bang Theory Season 3, Episode 15
Senior theoretical PARTICLE physicist
at CaITech, focusing on M Theory.
The Big Bang Theory Season 3, Episode 14
A sigma PARTICLE.
The Big Bang Theory Season 1, Episode 13
inventing a new
dark matter PARTICLE
The Big Bang Theory Season 11, Episode 13
"Higgs boson PARTICLE."
How could you not get that?
The Big Bang Theory Season 3, Episode 13