: Renowned physicist Brian Greene appears as himself, giving a book reading that Sheldon and Amy attend specifically to heckle.
: After hearing a rumor from Penny that Bernadette is considering breaking up with Howard, Sheldon and Amy decide to study "memetic epidemiology". They intentionally plant two rumors to see which spreads faster: a salacious one (that they had sex) and a mundane one (that they are starting a herb garden). [S4E20] The Herb Garden Germination
In the The Big Bang Theory episode (Season 4, Episode 20), the plot centers on a social experiment conducted by Sheldon and Amy to test the speed and "virulence" of gossip within their friend group. Plot Summary : Renowned physicist Brian Greene appears as himself,
: Refers to the mundane "control" rumor Sheldon and Amy used for their social experiment. In the The Big Bang Theory episode (Season
: As expected, the "juicy" rumor spreads like wildfire through the group, while the herb garden news is completely ignored.
: Unaware of the breakup rumors, Howard plans to propose to Bernadette. While the rest of the gang expects a public rejection based on the gossip, Bernadette surprises everyone by accepting his proposal.
You can find more details or watch the episode on platforms like IMDb or Apple TV . The Herb Garden Germination | The Big Bang Theory Wiki