Feeling sorry for Raj, Penny sets him up on a date with a deaf girl, for whom his lack of ability to speak to women isn't really a hindrance. As the relationship progresses, though, the group becomes concerned that she may be interested in Raj's family money than in the astrophysicist himself.
In another plotline, Sheldon decides to stop making any trivial decisions, but instead to let a roll of the dice make all of his decisions for him.
This Episode's Science
Double Blind Study - Drug trials, such as the ones conducted by Bernadette, are typically handled in the format of a double blind study. In such a study, there are two groups: one that receives a given treatment and one which receives a placebo, but neither the participants in the study nor the doctors themselves know which person is in what group. The reason for this sort of study is to make sure that all participants are treated identically, so that no bias will slip into the results (either intentionally or unintentionally). By learning that someone is in the placebo group, Bernadette has actually committed a violation of research ethics.
Higgs Boson - While discussing the work he's been able to accomplish since freeing his mind of the decision-making burdens in his life, Sheldon mentions that he's on his way to figuring out why the Large Hadron Collider has yet to isolate the Higgs Boson. The Higgs Boson is the last missing piece of the Standard Model of Particle Physics. Many scientists hope that it will be discovered by the Large Hadron Collider in the near future.
Penny: [speaking of Raj] Poor guy. He's so lonely. We should set him up with someone.
Bernadette: I met a really cute girl at work. She's married to a guy in one of our drug trials.
Penny: Hello, she's married.
Bernadette: Yeah, but her husband is in serious congestive heart failure and a little birdie told me he's in the placebo group.
Penny: Okay. So future grief-stricken widow is the one to beat.
Penny: Mustache is looking good there, Sheldon.
Sheldon: Don't thank me. Thank the dice. They told me what percentage of my face to shave.
Howard: Why are you still doing this?
Sheldon: Because it's working. In the past few weeks, unburdened by trivial decisions, I've co-authored two papers in notable peer-reviewed journals and I'm close to figuring out why the Large Hadron Collider has yet to isolate the Higgs Boson.
Leonard: You left out: got chafed testicles because you no longer wear underpants.
Sheldon: The dice giveth and the dice taketh away.