+ Show Spoiler +
Sheldon: ... (When Penny has sex, it involves) loud and unnecessary appeals to a deity.
Penny: oh god.
It's funny that Amy on the show is set to be a neurobiologist. The actress for Amy, Mayim Bialik, actually has a PhD in neuroscience from UCLA.
Which brings to the point of Kaley Cuoco, the actress for Penny. As you may or may not have heard, she recently broke her leg during horse-back riding and had to be temperarily removed from the show. While it is certain that she will be back, it is likely that she will be with a cast on her leg for a while.... something that needs to be incoperated into the scripts of future episodes.
From the way they set up Amy, I guess the writer will just say on the next episode (or the one after this), that Penny went back to Nabraska. The episode after that one she could return, claiming that she broke her leg while doing horse-back riding.
Anyways, I can't wait for the next episode.