The women take center stage in tonight’s Big Bang Theory, which pivots on two major plots. In one, the reboot of the Professor Proton TV show extends an invitation for a guest appearance – but not by long-time show admirer Sheldon, but by Amy. And in the other plot, Leonard writes a novel with a character who seems a lot like Penny, and that character isn’t exactly to Penny’s liking. Speaking of characters: the women on Big Bang, like the men, have evolved very significantly, and very humorously, since their initial introductions.