Sara Gilbert with Johnny Galecki, <EM>The Big Bang Theory</EM> Sara Gilbert with Johnny Galecki, The Big Bang Theory

A few weeks ago, New York Magazine invited a panel of real-life physicists to weigh in on the CBS' The Big Bang Theory, in which Johnny Galecki and Jim Parsons portray brainiacs with a surprisingly lot to learn. The opinions were... mixed, let's say, with some of the polled beautiful minds saying the laffer was being a bit funny with the facts of their life and work. When TVGuide.com spoke to Big Bang executive producer and sitcom giant Chuck Lorre, he had not seen the piece, but was surprised to hear of any backlash. "Well, now, hang on a second," he interrupted. "We're working with a physics professor at UCLA who is the real deal. We're trying our damnedest to get the science right. Minor misses we can live with, but I tell you, it'd be fairly interesting to put our consultants up against those guys [surveyed by New York] and see what happens."

When he isn't proposing smackdowns among the superbrilliant, Lorre is singing the praises of Sara Gilbert, who in tonight's episode (airing at 8:30 pm/ET) begins a short-term stint as a female geek and potential love interest for Galecki's Leonard. "She's perfect for the role, and we were very fortunate that she was available," Lorre says. "It's a gift to be able to work with an actress of that caliber." Make that work again with, as Lorre — like Galecki — toiled on Roseanne some years ago. Lorre, though, dismisses the suggestion that as such, Gilbert guesting on the show was inevitable. "I go back with Johnny and Sara, but that really wasn't a factor as much as who was the best actress for this part, and hands down it was Sara."

Gilbert's Leslie Winkle is in fact a coworker of Leonard's. Yet as much as they have in common, the two scientists find it hard to convert their chemistry into anything combustible. "It's not their 'home run swing' to have an intimate relationship," says Lorre. "They have this inability to express their feelings, and fear may be the tantamount reason that gets in the way."

Have Big Bang Theory's fans been able to demonstrate their love for the Monday-night newcomer? Thus far, the ratings would suggest as much, significantly building on the audience of lead-in How I Met Your Mother and thus setting the table nicely for Two and a Half Men (Lorre's other laughing baby). "We have this terrific ensemble," he notes, "and we're growing as we go, and we're learning about them as we write about them. The discovery process shows a history to the characters that we're starting to peel away at."

And not just the three leads (including Kaley Cuoco as the blonde beauty who besots the boys), but their extended circle of (usually geeky) friends. Says Lorre, Simon [Helberg] and Kunal [Nayyar, as fourth bananas Wolowitz and Rajesh] are being served more in further episodes, in terms of seeing who they are and how they came to be.

The answer to that last mystery isn't simply, "Way too much Star Trek"?

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