Everyone loves a good time travel fantasy, and the 1980s film Back to the Future is pretty much the cassic example of the genre. But Marty McFly stands to get some serious competition from John Cusack’s comedic crew in Hot Tub Time Machine, a new film due out in March that also stars Rob Corddry and Chevy Chase (via io9). When I first read about this project, I honestly thought it was a joke, but if the new trailer is any indication, it has all the makings of an instant classic.

Apart from the fantasy element of time travel, it’s tied to some fascinating physics; that’s why such temporal anomalies are a recurring element in science fiction. Ask a physicist, however, how well science fiction stands up to real science on the topic, and you’ll get your share of “face palm” moments. Sean at Cosmic Variance laid it all out in May with a post detailing his top ten rules for time travelers.

Granted, Hot Tub Time Machine isn’t out yet, but judging from the trailer, they’re probably going to violate Rule #3: Traveling Through Time is Like Traveling Through Space.

I’m only going to say this once: there would be no flashing lights. At least, there would only be flashing lights if you brought along some strobes, and decided to start them flashing as you traveled along your closed timelike curve. Likewise, there is no disappearance in a puff of smoke and re-appearing at some other time.

Killjoy. How can you have a hot tub time machine without including flashing lights? And everyone knows it’s way more fun to just plop our hapless buddies into their 1980s past. Comedy gold! Then there’s Rule #6: If Something Happened, It Happened.

What people want to do with time machines is to go into the past and change it. You can’t. The past already happened, and it can’t un-happen. … If you did manage to go back in time to your years in high school, something would prevent you from dissuading your younger self from doing anything other than what they actually did. Even if you tried really hard.

So the characters’ plans to make millions by re-inventing things like the iPod before Steve Jobs gets around to doing so, probably is doomed to fail. Well, what do you expect with a satirical film that didn’t even have a complete script when they started shooting? (The actors improvised a lot of their lines — pretty darned well, too, judging from the trailer.) Hot Tub Time Machine might violate Sean’s rules for time travelers, but it honors the conventions of the film genre, and it looks like it does that genre proud.