John Derbyshire, contrarian that he is, didn’t like Spiderman II.

Even comic-book movies must obey certain unities. In the realm of science fiction — and c/b movies are a species, even if a low one, of science fiction — the golden rule is: You can have one highly implausible bit of science. The rest of the science should be sound, or at least should follow logically from the central implausibility. THE TIME MACHINE is a great sci-fi novel because, once you have granted the central, fairly preposterous, premise that time travel is possible, everything else is just basic Darwinism and stellar evolution, as it was understood at the time.

The central notion in SPIDERMAN is that if you get bitten by a spider whose genes have been messed about with in a certain way, you will develop the ability to shoot 100-ft silk threads from your wrists (without, apparently, any loss of body mass). This is preposterous — though not at a sensationally high level, as spider genes can be messed around with in an infinity of ways, and we don’t actually know what would happen if you were bitten by a spider whose genes had been messed around with in way No. 29,485,672.

Having been persuaded to suspend our disbelief with respect to Spidey’s powers, we should not then be asked to swallow any more preposterosities. And we know perfectly well what whould happen if you dumped a fusion reaction into the East River — ka-BOOM.

I haven’t seen the movie yet, but I intend to, and won’t let this curmudgeonly review put me off of it, though I actually agree with the principle. That was one of the things that bothered me about the first movie. Once you tell me he’s been bitten by a radioactive spider, then fine, I’ll buy the superpowers on the part of Spidey. I’ll even accept the notion that, as Derbyshire points out, he doesn’t have to conserve mass.

But Mary Jane has no superpowers, yet she performs a superfeat near the end of the movie, when she falls off the cable that’s being flung around (face it, she wouldn’t have been able to hang on to it that long without her arms being torn off), and then catches the side of the cable car as she falls some distance toward it.

Sorry, just Not.Gonna.Happen. It defies physics and the strength, both muscular and structural, of a normal human body, even one pumped on adrenalin. I enjoyed the movie up to that point, but that bit really bugged me, because there was no good reason for it–it could have been just as exciting while being realistic.

And of course, there’s the other thing that bothered me about the movie–the ending.

Parker was under no obligation to keep Harry in the dark about his father’s end. Just because he was requested to, he didn’t agree to the request, and he did himself and Harry a disservice by allowing Harry to continue to live on in a fantasy world about his father’s true nature, a world that’s likely to cause him to attempt to kill Parker’s alter ego (and hence Parker) in the future.

At a minimum, he should have at least pointed out to Harry that the fact that Spiderman returned his father’s body to his home didn’t mean that Spiderman was the killer. He might not have accepted it, but there would have been no harm in exercising a little logic on him, even if he wanted to spare him the knowledge that his father was a murderer (though again, I think that was no favor).

Also, he’s not protecting MJ by not reciprocating her love. The key is to keep his identity a secret (though not from her). I found it highly unsatisfactory, but apparently it was more important to them to set up some dubious sequel plot than to employ logic, or ethics.

I guess that SF movies will never get made right until they hire me as a script advisor. And listen.

[Update on Tuesday]

For those endlessly or otherwise fascinated by bad movie physics, check out this site (including a review of Spidey I). It says The Core (which I haven’t seen, and probably won’t) takes the prize for the worst movie ever in this regard.