As a reminder of just how shallow the NBC think tank can be, the network tonight emits "Misfits of Science," a childish, pop-comic action show, at 8 on Channel 4. The two-hour premiere episode was originally to air Sunday, Sept. 22; perhaps a good deal of fine tuning was still to be done.

Ah, but all the fine tuning in the world couldn't elevate this horseradish beyond the level of witless plop. The program seems to have been predicated on the assumption that all those lousy movies about teen-agers and their science projects last summer turned out to be huge smash hits. With few exceptions, sitting through the summer's collection of infantile fantasies was like enduring a long, long night of bad NBC.

"Misfits of Science" is yet another of those shows that, as his breathless extollers are constantly reminding us, NBC Entertainment chief Brandon Tartikoff "created" with a few scratches on a memo pad. Perhaps the old memo pad ought to be taken away from Boy Wonder before he does some real damage to the ozone layer. "Misfits" would be annoying enough as a crash-bang Saturday morning cartoon. In prime time it's a tad more inexcusable.

Dean Paul Martin, actually squeezing a dribble of charm from the role, plays a bright young scientific whiz who works at the corrupt Humanidyne Institute, where Richard Nixon's picture is still displayed proudly on the wall, and stumbles across a plot to, oh, I don't know, destroy the world or something.

He also stumbles across a variety of benign mutated oddities: a frozen man who plods about the earth searching for Amelia Earhart; a 7-foot coworker (engagingly played by Kevin Peter Hall) who can shrink himself down to Walkman size, but only for 14 minutes at a time and only once an hour (such are the pointless complications); a rock singer who once got a 20,000 volt jolt on stage and now can mete out bolts like Zeus; and a young woman (cute Courteney Cox) who is "17 years old and telekinetic as all get out."

They should all get out.

To disguise the fact that there isn't sufficient budget for wowser special effects or elaborate action scenes, and the fact that there really is no idea here in the first place, the producers keep telling the adults in the viewing audience, all three of them, that it's all a joke, a spoof, a jape; they're just kidding, just funnin', just pretending. And so on. But the wisecracks land with thuds and the joshes curdle.

Perhaps this is all meant as hommage to Brandon Tartikoff's former boss, Fred Silverman, and to the Silverman epoch of "Buck Rogers," "Sheriff Lobo" and "Project U.F.O." It is true that most TV programs are designed merely to be time killers, but shows like "Misfits of Science" don't just kill time; they bludgeon it to death.