COMEDY / Positions on the slide rule: Or is it? Mark Wareham on Ben Moor and Jim Davidson's Sinderella

It had to happen. First came the Chaos Theory and the sexing-up of maths, then Stephen Hawking made black holes accessible to the great open- mouthed, and now, in National Science Week, the Irrational Geographic Society brings you Ben Moor, the world's only comic scientist (pace Magnus Pyke).

Moor's one-man show, It Takes Forever If You Go By Inertia, was a relative success in the context of last year's Edinburgh Fringe but, with its tight script and breakneck delivery, would be more at ease on the airwaves. His physical presence is humorous enough (the lovechild of Emo Philips and Mr Bean, though he would rather it were by Shaggy out of Thelma from Scooby Doo), but his flying elbows and geeky body distract from the density of the writing.

The show is riddled with the most appalling boffin gags (what are the Fanatical Sicilian Arithmetical Gangsters if they're not the Mathia?), but it wins you over in the last quarter as the most implausibly woven plot comes together. Any performer who can wrap a one-hour trip to the ninth circle of hell and back around the lyrics to 'Bohemian Rhapsody', suspend the punchline to a light-bulb joke in a parallel universe for half an hour, crack Nietzsche gags and still get a laugh deserves an immediate run at the Cambridge Theatre in London's West End.

Why? Because that's where Jim Davidson is currently occupying valuable stage space with his adult panto Sinderella. Davidson may be far more familiar with Nietzsche than you'd care to imagine, but let's not ruin the constructed image. Where he scores over someone like Ben Moor is in the marketing department. Moor was probably dead chuffed with his 50-odd punters, but until he learns that the male sexual organ is funnier than Pythagoras, we'll be stuck in a Jim Davidson continuum.

Sun man personified, old Nick Nick could not have produced a more down-market production had a think-tank from Big Break pooled their collective talents.

Ben Elton claims to be able to crow-bar a knob gag into any comic situation, but Davidson dispenses with the gag and concentrates largely on the knob. Look, boys and girls, here comes Prince Charming and is he pleased to see us? I don't think that's a pistol in his pocket. Oh and there's the pantomime horse, tripping over his fifth leg.

Occasionally, there is the odd flicker of cerebral activity. Hitting on the idea of a Fairy Godmother with wind presumably didn't occupy too much of the eight years that Davidson has been workshopping the show; but giving her a jet pack to lift her off-stage mid-fart did at least register a brief reversal in the downward trend of the show's creative juices.

Davidson, the show's creator, showed an admirable respect for tradition. It is stated in panto lore that your players must have at some stage, though preferably in the Seventies, made an appearance on The Des O'Connor Show. This was magnificently upheld. A cringeing cast included Jess Conrad, a split-second Sixties heart-throb, Diane Lee, one half of forgotten duo Peters & Lee, and Charlie Drake as Baron Hard-On.

Coasting serenely through this pre-kindergarten titter- land was Davidson himself. Not once, to his eternal credit, did he look embarrassed, not even when a fish-bearing Drake conducted the audience in a chorus of 'What wonderful fish are soles, are soles.'

It's humour Jim, but not as we know it.

'It Takes Forever If You Go By Inertia', BAC to 27 Mar (071- 223 6557); 'Sinderella' continues at the Cambridge (071-379 5299)

(Photograph omitted)