Steve Jones may know everything there is to know about genes - or, as he would put it, everything you can't know - but we can all take courage from the newly revealed fact that he can't ride a bicycle. Which makes you wonder if his parents could.

He was getting on a bike in order to investigate Flann O'Brien's Third Policeman for his new series Sci-Fi - Fiction Science not Science Fiction (R4). I remember reading this novel, like Jones, as a student: it's a frenetically absurd fable of crime and punishment which somehow doesn't seem quite so absurd in its rural Irish setting. But its real interest for Jones lies in a structure built on theories of time and quantum physics. Or, as it's phrased by the hero: the universe is different when seen from left or right.

O'Brien's idea was that the universe was sausage-shaped, and Jones managed to dig out a professor of physics in Birmingham who was prepared to play along. Jones also quoted from the physicist Schroedinger about undulations which sounded more like O'Brien than O'Brien himself. And then he told us that Schroedinger took refuge in Dublin and would have been walking the same Trinity quads as O'Brien.

Jones undoubtedly proved that there was a sense in this madness, but you can't help feeling that if you locked up 30 absurdists with 30 typewriters they would, sooner rather than later, tap out most of the theories of quantum mechanics.

In fact, all great thinkers teeter on the edge of the absurd, as The Dissection of Jeremy Bentham (R4) proved. Bentham's great idea was to popularise the donation of corpses to medical schools - in an age that genuinely believed in the physical resurrection of the body.

So, as well as drafting the Anatomy Act of 1832 (still in force), which allowed the unmourned poor to be put on the slab, he also insisted on being dissected himself. Except he was then reassembled. And he's still there, seated in a glass case in the foyer of University College London. Except that those jolly japesters from King's kept stealing the head and ransoming it for charity. So now the head's a waxwork and the real one's in a cardboard box in the basement, somewhat withered and, apparently, orange.

Ruth Richardson's intelligent side-light on social history told us how Bentham asked the great and the good along to attend his dissection - bring a couple of friends, the invitation read - and wrote an essay to encourage the possibility of creating one's own auto-icon (his word). He envisaged whole families becoming auto-iconised (my word) and being lined up like statues in cupboards or apartments. Tree lovers could be stood in their favourite avenue of poplars. Like I said, genius dances a constant two-step with the absurd.

But Richardson's real interest was how Bentham's seemingly enlightened law was actually a harbinger of the 1834 Poor Law, which established the workhouse and condemned the poor to fourth-class citizenship. Though Bentham did not himself advocate the subsequent exploitation of the workhouse, he does win the 1832 Michael Howard Memorial Award for suggesting that everyone should have their name and date of birth stamped (for life) on their foreheads to prevent crime. Don't even think about it.

The French astronomer Le Gentil was another obsessive scientist who took too long to discover the absurdity of it all. His determination was to chart the Transit of Venus (R3) and thus calculate the distance of the Earth from the Sun - even if it meant sailing off to Pondicherry and leaving behind the girl he loved and who loved him even more. Unfortunately, because of his friend's illness, he missed the Transit. He returned to France five years later and, as Demarais warned, was "bound to disappoint".

This was a carefully understated play by Maureen Hunter which used every one of its 90 minutes to perfection. It was repeated last week because it won Kelly Hunter a Sony Award for Best Performance as Celeste, the girl left behind. Usually it's the flashy, half-mad scientist figures (always men) who win the prizes (and have themselves stuffed in glass cases to boot). So it was good to see this award go to a performance of simple long-sufferingness, a girl who grows into a woman and makes her final decision accordingly.

Its language unequivocally evoked the late 18th century (far better than the predictable sub-RSC plumminess used for Bentham) and yet was sufficiently liberated to allow the characters' emotions to breathe and then shine through. Alison Hindell's direction encouraged the performances to combine the old and new.

That is also the Controller of Radio 4's ambition. He announced many changes to the schedule the week before last, all of them market-tested, most of them sensible, one or two of them unforgivable. And I don't mean the innovations. I mean the non-changes: what's the half-dead Letter from America still doing on air? Do we really need another episode of rural complacency each week (you work it out)? And why the hell has he reprieved Round Britain Quiz?

If the word "prissy" needs a working definition, tune in to the new series on Mondays. It's that programme where they ask prissy questions like "How did a letter complain- ing about a lack of women eventually shorten World War Two?" and "How do a golden goose and a part of Manchester's Motorway ... ?" The teams - well-read but prissy - clearly know half the answers immediately but pretend prissy ignorance in order to pad out the show: how could anyone recognise the song as being by Queen but need to ask "Is that ... [giggle-cough] ... 'Bohemian Rhapsody'?"

So I've got two questions for them. Does anyone still say "Oh Dash"? Answer: Yes, team-member Antonia Fraser. Q: Has anyone ever said: "It made me think of Melvyn Bragg, which is always a great pleasure." A: Yes, Antonia Fraser.

Please Mr Boyle, show me the focus group that got through an episode of this without begging to be auto-iconised on the spot.

Sue Gaisford returns next week.