Wimbledon, 5 Live<br/>A Brief History of Mathematics, Radio 4

A demonstration of infinity on Court 18

It might seem counter-intuitive to suggest that tennis can work on the radio – especially on grass, where rallies are often blink-and-miss – but it can be gripping.

The very speed at which the commentators have to deliver can get listeners' adrenalin pumping, and last Tuesday, with Andy Murray in action against Jan Hajek, the BBC's tennis correspondent, Jonathan Overend, was showing off his full motormouth capacity at Wimbledon.

Take this, for example: "Now he's going down the line with a forehand on the other side – he gets Hajek on the run – some spectators thought the point was over – it continues – Murray with a nice-looking backhand – and a backhand, long, from Hajek!" That took six seconds. Forty words in six seconds: nearly seven words a second. You try it.

The following evening, as the light was fading on Court 18, there were rather fewer machine-gun outbursts from Overend's colleague Russell Fuller. Which might have had something to do with the fact that the players, John Isner and Nicolas Mahut, were engaged in the longest tennis match in the history of the professional game. "Will these men be presented to the Queen tomorrow?" Fuller wondered. "Will they be told to come back next Tuesday, when they've recovered?"

Despite seven hours in the commentary box, Fuller was working hard till the last – "Isner looked like he was watching a subway train flash by," he said after a Mahut ace. Meanwhile, roving reporter Helen Skelton nabbed some lads making their escape from Murray Mound. "I ran out of Pimm's, I ran out of pizza, I ran out of patience," one of them said.

She gamely persuaded them to stay, but at that point the light finally gave out. Mahut and Isner reconvened on Thursday to finish their fifth set, which Isner finally took 70-68 to end a match that ran for 11 hours and five minutes and spanned three days. Given that, in theory, a final set could go on for ever, perhaps the wonder is that it's taken as long as this for an ultra-marathon set to happen.

Georg Cantor, who changed the way we think about infinity, might have been able to enlighten us, and on Tuesday, in the seventh programme in his fantastic daily series A Brief History of Mathematics, Marcus du Sautoy boggled minds (well, boggled mine) attempting to enlighten us about Cantor's contribution to maths, philosophy and, well, the nature of everything.

The nub of Cantor's work is that there isn't only one infinity – there's an infinity of infinities. In every programme, Du Sautoy does at least one segment on location, and Tuesday's took him to a greengrocer's market stall where he demonstrated, using strawberries and kumquats, that the infinity of decimal numbers is larger than the infinity of whole numbers.

I just loved the thought of the stallholder looking on, bemused.

"Are you going to buy those kumquats, then?"