Writer, broadcaster and National Treasure™ Stephen Fry has struck again. The ubiquitous luvvie revealed the depths of his technical understanding on the the panel show QI XL, the self-styled “home of highbrow know-how”.

First, GPS. How does that work, Stephen?

“You send a signal from your GPS device,” he explained. “You’ve got to be at least three, usually four or five satellites – that receive your signal. And the difference in time it takes to get from one satellite to the other to the other, which is milliseconds, allows them to calculate your position to within 10 metres.”

That’s amazing.

Warming to his theme – assuming the theme was talking utter tripe – the former Guardian technology columnist then had a crack at explaining TCP/IP.

“Any email or transaction on the internet uses what’s called packet-switching, which means the information is broken up into packets, and reassembled on the other side,” he said.

“But each side has to be exactly synchronised, otherwise the message is nonsense. So the caesium atomic clocks are necessary to make all this technology work.”

There you go. The interwebs would fall apart without atomic clocks.

An Apple user, Fry has cruelly been described as “a stupid person’s idea of a clever person” – but he has carved out a niche as an in-demand technology expert and pundit. The BBC hired him to sing the praises of DAB, and Sky enlisted him to explain 3D TV, so who are we to argue? But the depth of his understanding revealed by the ad-libbing suggests that to Fry, perhaps everything is just a voiceover script.

You can find the QI clip on iPlayer here [UK readers only], around the 14:45 mark.

Thanks to stalwart Reg reader Eponymous Cowherd for the tip. ®

Andrew warmly welcomes your explanations of how things work (Fry-style).