Richard Dawkins, the evolutionary biologist and author of The God Delusion, has helped launch an atheist summer camp for children. Alongside the more traditional activities of tug-of-war, swimming and canoeing, children at the five-day camp in Somerset will learn about rational scepticism, moral philosophy, ethics and evolution.

Camp-goers aged eight to 17 will also be taught how to disprove phenomena such as crop circles and telepathy. In the Invisible Unicorn Challenge, any child who can prove that unicorns do not exist will win a £10 note - which features an image of Charles Darwin, the father of evolutionary theory - signed by Dawkins, Britain’s most prominent atheist.

The receipt lists 36 items, all of which are white, including boil-in-the-bag rice, (£1.77) and Andrex toilet roll (£1.25).

Despite the estimated £30,000 price-tag, the piece comes with a list of instructions from the artist, stating that a new receipt must be used every time it is shown.

Because she is now based in Germany, the latest shopping trip was left to exhibition curator Andrew Wilson, who was simply told to base it on the original list, now archived by the Tate.

He explained: ‘Till receipts are light-sensitive and fall apart so they have to be replaced.

‘Also it is fixed to the wall, so each time it is taken down, it is ruined.’

Finally, I said, “Excuse me,” tapped my index finger to my earlobe, pointed to their headphones, and pantomimed, “Can you turn it down, please?”

“Go sit somewhere else,” one of the boys said.

“You can hear it through the whole car,” I said. Nothing.

Normally a resolute coward when it comes to subway confrontations, I summoned my inner Howard Beale. I inched closer and began reading aloud from the newspaper. And I mean aloud.

“Voyage of a girl moored in Brooklyn,” I read. “For Berlin, a modern makeover,” I continued…

Japan panics about the rise of “grass-eating men,” who shun sex, don’t spend money, and like taking walks.