teste

The center of this figure appears unusually bright, but it’s no different than the rest of the page. Interestingly, the pupils of both primates and rats constrict when viewing the figure, evidence of similarity in perception between humans and animals.

A little boy spent his first day at school. ‘What did you learn?’ was his aunt’s question. ‘Didn’t learn nothing.’ ‘Well, what did you do?’ ‘Didn’t do nothing. There was a woman wanting to know how to spell “cat,” and I told her.’ — John Scott, The Puzzle King, 1899 The 12-year-old Winston Churchill found examinations “a great trial”: “I would have liked to have been examined in history, poetry and writing essays. … I should have liked to be asked to say what I knew. They always tried to ask what I did not know.”

This year’s GCHQ Christmas Challenge is now live. Devised by Government Communications Headquarters, the British intelligence agency, this year’s quiz presents seven puzzles for children aged 11-18. They’re designed to test a range of problem-solving skills, including creativity and intuitive reasoning. Agency director Anne Keast-Butler said: “Puzzles are at the heart of GCHQ’s work to keep the country safe from hostile states, terrorists and criminals; challenging our teams to think creatively and analytically every day.”

This lugubrious statue stands in a niche in London’s Holland Park. It’s been there since the Formal Gardens were created in 1812, but it probably dates from at least the 16th century, which would make it one of the oldest complete outdoor statues in the city. No one knows who created it or the reason for its dour expression. It’s known as the Ancient Melancholy Man. It’s featured on the cover of Van Morrison’s 1986 album No Guru, No Method, No Teacher. (Thanks, Valérie.)

Draw a circle and choose 100,000 points at random in its interior. Is it always possible to draw a line through the circle such that 50,000 points lie on each side of it?