In this Oxford Mathematics Public Lecture, Ofra and Alexander consider a simple but intriguing mathematical argument, which purports to show how infinitely many clowns appear to have some surprising powers. They'll discuss what conclusions philosophers can and cannot draw from this case, and connect the discussion to a number of key philosophical issues such as the problem of free will and the Grandfather Paradox for time travel.

When Paul McCartney released his first post-Beatles solo album it didn't do well, at least with the critics. Compared to his radical bandmate John Lennon, he just seemed twee and lo-fi.

Many years later the album is seen as hugely influential. In fact the pendulum has swung on so much of his solo work. Even so, it is hard to believe no-one at the time thought 'Every Night' a great song.

We have just put our 100th student lecture on YouTube. But you can watch them all in one minute below.

Or, alternatively, in about 80 hours via our Student Lectures playlist.