Beatles Historian Mark Lewisohn, Thomasina Lowe on the Kennedy years and science writer Marcus Chown explains everything.

The Beatles are chart toppers again. In this episode David Freeman talks to Beatles Historian Mark Lewisohn about his mammoth history of the Fab Four.

Thomasina Lowe talks about her fathers photographs of the Kennedy presidential years and science writer Marcus Chown talks about his book "What a Wonderful World". that endeavours to explain almost everything.