This week Alok Jha meets astrophysicist Caleb Scharf from Columbia University's Astrobiology Centre to discuss his new book Gravity's Engine: How Bubble-Blowing Black Holes Rule Galaxies, Stars and Life in the Cosmos. Caleb discusses why these mysterious entities may be involved in the creation of galaxies and why they have captivated the imagination of scientists for more than a century.
Alok is joined by Guardian science correspondent Ian Sample to discuss the possibility of apes experiencing a mid-life crisis, why happy teens make prosperous adults and why the martian explorer Curiosity is unlikely to have found life on the red planet.
Also, producer Jason Phipps visits the Natural History Museum to find out about a new permanent exhibition titled Treasures. Jason discovers the importance of William Smith's ammonites and why Guy the silverback gorilla changed how we view great apes for ever.
