Kirsty Lang on

James Lovelock (pictured), the scientist and inventor who came up with the Gaia theory.

Ayman al-Zawahiri, the leader of the terrorist group Al-Qaeda.

Roy Hackett MBE, who led the Bristol bus boycott in 1963.

Dame Olivia Newton-John, the singer and actor who starred in Grease.

Producer: Emily Finch

Interviewed guest: Bryan Appleyard CBE Interviewed guest: Paul Martin Interviewed guest: Lynn Mareno Interviewed guest: Professor Kehinde Andrews Interviewed guest: Holly Thomas

Archive clips used: Web of Stories - YouTube channel, James Lovelock - The Gaia Theory (11/17) 17/08/2017; BBC Radio 4, Desert Island Discs - James Lovelock 17/11/1997; AP Archive, USS Cole Attacked 12/10/2000; BBC News, Bombings in New York 11/09/2001; BBC Two, Newsnight - London Bombings 07/07/2005; BBC Radio 4, Six O'clock News 06/10/1981; AP Archive, Muslim Extremists Trial 15/12/1982; PBS News Hour, President George W. Bush - First US strikes in Afghanistan 07/10/2001; CBS News, Biden announces death of Ayman al-Zawahiri 02/08/2022; BBC Ideas, Why I'm still fighting racism at 90 24/01/2019; BBC One, Paul O'Grady's Working Britain 15/08/2013; BBC World Service, Witness - Bristol Bus Boycott 10/10/2019; BBC One, Parkinson - Olivia Newton-John interview 02/12/1978; Paramount Pictures/Robert Stigwood Organisation (RSO)/Allan Carr Production, Grease (Film clip) 1978.