Journalist and author Helen Lewis meets groundbreaking thinkers to test out their big ideas.

From politics to economics, from tech to the study of how we live, things are changing fast. Old certainties are crumbling, and we need new solutions to shake up the status quo and shape the future. In The Spark, Helen Lewis meets 11 radical thinkers who are bidding to change our world, and puts their ideas under the spotlight to find out what they have to offer compared to the failures of the past.

Part one sees her interviewing American economist Emily Oster, who discusses how data-based parenting could have a life-changing impact on pregnancy and child-rearing; social entrepreneur Hilary Cottam, who believes that human connection should be at the heart of the welfare state; Nobel Prize-winning economist Paul Krugman, who explains why 'zombie ideas' are holding us back; and social psychologist Roy Baumeister, who talks about our inbuilt negativity bias and how to defeat it.

In part two, CEO and writer Margaret Heffernan argues that preparedness is the best way to deal with uncertainty; artificial intelligence pioneer Stuart Russell explains how we can keep AI under human control; former Frome mayor Peter Macfadyen takes us through his new model for community-based politics; and behavioural scientist Pragya Agarwal discusses our unintentional biases - how they affect our decision making, and ways of overcoming them.

And in part three, Helen's guests include economists Paul Collier and John Kay, who call for an end to destructive individualism in favour of mutuality and co-operation; educationalist Kiran Gill, whose organisation The Difference strives to improve the life chances of excluded schoolchildren; and barrister Chris Daw, advocate of a radical plan to abolish prisons and rethink our whole approach to punishment and rehabilitation.

Cogent, credible and compelling, these thought-provoking proposals will give you a whole new perspective on the problems our society faces and how we could solve them.

Presented by Helen Lewis

With: Emily Oster, Hilary Cottam, Paul Krugman, Roy Baumeister, Margaret Heffernan, Stuart Russell, Peter Macfadyen, Pragya Agarwal, Paul Collier and John Kay, Kiran Gill, Chris Daw

Produced by Eliane Glaser, Phil Tinline, Emma Wallace and Sarah Shebbeare