Most laws of physics tell us what must happen. Throw a ball in the air and it will come back down. But physicist Chiara Marletto, a Research Fellow at the University of Oxford, says that laws like this only tell us part of the story.

She believes that the rest lies in 'counterfactuals': things that could be.

In her new book, The Science of Can and Can’t (£20, Allen Lane), she explains how these counterfactual properties could solve many of science’s biggest outstanding problems.

Let us know what you think of the episode with a review or a comment wherever you listen to your podcasts.

• Subscribe to the Science Focus Podcast on these services: Acast, iTunes, Sticher, RSS, Overcast

Listen to more episodes of the Science Focus Podcast:

• Prof Avi Loeb on what 'Oumuamua tells us about the problem with modern physics
• Marcus Chown: Does the Big Bang really explain our Universe?
• Dr Douglas Vakoch: Should we try to contact aliens?
• Katie Mack: How will the Universe end?
• Sonia Contera: How will nanotechnology revolutionise medicine?
• Everything You Wanted To Know About… Physics with Jim Al-Khalili

---

See acast.com/privacy for privacy and opt-out information.