Claudia de Rham has rather an unusual relationship with gravity.

While she has spent her career exploring its fundamental nature, much of her free time has involved trying to defy it - from scuba diving in the Indian Ocean to piloting small aircraft over the Canadian waterfalls. Her ultimate ambition was to escape gravity’s clutches altogether and become an astronaut, a dream that was snatched away by an unlikely twist of fate.

However, Claudia has no regrets - and says defying gravity for much of her life has helped her to truly understand it.

As Professor of theoretical physics at Imperial College London, she now grapples with deep mathematics, where the fields of particle physics, gravity and cosmology intersect, on a quest to understand how the universe really works. She is a pioneer of the theory of massive gravity, a theory which could take us beyond even Einstein’s theory of relativity and shed light on why the universe is expanding at an ever-increasing rate.

Presented by Jim Al-Khalili Produced for BBC Studios by Beth Eastwood Reversion for World Service by Minnie Harrop

When you think of Artificial Intelligence, does it inspire confidence, or concern?

Although it's now generally accepted that this technology will play a major role in our future, a lot of conversations around AI and machine learning come back to the argument over us losing control and robots taking over.

Happily, Neil Lawrence has a more optimistic view of the power of AI, and how we might navigate the potential pitfalls. Neil is the DeepMind Professor of Machine Learning at the University of Cambridge, and over the course of his career has been involved in deploying AI and machine learning in both academic and commercial scenarios, with a stint at Amazon as well as working across fields as varied as movie animation, Formula 1 strategy, and medical research.

Speaking with Professor Jim Al-Khalili, Neil says ultimately his efforts are all about making a difference to our everyday lives - and that we need to learn how to embrace AI, albeit with a healthy dollop of scepticism; not least when it comes to how our data is used, and the power of 'the digital oligarchy'...

Presented by Jim Al-Khalili Produced for BBC Studios by Lucy Taylor Reversion for World Service by Minnie Harrop

A frozen, white world at the far-reaches of the globe, where you're surrounded by snow and silence, might sound rather appealing. Factor in temperatures that drop to -57°C and a few of us might be put off - but for glaciologist Liz Morris, that's very much her happy place.

Liz is an Emeritus Associate at the University of Cambridge’s Scott Polar Research Institute, and was among the first British women scientists to work on the planet’s coldest continent, Antarctica. Over the course of her career, Liz has gathered vital data on polar ice sheets and how they’re affected by climate change. She's also made numerous research trips across the Greenland Ice Shelf, and has a glacier named after her in Antarctica.

In conversation with Professor Jim Al-Khalili, Liz discusses her fascination with glaciers and ice - and explains her unwavering determination to break into what was once a heavily male-dominated field.

Presented by Jim Al-Khalili Produced for BBC Studios by Lucy Taylor Reversion for World Service by Minnie Harrop

Welcome to a world where medicine meets politics: a space that brings together scientific research, government wrangling, public push-back and healthcare conspiracies…

Dr Anthony Fauci was the Director of America’s National Institute of Allergy and Infectious Diseases for nearly four decades, during which time he not only helped study, treat and prevent viruses such as HIV/AIDS and Covid-19; he also advised seven US Presidents, from Ronald Regan through to Joe Biden.

Along the way, Tony Fauci's picked up a public profile and taken a fair amount of flack; not least because of his complicated relationship with President Donald Trump. But he's also made great strides in medical research and policy, from working with activists who initially challenged him on the government response to HIV/AIDS - to spearheading the USA's PEPFAR project to share vital medication with developing nations.

In a candid conversation with Professor Jim Al-Khalili, Tony discusses his childhood in Brooklyn, the dark early days of the HIV/AIDS epidemic and lessons from the Covid-19.

Presented by Jim Al-Khalili Produced for BBC Studios by Lucy Taylor Reversion for World Service by Minnie Harrop