The quest for a theory of everything – explaining all the forces and particles in the universe – is arguably the holy grail of physics. While each of our main theories of physics works extraordinarily well, they also clash with each other. But do we really need a theory of everything? And are we anywhere near achieving one?

Featuring Vlatko Vedral, a professor of physics at the University of Oxford and Chanda Prescod-Weinstein, an assistant professor in physics and astronomy and core faculty in women's and gender studies at the University Of New Hampshire.

This episode is presented by Miriam Frankel and produced by Hannah Fisher. Executive producers are Jo Adetunji and Gemma Ware. Social media and platform production by Alice Mason, sound design by Eloise Stevens and music by Neeta Sarl. A transcript is available here. Sign up here for a free daily newsletter from The Conversation.

Further reading: 

• The standard model of particle physics may be broken – an expert explains

What’s the difference between a living collection of matter, such as a tortoise, and an inanimate lump of it, such as a rock? They are, after all, both just made up of non-living atoms. The truth is, we don’t really know yet. Life seems to just somehow emerge from non-living parts.

Featuring Jim Al-Khalili, professor of physics at the University of Surrey, and Sara Imari Walker, professor of physics at Arizona State University.

This episode is presented by Miriam Frankel and produced by Hannah Fisher. Executive producers are Jo Adetunji and Gemma Ware. Social media and platform production by Alice Mason, sound design by Eloise Stevens and music by Neeta Sarl. A transcript is available here. Sign up here for a free daily newsletter from The Conversation.

Further reading: 

Life: modern physics can’t explain it – but our new theory, which says time is fundamental, might

It is hard to shake the intuition that there's a real and objective physical world out there. If I see an umbrella on top of a shelf, I assume you do too. And if I don't look at the umbrella, I expect it to remain there as long as nobody steals it. But the theory of quantum mechanics, which governs the micro-world of atoms and particles, threatens this commonsense view.

Featuring Chiara Marletto, Research Fellow of Physics, and Christopher Timpson, Professor of Philosophy of Physics, both at the University of Oxford, and Marcus Huber, Professor of Physics, TU Wien.

This episode is presented by Miriam Frankel and produced by Hannah Fisher. Executive producers are Jo Adetunji and Gemma Ware. Social media and platform production by Alice Mason, sound design by Eloise Stevens and music by Neeta Sarl. A transcript is available here. Sign up here for a free daily newsletter from The Conversation.

Further reading: 

• 'QBism': quantum mechanics is not an objective description of reality – it reveals a world of genuine free will

Interest in the multiverse theory, suggesting that our universe is just one of many, has spiked since the movie Everything Everywhere All At Once was released. The film follows Evelyn Wang on her journey to connect with versions of herself in parallel universes to stop the destruction of the multiverse. The multiverse idea has long been an inspiration for science fiction writers. But does it have any basis in science? And if so, is it a concept we could ever test experimentally? 

Featuring Andrew Pontzen, professor of Cosmology at University College London, Katie Mack, Hawking chair in cosmology and science communication at the Perimeter Institute for Theoretical Physics, and Sabine Hossenfelder, research fellow of physics at the Frankfurt Institute for Advanced Studies. 

This episode is presented by Miriam Frankel and produced by Hannah Fisher. Executive producers are Jo Adetunji and Gemma Ware. Social media and platform production by Alice Mason, sound design by Eloise Stevens and music by Neeta Sarl. A transcript is available here. Sign up here for a free daily newsletter from The Conversation.

Further reading: 

• The multiverse: how we're tackling the challenges facing the theory
• Curious Kids: how likely is it that there are parallel universes and other Earths?
• The multiverse: our universe is suspiciously unlikely to exist – unless it is one of many

Imagine a universe with extremely strong gravity. Stars would be able to form from very little material. They would be smaller than in our universe and live for a much shorter amount of time. But could life evolve there? It after all took human life billions of years to evolve on Earth under the pleasantly warm rays from the Sun. 

Now imagine a universe with extremely weak gravity. Its matter would struggle to clump together to form stars, planets and – ultimately – living beings. It seems we are pretty lucky to have gravity that is just right for life in our universe.

Featuring Fred Adams, professor of physics, University of Michigan, and Paul Davies, professor of physics, Arizona State University.

This episode was presented by Miriam Frankel and produced by Hannah Fisher. Executive producers are Jo Adetunji and Gemma Ware. Social media and platform production by Alice Mason, sound design by Eloise Stevens and music by Neeta Sarl. A transcript is available here. Sign up here for a free daily newsletter from The Conversation.

Further reading: 

• The multiverse is suspiciously unlikely to exist unless it is one of many

Without a sense of time, leading us from cradle to grave, our lives would make little sense. But on the most fundamental level, physicists aren't sure whether the sort of time we experience exists at all. We talk to three experts and find out if time could potentially be moving backwards as well as forwards.

Featuring Sean Carroll, Homewood professor of natural philosophy at Johns Hopkins University, Emily Adlam, postdoctoral associate of the philosophy of physics at Western University and Natalia Ares, Royal Society university research fellow at the University of Oxford.

This episode was presented by Miriam Frankel and produced by Hannah Fisher. Executive producers are Jo Adetunji and Gemma Ware. Social media and platform production by Alice Mason, sound design by Eloise Stevens and music by Neeta Sarl. A transcript is available here. Sign up here for a free daily newsletter from The Conversation.

Further reading: 

• Quantum mechanics: how the future might influence the past
• Four misconceptions about quantum physics

There are many competing theories about what causes Alzheimer's disease. For more than 30 years, Ruth Itzhaki has been accumulating evidence that viruses are involved in its development in the brain. We investigate this evidence in the third and final episode of Uncharted Brain: Decoding Dementia, hosted by Paul Keaveny and Gemma Ware from The Conversation.

Featuring interviews with Ruth Itzhaki, professor emeritus of molecular neurobiology at the University of Manchester in the UK, Dana Cairns, a postdoctoral research fellow at Tufts University in the US and Davangere P. Devanand, director of geriatric psychiatry and professor of psychiatry and neurology, Columbia University Medical Center in the US.

Uncharted Brain is produced by Tiffany Cassidy with sound design by Eloise Stevens. The executive producer is Gemma Ware. Read full credits here.

Further reading:

My work investigating the links between viruses and Alzheimer’s disease was dismissed for years – but now the evidence is building

Dementia doesn’t just affect older people. Chronic traumatic encephalopathy (CTE) is a form of dementia that athletes from a whole range of sports can develop. It’s now at the centre of a number of legal challenges involving sports from rugby to American football. In the second episode of Uncharted Brain: Decoding Dementia, hosts Gemma Ware and Paul Keaveny from The Conversation find out about the toll this type of dementia can take on family members, who are often unaware of what’s happening to their loved ones.

This episode features interviews with Matthew Smith, a senior lecturer in sport and exercise psychology at the University of Winchester in the UK and Lisa McHale, director of family relations at the Concussion Legacy Foundation.

Uncharted Brain is produced by Tiffany Cassidy with sound design by Eloise Stevens. The executive producer is Gemma Ware. Read full credits here.

Further reading:

• Sport-induced traumatic brain injury: families reveal the ‘hell’ of living with the condition

Scientists have been doing an array of regular health checks on the same group of people since they were born in 1946 – the world's longest running cohort study. Now the brains of some of its participants are revealing new insights into the risk factors for Alzheimer's disease. 

We find out more in the first episode of Uncharted Brain: Decoding Dementia, a new series from The Anthill hosted by Paul Keaveny and Gemma Ware from The Conversation.

This episode features Marcus Richards, professor of psychology in epidemiology, UCL, Jonathan Schott, professor of neurology at UCL and David Ward, one of the cohort study participants.

Uncharted Brain is produced by Tiffany Cassidy with sound design by Eloise Stevens. The executive producer is Gemma Ware. Read full credits here.

Further reading:

• We’ve been studying the same people for 76 years – this is what we’ve found out about Alzheimer’s disease

Uncharted Brain: decoding dementia is a new series from The Conversation exploring new research unlocking clues to the ongoing mystery of how dementia works in the brain.

In this three-part series, hosted by journalists Paul Keaveny and Gemma Ware from The Conversation, we'll delve into some of the findings from the world's longest continuously running cohort study, hear about the trauma of families effected by dementia and explore one researcher's investigation into the role certain viruses could play in Alzheimer's disease.

All episodes will be available via The Anthill on November 16.

Uncharted Brain is produced by Tiffany Cassidy with sound design by Eloise Stevens. The executive producer is Gemma Ware.