Everyone likes to be alone sometimes, but we also all spend much of our lives collaborating and sharing things with others. Many argue that on this increasingly crowded planet, we need to master the art of sharing much better if we are to survive and flourish. So what makes us want to share new ideas and pass on our experience?

Bridget Kendall discusses three very kinds of sharing - digital information, genes and national infrastructure. She is joined by Jonah Berger, marketing professor at the Wharton School at the University of Pennsylvania in the United States; Connie Jeffery, assistant professor of Biological Sciences and head of the Jeffery Lab at the University of Illinois in Chicago; Dr Elham Ibrahim, commissioner for Infrastructure and Energy for the African Union in Addis Ababa, Ethiopia.

(Photo: The Golden Gate Bridge, in California, provides a means to sharing infrastructure. Credit: Getty Images)

New ideas about volcanoes, earthquakes and other geological processes that both enrich and threaten us. Jack Stewart is joined by four leading Earth scientists in the city of Yokohama at the 2016 Goldschmidt Conference - volcanologists Tamsin Mather and Michihiko Nakamura, plate tectonics expert Carl Spandler and seismologist and Nature magazine editor John VanDecar.

(Photo: Mount Fuji in Japan. Credit: Getty Images)

If you think of your favourite foods – chocolate, maybe, or samosas, or pizza – do you really know where all the ingredients came from? Bridget Kendall asks the food scientist Chris Elliott, the software designer Jérôme Malavoy and the food labelling expert Monique Raats.

Photo: The food label on a box of brownies (Getty Images)

One of the first things that comes to mind when thinking of radioactivity is often a nuclear accident or dangerous rays. But radioactivity is in fact a much more varied phenomenon, one that can bring us great benefits as well as put us in danger. With help from three experts, Rajan Datar looks for a more nuanced picture of the role radioactivity plays in our lives.

Photo: A symbol for radioactivity is visible on a radioactively-contaminated container. (Getty Images)

Acts of defiance small or large have proved to be incredibly powerful throughout history, but when does defiance spill into aggression? Bridget Kendall asks the employment lawyer Lewis Maltby, the theatre director Olivier Py and the psychopathologist Dr Luna Muñoz Centifanti.

(Photo: Historic Marker at the bus stop in Alabama, USA, where Rosa Parks refused to give up her seat. Credit: Getty Images)

The Obama administration recently announced it will spend over a hundred million dollars on deepening our knowledge of the human microbiome - the bacteria, fungi, viruses and other organisms which make their home in and on our bodies. Bridget Kendall is joined by three people whose work in different ways enriches our appreciation of the world of human microbiota - the epidemiologist Mark Woolhouse, microbiology educator Christine Marizzi and gut flora researcher Jeroen Raes.

(Photo: The NYC Biome MAP part of the Collective Urban Biome MAP project. Credit: Genspace NYC and The DNA Learning Center)

We are at The Metropolitan Museum of Art in New York at The Met Breuer, where the exhibition "Unfinished: Thoughts Left Visible", is a springboard to explore the notion of things unfinished or incomplete. The concept of a work of art that is unfinished, the so called 'non finito' style, has been with us since the Renaissance. But it has taken on new meaning in modern art of the 20th and 21st Century. So how should we respond to a work which is unfinished whether it is a painting, a book, a piece of music, a film or a building? And, how does the idea of ‘unfinished’ translate into an ever-changing historical and political context?

Presenter Bridget Kendall is joined by Andrea Bayer, Jayne Wrightsman, Curator in The Met’s Department of European Paintings and co-curator of "Unfinished: Thoughts Left Visible" at The Met Breuer; Negin Farsad, a celebrated stand-up comedian, actor and film-maker of Iranian heritage; Kerry James Marshall, the internationally renowned American artist whose work will be the subject of a major exhibition at The Met Breuer this October 2016; Andrew Solomon, professor of Clinical Psychology at Columbia University in New York, and an award-winning writer who is also president of PEN American Center.

(Photo: The Met Breuer in New York. Credit: Ed Lederman)

According to the United Nations, we probably throw away over one billion tonne of waste every year. Some goes into landfill, some is destroyed and some is recycled. The mountain of cast-off litter is not just a huge environmental challenge, but a logistical one as well. Bridget Kendall explores ideas about how to harness waste with - Martin Medina, a global waste consultant, who suggests scavenging might be the answer to developing country’s growing waste problems; Dr Tom Licence, an historian at the University of East Anglia and ‘garbologist’, who uses archaeological beachcombing for historical rubbish to unveil our detailed past; Polly Morgan an artist who uses taxidermy to ascribe new meaning to what was once discarded and dead.

(Photo: A rubbish tip in Kolonawa suburb of Colombo, Sri Lanka. Credit: Getty Images)

These days everyone from schoolchildren to business owners is being told to become more resilient, but what does resilience mean in geological time? How and why do some organisms survive mass extinctions? And, on a shorter time-scale, how do people cope with the demands of dictators? Janina Ramirez and her guests discuss how to survive adversity across time and space.

(Photo: Caiman crocodiles in San Marcos, Sucre in Colombia. Credit: Getty Images)

What is the place of rivalry in human behaviour? What drives it? And where is the dividing line between competition as a positive force and one that wreaks havoc? Samira Ahmed discusses rivalry in sport, in cities and in our minds with psychologist Stephen Garcia, sport morality expert Maria Kavussanu and historian Philip Mansel.

(Photo: The finish line at the men's 100 meters final at the Seoul Olympic Games in 1988. Credit: Getty Images)