In the fourth episode, Professor Marcus du Sautoy concludes his investigation into the history of mathematics with a look at some of the great unsolved problems that confronted mathematicians in the 20th century. After exploring Georg Cantor's work on infinity and Henri Poincare's work on chaos theory, he sees how mathematics was itself thrown into chaos by the discoveries of Kurt Godel and Paul Cohen, before completing his journey by considering some unsolved problems of maths today, including the Riemann Hypothesis.

Everywhere you go, you generate a cloud of data. You're trailing data, everything that you do is producing data. And then there are computers looking at that data that are learning, and these computers are essentially trying to serve you better. They're trying to personalize things to you. They're trying to adapt the world to you. So on the one hand, this is great, because the world will get adapted to you without you even having to explicitly adapt it. There's also a danger, because the entities in the companies that are in control of those algorithms don't necessarily have the same goals as you, and this is where I think people need to be aware that, what's going on, so they can have more control over it.
We came into this new world thinking that we were users of social media and search engines. It didn't occur to us that social media and search engines were actually using us.

Frequent security expos feature companies like Megvii and its facial- recognition technology. They show off cameras with A.I. that can track cars, and identify individuals by face, or just by the way they walk. In China it's been projected that over 600 million cameras will be deployed by 2020. Here, they may be used to discourage jaywalking, but they also serve to remind people that the state is watching. Matching with the most advanced artificial intelligence algorithm, they can actually use this data, real-time data, to pick up a face or pick up a action.
A.I. is a technology that can be used for good and for evil. So, how do governments limit themselves in, on the one hand, using this A.I. technology and the database to maintain a safe environment for its citizens, but not to encroach on a individual's rights and privacies?

What connects amateur sleuths turning up at crime scenes, anti-social behaviour in schools and riots? Marianna Spring has spent one year investigating harmful behaviour on TikTok spilling out into the real-world. As well as crunching the numbers, Marianna tracks down TikTok users, victims and former employees to interrogate and expose how extremely high engagement on TikTok around particular topics appears to be creating these 'frenzies'.
The documentary explores how users go to extreme lengths in order to get more engagement in a battle for followers and likes. Marianna investigates the role TikTok's algorithm and format plays in what’s happening and reveals insiders’ concerns about the app. The film seeks to find out if this is the real danger and what impact it is having on society.

Wonder Woman is the most popular female comic-book superhero of all time. Aside from Superman and Batman, no other comic-book character has lasted as long. Like every other superhero, Wonder Woman has a secret identity. Unlike every other superhero, she also has a secret history. The history of her creation seven decades ago has been hidden away—until now.
A riveting work of historical detection revealing that the origins of one of the world's most iconic superheroes hides within it a fascinating family story-and a crucial history of twentieth-century feminism. Take a look at the very unconventional lives of the man and women who created this iconic pop culture figure.

BC's illegal marijuana trade industry has evolved into a business giant, dubbed by some involved as 'The Union', Commanding upwards of $7 billion Canadian annually. With up to 85% of 'BC Bud' being exported to the United States, the trade has become an international issue. Follow filmmakers Adam Scorgie and Brett Harvey as they demystifies the underground market and brings to light how an industry can function while remaining illegal. Through growers, police officers, criminologists, economists, doctors, politicians and pop culture icons, Scorgie examines the cause and effect nature of the business - an industry that may be profiting more by being illegal.