Ottoman Sultan Mehmed II wages an epic campaign to take the Byzantine capital of Constantinople. Twenty-three armies have tried to take the legendary city and all have failed. Out of the carnage, one ruler will emerge victorious and shapes the course of history for centuries. For one empire to rise, another must fall.
The Ottomans, former Anatolian warlords and nomads who've built a burgeoning empire are the biggest threat to the Romans' 1100-year reign. The death of Ottoman Sultan Murad II in 1451 unleashes a chain of events that will soon bring the Ottomans and Romans to the brink of war. After claiming the Ottoman throne, Mehmed II sends an unmistakable signal to Byzantine emperor Constantine XI.

Inside the heart of the atom, its nucleus houses energy. This hidden treasure was forged billions of years ago in distant stellar furnaces. The secret of starlight is nothing to fool with. It can bring a civilization to life and it can burn it to the ground.
Two atoms from different parts of the universe meet on a small planet. A deadly embrace between science and state altered the fate of the world and a gripping cautionary tale of others who grew used to living in the shadow of grave danger until it killed them all except one.

The fourth episode sees host Neil deGrasse Tyson exploring our eternal quest to end hunger and honoring Nikolai Ivanovic Vavilov, pioneer of modern plant breeding, who risked his life for a discovery that would change the history of science. Vavilov's story is marked by both the tenacity and creativity and is particularly tragic. Interwoven into Vavilov's somber narrative are warnings and treatments of science and its ethical implications, especially when science itself comes under attack from political forces.

In a provocative documentary, environmental campaigner George Monbiot examines the disastrous impact that farming animals for meat has had on the planet. He argues that the biggest problem driving us towards global disaster is how we feed ourselves, particularly on meat
George looks at alternative food sources, including synthetic meat, and a process that produces protein from just bacteria and air, and also explores revolutionary ideas that could change agriculture as we know it.

Two and a half thousand years ago, the Greek philosopher Socrates worried that the wide use of writing would have a negative impact on people's minds. He said that writing would create forgetfulness, because people will not use their memories. They would trust the external written characters and not remember themselves. In a world with an ever-growing tech industry, Michael Stevens tries to find out what effect technology has on our brains. He finds Technology isn't just changing our lives, it's changing our brains. In his experiments he tests what just 10 days of gaming does to things like our spatial memory.

Medical journalist Michael Mosley teams up with scientists whose latest research is turning common knowledge about fitness on its head. They reveal why 10,000 steps is just a marketing ploy and that two minutes of exercise is all a person needs each week. They discover how to get people to stick to their fitness plans and what exercise can actually make everyone more intelligent. Whether it is for couch potatoes who hate the thought of exercise, someone too busy to consider the gym, or even for fitness fanatics who are desperate to do more - science can help everyone exercise better.
By the end of January many people struggle to keep up their resolutions to be more active. The result is that people wastes millions on unused gym memberships. But new science has the answers.