The Ebola virus is one of the most virulent infections known to science. This special episode of Horizon meets the scientists and doctors from all around the world looking for the cure and hears first-hand accounts of what it is actually like to catch and survive the disease

The risk of human extinction has never been higher. Recent years have seen a global pandemic, a renewed nuclear threat and runaway climate change. New research predicts a 1 in 6 chance that life as we know it won't make it to the end of this century. This compelling science documentary looks at the greatest risks to humanity and what we can do about it. Are we all doomed?

Low Earth Orbit, 120 miles above sea level, is where the majority of space exploration has occurred. This 1,100 mile band around Earth is where--for a cool $20 million--any private citizen can take the vacation of his or her life on the International Space Station. Commercial prospects for LEO are huge; but dangers lurk for any individual willing to travel here--radiation, cosmic rays, and space debris numbering in the thousands threaten any spacecraft travelling in orbit. It's the new frontier, or the final frontier...and the possibilities are endless if you are willing to travel to the edge of space exploration.

A majestic presence, towering over Paris for more than 130 years, the Eiffel Tower is an iconic symbol of 19th-century progress and grandeur. When it was built for the 1889 Paris world’s fair, its creator, Gustave Eiffel, was at the height of his fame and ready to take on the dream of every engineer and architect - to build the world’s tallest man-made structure. He had just two years, two months and five days to erect his 300-metre iron colossus. Drawing on three decades of civil engineering innovation and works across the globe, Eiffel, a magician of iron building, was perfectly poised for this extraordinary feat.

This episode covers the European refugee crisis, the largest refugee migration since World War II. Following the refugees on their journey, Vice sets out to cover not only the trials of those seeking asylum from the Syrian conflict, but the reactions from the Western world and the countries that have sought to take them in. Unfortunately, but perhaps not surprisingly, the response in many regions has been oppositional, especially in the aftermath of the Paris and Brussels ISIS attacks. In addressing this modern world crisis, Vice depicts the severe trials and tribulations faced by the desperate refugees, and the consequences, noticed or unnoticed, of turning them away.

Dr Hannah Fry travels down the fastest zip wire in the world to learn more about Newton's ideas on gravity. His discoveries revealed the movement of the planets was regular and predictable. James Clerk Maxwell unified the ideas of electricity and magnetism, and explained what light was. As if that wasn't enough, he also predicted the existence of radio waves. His tools of the trade were nothing more than pure mathematics. All strong evidence for maths being discovered.
But in the 19th century, maths is turned on its head when new types of geometry are invented. No longer is the kind of geometry we learned in school the final say on the subject. If maths is more like a game, albeit a complicated one, where we can change the rules, surely this points to maths being something we invent - a product of the human mind. To try and answer this question, Hannah travels to Halle in Germany on the trail of perhaps one of the greatest mathematicians of the 20th century, Georg Cantor. He showed that infinity, far from being infinitely big, actually comes in different sizes, some bigger than others. This increasingly weird world is feeling more and more like something we've invented. But if that's the case, why is maths so uncannily good at predicting the world around us? Invented or discovered, this question just got a lot harder to answer.