Does the universe, have a limit? Does the universe have an edge? Looking out to the edge of the universe is tremendously important to understand our place in the cosmos and to understand the universe itself.
Inflation was a formative moment for our universe. By the time it stopped, the universe's basic characteristics were set. There could be regions of the greater universe where inflation didn't stop then. Occasionally a little region will stop inflating and just expand at the normal rate. We could imagine a super large-scale structure where there's different regions of the universe, domains, and each domain has different local constants and laws of physics.

We're unlocking the secrets of our planet's voyage and discovering that earth's journey affects us all. The Earth is extremely dynamic. It is spinning on its axis, it's whirling about the sun and it's corkscrewing throughout the this galaxy. And there is the fact than Andromeda and the Milky Way are currently 2.5 million light-years apart, but they're hurtling towards each other at over 250,000 miles an hour. A collision is inevitable. As stars, dust, and gas swirl around each other, gravitational interactions could slingshot our solar system out into intergalactic space.

The tropical island of Mauritius is home to Melrose maximum security prison, where 800 of the country's worst drug smugglers, sex offenders and murderers are locked up. Every convict is watched day and night and even the smallest infraction is met with extreme punishment.

After ending 120 years of civil war and reunifying Japan under his banner, Toyotomi Hideyoshi, the supreme ruler of Japan, lays dead. In a desperate attempt to protect his dynasty, just before his death, Hideyoshi created a council of five powerful warlords. They are to govern Japan until his young son comes of age. But the power hungry Tokugawa Ieasyu declares war on those who oppose him.

From the frozen poles to the searing deserts, this episode shows how animals have come up with strategies to survive the uneven amounts of sunlight that fall on our planet over the course of a year. The exception is on the equator, where the duration of day and night remain the same throughout the year. Here, this guaranteed sunlight drives the great diversity of life in the tropical jungles.

The world's shipping industry is facing a major challenge. If global shipping were a country it would be the sixth largest producer of greenhouse gas emissions. At current growth rates, if we do nothing, those emissions could double or even triple by 2050. But shipping companies and engineers are creating remarkable new machines to make their industry greener, using a resource that has moved man across the world’s oceans for thousands of years…Wind.