Nintendo was like an impossibly huge wall. But if Mario was the undisputed king, an underdog was about to declare war. For Japanese game maker Sega, mainly known for its arcade cabinets, the battle was about winning the home console market. Sega's Genesis console and its speedy character, Sonic, hit the market.
In the early '80s, sports video games existed, but they didn't really look real. And one visionary entrepreneur had already started tackling the challenge of taking sports from the stadium onto the screen. Electronic Arts kicks off a partnership with football legend John Madden.

Just about every solid, liquid, or gas in the world as we know it begins with reactions between individual atoms and molecules. Host David Pogue dives into the transformative world of chemical reactions, from the complex formula that produces cement to the single reaction that’s allowed farmers to feed a global population by the billions.

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.

Schwalmstadt Maximum Security Prison in Germany. Locked up behind the walls of this 12th-century castle are 188 of Germany's worst offenders. The prison is a fortress surrounded by a moat, and houses dangerous criminals, many of whom attend intense therapy sessions.

David Attenborough reveals the extraordinary ways that some animals use colour to hide and disappear into the background. New science reveals how the Bengal tiger in central India uses its orange-black stripes to hide from its colour-blind prey. In Kenya’s Masai Mara, the zebra’s black-and-white pattern confuses predators with an extraordinary effect called motion dazzle. And on the island of Cuba, a small snail uses colourful stripes in a surprising way to hide from its enemies.
Other animals use colour to trick and to deceive. On Australia’s Great Barrier Reef, a blue-striped blenny uses colours to mimic other fish and launch a sudden attack. In the grasslands of Zambia, the chick of a pin-tailed whydah mimics the patterns of its nest mates to ensure that it is not detected as an imposter. And specialist cameras reveal how a tiny crab spider uses bright ultraviolet colours to lure in its victims.

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.