The world's new tallest tower was just approved for Dubai -- and it'll dwarf the reigning Burj Khalifa by 100 meters. Meanwhile, Brighton, England unveiled the world's skinniest tower: It's topped with a space-age moving observation pod. Kazakhstan broke ground on a futuristic eco city that will host the World Expo 2017, while a gigantic green pyramid popped up in Paris. Elsewhere in the world, researchers used lasers to reveal lost cities hidden by jungle near Angkor Wat, and a gigantic "Gateway to the Underworld" opened up in Serbia -- and it's rapidly growing.
Hydrogen is a clean, renewable energy source that can be easily stored, but it tends to be expensive and difficult to produce. That's why it's exciting that California-based HyperSolar has developed a breakthrough technique for producing hydrogen fuel from water and sunlight. In other energy news, Australia smashed a wind power record last month by generating 1,299 gigawatt-hours of renewable electricity, and Scotland managed to reach its aggressive emissions goal a full six years ahead of schedule. We also spotted a self-sufficient mountain hut that generates all of its own electricity and a chic floating home that's powered by the sun. Finally, we shared 10 classic science experiments sure to inspire kids of all ages.