the Blu-ray format stores and plays movies in high definition—easy for new flicks shot digitally in HD, but what about classics like Metropolis (due out on Blu-ray next year) that were shot on film? The trick is to make a small digital file without losing too much information in the process, which could yield a poor-quality image. Here’s how it works.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.