Imagine that your laptop display weighs 800 pounds. But you can still open it and close it and re-open it as you like, gently pushing it to just the right angle. And when you let go, it stays exactly where you put it. That should give you a pretty good idea of what Facebook has done in designing an entirely new breed of hardware device for storing all the photos, videos, and other digital stuff uploaded by its more than 845 million users.
