The web is fine, but how do we get the internet we always wanted — a "real" space you can walk around in, like the Metaverse from Snow Crash? It's not a new question, but it's one that's being taken a little more seriously now that a huge company like Facebook is putting its weight (and its money) behind virtual reality. In this week's Big Future, we look at what it takes to build a convincing virtual world, why we're not there yet, and what we might do if we got one.

It's not that hard to trick your eyes

The quintessential virtual reality products are headsets like the Oculus Rift. In some ways, there's not much to them: you're strapping a flat screen to your head, and it's split into stereoscopic 3D and magnified by lenses to take up most of your field of vision. But it's incredibly important that it respond to your head's motion, even when the resolution is low.

We have no idea how to move

If you're doing something specific, like sitting in a virtual plane cockpit, we can build physical controls that mimic real life and feel pretty convincing. But all-purpose controllers are a different story. The interfaces we use for computers still feel unnatural, and we're in the very early stages of motion control. Getting your brain to believe you're actually walking around or touching something is incredibly important and incredibly hard.

We don't have to go live in the internet

We already have examples of "virtual worlds" like Second Life, and they'll only get cooler with immersion. But some of the most exciting possibilities involve blending the physical world with VR. Sharing experiences will become more intense, and online research takes on a whole new meaning. And then there's the entire field of augmented reality, where virtual and physical elements combine. If we figure out how to actually get there, the possibilities are endless.