First proposed by Elon Musk, the theoretical transportation system we call hyperloop would propel people- or cargo-filled pods over long distances through steel tubes. Magnetic levitation and big vacuum pumps would do away with pesky friction and air resistance, letting those bus-sized vehicles zip along at speeds approaching Mach 1. It wouldn’t just be fast, the boosters say: Hyperloop could be cheaper and better for the environment than the planes, trains, and cars in which humanity putzes about today.

And like so many promised panaceas, it’s actually quite simple—on the surface. The tubes and pods should be easy enough to build, but making hyperloop a reality takes more than a few good engineers and a small fortune or two. It will require a whole lot of legal maneuvering, regulatory wrestling, and a massive amount of political will and public buy-in. Infrastructure, you should know, is hard.

The First Hyperloop

The tubular tizzy started in 2012, when Tesla and SpaceX CEO Elon Musk suggested The Hyperloop as a new form of transportation, one that would be twice as fast as a plane and totally solar powered. He didn’t offer any engineering specifics at the time, but in August 2013 he produced a 57-page white paper that outlined his technical thinking for how this system would work.

Why is it "hyperloop," not "the Hyperloop"? Well, once upon a time, WIRED capitalized the H, and preceded it with the. You can see that in our early coverage. “When Elon announced the idea, it was Hyperloop: his name for his project,” explains WIRED copy chief Brian Dustrud. “Eventually, and fairly quickly I think, it went from one company’s project to a generic concept.” Along with the capital H, we dumped the article altogether. That's because we see hyperloop more as a kind of technology than a discrete object. So we talk about it the way we do ultrasound, lidar, or high-speed rail, all of which can exist in lots of forms. Plus, there is no working hyperloop in existence. Once that happens, though, we'll be happy to reconsider.

At its core, hyperloop is all about removing the two things that slow down regular vehicles: friction and air resistance. To do away with the former, you make the pod hover above its track, like a magnetic levitation train. Musk originally suggested doing this with air bearings, little jets of air on the bottom of the pod. Think of air hockey, he said, but where the air comes out of the puck instead of the table. Today, most hyperloop engineers have decided instead to rely on passive magnetic levitation. Where standard maglev systems are power hungry and expensive, this system uses an array of permanent magnets on the vehicle. When those magnets move over conductive arrays in the track, they create a magnetic field that pushes the pod up, no current required. A complementary magnet system (think of two magnets pushing off one another) would give the pods a push every few miles or so—the near total lack of friction and air resistance means you don’t need a constant propulsion system.

As for air resistance, that’s where the tube comes in. (Yes, tubes also just feel like the future, but that’s not the point.) The tubes enclose the space through which the pods move, so you can use vacuums to hoover out nearly all the air—leaving so little that the physics are like being at an altitude of 200,000 feet. And so, like a cruising airplane, a hyperloop needs only a little bit of energy to maintain the pods’ speed, because there’s less stuff to push through. More speed with less power gets you to where you’re going faster, greener, and—depending on energy costs—maybe cheaper too.

How Hyperloop Works

After explaining all this, Musk said he was too busy to build the thing himself. He was running both Tesla and SpaceX and didn’t have time to remake yet another industry. So he encouraged anyone interested to have a go. Let there be hyperloop, he said.