After teasing the concept in 2012, Tesla CEO Elon Musk released some thoughts on a high-speed transportation project called the Hyperloop in 2013. He then promptly renounced any claim on the idea and said he would not actually build the open source project. The hyperloop didn't die, though, and is still attracting new brainpower.

Hyperloop Transportation Technologies was officially formed with a JumpStartFund late last year, a few months after Musk made the concept public. The company has since grown into a collective of about 100 engineers who have full-time gigs with companies such as Boeing, Airbus, NASA and, of course, Musk's own SpaceX, Wired says. Some students at UCLA are taking part in the design process, which is detailed in a new "crowdstorm" document.

The idea behind the Hyperloop is to build above-ground tubes where passenger capsules devoid of friction (with the help of either air compression or magnetic levitation) can travel up to 800 miles per hour between cities such as Los Angeles and San Francisco. The HTT collective is already talking about having economy- and business-class capsules.

The good news is that the group says the early predictions for Hyperloop remain realistic. That means a timeframe of about a decade to complete the first system with a price tag of between $6 billion and $10 billion is still on the table. For now, at least.