‘Hyperloop’ travel idea gains fans, if not backers

LOS ANGELES — Billionaire entrepreneur Elon Musk released rough plans last week for a “Hyperloop” that would shoot capsules full of people at the speed of sound through elevated tubes connecting Los Angeles and San Francisco. Meanwhile, Musk himself has put aside the project and returned to his established transportation ventures: luxury electric car maker Tesla Motors Inc. and the rocket-building company SpaceX. The concept pulls together several proven technologies: Capsules would float on a thin cushion of air and draw on magnetic attraction and solar power to zoom through a nearly air-free tube. Others suggested his timeframe of a decade to completion was naive — that getting political backing and environmental clearances, much less land to build the tubes on, would be hugely time-consuming.