Elon Musk's plan to send passengers from Los Angeles to San Francisco in a half hour -- without crashing -- is short on details.
But the so-called "Hyperloop" is not short on science, according to reports.
Musk himself describes it as a system that never crashes, leaves when you want to leave, and is immune to the weather. He also describes it as a combination of a railgun, the Concorde, and an air hockey table.
To outrace airplanes, the Hyperloop must move at Mach 0.91, according to reports. But Musk mentioned railguns, which use electromagnetic forces to transport objects at high speeds. And he mentioned air hockey, which uses pneumatic force.
So maybe the Hyperloop is a "pneumatic transport system," a "closed tube" that loops between Los Angeles and San Francisco?
Of course, there are other mysterious claims, such as the one where you "leave when you arrive." So what does Musk mean, exactly? We should find out in a month.