Elon Musk rolled up to a Tesla press event tonight in an electric semi truck, unveiling his latest project to the world. The semi has been hotly anticipated since Musk first hinted at it last summer, and he’s been hyping it up on Twitter this week, promising that the reveal would “blow your mind clear out of your skull and into an alternate dimension.” The semi truck is the latest addition to Musk’s vision of an all-electric world, where cars, trucks, and homes are all powered by clean energy. What’s up with this electric truck? Well, it’s a semi truck... but with a battery instead of diesel tank. It’s automatic, and it has no gasoline engine or transmission, so it should theoretically require less maintenance than a normal truck. It’s also built on the bones of the Model 3—there are two Model 3 engines driving each of the rear axles, Model 3-style press-in handles on the doors, and two Model 3 screens in the cab—so there’s a lot of continuity between Tesla’s ca...