Elon Musk spelled out the difficulty of making Optimus dexterous, reliable, durable, and safe, and why it will be tough to ramp up production.

The Optimus robot weighs 154 pounds and is going to be produced where the Model S and X vehicles were made.

It is unclear how his dark vision of the future outside America fits with his AI utopianism. But even Mr Musk wonders if it all makes sense. At times, he says, he believes in a theory in which the universe is a computer simulation created by aliens. “The things I’m doing are so preposterous that it’s hard to believe they’re real.” ■

In results issued after markets closed Wednesday, the Austin company said revenue jumped to $28.24 billion. Still, profit fell as spending rose.