Give Elon Musk a hypothetical futuristic question, he’s got a thoughtful, logical answer.
But it turns out the one thing everyone talks about when they talk about the hypothetical future, Musk is not terrifically excited about. That would be flying cars.
Why? They’d probably be noisy and would get in the way, Musk said, speaking at the first Vanity Fair New Establishment Summit in San Francisco on Wednesday.
“If the sky was full of cars flying all over the place, it would affect the skyline, and it would be noisier, and there would be a greater probability of something falling on your head,” said Musk, who is CEO of both electric car company Tesla and commercial space travel company SpaceX. “Those are not good things. I get that you could get from one place to another faster. But if you eliminate the choke points in cities …”
And how exactly would those choke points be eliminated, asked moderator Walter Isaacson.
“Tunnels,” was Musk’s one-word answer.
Later in the session, Musk elaborated: “This may seem trite, but I honestly think tunnels should be given a lot more consideration.”
Musk divides the world into what’s above ground and what’s below. Cities like Manhattan have buildings with many stories into the sky, he noted. Whereas at the street level? There’s just the one story. Surely things could be better utilized.
So in Musk’s future world, transportation systems would include: Electric cars (he said this will happen whether or not his own company Tesla is successful), tunnels to route cars through congestion, tubes to get people longer distances (this is his so-called “Hyperloop”), vertical take-off and landing supersonic aircraft for distances over 500 miles and rockets to take people to Mars (that’s SpaceX).
However, the hypothetical future that does freak Musk out is better artificial intelligence, he said.
What if a machine decides the best way to solve a problem is to do something detrimental to humanity, Musk asked. What if it decides, for example, that “the best way to get rid of spam is to get ride of humans?” That wouldn’t be good.
And for a bonus hypothetical question from the audience, Musk was asked what he thinks about virtual reality.
“Well, maybe we’re in a simulation right now,” he responded. “Yeah … seriously.”
Musk explained: “If you’re in a full-body haptic suit with surround vision, it becomes indistinguishable from reality.” And since there could be billions of potential realities, he added, “What are the odds we’re in base reality? It could be one in billions.”
This article originally appeared on Recode.net.