The eccentric billionaire posted a GIF on Twitter showing the running track scene from Stanley Kubrick’s 2001: A Space Odyssey. “Running track in @SpaceX BF Spaceship will look something like this,” Musk said.

Running track in @SpaceX BF Spaceship will look something like this pic.twitter.com/563upTfV58 — Elon Musk (@elonmusk) June 8, 2018

Is Musk’s SpaceX actually working on a centrifugal device that would create an artificial gravity that would allow for such a track? It’s probably on a to-do list, but we wouldn’t expect it anytime soon. In the meantime, here’s a clip of such a device from 2001: