Elon Musk thinks the truth is out there. On Wednesday, the tech entrepreneur said on Twitter that chemtrails, the belief that contrails left in the sky by aircraft are actually chemicals sprayed into the atmosphere for ulterior motives, may have an element of truth to them.

“Hi Sir,” Twitter user Adolf Oosthuizen‏ said to Musk. “Help us out here, are #chemtrails real or not? Regards from RSA [Republic of South Africa]!”

“They’re so real,” Musk responded. “Anyone going to that much trouble must really care. I’d gladly follow their commands, but they’re so friggin obtuse…”

Chemtrail theories differ from source to source, but a common theme is that the government is using planes to spray chemicals into the air that have a negative effect on society’s health and the environment. A 2016 study from University of California, Irvine, and the Carnegie Institution for Science found that while almost 17 percent of the world’s population believe in a secret, large-scale atmospheric engineering program, 98.7 percent of surveyed scientists had seen no evidence of such a program that could be explained through other means. The one dissenting scientist had found high levels of atmospheric barium that they could not explain, which isn’t quite the same as saying that the barium was a sign of a conspiracy.

Chances are, Musk is joking. Although he’s put forward some bizarre theories in his time, like the idea he proposed at the Recode conference last year, where he said humans are all living in a simulation, he’s made a similar joke about chemtrails before. On April Fools’ Day, he took to Twitter to put forth his theory that chemtrails are part of an extraterrestrial conspiracy.

“Technology breakthrough: turns out chemtrails are actually a message from time-traveling aliens describing the secret of teleportation,” he said. “Why did we waste so much time developing silly rockets? Damn you, aliens! So obtuse! You have all this crazy tech, but can’t speak English!?”

With Musk exploring the effects of advanced artificial intelligence on society, revising his plans to send humans to Mars and working to bring the Tesla Model 3 to the mass market, it’s no surprise he wants to relax from time to time.