Elon Musk — the eccentric and hình ?nh th? damvery online billionaire — returned to Joe Rogan's podcast shortly after his child was born.

In case you missed it, Musk and his partner Grimes set the internet ablaze by naming their child — who was born on May 4 — X Æ A-12 Musk. A lot of folks wondered how, exactly, you pronounce that name,

Rogan asked the Tesla founder about that immediately.

"How do you say the name?" Rogan asked. "Is it a placeholder?"

"First of all, my partner is the one who, mostly, actually came up with the name," Musk answered.

"I mean it's just X, the letter X," Musk explained. "And then the AE is like pronounced 'ash'... yeah... and then A-12 is my contribution."

Rogan asked, "Why A-12?"

Musk explained it was in honor of the plane the Archangel 12, the precursor to the SR-71, which the billionaire described as "the coolest plane ever."

So, if we put that all together, phonetically it's something like: "X-ash-A-twelve."

Rogan and Musk go on to discuss what it's like to have a child in the middle of a pandemic, one that the Space X founder has played down.

Grimes has previously explained the baby name via tweet, only to be corrected by her partner on Twitter.

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While Musk and Grimes might want to name their child X Æ A-12, the state of California might not allow it.

"[Grimes and Musk] have an opportunity to appeal the rejection of the birth certificate application but it's unlikely that it will be granted because, again, California ... has been struggling with using symbols," David Glass, a family law attorney, told People.

The podcast with Rogan and Musk is about two hours long and dropped at noon eastern time. In just the first twelve minutes or so, they touched on everything from Warren Buffett, to selling away possessions, to the idea that "billionaire" is a pejorative term, to owning (and selling) Gene Wilder's house.

Still, it'll be tough to outdo the last appearance on The Joe Rogan Experience, where he talked about AI and got into a bunch of trouble for smoking weed.