Elon Musk announced the arrival of his first son with musician Grimes and the world simply cannot make up its mind about the baby’s name.

The 48-year-old SpaceX founder tweeted on Monday to his 33.6 million followers that “Mom & baby all good”. (Ahem, May the Fourth be with him?). When prompted for the new arrival’s name, the tech billionaire wrote that the baby's name was X Æ A-12 Musk.

The Tesla Chief Executive shared a photo to Twitter, with both father and son appearing to be healthy and happy.

And then one a bit more on the edgy side. Musk posted a second image of a filtered X Æ A-12 with face tattoos that would be the envy of Post Malone.

For a while, nobody was sure if Musk was joking about the baby’s alleged name. IFLScience even tweeted Musk but had not received a response at the time of publication. Now, Grimes appears to have come forward to confirm the name, and its meaning.

But not before people had a few stabs at working it out themselves. Some people have proposed that the equation-like name may simply be a mathematical problem that leads to the unveiling of the baby's alphabetical name. Another suggested the name is simply a code. 

Grimes, who announced in February she would be letting their child identify their own gender, took to Twitter to apparently confirm the unusual name, and the meaning behind what appears to be random letters and numbers.

"X, the unknown variable, Æ, my elven spelling of Ai (love &/or Artificial intelligence), A-12 = precursor to SR-17 (our favorite aircraft). No weapons, no defenses, just speed. Great in battle, but non-violent," she wrote.

How to pronounce it is anyone's guess.

Is it even legal?

It's thought the baby was born in Los Angeles, where the couple lives. In California law, only names using “the 26 alphabetical characters of the English language” are permitted, so it's unlikely X Æ A-12 is on the birth certificate.

It's probably worth remembering this is a living, breathing creature, not the next Tesla invention. (Fun fact: 141 babies were named Tesla in 2017.)

Or are they?

We'll let you be the judge.