It’s not the kind of name most people would say is infused with tenderness, but Elon Musk and the singer Grimes have showed they are unafraid to divide opinion after they said they are going to call their new baby boy “X Æ A-12 Musk.” Musk tweeted the name to a fan who inquired and Grimes later sent a fuller breakdown of the name’s components late Tuesday, posting: “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 + (A=Archangel, my favorite song) (metal rat).” Musk offered another update Tuesday, tweeting that his son, his seventh child, is “happy, healthy & cute as a button :)”