From rockets to brain implants, here's a look at Elon Musk's vast empire

NEW YORK — Elon Musk, the world's richest man and now first-ever trillionaire, controls a lot of different businesses. Electric vehicles. Brain implants. Underground tunnels. A social media platform once called Twitter. And a rocket maker that blasted off its trading from Wall Street this week. Over time, more and more of these ventures have found themselves under the same roof. Musk merged SpaceX — which went public on Friday — with his artificial intelligence company xAI just