 Even though Mr. Arnault is of advanced age, he has no intention of stepping back. He is in it for the long haul. That's the editor of Bloomberg Businessweek, Brad Stone. The latest issue of the newly redesigned monthly magazine on newsstands now on the Bloomberg Terminal and at Bloomberg.com slash Businessweek. All right. Now to an individual who is often the subject of a Businessweek story, including recently. We're talking about Elon Musk and to some numbers you should know about Elon.