The tycoon’s long-term goals (Humans on Mars! Brain implants! Humanoid robots!) are famously and wildly ambitious. Aggressive targets are also part of the day-to-day operating culture at his firms.

Project Sapphire was a logistical nightmare that would be difficult to repeat in a hostile country such as Iran today ...

A common assumption is that restricting eligibility reduces risk of premature access or errors in assessing cases. But for ...