If a group of chemists found 18 more potent versions of a drug out of a sea of 3,000 potential chemicals in the span of a few weeks, they might be hailed as superhumans. That actually happened at Relay Therapeutics, said Dr. Donald Bergstrom, the company's head of R&D. But the driving force behind it wasn't human at all -- it was artificial intelligence. AI and machine learning have been hailed as a powerful new tool for drug discovery. But despite the hype, there is still a huge gap between the potential and the reality.