Anything you can do, A.I. can do better?

Once large law firms had armies of first-year law graduates, combing documents for relevant information; now machines largely do it. New artificial intelligence diagnosed lung cancer 50 percent more accurately than radiology experts last year. And the U.S. Postal Service plans to deploy autonomous trucks by 2025. These are signs of big change, precipitated by a wave of new artificial intelligence resulting from a perfect storm of investments and development these past five years. And coming developments will increasingly enable machines to do more mental and physical tasks faster, better and cheaper than humans.