The National Transportation Safety Board said two recent commuter rail accidents that killed one person and injured more than 200 others were caused by engineers falling asleep at the controls.
With three fatal train accidents in recent weeks, there's been a cry for Positive Train Control, a system that will automatically stop trains before certain types of accidents can happen. WIlliam Vantuono, editor-in-chief of Railway Age, explains how PTC works and why it's taking so long for it to be widely adopted.
The National Weather Service says a private company erroneously released a routine test message as an official warning. But AccuWeather blames the NWS for miscoding the message.
Steve Inskeep talks to Tristan Harris of the Center for Humane Technology about how to protect children and ourselves from what some call the "crisis of online addiction."
Computers use artificial intelligence to do everything from drive cars to pick music we like. But what exactly is artificial intelligence? How does it work? What are its limits?