By Brad Horn, from NPR
Caves are some of the last places on the planet left to explore. Though caving is relatively safe, if something goes wrong deep inside the Earth, a rescue can take days — in part because cell phones and walkie-talkies don't work underground. But a remarkable teenager in New Mexico has invented a device that may significantly speed that process with the ability to text from underground caves. The young man's invention may have other applications, as well.
Underground...
