Call 911 from the side of the road, and GPS satellites can tell dispatchers exactly where to send help. Airline passengers have access to detailed maps that show exactly where they are during their journey. Hop onto WiFi, and somehow Google knows whether you're logging on from Lima or London, and will give you detailed suggestions about what to eat.
For all these abilities, how is it that we have no idea where Malaysia Flight 370 has gone? The answers offer a humbling look at the limitations of our current technology.
What happened to radar?
Radar only extends so far. Most of us landlubbers understand that air traffic controllers typically use radar to monitor a flight's progress. That's all very well over land. But radar also has a limited range, and you can't put a radar station in the middle of the ocean. So pilots often have to stay in contact through other means, such as periodic radio check-ins. In between check-ins, the controller has only a general idea of where a plane is and where it's headed.
According to the Associated Press, Flight 370 may have been in contact with military radar in its final moments — but whether a civilian air traffic controller knew where it was is less clear. We know that Flight 370's transponder signal was lost just as the plane was supposed to be entering Vietnamese air space — and because transponders are meant to work with radar, that suggests the plane was close enough to shore to be on somebody's screen.
Could somebody have turned off the aircraft's transponder?
That's a tricky question. Pilots can send coded messages over the transponder in an emergency. But we're not really sure what happened to the transponder in this case. We don't know, for instance, if anybody tried to tamper with it. But why would they? Reports suggest that nobody on the plane made a distress call of any kind — no radio transmission, nothing. That implies there wasn't time to cry for help in the midst of a technical breakdown or a violent struggle. If that's the case, it's not likely an attacker — if there was one — would try messing with the transponder while they were still trying to gain control of the aircraft.