We don't know all the details, but it seems that the mystery of Malaysia Airlines flight 370 is mostly solved.
In truth, a lot can now be known with certainty about the fate of MH370. First, the disappearance was an intentional act. It is inconceivable that the known flight path, accompanied by radio and electronic silence, was caused by any combination of system failure and human error. Computer glitch, control-system collapse, squall lines, ice, lightning strike, bird strike, meteorite, volcanic ash, mechanical failure, sensor failure, instrument failure, radio failure, electrical failure, fire, smoke, explosive decompression, cargo explosion, pilot confusion, medical emergency, bomb, war, or act of God--none of these can explain the flight path.
The why is still unclear. The most interesting hypothesis I've read is that the pilot was involved in a conspiracy to steal cash, gold, or jewels that were frequently transported on the flight by Chinese plutocrats smuggling their wealth out of China. In this scenario, the pilot was simulating the flight path of the airplane at home because he wanted to make sure that it wouldn't be recovered easily and no one would figure out that a) his body wasn't on board, and b) neither was the treasure.
