Why would flight 370 end up in southern Indian ocean when it was headed north to Beijing?

At this point no one knows what happened, other than the plane seems to have made about a 300 degree left turn, then continued on that course until the fuel ran out.

There would seem to only be a few likely explainations. One would be a deliberate act - ether an act of suicide by one or more of the pilots, or a highjacking.

One other is a mechanical problem (fire, depressurization) that prompted the pilots to turn toward the nearst airport, but disabled the flight crew minutes later, resulting in the plane flying on autopilot on the last selected heading.

It was detected changing course on military radar after the transponder was switched off. Because there was no alert at the time, it was ignored as routine by the military radar operators. Finding the flight recorders is of importance to determine exactly what happened.

The currents in the sea and the plane may of went of course

It slowed way down to save fuel so the spinning of the earth and the Coriolis effect made the land that was under it to the east rather than the north.

the games a foot watson

This is the best theory I have seen so far:

http://www.bofads.com/stories/planesecrets.htm