If the Australians or anyone else locate the first wreckage on missing Flight MH370, don't expect immediate answers as to what caused the plane to go down.
Debris needs to be tracked back to the main wreckage and then the all-important black boxes must be recovered.
The first thing investigators will do is try to determine if any debris matches something consistent with an airplane. Luggage with tags is obvious. There should also be serial numbers on Boeing plane parts that can be quickly tracked back -- presuming those items haven't sunk.
If it is confirmed that wreckage is associated with the flight, investigators will work with oceanographers to begin to determine currents and winds.
Large pieces of the plane will have sunk beneath what could be deep ocean. Small pieces will be blown by winds and pushed by currents. Debris could easily be hundreds of miles away from the main wreckage.
Finding the main wreckage, if it is located deep under water like Air France 447 will be a complicated and very expensive prospect, but it's important to aviation safety to get an answer.
One thing investigators will look for if they recover debris is any signs of scarring or pitting that might indicate an explosion.
Ultimately, even if the debris is found, it may take years before there is an answer to this mystery.
And of course, there's always another possibility: This could just be stuff floating in the ocean.