Perhaps the most plausible hypothesis for the disappearance of Malaysia Airlines Flight 370 that I have seen comes from former airline pilot Chris Goodfellow. He posits that a fire could have knocked out the airplane’s communications. This would have shut off the transponder and, eventually, the Aircraft Communications Addressing and Reporting System (ACARS), possibly unbeknownst to the crew. The fire could have been electrical in nature, but fires have also started because of an overheated landing gear tire. The pilot would have tried to divert to the closest available airport, and Goodfellow believes that the plane’s course change could have been intended to get the plane to an airstrip on Pulau Langkawi, an island just off the west coast of the Malay Peninsula. The possible changes in altitude could have been the pilot’s effort to put out a fire by minimizing the amount of oxygen around it. The whole article is worth reading.

I’ve seen several people refer to the “fire hypothesis” as the best possible explanation if one applies Occam’s Razor. The problem there is that, while fire may prove to be the most plausible scenario, it still requires a substantial number of assumptions not currently supported by the available evidence.

People tend to think that Occam’s Razor means that the simplest explanation out of a set of possible explanations is usually the right one, but that’s not exactly it. For starters, have you ever wondered why it’s called a “razor”? The purpose of Occam’s Razor is to “cut” away all of the assumptions, biases, and other parts of an explanation that are not supported by the evidence.

William of Ockham, who didn’t invent the concept but gets the credit for it, stated it as “Pluralitas non est ponenda sine neccesitate” or “plurality should not be posited without necessity,” according to the Skeptic’s Dictionary. Stephen Hawking described it as “cut[ting] out all the features of the theory that cannot be observed.”

Occam’s Razor would therefore eliminate any explanation that involves assumptions or embellishments beyond what the evidence says, even if it is entirely plausible. If they were to call off the search for the plane today, Occam’s Razor would not make the fire hypothesis the “correct” explanation for what happened. Only direct evidence of fire, like charred electrical circuits, burnt tires, or whatever else would serve as physical evidence of a fire aboard an airplane could do that.

UPDATE (03/19/2014): As my friend Jeff pointed out (see also here), Occam’s Razor is not so much a means of finding the “correct” answer as finding the most likely explanation out of a given set of explanations. That is not how most people seem to use it, though, so it’s important to note that it is still possible, in many situations, that none of the available explanations are “correct,” so to speak.

And, as it turns out, quite a few people have expressed their opinions, applying more knowledge and information than is available to me, that Goodfellow’s hypothesis is wrong.

Photo credit: William of Ockham, from stained glass window at a church in Surrey, by Moscarlop (Own work) [GFDL or CC-BY-SA-3.0], via Wikimedia Commons.