Built on Facts

In Episode 82 of the best applied science show on TV, the Mythbusters looked at some myths involving snow. The basic idea of science is that if you have a question about nature, you set up an experiment and find out the answer for yourself. The Mythbusters do this with verve and alacrity. Occasionally they take some gentle chiding from professional scientists for not doing “real” science with mathematical rigor and constant retesting, but I think that’s a bit of a red herring. Mythbusting is every bit real science, it’s just not academic-style science. Professional scientists are working on difficult unsolved problems by definition, and so those kinds of problems have to be attacked much more carefully because if they were easy they wouldn’t be unsolved. “Will your tongue freeze to a cold pipe like in A Christmas Story?” is a scientific question with a scientific answer, but not one that needs hardcore academic methods to address.

However in this particular episode, they did manage to run head-on into a type of problem that Mythbusting methods aren’t well equipped to handle. It’s a problem with a low signal-to-noise ratio.

Signal-to-noise ratios are in concept like looking for one person you know in a large crowd. While you’d easily be able to pick out your friend in a room with just a few people, a stadium full of people might mean you’ll be looking for a while. The signal (your friend) is small in comparison to the noise (the crowd). The only solution is to do a better experiment (maybe call him on the loudspeaker) or run your original experiment longer.

The Mythbusters question was whether an avalanche could be triggered by a loud noise, such as yodeling. Adam and Jamie tried to create avalanches by using noise, and tested their sonic efforts against more traditional methods like explosives, machine guns, and air cannons. There was limited success with any of those, and no success at all with the yodeling.

You wouldn’t really expect there to be. To start an avalanche, the snow pack has to be very close to slipping slipping. All it takes is a push to get it going. Usually the push has to be something significant - one of Jamie’s bombs, or an unlucky skier. Sounds waves are very, very weak and so that snow would have to be absolutely right on the barest possible threshold before avalanche in order for a sound wave to get it started. It stands to reason that snowy mountains balanced that finely will be few and far between.  But it’s very probably not impossible.

Things that seemingly stand to reason have been wrong before though, so we’re caught in a quandry. The Mythbusters can stand with the data and declare the myth busted. Or they can make a judgment contrary to data and declare it plausible on the basis of physical principles and reports from the field. Neither is very palatable. The dillemma was only given a very brief discussion at the end; Adam insisted that the myth was busted because in the final analysis the show must defer to data. Jamie agreed to an extent, but also thought that the myth needed to be revisited.

I agree. This is one of those situations where the rigorous academic science method of taking lots more data would have come in handy. If you deal 100 hands of poker, you might conclude that the royal flush is a myth, but in reality you just haven’t played enough hands yet. Instead of just “confirmed”, “plausible”, and “busted”, maybe there should be an “inconclusive” for those times where a one-hour show just isn’t enough time to adequately do the experiment.