Over at Bad Astronomy, Phil Plait tries to explain why astronomers don’t seem to notice any of the countless alien spacecraft supposedly buzzing overhead. According to Phil, most UFO reports are misidentified planets, stars, weather balloons or satellites buzzing overhead, everyday things that both amateur and professional astronomers know how to distinguish from say, a mother ship piloted by an advanced extraterrestrial civilization all the way from Tau Seti or Zeta Riticuli. It makes perfect sense that UFOs would be extremely rare. If even half of all the reported sightings were honest to goodness alien craft, any military on the planet would be in a state of sheer panic right now.
But wait a second. Why do ufologists like to mention the sheer volume of flying saucer reports when all we really need is just one, concrete case with solid evidence? When it comes to science, an argumentum ad populum is pretty much meaningless. Thinking that something happened in the absence of falsifiable proof makes your position a belief. People agreeing with your interpretation of a puzzling event and reporting similar ones, makes that position a popular belief. And yet none of them prove that your stance is backed by anything other than your opinion. It’s just like the pareidolia responsible for constant sightings of saints on cheese sandwiches or in knots of tree bark. Lots of people see it, but it’s hardly definitive proof of the supernatural.
So why focus on quantity rather than quality? Because humans are social creatures and we’re very prone to jumping on bandwagons, often accepting the flawed premise that because many people believe something, there must be at least some truth to it. This is why we have bestsellers and “most popular” sections on news sites and blogs. Ufologists who invoke the sheer amount of sightings people can’t immediately explain, are appealing to our social nature, using it to bolster a point in the absence of solid proof.
The fact of the matter is that alien craft designed to cross interstellar space would have to be huge in order to generate the energy required to make the trip. We’d be able to detect the bursts of radiation coming from their engines. And if they show up multiple times, they’d need to be more or less uniform rather than come in the wildly different shapes, colors and arrangements we hear about today since making every spaceship in a huge fleet unique is not what a species that can manufacture spacecraft on an industrial scale is likely to do. Real alien encounters would leave consistent, falsifiable proof and all we’d really need is one good case to say that there’s just might be something to this whole UFO thing.