Tungusksa: Pseudoscience according to "Sightings"

      I recently had the misfortune to make a mistake when recording my VCR. I expected to get Star Trek Deep Space Nine, I admit to liking science fiction a lot. What I got instead was a recording of the show Sightings. Because they were "reporting" on something relating to astronomy, I decided to watch as much as my stomach would allow. What I witnessed was some of the worst interpretation of data I've ever seen. Worse yet, it was clearly manipulating the public by presenting half truths and omitting relevant data. Sightings wanted to public to believe something exciting and "strange" happened, people by nature like exciting things and thus the popularity of pseudoscience.

      This particular show was covering the Tunguska Event. The show reported that back in 1908 there was a tremendous explosion in Siberia. Witnesses, said Sightings, reported a brilliant flash on the horizon and the explosion was heard over 600 miles away. More remarkable was that one person standing 36 miles away was knocked over by a shock wave, and trees were knocked over radially for a distance of 9 miles. Now that's a pretty impressive explosion, no denying that.

     Now the question is: what caused this tremendous explosion? The most widely thought cause was of extraterrestrial origins. But the show quickly cut this idea down. They said that astronomers admit they don't think it was a meteor. First of all, there is no typical impact crater. Secondly, there are no chunks of meteor to be found. So, Sightings explained, it was not something from outer space, there was no evidence, it had to be something else. Then they moved into speculation. About this time there was a scientist named Nikola Tesla. Originally from Yugoslavia, Tesla later became a US citizen. Tesla experimented with electricity. He was very good, for awhile he worked for Thomas Edison and some of his inventions were purchased by George Westinghouse. But he did more, according to Sightings. Specifically he developed a "death ray" and tested it in Siberia. That, according to the show, was the cause of the Tunguska Event.

      Now, the science behind it all, the portions that were conveniently left out in the show. It is true that there is no crater at the Tunguska site. Meteor impacts typically leave a crater many times the size of the impacting object when they hit. Typically too, there are fragments of the meteorite found in and around the crater. And yes, some astronomers do believe it was not a meteorite impact that caused Tunguska. What these astronomers do believe, and what was omitted, was that they believe that a small comet impacted in Tunguska. Comets are composed mostly of ices and gases and they would have vaporized on impact, leaving no evidence.

     But the current theory accepted by most astronomers and geologists is that it was in fact a meteor which caused Tunguska. What they believe is that the meteorite exploded while still in the air over Tunguska. The devastation on the surface was caused by the resulting detonation wave in the air. And there is a "smoking gun" of evidence for either a comet or meteor impact. Core samples were taken of the soil around the site, and high concentrations of iridium were found. Iridium is a rare element on Earth, but common in meteorites, asteroids and comets. There is no evidence for the "death ray."

     It is hard sometimes for us to discriminate truth from falsehood if we are not versed in that particular field. One rule of thumb to follow is known as Occum's Razor. Occum's Razor is a hypothesis which states that generally, the solution to a problem is most often the simplest. In the case of Tunguska, it seems far more logical to believe that a comet or meteor exploded in the air rather than some "death ray."