Monday, July 06, 2009

What Skepticism Reveals about Science - Michael Shermer

Michael Shermer is his usual entertaining self.


What Skepticism Reveals about Science

A skeptic's journey for truth in science

By Michael Shermer

In a 1997 episode of The Simpsons entitled “The Springfield Files”—a parody of X-Files in which Homer has an alien encounter in the woods (after imbibing 10 bottles of Red Tick Beer)—Leonard Nimoy voices the intro as he once did for his post-Spock run on the television mystery series In Search of...: “The following tale of alien encounters is true. And by true, I mean false. It’s all lies. But they’re entertaining lies, and in the end isn’t that the real truth? The answer is no.”

No cubed. The postmodernist belief in the relativism of truth, coupled to the clicker culture of mass media where attention spans are measured in New York minutes, leaves us with a bewildering array of truth claims packaged in infotainment units. It must be true—I saw it on television, at the movies, on the Internet. The Twilight Zone, The Outer Limits, That’s Incredible, The Sixth Sense, Poltergeist, Loose Change, Zeitgeist the Movie. Mysteries, magic, myths and monsters. The occult and the supernatural. Conspiracies and cabals. The face on Mars and aliens on Earth. Bigfoot and Loch Ness. ESP and PSI. UFOs and ETIs. JFK, RFK and MLK—alphabet conspiracies. Altered states and hypnotic regression. Remote viewing and astroprojection. Ouija boards and Tarot cards. Astrology and palm reading. Acupuncture and chiropractic. Repressed memories and false memories. Talking to the dead and listening to your inner child. Such claims are an obfuscating amalgam of theory and conjecture, reality and fantasy, nonfiction and science fiction. Cue dramatic music. Darken the backdrop. Cast a shaft of light across the host’s face. The truth is out there. I want to believe.

What I want to believe based on emotions and what I should believe based on evidence does not always coincide. And after 99 monthly columns of exploring such topics (this is Opus 100), I conclude that I’m a skeptic not because I do not want to believe but because I want to know. I believe that the truth is out there. But how can we tell the difference between what we would like to be true and what is actually true? The answer is science.

Science begins with the null hypothesis, which assumes that the claim under investigation is not true until demonstrated otherwise. The statistical standards of evidence needed to reject the null hypothesis are substantial. Ideally, in a controlled experiment, we would like to be 95 to 99 percent confident that the results were not caused by chance before we offer our provisional assent that the effect may be real. Failure to reject the null hypothesis does not make the claim false, and, conversely, rejecting the null hypothesis is not a warranty on truth. Nevertheless, the scientific method is the best tool ever devised to discriminate between true and false patterns, to distinguish between reality and fantasy, and to detect baloney.

The null hypothesis means that the burden of proof is on the person asserting a positive claim, not on the skeptics to disprove it. I once appeared on Larry King Live to discuss UFOs (a perennial favorite of his), along with a table full of UFOlogists. King’s questions for other skeptics and me typically miss this central tenet of science. It is not up to the skeptics to disprove UFOs. Although we cannot run a controlled experiment that would yield a statistical probability of rejecting (or not) the null hypothesis that aliens are not visiting Earth, proof would be simple: show us an alien spacecraft or an extraterrestrial body. Until then, keep searching and get back to us when you have something. Unfortunately for UFOlogists, scientists cannot accept as de­finitive proof of alien visitation such evidence as blurry photographs, grainy videos and anecdotes about spooky lights in the sky. Photographs and videos can be easily doctored, and lights in the sky have many prosaic explanations (aerial flares, lighted balloons, experimental aircraft, even Venus). Nor do government documents with redacted paragraphs count as evidence for ET contact, because we know that governments keep secrets for national security reasons. Terrestrial secrets do not equate to extra­terrestrial cover-ups.

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