Als er één ding is dat ik geleerd op de universiteit, het was hoe ik mezelf gemakkelijk af te leiden. Ik heb de neiging om mijn TV op de achtergrond te houden, terwijl ik bezig ben op mijn computer, vooral 's avonds als ik gewoonlijk vechtend een winnende oorlog tegen de slaap. The other night something did catch my eye: a man holding dowsing rods in his back yard. Volume up, let the bullshit flow. It was just a flash of idiocy in an otherwise good program on home improvement. I’ve become accustom to crap-based TV on networks such as the History Channel or a Discovery network (quality of their shows include gems like “The Haunted: ghosts and pets”), but I was a little surprised to see BS grace my local PBS station.
Over on the “American Woodshop” host Scott Phillips was constructing a beautiful garden arbor. You can watch the entire thing here for free: Episode 1609: Period Architectural Moldings and Trim. There are no time stamps on the clip, but the dowsing comes in around the mid-point. While demonstrating the materials needed to secure the wood to the ground he cautioned against digging haphazardly into your yard without knowing where the underground water, electrical or gas lines were: solid advice. So in order to do this you should (paraphrased) “take pieces of coat-hanger, anything will do, turn them into an “De”. As I walk forward the bars cross – er (they cross) – right there is the irrigation line. 9 out of 10 people have this ability, but you should call in a professional if there is any doubt“. My translation “OK guys, don’t worry about calling in some guy to do this, figure it out this way”. Please tell me what man who seriously watches a home improvement show at midnight would cede authority to someone else before giving it the good ol’ college try? Even if we grant for a moment that 9 out of 10 people could do this, what about that one guy who can’t? Isn’t it irresponsible to suggest that you can avoid power/water/sewer/gas only 90% van de tijd? Oops, hit that pesky gas line…
Being a scientist, a skeptic and a procrastinator – I wrote Scott a message about this so I could avoid my work at hand. Today he kindly replied saying: (excerpt)
“Our bodies are electromagnetic fields. Disrupt a field and things happen…. I learned the technique mentioned from a city worker that they used to find lines. Not from a charlatan. My team witnessed the objective use of this technique.”
Briefly, no, our bodies are not electromagnets. Everyone can hold a compass, or TV… without screwing them up. Franz Mesmer coined the idea of “Animal Magnetism” in the last half of the 18th century (also invented “mesmerization” AKA hypnotism) – and had it abruptly debunked by Benjamin Franklin and others. I’m also a bit worried to hear that city workers are relying on dowsing to locate public lines! But to move onward, let us dig into the myths of dowsing. I agree that there seems to be somewhat of an intuitive truth when it comes to dowsing, however false it is scientifically, it remains compelling. Zeker… electrical things underground effect sensitive wires above. And wow, look at all these guys who can find water, or power, of… lost people… of bombs? OK, let’s stick to water for this conversation.
(continued)
Rule number one: Occam’s razor. The simplest explanation is the most likely. Why do the wires move? Easy – because his hand moves. If you are equally compelled as I am, go load the video I linked above of Scott and his dowsing rods. Watch him walk through the gate with the wires and watch his right hand. It CLEARLY twitches inwards to move the wire. I watched it 10 times and each time it becomes more obvious how he gets the wires to move. In the beginning his thumbs are tightly clamped on the top to prevent movement. While walking he loosens his grip, then tilts his hands. Voilà, the rods move. Is he doing this intentionally? In my opinion it is extremely unlikely. Scott has no motive to trick his viewer, he clearly is an honest believer in this method. Not to unfairly single Scott out – let’s throw someone else into the mix. Here is a great clip from James Randi; featuring Greg Price as he attempts to demonstrate “dowsing”.
[youtube=http://www.youtube.com/watch?v=rMtuWymUzz4]
So why then doesn’t he notice his hands moving? It is a well understood phenomenon called the ideomotor effect. Essentially the wires are moved unconsciously by the user. Anyone who has ever held “dowsing” wires knows just how hard they are to hold still! Randi is a master at explaining just how these effects are generated by the user. And here is another video illustrating just how much more can be at play.
Or how about a clip from someone I actually like(d). Survivorman Les Stroud: skip to exactly 1:00. Come on Les… echt?
[youtube=http://www.youtube.com/watch?v=YFGLYN05rRE&feature=related]
Dus, in the Canadian forests next to a lake you dowse for water. Of course you find it. And if you go to part 6 of the series and skip to 6:51 in, you see them actually dig the well. They find water… but with shallow bedrock too close to the surface to gather water. FAIL.
Many dowsers claim they can find “veins” of water running under the surface like rivers. Droevig, nothing in reality supports their claims. Most underground water exists as part of a water table, where water permeates all of the soil more or less evenly and in accordance to the topography and rock layers. Simple explanation for dowsing success: if you walk into a back yard and point down you will hit something eventually. This leads us into part two.
Rule number two: Psychology. Throughout the eons of human evolution we have been granted one special gift, the ability to be naturally horrible scientists and skeptics. Building your skeptical shield is a process that does not come naturally, and is a skill that has to be maintained. After-all just being skeptical does not mean I can’t be a sucker every once in a while. Thankfully it does an amazing job at absolutely protecting us from alien abductions, hauntings and rogue Bigfoot attacks. When it comes down to it we are social creatures that desire to conform to the group. This recent paper (.pdf) out of the University of Maryland sadly illustrates just that point. While surveying people on paranormal beliefs they seeded the participant with knowledge of the popularity and/or the scientific stance on the issue (not necessarily conforming to reality). Participants not only strongly favored group conformity, but outright rejected the scientific consensus especially when it was not popular. Bad news for us skeptics, great news for your neighborhood fortune teller. Advice from a peer is extraordinarily more effective than hard facts, especially if it comes from a person of authority. Here is another example using the vaccination drama. Parents believe parents and are naturally distrustful of government and science. (bedankt SGU for first discussing these papers on the podcast). My solution is to clone Carl Sagan – een “Carl for every classroom” will be a platform I can stand on. (<— copyright me, 2010).
How many of us are professional scientists… and how many are professional scientists working for the government or are federally funded? *slams head on desk* I think the best we can do is to plant the seed of doubt and hope some day for positive results. But here again we face more roadblocks, people have terrible, terrible memories. Regardless of how certain you are of your memory it may easily be incorrect. There is a well documented neurology behind the formation of false memories. On top of this, we run into even more trouble: people become more likely to remember something is true if you tell them it is false. When you get down to it that makes sense. “Hey Mom – did you know that you can balance an egg any day of the year and not just on the equinox?” Mom will later recall (hypothetical conversation!) “oh yea… Chris was telling me something about how you can balance an egg only during the equinox”. Be careful how you word your rebuttals and try place them within a better context. If you remove “not just on the equinox” you leave a more permanent memory fragment – hopefully.
Psychology continues to get in our way when we get in the misty waters of statistics and logic. So as a dowser you set up tests and often jump at the opportunity to prove the powers you behold. Scott readily appeals to his anecdotal evidence, which I am sure he strongly believes. But what is too easily missed is the reason why those city workers can accurately dowse. They have the maps! Instead of surveying with a high degree of scientific accuracy they whip out a map, find the lines in the ground, and go out and eyeball the site. What is most likely is they are just thinking about where the lines were on the maps and subconsciously dowsing “accurately” for them. These workers are committing the logical fallacy of post-hoc reasoning. That is, they unintentionally skew their own tests by knowing the answers ahead of time. They walk in the field, get a successful hit, and attribute it to the dowsing and not the map. But of course if they hit a line then damn, that map was wrong! They assess the accuracy of their method based only on positive results. While Scott probably is in that same boat, he is also committing the logical fallacy of appeal to authority/popularity – of “ad populi”. These official city workers showed me, therefore it is true.
Rule number three: Cheating, a much less likely option but valid nonetheless. In no way am I suggesting that Scott Phillips is a cheater – just gullible, in my opinion. Knowing that psychics do not exist I can not ever truly know the intentions of another person. I would rather assume someone is ignorant or gullible before believing them to be a cheater. Maar, sometimes you can’t help but to wonder (cough*Sylvia Browne*cough).
Foei, that should cover it, for now…
