When I was maybe ten, I was at my grandparents' house, and there were some aunts and uncles there, as there tended to be during that time period. One of them called me into the living room, and handed me two L-shaped pieces of wire hangers, about a foot long, with the short part of the L being handles. They told me that something was hidden in the living room, and that I was supposed to hold the two pieces of wire loosely, by their handles, with the length of them pointing forward, and then I was supposed to follow where they pointed, to lead me to the hidden object.
Different people have varying definitions about what dowsing is, but there are some common elements. A dowser is someone who uses an instrument that relies on physics to gain information. So, in this definition, a tarot-card reader is not a dowser, but someone scrying with a pendulum, walking around with a forked stick, or using the L-shaped wire hangers like in my example, is a dowser.
And addendum to that definition would be that the feedback from the dowser's instrument/s seems always to rely on the minute, unconscious movement of the muscles. Called the ideomotor effect, it's what makes the pendulum swing, and what makes the tensed branch dip. Our minds dictate these movements, even if we're not causing them intentionally. Contrary to popular belief, most popular writing on the subject does not contradict this. Most instructional books on dowsing seem to come from the point of view that, yes, our subconscious is moving the objects, through our muscles, but since our subconscious is connected to the rest of the universe, it's still a good source of info.
You can do it yourself, with no practice, and at no cost to you. I encourage you to, even sitting in front of my blog. Go find a nut (not a bolt, but a nut) and maybe a foot and a half of fishing line, or thread. Tie the heavy one to the end of the long one. You now have a pendulum, and are ready to tap into the knowledge of the universe.
Grab the length of string between your finger and thumb, and put your elbow on the desk. Bend your wrist so that the string is hanging parallel to your forearm, and the nut is about an inch from the surface of the desk. Following me so far? Now (and keeping a straight face, you silly skeptics) tell your fancy new pendulum something with your mind. Start with, "Pendulum, please swing counter-clockwise." I'm not sure if it's psychologically important that you address it as pendulum, but that's what I did.
It's important that you try your hardest to keep your hand still. When the thing starts to swing, as it likely will, it should be pretty surprising. Once you've had it swing counterclockwise, and clockwise, and along the x axis and the y, it's time to start getting more information than you put in. It's at this point that the whole things starts breaking down for me.
You may not expect it to give you the lottery numbers, or tell you what the neighbor is watching on TV, but as I experimented with this I was at least interested in whether it could tell me what I already knew, but was unable to remember. Things that, if my unconscious mind is the sponge it's supposed to be, should be in there. I tried to remember where I had put my headphones, and, using the pendulum, narrowed it down to within a foot of my bedroom television. Well, unless I'm quite blind, that was a miss. For how fascinating it is to watch the thing swing on command, when it came to practical applications it stopped impressing me pretty quickly.
Maybe it's because I'm a skeptic, and I'm resistant to things that are just a little too nifty. I can't say. Feel free to email me with any dowsing stories you've got. It seems like something that taps into the unconscious mind should have some practical applications, but I have never had any luck on that front.
So, there you have it. If you've followed my directions, you have a firsthand understanding of the ideomotor effect, and you can test, yourself, in your living room, whether dowsing works. I'd say that, with that kind of opportunity, you shouldn't enter another single debate on the subject until you've tried it. Because, of course, an ounce of experience is worth a pound of speculation.
And all it costs is a nut and a string.