What's the dope on "dowsing" for graves?

Great Debates
61

Not at all.

If you feel a specific test aimed at supporting dowsing has flawed methodology, and that impression is backed up by facts (I haven’t yet seen that here), all that shows is the test is unreliable. Even if others cite the test as a major reason for not believing in dowsing, all that shows is that they are citing an unreliable test, not that the dowsing “seem(s) more plausible” as a result.

As always, when a dubious claim is made (particularly one that invokes a sort of supernatural ability), the onus is heavily on believers to support that claim with evidence, not on skeptics to “prove me wrong”.

*Dowsing supporters appear heavily prone to the excuse that “your science can’t measure my woo”, given the varied and sometimes hilarious explanations as to why dowsers can’t reproduce their abilities under controlled conditions.

That illustrates why I’m grateful I don’t occupy a cubicle next to one used by an SDMB poster. :slight_smile:

62

Not according to people who have studied maths. They tell me that 22% is in the part of the bell curve marked as “highly significant” because it would occur by chance fewer than 1 time in 100.

They tell me that there is a greater than 99% chance that something other than chance was happening here.

63

The test wasn’t designed to determine a relatively minor success rate. The sample size was too small for that.

You see, when designing a test, if you want to examine very small differences, you need a lot of samples. If you want to design a coin flip test to determine if someone’s flipping ability will make it land on heads 50.5% of the time, you can’t just flip it 20 times to find out. You’d probably have to flip it a few thousand to prove such a small deviation from the expected. But if someone claimed to be able to make it flip heads 100% of the time, it would only take a few samples to prove them wrong.

The dowsing test I’m referring too only used a few trials and only 12 people. Which is an insufficient sample size to tease out a small effect. But, those 12 people claimed they could do it with 92% accuracy. If the expected number is indeed 10% for random change, but they claim 92% accuracy, that’s such a huge gap that you don’t need that many trials to show a real effect at work.

The problem with this is exactly your mistaken impression - since the test was not designed via sample size to rule out a lucky run above chance, it would appear that they achieved success. But the test would’ve had to have been designed differently if we only wanted to ascertain a 22%, rather than 92%, success rate. This doesn’t mean that the test was badly designed - it means it was designed to test the claims of people who claimed they had the power to get it right 92% of the time. For the goals set out in the test, it was perfectly scientifically valid. For you to point this out as proof that dowsing works is gross misunderstanding of science, which is ironic since that’s what you’ve been screaming about all thread.

Again, the test was designed to examine whether their claims of anything like a 92% success rate were true. If they wanted to see if anyone could score above chance, the test would’ve had to have been designed with way more samples.

If you aren’t advocating the dowsing effect being real, what is your purpose in this thread?

How does a water dowser scientifically explain their abilities? A gold dowser? A dowser for bombs? A dowser for graves?

Specifically, who has lied and how?

I mean - not only are you saying that they’re wrong, but they’re lying. Part of the grand JREF conspiracy I guess. So be specific here.

64

That’s exactly what I’m saying.

But certain people such as Musicat and Czarcasm and the usual suspects keep citing those flawed tests, in the belief that they are proving something. Really, they are just damaging their own side.

65

So, you appear to be claiming that a test for question X fails to answer question Y and, on that basis, are accusing other posters of dishonesty.

Your accusation is out of line for this forum and your claim is silly.

Just stop it before you get yourself in trouble.

[ /Moderating ]

= = =

And I will spell out for you exactly what I am saying:

Some number of dowsers have claimed a 92% success rate.
When tested by JREF, those dowsers have had only a 22% success rate.
JREF claims that the tests show that those dowsers are inaccurate in their claims, (92% vs 22%).
You claim that since 22% is greater than some unattributed claim that only 10% would work, that JREF is wrong.
You are moving the goalposts from testing the claims of dowsers to testing some hypothetical act of dowsing.
This may make you happy, but it is a straw man lodged against JREF and your use of that straw man claim as a basis of charging other posters of dishonesty is going to get you Warned if you continue.

66

Forum rules prevent me from identifying specific liars. I can only tell you in general terms.
A debate that I have often had with certain pseudo-sceptics follows this pattern.

**PS: **Dowsers always find water because the is always water to be found everywhere. A really great test would be to dare them to find dry spots instead. If they can find dry spots that would prove paranormal ability.

**Me: ** I think you’re wrong. Here’s a geologists survey.

PS : It’s obvious that you don’t understand it. How stupid you are. We sceptics have repeatedly dared dowsers to find dry spots. They *always *refuse.

**Me: ** Okay, I’ll accept the test then.

**PS ** What?

Me: I’ll show you an ability to find dry spots.

PS : No, you can’t do that.

Me: Why not, exactly?

**PS:**Because it’s not paranormal.

**Me:**I never said it was. In fact I openly state, there is nothing paranormal about finding dry spots.

PS: you’re trying to cheat. It’s not paranormal. You can’t do the test.

Me: I’m not cheating. I’m offering to take the test exactly as you set it. And YOU are claiming it as a paranormal feat, not me.

PS: But it isn’t paranormal. I won’t do it. You can’t take the test. Wah. I hate you, jibber, jibber, jibber…
I’ve had exactly that conversation with several people on this board. I’m not allowed to name them, but they know who they are. It’s obvious to me that they never believed their claims in the first place. They know that water is actually hard to find underground. They know that “find a dry spot” is a poorly thought out test. They know that they would dowsers have not refused to be tested this way. They know that the dowsers would win, if this test were ever carried out.

I am still waiting for response from Musicat and Czarcasm on this point. It’s remotely possible that they actually believe what they are saying, in which case they would agree to me taking the test, and would declare it paranormal (in their opinion, not mine) if I succeed.

67

No, that’s isn’t what they claim.

I do not claim that.

68

I don’t agree with your parsing of the rules, and since you were suspended recently, I don’t think the staff is going to have a lot of patience with you if you keep playing these kinds of games. When you are posting in GD, don’t call people who have argued against you liars, and save nonsense like “Wah. I hate you, jibber, jibber, jibber…” for the Pit. At a minimum, if you do this again you will be warned and instructed not to post in this thread anymore.

69

I’m a hydrogeologist!

You’re talking about different things. Peter Morris is talking about the surficial aquifer, which is unconfined groundwater found in glacial deposits. Compare his map to the map of the thickness of those deposits - the surficial aquifer is pretty strongly related to the thickness of that till. The Door Peninsula has a very thin layer of these sediments, so the groundwater found there is not considered part of the surficial aquifer.

That certainly doesn’t mean there’s no water there. It’s part of the Silurian-Devonian Aquifer, which is primarily carbonate and dolomite deposits 440 - 360 million years old. In that particular location, the aquifer is unconfined and is overlain by a small amount of surficial glacial till. The depth of the till is apparently not enough for the USGS to consider it part of the surficial aquifer, but it behaves the same way. At some point, calling it “surficial” or not is an arbitrary distinction.

Also - if there’s a conflict between an incredibly small scale map and your own (or somebody else’s) observations, then your map is probably either a) wrong, or b) too small to capture local features. Maps are awesome, but they’re not always right and they don’t always show what you want to know. They’re certainly not a reason to claim that somebody who tells you he has well water is lying.

And since I’m here: in my professional opinion, dowsing is bunk.

It’s true that you can’t sink wells randomly into an area colored yellow on a map, but who in their right mind would expect that you could? “Wet spots” and “dry spots” are meaningless, though - what a farmer might consider a “dry hole” for irrigation purposes is perfectly adequate to supply a single family home. A lot of work goes into selecting a good site to drill for a particular purpose, but none of it is magical. An experienced hydrogeologist could probably pick a decent spot for a shallow well by looking at surface features, topography and soil and vegetation types. If (s)he can do it, a good con man could do the same thing.

70

It seems as though there would be an easy way to test dowsing.

Have a team of “dosing experts” and a “skeptic geologist” team up with an open minded well drilling company. Any time the drilling company is called to drill a well and has some leeway as to where to place it, a coin is flipped and depending on the result either the dowser or the skeptic identifies where to drill goes to the site alone and marks the place to drill with a flag. The drill team arrives the next day drills at the designated site (without knowing how it was determined) and indicates how far they needed to drill to discover water. This is repeated a large number of times (determined by an appropriate power calculation) and then the results of the dowsers are compared to the results of the skeptic via an appropriate predetermined statistical test (such as wilcoxon ranksum)

This would be a direct blinded test of dowsing ability under real world conditions. If a dowser can’t pass a test under these conditions than there is clearly no benefit to hiring a dowser, since this setup would be exactly the setup that would be used if an actual dowser would be beneficial. If it was shown that the dowsers were more successful, then further studies could investigate how it works (such as subconscious sensitivity to geologic clues), but it would be clear that dowsing does provide some benefit whether or not its supernatural.

I don’t think it would be particularly onerous for any of the parties involved, (except possibly the dowsers who would have to do some pro-bono work but who also have the most to gain if their beliefs are correct), and you could probably get the investigators could probably get a paper out of it somewhere.

71

A point of clarification here is what is meant by ‘dry spots’ when it comes to dowsing tests. The aforementioned ‘dry spot’ locating Randi discusses is his retort to the notion of ‘underground rivers’ dowsers hold (or used to hold, some say dowsers have adapted to the idea of aquifers, YMMV). With these ‘underground rivers’ in mind the ‘dry spot’ is not a location with low flow, or a well that strikes damp soil, but a completely dry spot. The difference should be between standing 50 feet from the edge of a river and actually being in the river. It should be as different as a moonless midnight is to high noon. The terminology as used by well diggers and the like might consider a low-flowing well to be ‘dry’ but that is not relevant to what is being discussed. That definition is being abused, however.

72

Buck Godot, your suggested test would be good to do. The biggest problem I see is the extreme expense of drilling. My well was drilled over 20 years ago at $10 per foot and we had to go to 330 ft to fulfill state health requirements. It is not unusual for a well in my area to cost $10,000 today.

So drilling multiple wells would be quite expensive, and each one can take days, depending on depth and kinds of soil or rock encountered. There’s always the fear that even if we don’t find water at depth of X, if only we went down to X+10, we might have. So where do we stop?

If dowsers would insist that their rods don’t work over water-filled jugs, we would be left with drilling as the only option. But many dowsers do insist, with confidence, that they can detect water in jugs, not to mention lost dogs and missing jewelry. Indeed, in the tests I’ve seen, they are 100% accurate* when they know which jugs are the water-filled ones,* but can only perform at the level of chance if they do not. Either a jug has water or it does not; this assurance cannot be made by drilling unless you can drill infinitely deep.

If you can fill 1 out of ten jugs with water, you can establish the mathematical odds of detection (1/10). But what are the odds of finding water by drilling? If they are 100%, as is true in some areas, then finding water by a dowsing rod would be unremarkable, would it not? Conversely, in a dry area, finding any water might be impossible. In any geological location, there is more at work than just a purely mathematical odds calculation, and that renders a drilling test much less valuable than we would like. We’d best stick to the simple and cheap.

I’m not sure how a test for grave dowsing would be done. I guess the first step would be for the dowser to explain just what he thinks he is detecting – dead bodies, caskets, vaults or cavities.

Enginerd, thanks for stopping by and gracing us with your knowledge. I don’t know how familiar you are with the Door Peninsula, but I’m sure you know it is karst country, with thin soils on the surface and many cracks below. It also is surrounded by water (Lake Michigan, Green Bay), so if I were a dowser for money, this is where I’d like to practice!

73

Yeah, but the trouble is that the dowsers are right about those ‘underground rivers’ and Randi’s reaction to it is totally misinformed.

To be clear, the dowsers usually talk about ‘channels.’ The word ‘rivers’ is Randi’s substitution.

74

To be clear, I usually have read about dowsers referring to “rivers”, and rarely have I heard them use the term “channels” unless in reference to “channelling”.

75

I’m your private dowser,
A dowser for money,
I’ll find lots of water for you.
I’m your private dowser,
A dowser for money,
I can find your lost car keys too.

76

In general, neither underground “channels” nor “rivers” exist, except in areas of specific geological formations (like the karst settings Musicat mentioned).

For the most part, what we call a groundwater aquifer is what a layman would call mud - it’s water flowing in the pores between the grains of soil particles. In other cases, it’s water flowing in interconnected fracture networks within consolidated material. Neither of these cases form anything that could reasonably be described as a channel.

77

I used to play with Ouija boards. Sometimes I would move the planchette myself to give the other person the messages I wanted to convey and I found that I could actually direct it more when my touch was lightest on it. I knew intelligent people who swore by the “messages” they got when it was really me working it or even when they were working it themselves- the same with pendulums and other New Age accoutrement.

A test I tried once with Ouija boards: I went diving in a dictionary, chose a word at random (I still remember it was obsequious), wrote it on a piece of paper and turned it face up on top of a refrigerator, and asked the two people doing the Ouija to ask the “spirit” what was written on it. They couldn’t do it of course. I tried it myself as one of the planchette touchers and, though I absolutely did not think I was controlling it, it began spelling out the right letters. That’s when I knew that I didn’t have to be consciously controlling it to be deliberately spelling out what I wanted or expected it to say. (My cousin I was working it with put this down to the logical explanation that the spirit was using my eyes to see through or some such.)

From all I’ve read and seen dowsing works in a similar fashion: the person holding it is really the person controlling it but often they themselves are unaware of it. Sometimes it might even be nothing more than nerve endings saying “I’m tired”, but I think to the extent it works at all it’s most likely that the person notices “there’s some disturbed dirt/a slight depression/it looks like a grave” and their subconscious directs this to their fingertips. I think to the extent

78

I think “gracing” might be a little strong, but thanks for this just the same. I’d definitely try out my dousing abilities somewhere similar. My other choice would be a coastal river delta - in a wide, flat alluvial fan alongside an effectively infinite body of water, you’d be hard pressed to miss!

79

This is another of Randi’s made up stories. It doesn’t actually happen in real life.

In reality, Randi tries to blackmail the dowsers who apply for his test. He makes a direct threat against them. Either they state that they are getting 100% in the open test, or they are disqualified. No flexibility.

The fact is that almost all dowsers refuse to do it. Only a tiny number have ever gone through with it. Each one of them only said it after they were threatened. And some of them went on to get much higher than chance on the actual test.

Again, let me say, the higher than chance score reflects poor test design, not actual dowsing skill. But Randi’s claim that they "only perform at the level of chance " is a lie.

80

Aside from the Randi tangent, you are aware that dowsing isn’t real, right? It’s made up.

I just want to make sure what you’re arguing here.