Okay, this is an old one, but I didn’t find it covered anywhere on the site. Not sure about Alex’s books. Boingboing sums it up better than I can (especially at this hour) so I will quote them here:
Hollow Earthers’ favorite experiment analyzed
In 1901 a mining engineer named J.B. Watson was said to have dropped plumb bobs down two 4250 foot mine shafts spaced 3200 feet apart. His measurements indicated that the plumb lines were farther apart at the bottom than than they were at the top. In other words, they diverged as they descended. Common sense would tell you that the lines would converge as they descended, because the lines should point towards the center of the Earth.
For the last century, some people like to point to the Tamarack Mines experiment as proof that the Earth is hollow.
Donald E. Simanek, who writes for MAKE magazine about curious physics (here’s his article about perpetual motion that appeared in Vol 9), has an excellent article on his website that recounts the history of the alleged experiment, and examines the different frequently-offered reasons why plumb lines might diverge like this.
Well of course they diverge… Da’ Tamarack is in ‘da U.P. of Michigan… which is Heaven.
Since everyone knows heaven is “UP”.... it is obvious why the strings diverged.
(note: explanation of Michigan humor… The Mackinac Bridge connects the Upper peninsula to the Lower peninsula… people living in the Lower peninsula are nicknamed “trolls” by those fortunate enough to reside in the Upper… )
Anyone who has ever tried to use a plumb bob in their home knows how difficult it is to get the plumb bob to stop swinging. And this is a problem when the length of the plumb bob is only 7 or 8 feet. Imagine the difficulty if the plumb bob is 4000 feet long! My question is, how did Watson know the weight at the bottom had stopped moving? I suppose if you left it for a couple of days or weeks you could assume it was stationary. Then there is the problem of measuring the distance between two plumb bobs that are 4000 feet underground and 3200 feet apart. The only way I can think of (with 1901 technology) is to suspend them from a great height above the top of the hole, measure across at the ground and up at the attachment point. If done carefully this could give acceptable accuracy. Of course in modern construction work, the plumb bob is obsolete. Today they use lasers on a level. They’re quicker and more accurate.
All that aside, what we are seeing here is typical pseudo-scientific nonsense. They point to this single event and ignore the overwhelming amount of evidence that contradicts it. Has anyone repeated the experiment since and gotten similar results? In my line of work (oil and gas exploration) we drill holes in the ground every day. Often these holes are what we call directional wells. That is, after starting off vertical for 500 to 1000 meters, they intentionally go off at an angle. To get to the target location we use equipment which has accelerometers and magnetometers that tell us the angle and direction we are drilling to a fraction of a degree. We know where we have to go because seismic surveys done previously show us the places where petroleum is trapped. We know we drilled to that spot because we find oil or gas in the places the instruments tell us we drilled to. If Watson’s experiment proves the earth is hollow, then our directional drilling system, which assumes the earth is solid, would not work. So I think it’s safe to say the Hollow Earthers are full of it (pardon the pun).
It states that the bobs were immersed in oil at the bottom to minimize vibration, and I assume they waited a very long time before making measurements to assure themselves that the bobs were done swinging. The whole setup sounds very scientifically done, I don’t think there was anything half-assed about it. It sounds like their observations were very scientific, on the whole, trying to take things such as air currents and magnetic attraction into account on their various attempts. And they were only replicating earlier experiments which reached similar conclusions.
Although I haven’t finished reading then entire article, I would assume the shafts ended in the straight horizontal shaft that allowed them to run a tape just as on the surface.
A U.S. scientist and a small band of believers are planning a journey to the Canadian Arctic for what they call “the greatest geological expedition in history.”
Are they searching for Arctic oil reserves? Documenting evidence of climate change?
Not quite. They’re looking for a fog-shrouded hole in the Arctic Ocean that leads—they say—to the centre of the Earth, where an unknown civilization is lurking inside the hollow core of the planet.
This time next year, Kentucky based physicist and futurist Brooks Agnew hopes to board the commercially owned Russian icebreaker Yamal in the port of Murmansk, and to sail into the polar sea just beyond Canada’s Arctic islands.
“Everest has been climbed a hundred times,” Mr. Agnew says. “The Titanic has been scanned from stem to stern. [But] this is the first and only expedition to the North Pole opening ever attempted.”
Who is nearby and willing to join them as a MoH investigator?