Two 4000 ft plumb bobs hung down a mine shaft, with baffling results (1901) | Hacker News Reader

Two 4000 ft plumb bobs hung down a mine shaft, with baffling results (1901)

lockhaven.edu

Skimmed, but what I gathered is:

The plumb lines diverged a bit. According to Palmer this means the earth is hollow, and everyone except him is chocking it up to air currents. Clearly, they can be pretty significant at that sort of distance. Few have been able to replicate the results all, and most get the expected results (parallel, with room for jostling / air currents randomizing).

Feel free to correct me if I'm wrong. It's too much to absorb right now.

That, and he completely ignored coriolis forces, which apparently explain the divergence nicely.

This is long, but interesting so let me try to summarize.

In early 1900s, two lines measuring 4250 feet each were hung down a mine shaft on several occasions in order to calculate the radius of the earth. Scientists expected the bottom of the lines to be closer together than the top, but the opposite was found to be true. The bottom of the lines was 8.2 inches further apart than the top. Several theories were put forth to explain the reasoning behind this, but all failed to account for the large discrepancy from the expected results.

This was my favorite theory: One central tenet of Teed's philosophy held that the earth is a hollow rock shell, and we live and walk on the inside surface of this shell. The entire universe, which is mostly an illusion caused by gravic and levic rays and light, lies within this shell. This complicated view was called the cellular cosmogony, the earth-cell theory or the Koreshan cosmogony.

Hmmm. I wonder want's on the outside then... Seems to cause more problems than it solves, even for the simple-minded folk who believe this (and I have met at least one guy who believed this).

Don't forget, that first space flight came 50 years later...

this sort of story illustrates what a wikipedia type repository of knowledge misses. wikipedia will typically have the most up to date explanation of an event or phenomena, but it can be very illuminating to see past wrong explanations and the people and situations which gave rise to those incorrect explanations. this is even more valuable on topics where heavy revisionism has made it difficult to discern why the current explanation is accepted.

This can be put on Wikipedia. They keep known-false things in there, with adequate flagging that it is such.

As long as it exists somewhere else, it can be on Wikipedia.

As long as it exists somewhere else, it can be on Wikipedia.

Unless it's not "notable" enough to warrant inclusion.

Eventually, Wikipedia will also be a source of past-wrong explanations, in the form of years-old page revisions.

i have a feeling that old page revisions aren't considered that valuable and significantly old ones may be dropped.

No, they're not dropped, as that would violate attribution requirements. They are, however, compacted and compressed to take less space (at the expense of more CPU to access, but the typical user won't notice this)

Divergences are given in so many units it's really hard to compare anything. Examples: 0.018 foot, 0.04 inch, 0.045 cm.

There are 12 inches in a foot, and 2.54 cm in an inch. What's the problem?

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