My copy of 'Handbook of Unusual Natural Phenomena' by William Corliss makes for some interesting reading for those interested in unusual phenomena of our natural world, which have been described in some very significant scientific literature over the last century. I cannot attest to the accuracy of every report by Corliss, in his Sourcebook Project, but I have seen/experienced some of the phenomena described in this book, and have no reason to suspect the others that are also described.
Spook lights...seem to be a variety of phenomena that seem to be discrete localized, glowing balls of light encountered on certain dark roads. They behave irratically, and disappear when you get too close. I am reminded of ball lightning and other electromagnetic phenomena which have recently become respectable science. No one has a very good explanation for 'spook lights', although I have not really bothered to read the literature, mainly because there is too much fluff and not enough physics in it. They also seem to be a companion to reports of ghosts and hauntings which in many cases are just plain absurd.
Singing Sands Apparently there are several locations throughout the world where desert sand dunes composed of very minute grains, produce sounds as they move that can appear as musical notes, pitches, booms or other non abrasive sounds. The book notes a 'hill of moving sand' in the eastern part of Churchill COunty nevada about 60 miles from Land Springs Station, about 4 miles by 1 mile wide. The sand is so fine it leaks through burlap bags, and when parts of it move, it sounds like wind blowing across telephone wires, but so loud that it can be heard for miles. There are also the musical sands of Jebel Nagus in the Sinai on the western-coast range about 5 miles north of the port of Tor. The slope is about 200 feet high and 80 yards long. Sandstone cliffs overhang it and bound it on either side. When set in motion, the sand sounds like a wet finger moving along the rim of a glass. For a bit more, see the discussion of friction by Dr. Guran over at the Department of Electrical Engineering at the University of Southern California, or the tourist information over in Scotland under Garraig Fhada Lighthouse and Farm which includes a tour of the beach and Singing Sands. Under 'Singing Sands' with AltaVista, you get about 100 hits. Under 'Musical Sands' you get 4 hits.
In the March 6, 1997 issue of Nature vol. 386, p. 29 there is a letter to the editor by three engineers/physicists at Laurentian University, Sudbury Ontario, "Natural and Artificial 'singing' sands". They say that the squeaks and rumbles reported by these sands is well known, but still poorly understood. They propose from experiments with various grades of fine sand and sand powers, that many singing sands are well-sorted with sizes from 100 to 500 microns, round shapes, and high in quartz content. They all share a broad spectral feature from 2800 to 3400 /cm which they say may be due to clusters of water in an amorphous silica layer on the surface of each sand particle. They discovered that sands that do not sing can be made to do so by grinding the grains in a mill, removing the 'fines' and adding water to surface polish the grains. Once they show the characteristic 3400 /cm band they start to sing. The 'Kaui Singing Sands' in Hawaii show this spectral feature and are also small polished grains. They obtained a commercial silica-gel powder from Fisher Scientific with a grain size of 200-500 microns. Sharp shaking of about 200 grams of this material in a glass bottle produced a loud sound similar to singing sand at a frequency of 450 Hertz, and also had the 3400 /cm feature. They concluded that ...the emission of a coherent wave pattern requires a minimal number of grains to stick together, and that these particles when stimilated by rolling down a slope of a sand dune cause a natural resonance. This phenomenon can now be replicated in the lab for sloser acoustic study.
Mistpouffers...also called Brontidi in Italian, Uminari in Japanese or Barisal Guns in India, these are sharp acoustic reports that sound like cannons or sonic booms, which seem to be reported in many coastal communities around the world. Most recently in the northeast seaboard of the United States, in 1978 and 1979, they were explained as aircraft sonic booms, although no identified aircraft were ever discovered ( Science News, vol 110, p. 346, 1978). But they, or something like them, have been heard for centuries, and even inland communities have their own equivalents 'landguns'. Among the explanations have been meteor impacts ( highly plausible in some cases, but not for sites where the sounds repeat day after day, or year after year!) or gas escaping from below the surface through narrow vents.
I would love to hear more accounts of these in modern times. Most of the reports in Corliss's book seem to date only from the last century or early in the 20th. Has our environment become too noisy in modern times, or have more critical observations dispelled the existence of many of these phenomena?