In what are considered to be persistent regional anomalies like "mystery lights" that seem to have high crystalline content geological deposits that may or may not be a link to transient atmospheric plasmas or piezeoelectric effects, http://en.wikipedia.org/wiki/Piezoelectricity
, there have been equally persistent observer reports of these brilliant, high velocity , high frequency lights (contained within an unknown membrane), shedding material to the ground as it dissipates in brightness. The Bentwaters Case comes to mind. Was there residue found? Was it even searched for? The same situation has occurred with some, but far from all UAV reports.
From the Sturrock Panel Report is a typical case that occurred in Trans-en-Provence, France, on January 8, 1981 . Dr Vallee was involved in this particular case.
"A team from GEPAN/SEPRA carried out a site visit on February 17, 1981, 40 days after the event. The trace was still visible since there had been very little rainfall since January 8. The arc-shaped area, lighter than the rest of the terrain, was still visible. The soil in this region was heavily compacted, forming a crust. Soil samples were taken both on January 9 and on February 17. These samples were then forwarded to various laboratories equipped for physical and chemical analyses. It was found that the compacted soil had a thickness of 6-7 mm. There was no trace of organic compounds such as one might expect to be produced by combustion. There was some evidence of iron in the form of striations about 1 micron thick, but the iron was not accompanied by chromium, manganese or nickel as would be the case for steel. There was some evidence of polymers. Traces of phosphate and zinc were also found. Traces visible as striations seemed to have been produced by a combination of mechanical and thermal effects.
Visual and microscopic examination revealed that, apart from the striations, the soil had been compacted without major heating, since the structure of calcium carbonate was not affected. Velasco has made an order-of-magnitude estimate indicating that, to produce the measured compression of the soil, one would need a stationary object of about 700 kilograms. On the other hand, the same indentations in the soil could have been made by an object of lower mass if the object were moving at a few meters per second at the time of impact. "
We know that high purity magnesium samples have been analyzed that have been purported to be from some UAV incidents. The residue of powder like substances in several cases both here and in Europe, have been analyzed but the results have been inconclusive. All laboratory experiments have failed to reproduce anything but ridiculously transient effects ( in fractions of a second) that are anything like what is observed in the field. So, there a lot of tantalizing bits and pieces of the physicality of the phenomenon ( like luminosity to amplitude studies) as well as effects on cellular biology, but none have these have been correlated into a coherent theory. My interest is the the psychological, neurological and physiological end of the phenomenon as in mythologies, anthropology and sociology. I think there is a direct linkage to a third state of matter, between the classic wave and particle models, that is transient and requires certain preconditions to occur locally..much like a weather system which is self organizing to an extent...which I think is also linked to the nature of the mind, which science is just beginning to explore with quantum models , specifically the neural, pre-synaptic connections that are capable of a quantum state, which may be a gateway, if you will, to parallel experiential realities. It's all a fascinating business..which I honestly believe one day will be somewhat better understood.