[- Tectonic Stress Theory -]Two theorists, Michael Persinger and Paul Devereux, have independently proposed geophysical explanations for anomalous phenomena. Persinger's idea, called the tectonic stress theory (TST), argues that strain fields within the earth's crust produce electromagnetic charges which create bodies of light or generate hallucinations, based on images from popular culture, of alien craft, beings, communications, or creatures. A variant of the theory is Devereux's notion of "earthlights."
Devereux's approach differs from Persinger's in holding triboluminescence rather than piezoelectricity to be the "more likely candidate" for the production of naturally occurring UFOs. Whereas Persinger contends that UFO-like lights may manifest hundreds of miles away from an area of seismic activity, Devereux generally restricts such effects to the immediate vicinity of a fault line.
Beyond this, however, Devereux's is the more radical hypothesis. In his view earthlights may possess intelligence and even be able to read witnesses' thoughts. He ties this putative energy-which he calls an "unfamiliar form of electromagnetism or ... of a completely unknown order ... a secret force"to a transformative, New Age vision. Earthlights research, according to Devereux, "holds the potential of creating a whole new area of human study, one of evolutionary significance, one that can help heal the fragmentation that bedevils our contemporary way of thinking about so many matters."
Persinger's theory has been published-and criticized-in the scientific literature. Its empirical base is weak, and its critics complain that Persinger tries to explain one unknown, UFOs, with another. They also note that UFO and "monster" sightings occur in seismically inactive areas. To skeptics such as Chris Rutkowski and Greg Long, alleged TST effects and earthlights are as likely to be known natural phenomena-ball lightning, earthquake lights, will-o'-the-wisp-as the extraordinary counterparts Persinger and Devereux suggest.
Concerning Devereux's attempt to explain UFOs, Long writes, "Devereux fails to recognize that when the various reports of 'earthlights' are carefully studied, a wide variety of lightforms is quickly noted; but even more, the reports describe objects so artificial in appearance, so intelligent in their behavior, so purposeful, that it is impossible to conceive that the objects are anything other than technological machines. Nothing in these accounts remotely suggests a ball or mass of energy." Rutkowski says, "Although the hypothesis that the lights represent a kind of EM [electromagnetic] phenomenon is supported by some circumstantial and observational evidence, the empirical question of whether or not such energy can actually exist needs further study."