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This discussion brought to mind Professor Keay's theory of electophonics and the passage of bolides through the atmosphere.Those of you who have association with our Newcastle university in the Hunter may already know of his ideas. I have briefly extracted some development of this theory from an essay i found on the web titled "What planet is this?" Essays by Sean B palmer .30 Oct 2005. This extract is as follows:
Electrophonic Sounds from Bolides
On 19th March 1719 a very bright meteor, usually known as a fireball or bolide, was seen across England and Scotland .Edmond Halley, who would replace John Flamsteed as Astronomer Royal the next year, collected a series of accounts of this bolide and published them in the Philosophical Transactions of the Royal Society. The sightings enabled him to derive the bolide's course by triangulation, and as Halley concluded, "they abundantly evince the height thereof to have exceeded sixty English miles." Halley also wrote about the effects of fancy that people under the bolide's path reported, including "hearing it hiss as it went along", feeling "the Warmth of its Beams", and such like .Meanwhile People continued to report sounds associated with meteors, and after another remarkable bolide in 1783 the physician Sir Charles Blagden published a study into the subsequent hissing reports. The debate carried on into the twentieth century. In 1933 noted meteor researcher C.C. Wylie dismissed noises accompanying meteors as a purely psychological phenomenon. In 1937 Stanley Smith Stevens coined the term "electrophonic noise" for sound heard by electrical stimulation, which Peter Dravert adapted in 1940 as "electrophonic bolides" for meteors which cause electrophonic noise. The first major turn towards the acceptance of electrophonic bolides came with C.S.L. Keay's (Of our own Newcastle University) 1980 theory of Geophysical Electrophonics whereby radio waves emitted by meteors could be transduced into audible noise by objects on the ground. It was another remarkable bolide that had prompted his studies, one which passed over Sydney, Australia, on 7th April 1978. First published in the journal Science, Keay's theory was such that meteors can emit radio waves in the VLF range, which is an equivalent frequency to audible sound. It also proposed a mechanism by which these radio waves could be produced, called the "magnetic spaghetti" effect, though it wasn't until 1990 that they were first detected by a Japanese team at Nagoya University.
philip
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