Documents / Report
The Roswell Report: Fact versus Fiction in the New Mexico Desert was published by Headquarters United States Air Force in 1995. The Black Vault distributes this copy. It reproduces the report by Col. Richard L. Weaver and the synopsis by 1st Lt. James McAndrew, both written after a General Accounting Office inquiry requested by Representative Steven Schiff. The Air Force search found no evidence of an extraterrestrial craft or crew. It concluded that the Roswell debris most likely came from NYU Flight No. 4, a Project MOGUL balloon train.
“Blanchard”20 pages
## I EXISTENCE OF A SOUND CHANNEL IN THE ATMOSPHERE In September, 1944, it occurred to me that there is a similar sound channel in the atmosphere with the axis at a height of about 45,000 feet, and that, with source and receiver placed at this height, we might exceed the accepted ranges as enormously as we had in the ocean. In other words, it might be possible to detect sound half way around the world. The fundamental data on this subject as revealed during a hurried search of the literature (mostly prior to 1930), show that, for a typical large explosion, there is audibility from 0 to 25 miles and from 90 to 125 miles, with a zone of silence from 25 to 90 miles. The accepted explanation of the total collection of these data is that the speed of sound decreases from about 1090 ft/sec at the surface to about 970 ft/sec at about 45,000 feet, and then increases to about 1165 ft/sec at about 130,000 feet. (Reference 2) Thus there is a sound channel in the atmosphere with its axis at a height of about 45,000 feet, and if both sound source and receiver are located at this height, we may expect extraordinary ranges and all the other useful phenomena which have been found in the sound channel in the ocean. This means that the signals will have highly characteristic identifying features and that they will permit accurate triangulation. ## III PROBABLE MAXIMUM RANGE The maximum range for sonic signalling in the atmospheric sound channel will depend primarily on the absorption coefficient, which is the rate at which the acoustical energy is converted into heat by frictional losses. Following Kayleigh (Reference 3, p. 316), it may be calculated that the distance at which sound of frequency 50 cycles per second would be reduced in intensity by the factor 7.5 by the effect of friction alone is about 24,000 miles at sea level, and about 4500 miles at 45,000 feet. As these distances are inversely proportional to the square of the frequency, they would be one hundred times greater for sounds of frequency 5 cycles per second, which have often been observed when large explosions were studied.
Report, cited by the archive. The PDF is mirrored here; the original link is under it. The text was read from the page images by an OCR model; expect the odd misread word. 882 pages are in the text index: search them above, or from the library's search.