Evening star., 1948-05-21
sto,s. Men and Atoms
Ieoping Sound Discovery
Is Reported by Physicists
Helisoland Blast Reverberations
Measured at Observation Posts
By Thomas r. Henry

By Thomas r. Henry
"Leapang sound" hitherto undemonstrated
natural phenomenon. Is reported by Naval
Ordnance Laboratory physicists.
Headed by DR.. J. v. Atanasof, who was
working on q project instituted. by the Office
of Naval Research, they maintained string
of ten observation posts stretched across
Europe from Cuxhaven, Germany, to Goritza
Just outside Trieste when the British Army
destroyed the Notifications Of Heligoland with
5000 tons Of high explosive last summer.
Their Job was to measure the intensity and
determine precisely the arrival times Of the
inaudible sound waves in the atmosphere set
up by the worlds greatest man-made explo-
sion. The explosive charges were so arranged
with different lengths Of quick burning fuses
that the entire 5000 tons went OF at once,
so thoroughly devastating the North Sea is
land that presumably it never can be fortified
again.
Train Of Reverberation.
Such a blast naturally started an enormous
train OF reverberations in the atmosphere. The
audible sound waves quickly became too at
tenuated to be detected by human ear.
However the extremely sensitive sound-de-
tecting mechanisms with which the Naval
Ordnance Laboratory stations were equipped
were able to detect family the inaudible waves
Of lower frequency at distance Of 600 miles.
When work Of analyzing the results was
started In Washington-it is an enormous
job still far from completion-it soon became
apparent that this train of sound waves was
not acting entirely in accordance with physical
theory. Sound moves in straight line
through air at precisely determinable speed
about eleven hundred feet second. Ac-
tualy they were minutes late in reaching some
observation posts although almost exactly on
time at the stations next in line. The con-
clusion was that parts of the train of sound
waves had taken flying leaps of few miles.
A similar phenomenon, although due to
quite different causes, is experienced in the
case Of radio waves which will skip long dis
tances. This is due to the so-called .Heavyside
layer, one Of the electrical roofs of the earth,
which reflects these waves and prevents them
from escaping into space thus making long
distance transmission possible.
Temperature Strata.
The phenomenon observed from the Heligo-
land explosion is described by DR.. Atanasoh
as sort of acoustic Heavyside layer"
Speed of sound varies with the temperature
of the air through which it passes Although
held theoretically for some years, 1t has only
been demonstrated by W. rocket flights in
the past few months that above the strato-
sphere there is rapid increase in tempera.
ture, followed by sharp decline to far be-
low zero and then by another rise to more
than tropical heat.
Apparently these different temperature
strata act on sound waves in somewhat the
same fashion as the electrical strata on radio
waves. The arrival times check WELL DR..
Atanasof says, with calculations based on the
recent W. findings. One practical possibility is
that of determining temperatures at different
points in the upper atmosphere by sound
waves.