The Bourbon news. [volume] (Paris, Ky.) 1895-19??, 1904-02-16
NOISE MADE BY BgETEORS.
Various Theories 10 Account for ths
Rumble That Is Sometimes
Heard.

Heard.
The great majority of netcors arr
Silent. They slide through the air with
"ut eEcounteriLg much resistance, be-
fause the bits OF stone Ct which iney are
composed are usually very small-ro;
eigeer than pebbles. perhaps. They H.
with such velocity, though, that friction
with the air makes their surface incan-
descent, and t1ey are visible at a con-
siderable height, even if noiseless. Al
rare intervals, however, the atmosphere
IS penetrated by what are probably lar
ser masses Of stone or metal OWNS tc
the fact that the exterior expands rem
neat mere rapidly than the Interior
W1lch retains the Theoretically low ten
per2tUra OF outer space for several sec
cnCs, CT from some othsr cause, these
treballs' are attended by 3 sound. This
has been described Is resembling the
Eoise produced by moving heavy piece
OF furniture over bare floor, or distant
thunder, or prolonged volley of mus
kerry.
The meteor moves so rapidly that
there is, as it were, a straight line many
miles long and 100 nii2s distant from the
observer which becomes the source Of
sound waves starting almost simultane-
ously from the whole length Of the path.
According to the United States Weather
Review, the ncentration of these
waves at the observers station explains
the explosive noise and the subsequent
rafting, but what makes the Original
violent sound waves? There are four
ideas as to this, all OF which may -
true:
First-The meteor strikes the air sc
violently as to produce the same effect
as when it strikes liquid or solid
Secord-The rapid movement Of the
meteor leaves a long vacuous trail, into
which the surrounding air rushcs and
the impact Of air on air starts the sound
wave.
Third-The meteor revolving rapidly
on its axis, striking the al. myriad OF
tines On all sides, produces rapid sue
ccss:on Of waves.
Fourth-The meteor is so heated By
tA-C I'LL CSS&O1 VI Ill IL ~ O-lI I-Ic-L II
burns aid cracks, ard there is a cCntin-
ucus suffering as its surface particles
burn up, split eff and flow away.
What are the phenomena Of sound OBJ
served a short distance froEl the path OF
proiectile when going past the observer
at the greatest possible speed? This
question the editor CT the Review pro-
pounded to a number of naval officers
One Of them replied: while in the ofice
at the naval proving ground l have, OF
course, frequently heard the sound Of
passing projectiies. AS the disturbed
air wave reaches you, sound is made
that is about half way between boom
and a crack, and then moment later
comes the boom of the discharge The
crack is almost as loud as the boom,
and perhaps a little more annoying.
When large shot tumbles, the rumble
sounds to those near the trajectory like
that Of railroad train"
Probably 70 shot from a cannon
travel faster than $500 or 5000 feet
second. This is from half to two-thirds
Of a mile. Many meteOrs move at the
rate OF ten, Is and even 90 miles second.
Besides, their irregular shape ought to
make mere of a disturbance than
smooth and Symmetrical shot from 4
cannon. The editor Of the Review does
rot himself choose between the four
theories that have been advanced, but
oHe Of tie military officers who was per-
haps thinking OF the commonly accepted
Lct:0I of thunder. lays much stress or
the thrush Of air into the vacuum created
by tie passage Of the meteor.