Richmond times-dispatch. [volume] (Richmond, Va.) 1914-current, 1920-03-21
(s0ME. CURIOUS FACTS AS
EXPLAINED by SCIENCE
Eminent Astronomer md Observer
Gives Some Interesting Data
to tho Reader,
ny GARRETT p. sERyIss

..
Does bullet travel faster than the
sound OF the gum asks a reader.
That depends. for the speed OF sound
is nearly uniform (abodt 1885 feet per
second in dry air at freezing, with n
small increase with the rise OF tenn
peraturo). while bullets not only star.
with various speeds. according to tho
force Impaired to Thorn by the powder
gases, but they lose speed the farther
eey go.
think that projectiles from most
riodcrn scns easily outstrip sound
throughout their effective striking
taes ee ept this %as mot the Win
q Springfield rifle gave a ,duzzle We
locity of l.S0o feet per second. which
M So naeS sat ia soand Of f he
explQs:on. travelling uniform speed
Of abou. LILO feet per second, would
thare- But now tho best rides give
muzzle "clocities double, or some times
inore than double. tho velocity OF
Can scientists tell at what distance
Inc moon would lose, or cease to reflect
The moon would not cease to re-
feet sunlight at any distance. There
Is no satisfactory evidence that light
u u !; Limited ~ IL, in its range; it's intensity
20 the square or the distance. The
"albedo." or rejecting power OF the
rra aon Esneraiy at the
moon, as whole. reflects about one
si1th OF the sunlight that falls upon 1t.
,n All the distance OF the moon were
upon IL would be reduced to one-quar-
Yer OF what 1t is at the present dis
OF light reflected would probably re-
main the same. tho only effect being
that the, intensity. OF moonlight on
INC earth would be one-quartcr as
DO solids have tho same tempera-
dnro Throughout under the same con-
ditions: block OF ice. for instance
naa IT the aamc temperature on it's
surfaces as its center?'
with a smalr mass, such As block
% ice. the temperature would be vir-
baly the same throughout unless tho
surface temperature was raised by APP
piication OF heat from without. caus-
iinnE rise OF temperature to begin at
.he surface and extend inward But
fi.pesy great mass. like the earth, or
Internal Ihan ef has miariedly higher
owing to the Eravitational Drcssure az
IT'S own particles.
,.mpera,afe se ean cause rise of
ergy il convertibe into heat. and
me motion o or the molecules OF, a com
persiur. suG bea, ,t Increases the ten
molecular. agitation. You ask If The
,msight OF block OF ice raises tho
e spn,peI II los. at tho bottom 1heoreti
elect might be perceived the block
would have 10 be of great size. There
seen the effect or "t pressure e"o on pee ice
anu on the majority OF other solids.
is special property OF water to
follows that when Ice mcIts its
volume contracts Then. IL pressure
- PVT upon Ice. tending to squeeze
virtually. TO lower the melting point
OF the Ice. go that under pressure
nee turns to water at a lower tenn
met II no pressure were applied.
4 uut most substances. rock for in
stance, contrac, on soiidifying and ex-
The effect of pressure is exactly the
opposite 10 what II is in tho case Of
ice; In other words il, tends TO raise
The melting. or iiquefying, point The
reason - evident. since in ordcr to be-
come liquid the substance. by the law
o, us nature: must expand. but The
itossnre resists the expansion. SO thai
,hs neat or molecular agitation neces-
sary TO force Iiquefaction must DO
sreatnr than WHO'RE no pressure is
This fact lies, in certain way. a.,
the. bottom OF the safety of the world.
wing to The great pressure inside the
earth the heat there is enormous vet
the globe remains rigid. and does not
Weld to the disastrous extent that it
oncs to wSsh it is zu uhs naas
tidal strain. The heat at n depth Of
b twenty or thirty miles is probably
sufficient to liaucfy the most obdurnte
thermal condition at the earth's CEN
ter: but. on the other hand, the pres
sure producing this heat at the same
sine raises the melting point OF the
rocks so high that actual liquefaction
cannot take place. Suddenly release
the pressure and the earth would flash
into a ball OF liquid fire! On the con
trarN- IL the earth had been u bail
OF Ice the internal pressure would
have turned II into a sphere OF water,
kind of celestial fsh-Globc!
Sh.pe EIan.eIs rbornnrL