Richmond times-dispatch. [volume] (Richmond, Va.) 1914-current, 1919-12-07
WEIGHT OF LIGHT
IS DETERMINED
Artitlcially Made 1t Costs About
$5o,ooo,ooo an
Ounce.
RESULT OF ECLIPSE STUDY
British Scientists Report Find
ings Made While Over
in Brazil.
ny CHARLES DAVIDSON. +. II. A. $

by CHARLES DAVIDSON. T.. II. A. s..
LONDON, Dec. 6.-Thc result OF the
British n exnedi,ions to sobnal, in Erazh
west coast of Africa. in nontecnnical
language is to prove that light has
M ma,er h IN proportion hI, to It's mass as
amount OF light to weigh an ounce.
The cost OF light as supplied by gas
and electric light companies works
o.!o at at o,6 something like iio ooo.o
the moral OF daylight saving. the
sun snowe7s down on US 100 tons Of
TINS valuable STUFF every day, and yet
We often neglect this free gift and
prefer to pay E1o.000OO0 an ounce for
much inferior quality.
There are two theories Of light
The corpuscular and the unduiatory.
Tho corpuseular supposes that light
is composed Of stream OF PARTICLES
rms is not accepted now, but was the
theory held by Sir Isaac Newton who
in consonance with the law of gravi-
tation that light in passing the sun.
would be detected from the straight
In the early part OF the nineteenth
century the corpuscular theory gave
place to the undulatory theory. which
hypothccated for the transmission OF
light. or late years it has gradually
appeared that matter is electrical In
IFS nature. and that its mass is the
electro magnetic energy bound up in
rs ,; atoms: Its weight. though not
mite proportionality 10 it's mass
Light is form OF electro ghetto
energy. and therefore has mass, but
me question TO be solved by the eclipse
expeditions was whether light had
weight If ligih, had weight as well
as mass. It would be DETECTED OH pass
the only way in which this could be
Tested was by observing stars close
70 the sun, and the only time at which
eclipse. 'o'a
The eclipse on May % last was a
tSs t;,n one fer the purpose. as at
Stars easd the % EFo4R hi of e S5Fhs
ths North on of ! souah
'nid-Atiantic and Central Africa.
Huge Telescope. Used.
tach OF the British expeditions took
telescope of thirteen inches aperture
and eleven feet focus as this teIe-
scope had been proved suitable on a
former occasion. In addition, the So.
, brai expedition took a supplemen,ary
nineteen feet focus. BY .Snic6 IL S wai
noped the brighter stars mig.t be
| Photographed.
was carried through successfuiiv
,housh at Principe they were con
A. sobra aithoush to YAH by wa SloS ihe
tthhe clouds U:.iy cleared away Just be,
lore IT began.
With the large telescope at Sobral
nineteen plates were exposed fif,esn
OF which were quite satisfactory: ms
o otneFs were spoilt by cloud With
the iour-lnch telescope eight plates
were exposed. OF which seven were
II ligh, were subject to gravity. fol-
grazing the limb OF the sun sun would be
aisplaced outward by QUANTITY
rather less than-th the two-thousandtb
part OF the diameter Of the moon
New Gravationnl Theory.
or recent years. however. a new
SravatlonaI theory has been put for
H Wnrn oy a German mathematician.
h h;o Einstein; and. according % TO-
twice as great. The eclipse EN- expedi lie
tons went in order to deternIinc
whether, ligh, was detected at All I'' nr
not, and. II detected. Whether IA az w or
according, to the Newtonian or rLs
Einstein law. " the
Having secured the eclipse nboto
graphs of The Hyades. il was neceS-
saEf lor the Sobral observers TO re-
main couple OF months in order to
secure the same field of stars in thc
nisht SKY, the whole test CONSISTING
IN "hether the presence or absence
OF the sun made difference in the
s stIrs relative positions OF the
Stars; These photographs were Sc
cured In July and the observers 70
turned to England. The photor5,nSs
nave now been measured and the 70.
of Einstein. '"e 'heor'