New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1903-10-26
rs THERE RADIUM IN THE SUM-

Several letters which have appeared in Nat
ure'' during the last two or three weeks show
that the discovery of radium has given new
turn TO astronomical and geological thought AS
If the properties of that substance We're not
wonderful enough in themselves, it is now
limited that they may furnish new clews to the
age of the sun and earth. over which the gravest
philosophers have permitted themselves to spec
ulate.
Concerning the former of these two bodies,
Lord Kelvin once made an impressive computa-
ton. 1t was based on the Helmholtz theory Of
the source of solar heat-that the latter was a
product of mechanical compression through
gravitation-and an estimate of Pouillet con-
corning the rate OF radiation Lord Kelvin
thought It almost certain that the sun could
not have been throwing off energy for 100000
600 years and that its age was probably" not
over 1OO,OO0O0O. Professor George II. Darwin
now points out that IL Langleys solar constant
had been substituted for Pouillet's the result
would have been still smaller-6O. 100000 years.
He adds however that he sees no reason TO
assume that the sun is incapable of liberating
atomic energy to a degree at least comparable
Ito that of radium." He thinks that the way Is
open to increase the estimate of the sun neat
from ten to twenty times. He does not say ex-
plicitly whether he would multiply the output
at any particular time or prolong the period
during which radiation has been going on. He
merely insists that, since new source of energy
has been found, lit is impossible TO say how
long the suns heat has already existed. or how
"long il will last in the future y passing
reference made to the chance that others be-
sides himself may have considered THE bearing
Of radio-actvity on the cosmical time scale still
further indicates his thought.
Ifxrr rI..f
whether it is feasible to detect the presence of
radium in the sun. An attempt has been made
at Cambridge England. by w b. Hardy to OBJ
tain evidence on this point 1t is known that
solution of iodOform i'm chlorOfOrm. if placed in
the vicinity of the new element. will quickly ac
| qure purple color. Bottles containing that
mixture have been exposed 10 the sun for sew
,ral weeks without any apparent effect at all.
Such an experiment is by no means conclusive.
Failure might be due 10 any one of several
causes The spectroScOpe would seem TO offer
greater promise of usefulness in such an inquiry
Yet even if that instrument remained uncOm-
muncative in the hands of experts, the question
might still be regarded as open. Both the gen.
eral belief of astronomers that the planets
made of the same stuff as the sun and the
actual Identification of about forty terrestrial
elements in the latter body lead TO the suspicion
that the other forty are also there. LOckyer has
shown that the spectrum of a single element I'M
dergoes mysterious changes, probably in conse-
quence of temperature fluctuations in the sun.
Hence some of the lines already noted in the
solar spectrum, but not hitherto interpreted, may
be due to radium. Again, it is conceivable that
not only this, but other elements also. may be
so placed in the solar mass as to give no infor-
nation to the spectrOscCpe.
The age of the earth has also received atten-
ton from Lord Kelvin. Years ago he declared
his unwillingness TO cOncede the 100.0OO,0o0
years which some biologists and biologists de-
manded. He could not satisfy himself that
more than 20G00O00 years had interviewed be-
tween the stage when the globe was semi
molten mass and that when il reached a degree
of GOODNESS that would permit it 10 sustain life
The important factors in this calculation We're
the conductivty and radating qualities of the
different kinds Of rock of which the crust of the
earth is composed Professor Perry, of Trinity
College, Dublin once tried 10 invalidate Lord
Kelvin's reasoning by pointing cut what he re-
carded as defects in his premises. Another
Irishman, Professor Jolly now calls attention to a
different possibility that has been overlooked.
The beginning of the cooling process which
Lord Kelvin had in view may have been de
"ferred indefinitely during the exhaustion OF
"stores Of radium and similar bodies at greater
'or shallower depths" How far a suggestion
like this may induce Lord Kelvin to modify his
own convictions. and how far the confidence of
other physicists in the correctness of his views
may be shaken, it is impossible TO say II will
probably not exert much influence until more is
known about the quantity of radium the world
really contains. Still, the idea is not .vithout
| force.