Weekly Trinity journal., 1878-02-02
NUMBER 5.
THE AGE OF THE SUN.

There has been n long dispute between
the physicists and the mathematcans on
tho one hand land the geologists and BIZ
ologists on the other, as TO the age Of tho
earth, or rather, since that is equally in
volved, the age of the sun. DR.. Croll,
the distinguished Scotch geologist, has
recently offered u theory which is not al
together new, but admits of some novel
Arguments, and which may serve all par
ties to the dispute. Beginning with q
review of thesditlerent theories as to tho
suns heat, he rejects tho com mbuston the
ory as totally inadequate, since if the sun
were all mass Of burning coal it would
not last over 5000 years the chemical
theory does not prolong the duration sut-
ticiently ; the metooric theory will not
serve the only remaining explanation
is tho gravitaton or condensation theory.
This supposes that the materials of tho
solar system were originally hebula,
extending through space many times
greater than the orbit of Neptune. The
falling together, tho condensation of this
amount of matter, il can be mathemati-
cally shown, would supply enough heat
to keep the sun at its present temperature
for 10000, 600 years. Unfortunately, that
period is not sufficient for tho goologist.
He demands ut least 100, 900 900 years for
tho changes of the earth's surface, and
would prefer twice that length Of time
The arguments of tho gcologist arc al
most unanswerable those of tho biolo-
gist, who believes in evolution, tend to
the same point, so far as they go. Prof.
Croli says that there is way out of this
difficulty, by supposlng that tho nebuIa
was not cold, but hot. II you suppose il
hot enough 20 start with, you will have
heat enough to carry you through. OBJ
viously 1t is just as easy to suppose hot
nebula as n cold one. But Prof. Crol
proposes to provide for this original heat
II the solar system had originally consist
cd OF two masses, each Of half tho densi-
ty of the whole, at some immeasurable
distance apart, and they fell foul of each
other, owing to their mutual gravitaton,
they would strike with speed of 274
miles per second. Ii their motion WAS
stopped by tho conclusion, nm amount OF
hent would be developed sufficient to con-
vert tho whole into nebula that would
take 5O,OO0,OO years to cool. This Is do
cidedly an improvement on the cold neb-
ula. But this supposes that tho compo-
mont halves, before they started on their
way to collision, had no motion. Let
us suppose that thoy were moving before
hand ut the rate of 202 miles per second.
and that this speed was added to what
they got by gravitating toward each 9TH
or; then we get, when they struck, n
ncbula extending beyond Neptune, and
with hcat enough fora sun for 100, ,000,000
years duration. Ii you insist upon 200,-
100000, you must give tho original mass
es II speed Of 67G miles per second before
hand. 1t will bo objected that no such
motion had been observed in space
Even the planets do not mako such fast
time the earth, for instance, going only
| 900 miles in II minute. Tho fixed stars
are those tha have gone through the col
lision process and have lost their motion.
Tho new hypothesis goes behind the ordi-
nary nebular theory in point of time,
giving nm explanation for tho formation
Of the nebua. But II prosupposes that
there may be vast, cold, invisible masses
of matter rushing through space with
such velocity that their more touch would
convert our globe into red hot gases and
distribute it through infinite space. Tho
conception is not incompatible with tho
sudden flaming out of new star aud its
conversion into anebula, ms seems TO havo
been the case with tho Schmidt star In
Cygnus but the facts in that remarka-
BILE case were probably not known tp
Prof. Croll atthe time his essay was writ
ten.-Ihttadetphia 1eiegraph.