Belmont chronicle. [volume] (St. Clairsville, Ohio) 1855-1973, 1880-12-02
HOW LONG WILL THE sun
LAST?
Professor C. A. Young Gives his
Views on the Future of the
Universe.

| hOW 10 Ilc utdl VI TIE sun LldlHGdlH-
ed? How long has it lasted already ?
How long will it continue? Are there
any signs of increase or of diminution?
After affirming that, in the present state
of science, only somewhat vague and un-
satisfactory replies are possible, Prof.
| Young holds that, so far as observation
goes, we can only say that the Outpour-
ings of the solar heat, amazing as it is,
appears to have gone on unchanged
through all the centuries of human his
tory. The author thinks there is some
truth in each of the two theories which
have been proposed to account for the
suns fire.
/ As to the first, the impact of meteoric
matter, it is quite certain that solar heat
is thus produced; but the question is
whether the supply of meteorIc matter
is sufficient to account for any great pro-
portion of the whole. After giving Sir
William Thompson's calculation of the
heat which would be produced by each
of the plannets falling into the sun from
its present orbit, by which it appears
that Jupiter would maintain the suns
present expenditure of energy for 32,254
years, and Mercury for six years and 219
days. and that the collapse of all the
planets upon the sun would generate
sufficient heat to maintain its supply for
nearly $4,000 years; and after estimating
that matter equal to only about one
hundredth part of the mass of the earth,
falling annually upon the solar surface
would maintain its radiation indefinite
ly, Prof. Young thinks it improbable,
from astronomical reasons, that any
such quantity of matter can be supposed
to reach the sun. So large quantity of
matter would necessitate a vastly great
sr quantity circulating around the sun,
between it and the planet Mercury. But
if there were near the sun metsoric mat
ter equaling. for example, the mass of
the earth, it ought to produce an observ-
able effect on the motions Mercury, and
no such effect has yet been detected.
Astronomers, therefore, failing to find
full explanation of the cause of solar
energy in this hypothesis, have adopted
a second one, which is, that the suns
diameter is slowly contracting, and that
the gaseous mass is gradually liquefy-
ing and becoming solid. The conclusion
is dawn that, if this theory is correct,
there must come time when there will
be no solar heat, as there has also been
a time when it began. How far forward
is the end, how far backward the begin
ming? Newcomb is authority for the
statement that, with the present radia-
ton, the sun will shrink to half its pres
ent diameter in about five millions of
years. Reduced to this size, and eight
times as dense as now, it would cease to
be mainly gaseous, and its temperature
would begin to fall. Hence Newcomb
assigns as the term during which the
sun can supply heat enough to support
life on earth, as we know life, period
of ten million years.
The writer somewhat more confidently
casts his eye backward, and concludes
that the sun cannot have been emitting
heat at the present rate for more than
eighteen million years if its heat has
been generated in the manner described
If the sun has contracted from diane
ter even many times larger than that of
Neptune's orbit to its present dimensions,
as is probable true in the main, 1--WE are
inexOrably shut up to the conclusion
that the total life of the solar system,
from its birth to its death, is included in
some such space of time as thirty mil
lions of years; no reasonable allowance
for the fall of meteoric MATTER" &c.
could raise it to sixty millions" The
possibility of collision with wandering
stars, and the suggestion of ways as yet
unconceived of for restoring wasted en-
ergy, are allowed by the statement that
'the present order of things appears to
be limited in either direction by terminal
catastrophies which are yelled in clouds
as yet impenetrable. "-[From the Popu-
lar Science Monthly.