The Vancouver independent. (Vancouver, W.T. [Wash.]) 1875-1910, 1881-03-10
HOW LONG WILL THE kUy LAST ID?


How is the heat of the sun maintained?
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 vague and somewhat unsat-
isfactory replies are possible. Prof.
Young holds that, so far as observation
goes, we can only say that the outpouring
OF the solar heat, amazing as it is, APP
pears to have gone on unchanged through
all the centuries of human history. The
author thinks there is some truth in each
of the two theories which have been pro-
posed 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
amount of heat which would be produced
by each of the planets falling into the
sun from its present orbit, by which it
appears that Jupiter would maintain the
suns present expenditure of energy for
80, 254 years, and Mercury for six years
and 2l9 days, and that the collapse of
all the planets upon the sun would gen.
crate sufficient heat to maintain its sup
ply for nearly 5000 years; and after
estimating that matter equal to only
about one-hundredth part Of the mass Of
the earth, falling annually upon the solar
suaface, would maintain its radiation
indefinitely, Prof. Young thinks it i'm
probable, from astronomical reasons, that
any such quantity of matter can be sup
posed to reach the sun. So large guam
tity of matter would necessitate vastly
greater quantity circulating around the
sun, between it and the planet Mercury.
But if there were near the sun meteoric
matter equaling, for example, the mass
of the earth, it ought to produce an OBJ
servable effect on the motions of 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
second one, which is, that the suns
diameter is slowly contracting, and the
gaseous mass is gradually liquerfying
and becoming solid. The conclusion is
drawn that, if this theory be correct,
there must come time when there will
be no solar heat, as there has also been q
time when it began. How far forward is
the end, how far backward is the begin
ming? Newcomb is. authority for the
statement that, with tspresent radiation,
the sun will shrink to half its present
diameter in about 5000, 900 years. Re-
duced to this size. and eight times as
dense as now, it would cease to be MAIN
ly gaseous, and it's 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, a period OF 1O,-
600, 900 years.
The writer somewhat more confiden-
TALLY casts his eye backward, and con-
cludes that the sun cannot have been
emitting heat at the present rate of more
than 10, 900 900 years if its heat has been
generated in the manner described. If
the sun has contracted from a diameter
even many times larger than that of Nep-
tunes orbit to its present dimensions, as
is probably true in the main, 1--WE are in
exOrably shut up to the conclusion that
birth to its death, is included in some
such space of time as 30 ,OOO, 600 of years;
no reasonable allowance for the fall of
meteoric matter" etc., could raise it to
sc, 600, 0O0." The possibility of collision
with wandering stars, and the suggestion
of ways as yet unconceived OF for restor-
ing wasted energy, are followed by the
statement that "the present order Of
things appears to be limited in either
direction by terminal catastrophes which
are yelled in clouds as yet impenetra-
ble."-[ Popular Science Monthly.