The Weekly Kansas chief. [volume] (Troy, Kan.) 1872-1918, 1880-12-02
HOW LONG WILL THE SUN LAST?
Prof 4. 4. Young Give. Hi. Views ON the Fu-
O the Universe,

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
dminution. After affirming that in the pres
ent state of science, only somewhat vague and
unsatisfactory replies are possible, Prof. Young
holds that, so far observation goes. can
only say that the outpouring of the solar heat,
amazing as it is, appears to have gone on nm
changed through all the centuries Of human his
tory. The author thinks that 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 produc
ed: but the question is whether the supply of me-
teoric matter is sufficient to account for any
great proportion 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
bit, by which il appears that Jupiter would
maintain the SUMS present expenditure of energy
for 81, 30 years, and Mercury for six years and
2l9 DAYS and that the collapse of all the planets
upon the sun would generate sufficient heat to
maintain its supply for nearly 5000 years; and
after estimating that matter equal To only about
one-hundTedth part of the of the earth. fail
ing annually upon the solar surface, wOuld main
tain its radiation indefinitely, Prof Young
thinks it improbable, from astronomical reasons,
that any such quantity of matter can be suppOs-
ed TO reach the sun. So large a quantity of rlat-
ter wOuld neceSsitate vastly greater quantity
circulating around the sun, between il and the
planet Mercury. But if there were near the sun
meteoric matter equaling, for example, the mass
of The earth, il ought 10 produce observable
effect the motions Of Mercury, and no such
effect las yet been detected.
Astronomers, therefore. falling 10 find a full
explanation Of the cause OF solar energy in this
hypothesis have adopted a second one, which is,
that the SIMS diameter is slowly contracting.
and the gasconS mass is gradually liqucfying
aud becoming solid. The conclusion is drawn
that If this theory lie correct there must come a
time when there viii be no solar heat, AS there
has also been time when it began. How far
forward is the end, how far backward is the he
ginning! Newcomb is authority for the state
ment that, with its present radiation, the sun
will shrink To half its present diameter in about
5000. 600 years. Reduced To this size, and eight
times as dense as now il would cease to he main
~ gaseous, and its temperature would begin to
fall. Hence Newcomb assigns as the term during
which the sun can supply heat enough to sup
port life on earth, rs we know life, period of
10. 600 coo years.
The writer somewhat more confidently casts
his eye backward, and concludes that the sun
can not have been emitting heat at the present
rate for more than IL coo 900 years. if its heat has
been generated in the manner described. If the
sun has contracted from diameter even many
times larger than that of Ncptunes orbit to its
present dimensions, rs is probably true in the
main 1--WE are inexorably shut up to the conclu-
sion that the total life of the solar system. from
its birth to its death. is included in some sucll
space of time as 10000 600 of years. no reasona-
bic allowance for the fall of meteoric matter
etc ..coud raise it to 6O0OO,0OG.- The possibil-
ity of collision with wandering stars, and the
suggestion of ways as yet unconceived of for re-
storing wasted energy, are followed by the state
ment that 1.-THE present order of things appears
to be limited in either direction by terminal ca
tastrophes which are yelled in clouds as vet
impenetrable.' Popular Seieace Monthly.