The Republican. [volume] (Oakland, Md.) 1877-current, 1893-09-21
HEAT OF THE SUN.
Sustained by Gradual Contraction of thu
Solar Volume.

Sustained by Gradual Contraction of thu
Solar Volume.
So far as our present knowledge goes,
it would seem that the brightness of
any sunlike body is to be attributed
solely to the transformation in some
fashion of mechanical power into heat,
To take our own sun as an example, it
is now an assured doctrine that the
heat so necessary for our welfare is
sustained by the gradual contraction
of the solar volume. The energy avail
able for transformation into heat in
this process seems sufficient to supply
the radiation of the sun, not only for
ages such as those which we reckon in
the human period, buteven throughout
lapse of time so vast as that which
| geology demands for the formation of
the earth's crust. But it is certain
that the quantity of possible light and
heat to be dispensed by the sun is linn
tied in amount
The sun can not shine on forever. A
time must assuredly come when the
mighty orb, at present so brilliant, will
have no more potency for the radiation
of light than is at present possessed by
the earth or the moon. In like manner
it can be shown that the materials
constituting the sun have not always
been luminous. We can not indeed say
with certainty by what influence their
brightness was originally kindled. 1t
probably arose from q collision, or an
approach to a collision, between two
dark masses which happened to come
to an encounter with enormous veloci-
ties in their progress through space.
1t is, however, plair. that the ages
through which the sun has been bril-
liant form only an incident, so to
speak, in the infinite history of that
quantity of matter of which the solar
system is constituted.
Notwithstanding the millions, or thou
sands of millions, of years for which
that matter has existed, it has, per-
haps, only once become so heated
owing to circumstances which we may
describe as accidental or casual as to
have acquired the ample light-dispen-
sing power of a sun. 1t is, however, pos
sible that such periods of light-radi-
ating capacity should have occurred
more than once; they may possibly
have occurred several times through
out the ages of time past. Nor is it
likely that the last phenomena of this
kind have yet arrived.
The sun, after the lapse of uncounted
years, will lose all it's heat and pass
into black dark mass. In that form
it may endure for an epoch so pro-
tracted that the spell during which it
has acted as the luminary of our sys-
tenn will appear but moment in COM
parison with the dark ages which sue
coed the solar splendor.
But we can conceive that the dark
ness, which is the doom of our system
need not necessarily be eternal so far
as its materials are concerned; it may
be that again in the course OF it's wan
derings through space the tide of
chance may at length bring the dark
and tremendous globe so near some
other orb that another collision should
take place with appalling vehemence.
The solid materials shall again become
transformed into a stupendous glow
ing Hcpuid' anu tHen, IN Jne course OF
the tedious contraction of this nebula
another protracted period of brilliance
will diversity the career of this great
body, and may last long enough for
the evolution of planets and of whole
races of highly-organized creatures.
The essential point for our present con-
sideration must not be misunderstood.
A little reflection will show that any
periods of brilliance must be regarded
as exceptional periods in the history of
each body.-Fortnightly Review.