Evening star. [volume] (Washington, D.C.) 1854-1972, 1908-09-10
THE ORIGIN OF THE EARTH
THEORY OF LAPLACE CoNSID-
Erred UNTENABLE.
The Nebular Hypothesis Fails to
Satisfactorily Explain Marvels
of Creation.

| Rollin D. Salisbury In the World Today.
The nebular hypothesis of the origin OF
the solar system is so well known that
| few sentences will recall its essential
features, even to those who are far be-
yond the time when it's simplicity and
beauty fascinated their schoolday imagi-
| nations.
The hypothesis is that the sun and all
+ his family Of planets and satellites were
once glowing. rotating. spherodal. gas
eous nebula, which occupied the space
from the sun out to the orbit of Neptune
or beyond. How such a tenuous body
acquired its heat and its rotation was not
explained, but the absence of an eXplana-
ton Of these fundamental points does not
| seem to have been accounted serious
! defect. The nebula was assumed to be In
process of cooling, and the cooling caused
! shrinkage. The shrinkage accelerated
the rate of rotation. and this in turn in
creased the equatorial bulge which rota-
ton developed. The progressive increase
Of cooling, rotating and bulging finally
led to the separation of an equatorial ring,
| analogous to the rings of Saturn. As the
central body continued to shrink 1t drew
| away farther and farther from the ring
until, at length. the ring was thought to
have been disrupted. Its matter was then
aggregated into a planet rotating on an
| axis and revolving about the central body
| which at length became the sun.
A series Of rings was supposed to have
| been separated In this way. the first CIV
ing rise to the outermost planet. and the
alter ones to the other planets in turn.
The size of the orbit of any planet was
supposed to give some indication of the
space occupied by the central nebula at
the birth of that planet. At the time OF
their formation the several planets were
thought to be hot and gaseous. Their
rotation caused bullying of their equa-
torial zones. while progressive cooling and
shrinkage increased the rate Of rotation
and the amount of bullying, and some
of the planets, following the example OF
their parent body. sloughed off rings
which became satellites. According to the
hypothesis the satellites should revolve
about their planets in the direction in
which the planets rotate, and the period
of revolution of the derived body should
not be less than the period Of rotation of
the parent body.
In support Of this ingenious theory.
which commonly bears the name of La
place. many harmonies in the motions Of
the members of the solar system were
cited-harmonies which are so striking
and SO manifold that they can hardly be
accidental.
In the early days of the hypothesis, the
phenomena of existing nebula were
thought to give 1t much support, for
among the nebula then known there
seemed to be aggregations of matter in
various stages of development, from diff
fuse unorganized nebula on the one hand,
to suns. with only little attendant nebu-
lous haze, on the other.
Students of celestial mechanics have
always recognized deficiencies and diff
culties in the hypothesis and never gave
in their unqualified support; but to those
who studied the theory less critically. and
who did not follow the rigorous mathe-
NAUTICAL reasoning on which its truth or
falsity must rest, the hypothesis has
seemed to afford a comfortable starting
point for the history of the earth and the
solar system. and it has been accepted by
them as II its foundations were firm.