Evening star. [volume] (Washington, D.C.) 1854-1972, 1877-10-20
The Nebular Hypothesis

ITS WEAKNESS AND DEFECrs-FA1Is To
ACCOUNT FOR RECENT DISCOVERIES.
Mr.. Richard A. Proctor, in a communica-
ton TO the London Times on the proba bllItv
OF satellites having attendants makes the
following remarks In regard to the Nebular
1t seems to me we have physical reasons
in the processes by which our system proba,
bly, reached its present condition. for expect
ing some such relations as actually exist
among the satellites. Laplace's nebnIar. or
rather gaseous hypothesis, regarded as Of
Itself sufficient to explain the phenomena of
the solar system, has long seemed TO me un-
satisfactory, dynamically as well as pbysi-
cally lin fact, physically il is omen to over
whelming objections, which physicists have
, Oeen unsPt 20 urge, because perhaps of La
has received its death blow, / venture To
assert, in the interesting discovery lately
announced by Lord Lindsay, that a SO called
new star has cooled into n so called gaseous
nebula. Facts aresnow known to MS how
ever, which afford means for a far more sat
system, theory which, without abSo-
lutely rejecting the admittedly hypofheti-
cal part OF Lapisce's reasoning, briggs toto
action processes still going on, though no
lon ger with the activity which f,rmerIV
chs racteiized them. At the founiation of
this theory, which l have advocated for the
last seven years. lie two circumstance
first, that the Debulous mot wholly gaseons,
na'erlsl out of which the solar system was
To be formed, must have been sparseiy
strewn al the outskirts and deusely streWn
at the center gradually incre asing IN den sitv
Of distribution inwards: secondly, that the
motions OF It's component meteoric and
cometic members must have been SLOW al
the outskirts about three miles per second al
twice Neptune's distancel, very rapId near
the center, about $50 miles per second at the
present position of the suns surface Fror,
these two facts, the former almost certa i'm
the latter absolutely certain, all the general
relations of magnitude, rotatlonal motion
aXial position, satellite abundance, aud so
forth, OF which, be IL re1embe red, Laplace's
hypothesis gave no account Whatever are
easily and naturally explained. IL was NOT
an absolute necessity for this theory but IL
was much 10 be expected that the nuD1-
Der OF satellites should first (proceeding
from without inwards) increase up 10
the region OF maximum deyelOpusnt
afd thence decrease. H. is q natural
eject OF The Two circumstances above
mentioned, that az some mid-region the lar
gesi planets would be found, and there or
therea bouts the greatest cOmpleXity of struc-
lure. Within the former region marked h.
Juplter's pre- eminent mass there could be
only very small planets, aud outside this re-
glon planets OF smaller dimensions than the
giants of the system. From the region of
greatest completely of structure marked bV
the wonderful Saturnian system, there would
be certainly diminishing conn lexity of
structure inWards (such as we recognize ia
the diminishing number OF moons attending
on Jupiter, Mars, the Earth, and Venus1
ana PROBABLY similar dimInution out-
wards, as we seem TO recognize in the moon
systems of Uranus and Neptune.
In MS ring system, Saturn may be said to
nave millions of satellites; and, as neither
Uranus nor Neptune has any rings we per
celve that any analogy which would lead us
10 expect greater cOmplexity of structure
with mere Increase OF distance is illusory
Lord Lfndsay's discovery accords IN the
rather. the nebulo- meteoric theory of the
genesis of our solar system,