New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1880-01-30
The NEBULAR HYPOTHESIS.
ARGUMENTS For AND AGAINST.

HOW DIFFICULTIES AGAINST lis ANChFI-
ANCE HAVE BEEN EXPLAINED AwAY-PRo-
FEssoR KIRKwoOD's OBJECTIONS.
To the Razor OF the Trt6Une.
SIR, The Nebular Hypothesis of Laplace,
like Newtons law of Gravltaton, encountered many
ccules be surmoun,e ed but while the law OF grayi
taiiuu is considered firmly established, the
nebular hypothesis sin with obstacles winch pre-
vent Its being generally accepted an established fact
At first It not easily how motion Of rotation
could begin IN the solar nebula from which Lapace
conceived the aud planets formed but that
is easily explained; then the retroerade motion Of
the satellites Of Uranus and Neptane regarded by
dsproying the tru b OF Laplaoe's hypothesis
but that offers difficulty
Professor Daniel Kifkwood has for years
thought and written GOOD deal on Laplaces theory,
and recently published, the proceedings Of the
American Philosophical Society, paper The Coz
mogony Of Lapace," In winch he ponts out other diff
euties which al first very troublesome to clear up
He sums up as lolows
alt been shown ~ that the hypothesis Of Iapace
gives explanation ~ tne immense interval, between
the planetary orbits; GU that apart rom TINS ouleclo
periods required Tor the formation OF planets from
ns Sg bs Il t "S er e p
Of satellites; ma az that II Is apparently Incompatible
evable that this celebrated hypothesis must yet be
abandon d, thai its principal features must be essen-
tally modified"
II we suppose the whole solar system gas
Of uniform density, and expanded to include the
orbit Of Neptune and II the polar axis OF
sphe oida body to be the thoussndh part o. the
equatorial diameter. the density OF such body would
be about the one hundred and siKteth of that of
gas at the surface OF the earth We at once see
that such nebua could reyolve about axis, or
a centre, n single body. ayd yet nearly all cacula-
that made the rotary motion OF the solar
nebula, based the supposition that the whole
body rotates at once and with angular motion.
AN conclusions drawn from such a hypothesls can have
but very little bearing on Lap'ace's Cosmoguny We
also Sec as Professor Krkwood has shown that such
rings as Laplace contemplated could possibly be ADAM
doned
But in what part Of the solar nebula did a rotation
beginOn the surface The equatorial parts in The
interior, or throughout the whole msssi The prob
ability is largely 10 favor OF the first suppOston, and
this IL the hypothesis OF Professor Ennis and II enables
us to explain pbenCmenon that appears all paris Of
the solar In accordance with 1t the process
of condemnation would have resolved the solar Debua
into system OF elementary rings aud these rngs
wOuld nnay break up into separate masses In accord
ance law OF the peru batOns Of motions based
the near comneBsuabiniy OF periods OF revolution.
Professor Kirkwooi has explained Rthis way the per-
mauenI intervals N the rngs OF Saturn, which have
been produced by attraction Of the saetc aud also
a certain the orbits OF the asteroids
caused by the attraction OF Jupiter. We have
discuss this point further now. with THIS Dodi-
As 70 the Of the solar must admit that
We know nexi nothing about IL. Some estimates
relation point based solar radiation OF the
contraction SUMS volume have been made, bu.
tnev suppose the to always give out the same
am0unt OF heat in a .nven tlne rms. hOWeNer.ls
most uncertain element. We have means OF knowing
how rapidly sic WHY changes the solar nrbuia took
mace Besides, when matter borders closely on tho
ultrs-gaseous condition "a tho sonar system probably
once did. we predict nothing In regard 10 its
changes for yet are roo gnOraTt or lie Dhtnfe OF
matter In that 8 far KNOWLEDGE will vet
spr, US need feel that there Is lack OF tmr
10 work all the changes that have taken place III the
solar system.
II We suppose all parts OF the solar nebua 10 have
rotated Win the angular velocity at the same
time II show that changes would take
place which would appear 20 be in opposition to KEEP
dtion OF the nebula such TO preclude any such
Ides In relation 10 The angular velocity OF the DIFF
fereBt parts would probably accord more nearly with
Keper's Law. 80.
After the discovery of the satellites OF Mars land IL
WAS that the inner revolvrd ia lees time than
the period OF MaTs's rotaouD, twas Thought that ts
fact could not be explained in cOrdsnce with the Deb
MIA hypothesis nnut drawing some power OF re-
such ether meteors, by wnie the motion
OF satellite had been accelerated ny causing II 70 aI
proacb the planet But the me difficulty. though In "A
less degree. exists IN the system OF Saturn OF Jupiter
the earth and mOOn aud the primary part OF the solar
system II Vulcan exists. 1t appears revove In ess
time than sun requlrrs to rotate theory teaches
that the dusky Of Saturn reyolyes IN less time
tnan requires TO rotate and The real velocity OF
the moon greater than the equatorial We
lOcity OF the earth. Professor EnDiss hypothesis,
already refer red to- easily explains all these dcuiies
DAVID IRowBRIDGE
Water6urgh. N. y, Jan. 27. 1880