Evening star. [volume] (Washington, D.C.) 1854-1972, 1904-03-30
THE 1MMuTABLE IN ASTRONOMY.
Prof. See Accurately Traces Out the
Position Of Laplace's Invariable Plane.

Z .
From the New York Sun.
The February edition of the Astronon,-
ische Nachrichien of Kiel, the leading as
Economical publication of the world, con-
tains some interesting scientific researches
by Prof. T. ]. See, U. 8. NJ. on the degree
Of accuracy attainable in determining the
position of Laplace's invariable plane Of
the planetary system. This invariable plane
is a very remarkable foundation in as
tronomy, in that 1t is wholly inmovable
1t was first discovered by the great French
astronomer, Laplace, in 1854, but it Is only
recently that the elements of astronomy
have been sufficiently exact to enable a
mathematician to compute its position with
great precision.
This is plane more fundamental than
either the equator or the ecliptfc, to which
astronomers usually refer the position of
the stars. Prof. See bases his determine
ton of it upon the profound researches of
Newcomb and Hill, the American mathe-
NAUTICAL astronomers. Heretofore only three
mathematician have determined the posi-
ton of the invariable plane-Laplace and
Pontecoulent of France, and Stockwell, the
American, and none of these attained any
thing like the precision that has been reach
ed by these later researches.
1t is said by those acquainted with the
work that the true position OF the invariabte
plane has been found with such precision
that 1t may be used with almost as much
accuracy as the ecliptic and the equator.
The difference is that the ecliptic and the
equator are continually changing their
places in the sky, while Laplaces plane is
immovable through all ages.
1t is the only plane in the universe that
is perfectly fixed. Everything else changes
necessarily. Precision of the equinoxes
carries the earth's axis around circle
Al degrees in diameter in the course or
25,S6S years, and this shifts the equator
nd a
aspect of the consultations. Again. the at
fractions Of the planets upon the earth after
the position of the ecliptic, which Is the
earths path in space. These changes go
on slowly for thousands of years.
Laplace's plane, however is perfectly in
variable. 1t has the same position among
the stars now as In the days OF caesar OF
Job, and will have 1t million years hence.
If one could see the invariable plane
traced out on the background of the sky as
a narrow band Of fire among the stars, us
track would be as immovable as the sphere
of the heavens itself. The fixed stars
might move individually or in groups, the
planets might wander, comets might come
and go, and the sun with all his planets
might keep on moving toward the constel-
lation Hercules, as Herschel discovered
about century ago: yet the invariable
plane first discovered by Laplace. and now
accurately traced out for the first time,
would remain perfectly fixed.
If the Milky Way ITSELF in future ages,
should break up and the whole aspect OF
the starry armament should change, we
could still depend with mathematical ac-
curacy upon the unalterable position of the
invariable plane of the solar system. IN
the course of innumerable ages 1t will still
be a sheet anchor for the astronomers, ana
the only one of the kind ever known to
science, in the midst of the universal
changes of the heavens.
AS a foundation of the starry heavens.
the character of this plane is unique-"the
same yesterday, today and forever.