The herald. [microfilm reel] (Los Angeles [Calif.]) 1893-1900, 1895-01-20
as an accurate result, but rather "a an
in teresting speculation.
REACTION OF THE EARTH.

law OF motloni tnhb 10 every dCblon tneIe
must always be an equal and opposite
reaction, it may be asked in what way
this reaction exhibits itself in the tidal
action OF the earth-moon system. The
moon; as we have sson, acts upon the
esrth by retar ding her axial rota ton
the earth conversely reacts upon the
moon by pushing her further and
further away. In this manner reaction
exhibits itself. AT first thought there
does not seem to be much importance
attached to this reaction, but a little
reasoning will soon show that in this
phenomenon we are dealing with a
problem which for fsr-reaching cons
clusiona is perhaps unparalleled in the
whole solar system.
At present the distance separating the
two bodies is about GAO, 900 miles, and
the length OF the day 10 about "a hours.
II the theory OF tidal friction be true
then both the distance of the moon and
the position of the earth must have
been shorter yesterday than today,
shorter the day before yesterday than
yesterday, and so on. Looking back
ward million years the revolution was
perhaps only some minutes shorter
than il is today, and the radius OF the
moons orbit-whch OF course is the
distance of the SATELLITE from the earth
wac correspondingly shorter.
OTHER DYNAMICAL CONSIDER ATOMS.
Before arriving st the critical result Of
this analysis, there are two other dynsm-
ical clements which must be taken into
consideration and thoroughly under
stood. First, that in accordance with
Keppler's second law that the radiue
veotor always describeB equal arean in
equal times, it follows that the moon in
past ages must have completed her
lunation in shorter periodic time than at
present. Second, that the quicker the
earth turns On its axis the moro centri-
fugal force becomes displayed and then
ii the rotation becomes too quick the
centrifugal force will become go pros
nounced that it will overcome the co.
hssion of the particles Of the earth and
tine gravitstion which attracts them
toward the center. The result would
be that the globe would fly to pieces, or.
which Is etill more likely, would leave C
ring behind from off itH outward bulged
equatorial zone.
THE CRITICAL EPOCH.
Thus then by retracing our stops
backward in time in accordance with
tidal evolution we will anivs at criti.
cal time, when the moon muet have
been grazing the surface Of the Garth,
and when one revolution of the earth Oh
its axis must have corresponded to one
lunati0n OF the moon. 1t would appear
that the time required was about three
hours.
Prof. G. H. Darwin OF Oxford has Gals
oulated that this state of affairs OF the
earth-moon system could not have ex.
listed less than $4,000, 600 yeara ago.
Studying the theory of tidal evolution
of the past, we therefore find that it
inseneibly leads MS to a belief that the
moon was once a part of this earth, and
that from preponderance of the centrif.
ugal force it became in some way or
other fractured off and left behind.
This, of course, muat have taken place
when the matter Of the eystem was still
in plastic or molten, or perhaps even in
q gaseous state.
THE NEBuLAR HYPOTHESIS.
But plainly this is nothing but an il
| lustration of the celebrated nebular
hypothesis-that all the pondersble ma
terial now constituting the various
bodies Of the solar syssem once existed
ae farefed mass Of gaseous matter-a
nebula-and that az this nebula cooled
by radiating its heat into space, it
cooled and contracted and was gradually
shaped into its present form.
In the future the moon will continue
to retard the earth in her diurnal mo-
ton and to increase and separate herself
more and more from her primary. In
the same way that the earth has caueed
our satellite to complete one revolution
on her axis in the same time as ia re-.
quired for her lunation (thereby forcing
her to always exhibit the Same face to-
ward the earth); in exactly the same
way the moon will compel our earth to
slow down the time Of the diurnal mo-
ton until it corresponds exactly to the
moons periodic time. lie has been
computed that the length of the month
az we'll az the length of the day at the
important epoch would be about "a of
our days or about 1400 hours.
STABLE DYNAMICAL EQUILIBRIUM.
We will then have what is known as q
stable dynamioal equilibrium, with the
earth and the moon always presenting
the same faces toward each other. and
this state OF affairs would last forever
providing shat no exsraneous forces were
brought to bear on the system.
SUMMARIZED TIDES.
But SO every particle of matter at.
tracts every other particle in the uni
verso it follows that they must, the aun
also, in the same way as the moon,
raise tides on the earth. So the sun
does, too, but SO the tide forcing power
of attraction, as far an distance goes,
acts on the inverse square, we have so
far not found 1t necessary to even mon
ton the solar tides. But when the
earth-moon nystem has attained equi.
librium the aun-raised tiden will con-
tinue right on in their action. To be
sure, they are very small compared to
those raised by the moon, but it is we'll
to remember that it is just these small
iorces acting day in and day out, ilently,
quietly, peraistently, uninterrupt eddy in
the same direction, which in the end
accomplish stupendous results. When
the earth and moon shall have come to
q mutual rest, tho solar tides will con-
tinue to retard the earth in her diurnal
motion until at last the day will bscome
longer than the month.
AN APPARENT PARADOX.
This may seem to many to be an i'm
possible Dtate of affairs-that the month
which ia now 81 times longer than the
day should actually become shorter.
But why not? II these conditions ex-