The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1896-11-08
AND THEIR COURSES.
RY sIR RoRERT BALL.


q copyright. 1896 by S. s. Mcclure Co.
Let US suppose that there was n,
& other star in the universe than on
own sun, and let US further, for tn
sake of making the argument clearer
suppose that the sun is deprived of it
system of attendant worlds Next, lie
some other object be introduced which
{ we may suppose TO be extremely light
like a wlsp of vapor, and let it be sit
uateu at a distance from the sun which
we may regard as Indefinitely great
These two bodies, namely, the sun and
THIS WISp OF VaDor, are then supposed
TO be abandoned TO their mutual at
fractions. Each Of these objects viii
pull the other, and the result of the at
traction between the two bodies will
be to make them approach each other
AS, however, the mass of the sun is sc
vast, while the mass of the Wisp is sc
small, we may fairly assume that the
greater part of this movement will be
done by the wisp, while the sun will
remain comparatively at rest The
case is indeed much the same in this
respect as in the fall of a stone to the
ground The stone goes down to meet
The earth, but the earth at the same
nne comes up to meet the stone. AS,
however, the earth is more massive
than millions of millions of stones. the
unappreciable. We may therefore say,
with truth enough for all practical
purposes, that it is the stone which
does ali the moving, while the earth
remains Al rest.
TREMENDOUS RATE OF VELOCITY
In the same manner we may suppose
the sun to be at rest, while this Wisp
of vapor is drawn toward it from the
depths of space. AT first, no doubt the
motion may be extremely slow: for the
attraction OF the sun decreases with its
distance. Indeed, the wisp of vapor
might be so remote that il would re-
quire thousands of years to move over
an inch But as the motion progresses.
the BODY will gradually acquire speed.
until after the lapse of a time, so long
that We shall not attempt to express
IT In figures the little object will be
found hurrying in toward the sun with
the speed of an express train; STILL the
pace VIII grow until the approaching
object will be moving as quickly as a
rifle bullet. The intervening distance is
now rapidly diminishing out as thai
distance lessons, the intensity of the
solar attraction increases, and. conse-
Guently, the pace at which the object
is urged onward becomes greater and
greater From moving at the rate of a
mile IN second, the little object would
gradually attain a speed of not less
[.
namely, about IS miles a second Still
the body passes onward, until a pace
could be reached of 100 or 200 miles q
second. Finally, when the vapor would
be about to make the terrific plunge
into the glowing sun, its speed would
be upwards of 400 miles q second. The
vastness of this speed may be realized
from the fact that a body animated by
so great velocity, would accomplish
complete circuit of the earth in about
a minute
The case which I have supposed is. |
however, not exactly that of a comet !
me movement would hardly take place 1
in the way just described, in which the
sun and the wisp of vapor were origin /
ally both at rest. Such a state of (
things could hardly be possible in ma |
ture- We may, no doubt, suppose the /
sun to have been at rest for it is only
the relative movements of the two
bodies which concern us But we can
hardly imagine that the wisp of vapor
could have been so delicately placed as
to have had absolutely no motion
whatever, except, indeed, in the direct
line toward the sun. If, at the moment
of starting, the object possessed a
movement which would carry it in The
course of time out of the direct line of
the sun, then a totally different condi-
ton of motion would result.
MISSES THE SUN AFTER ALL.
All the time the sun was drawing
this wisp OF vapor toward it, the trans
verse movement would be gradually
moving the wisD out of the direct line.
Now, though the speed of that move
ment may be very small, yet in the
lapse OF those millions of years that
are required 10 draw the body into fRs
sun, this transverse movement will
have increased to such an extent thar
the object viii miss the sun instead of
hitting it. In fact, after its stupen-
dous voyage, from the Indefinitely re-
mote depths of space, during which it
has acquired its scores or hundreds of
miles second, the comet will be found
not plunging into the sun, but passing
TO one side of it. While the two OBJ
jectS are in such close proximity. their
mutual attraction is of course of ire
nendous vehemence. In virtue of this
attraction, the rapidly moving comet is
whirled around the sun. and conse-
Qaently begins to retreat again toward
the same side from which it has come.
In this majestic sweep the comet de-
scribes a graceful curve. Coming in
from intinity it approaches the sun,
wheels round the sun and then again
retires to the depths of space
AS the comet has swept in toward
The sun, in consequence of the attrac-
lion of that body, it may seem difficult
to understand why it should then re-
treat outward again, Notwithstanding
The attraction which now seeks to draw
i back. This may, however, be illus
Lrated by a very simple continuance.
Let a weight be hung from the ceiling
by a string. Let that weight be drawn
aside and then released 1t will of
course swing down TO the lowest point,
ana then, having passed through the
owest point, the weight will begin to
ascend The attraction of the earth
,ulls the body DOWN, but as it descends
T acquires speed, and in virtue of this II
peed it is enabled TO pass the lowest
POINT and to ascend in opposition to
-ravity on the other side. In the same
way, the speed acquired by the comet s.
. its long voyage toward the sun from Il
he depths OF space, enables it to swing s;
ound The sun without being captured it
nd then TO pass away, perhaps never t.
more to return The nearer the comet b.
5 - the solar surface, the greater is al
ne speed with which it moves. and II
or.sequently the more brief is its So a.
ourn in the vicinity of the sun. A Il
omet has, in fact, been known TO rs
rae the sun so closely that it passed II
within one-seventh part of the suns e.
adius. In this case a period of two la
ours sufficed for the comet to COM tn
ietely turn round the sun and COM ST
aence its retreat into space al
COUNTER ATvTR REACTIONS AT re