Vermont phÅ“nix. [volume] (Brattleboro, Vt.) 1834-1955, 1883-11-02
The Possibility Of Astronomical Col.
IiatOna.

There is a prevalent impression that the
immunity from collision between the heaven
ly bodies depends mainly on their being held
in orderly orbits by central attraction and
it is true that their orbital constraints make
it quite impossible for the planets to collide
with each other or even approach each other
very closely. But very impressive picture
is sometimes drawn of what would happen if
the earth. for instance, should some time free
herself from the bonds Of gravitation-how
she would fly into space (Which is true, OF
course) and soon dash herself TO pieces
against some other wandering world, (which
is not true at all, or at least not probable.
Most likely il grsvitation were suddenly to
cease, the earth would travel for millions, not
Of years, but Of ages, without ever encoun-
tering anything more important than mete-
ors, such as are now falling continually upon
her surface. Aud these meteoric encounters
even, would probably be far less frequent
than at present, since there is reason to sup.
pose that such bodies are much more numer-
Gus in the region of the sun and of other
great stars than in the rest Of space. Evil
IDENTIFY, however, the attractions between
wandering star aud others lying near its path
must considerably increase the chances of
collision, though not to so great an extent as
perhaps might be supposed. A body enter
ing our system at distance from the sun 500
times as great as the radius Of the esrths or
bit, and moving with no more than the veloc.
ity natural TO a comet at that distance, (about
two and two-third miles per second would
not strike the sun unless its path were direct
ed within less than half degree (23.G Of
the suns centre and il its velocity were
greater the aim would have to be still more
accurate to score a hit. If bodies were shot
into space at random from the position and
with the velocity indicated only about one in
Sc 600 would hit the sun. Were It not for
the suns attraction, however, the proportion
would be 20, 600 times smaller still-only one
| in seventeen hundred millions. 1t is obvious,
therefore, that encounters between heavenly
| bodies of considerable magnitude must be
extremity rare. There is not in all the record
a single certain instance of such an occur
renee. And yet it may be confidently assert
| ed that some time or other in the past such
events must have happened, and some time
in the future will happen again, simply for
the reason that in a sufficient length of time,
the most improbable things if only not i'm
| possible are sure to come to pass. Now, it
| is almost certain that the stellar motions are
not such as to render collisions impossible
| the planets, it is true, as has been said be-
| fore, can never run into each other, because
of the sze and nature of their orbits but so
| far as can now be ascertained, nothing of the
sort holds good for the motions of the stars.
| We already know enough about some of their
so-called proper motions" to be quite sure
that, as a fact, they are not travelling in any
simple curves around any common centre,
and also that some stars are flying through
| space with such velocties that no attraction,
such as can reasonably be supposed to act in
the premises, can control them. Nor does
theory, any more than observation, indicate
a structure of the stellar universe at all anal
ogous TO that of the planetary system. Among
the stars there is no central dominance and
no imperial power, but we have to do with a
republic of comparatively free and independ-
ent members. PREF. Young in the North
american ReDielo.