The Milan exchange. (Milan, Gibson County, Tenn.) 1874-1978, 1878-04-04
Some Astronomical Wonders.

If the dignity of science is to be
measured by the inability of the human
mind to comprehend its teachings, as
tronomy is certainly the nOblest of all.
We very much doubt if any man really
has clear idea of all that is implied
when the distances of the planets from
the sun are stated; and it is hardly less
difficult to understand all that has been
discovered in relation to the sun itself
How much can we comprehend about a
place where the diameter of the earth
would be q convenient measure with
which to ascertain the height o. flames?
Have we any Just conception of the in
tensity of heat sufficient to yapOrize
iron? 1t is, however, when we, in inn
agination, leave the solar system, and
start on journey to the stars, that We
begin to understand how insignificant
our earth really is. 1t might serve to
measure the distance of the stars, but
for the distance of the very nearest star
known to us, lpha Centauri, we must
make another measure. E. the DIS
lance of the earth from the sun. Alpha
Centauri is more than 100000 times the
distance, and if the reader wishes to test
his powers of comprehension let him at
tempt to grasp the import of this state
ment He may be aided by comparing it
to things familiar to us. Fifty miles an
hour is very fast time for an express
train; but at this speed a journey to
that star would take OUer tory mi. lions
of gears. The velocity of light Is over
100000 miles a second; and it requires
over three years for the light of the
nearest star t. reach us.
The brightest star visible to us is
Sirius, which is at five times as great a
distance from us as Alpha Centauri. 1t
has been calculated that this star gives
out three hundred times as much light
as the sun. Now, we have no means of
knowing the size of Sirius; but if the
light of that star is equal in intensity to
that of the sun, its diameter must be
nearly Is times, and its mass over 1900
times as great. 1t is possible that its
light is more intense than this, but even
if twice as bright as the sun, it must be
u times as great in diameter. Even
this diameter, over ten millions of
miles, is beyond any thing of which we
have an actual idea An express train,
at so miles an hour, would require more
than seventy years to complete the cir
cult of such a sphere.
The next star to Sirius in brightness,
as seen from the earth, is Campus, a
star which can not be seen further
north than the most southerly portions
of the United States. The star is be-
tween one-half and three-quarters as
bright as Sirius, and as it shows no dis
placement from the annual motion Of
the earth, we are forced to the conclu-
sion that it must be larger than Sirius
perhaps many times as large. The dis
lance of only about ~ stars has been
estimated, and of the others visible, we
can not even guess at their distances or
sizes. All we can safely say is that they
must be bodies of enormous siZein com
parison with the planets. Doubtless
many of them are far larger than the
sun. Even the stars, seen only through
the most powerful telescopes, must be
large as compared with the earth. They
may appear faint from being really
small, but it would seem more reasona-
BILE to suppose that they are, as a rule,
comparable to our sun, and that they
are faint merely from the effect of dis
lance. IN rcastile Journal.