The sun. [volume] (New York [N.Y.]) 1833-1916, 1914-04-30
WINNING At VENUS.
Possible But Expensive TO signal Lady
FRIEND Of Mars.

To THE EDITOR OF THE SuN-Sir: Two
noted astronomers have got into "A friendly
discussion AS to whether Mars is IN
habited or not. and whether the great
necessary expense in an effort TO commu-
nicate with Mars by signals would be
justified. Another eminent astronomer
says In substance. that Mars and Venus
are surely inhabited by living beings of
some kind. but that. the atmospheric con-
dtions of Venus being similar to those of
the earth. the probabilities OF its being
inhabited are greater than those of Mars.
Now. with all this glib talk of signalling
to Mars. no one has Yet got down to
brass tacks' with a plan of how to do II.
or its cost. a most important item. By
any plan attempted. however. Its cost
would make that Of the Panama Canal
look like the traditional thirty cents"
owing to the fact that the orbit of the
earth is inside that OF Mars any signalling
that may be attempted TO that planet
must necessarily be done BY electric or
other powerful lights and at the time also
that Mars in its passage around its orbit
would be nearest the earth. or about 40
100000 miles distant. Unfortunately for
purposes OF signalling. at this time the
earth is between Mars and the sun and
would be invisible TO the Martians IL
would at the same time he broad day
light in Mars and the Inhabitants OF that
planet must look in the general direction
of the sun to see the earth, which, being
dark OH that side. gives no light and can
not be seen. The conditions are such that
1t is quite improbable that the most pow :
erful light that could be produced or even
imagined on the earth could compete with
sunlight and be noticed on Mars. even
through the powerful telescopes they are
supposed TO possess. 1t would therefore
be impossible for the earth to signal 10
Mars by any means we now have
In the case of Venus, however, tho con-
ditions are somewhat different, her orbit
being considerably smaller than that OF
the earth. In travelling around her orbit
and at the time OF her inferior conjunc-
ton with the sun Venus approaches 10
within about 30.o00,0O0 miles OF the earth,
but Is Invisible to US as she is then be-
tween the earth and the sun. We could
signal Venus at such times by means of
large white spot, and Mars could signal
TO us in the same way, but We could get
no answer from Venus nor could we an
swer Mars, II being just as impossible for
Venus TO signal the earth as for the earth
TO signal Mars; any light either one could
produce would be overpowered by SUM
light. Consequently IL we We're 10 at
tempt to send signals to Venus We should
never know whether they had been re-
CeIved or not
miles square. one two hundrcd'h Of the
esrths diameter. Such spot should be
easily seen through the powerful tel.-
scopes of Venus. To produce the white
spot large number of planes about live
by ten feet In size should hc made
and mounted on gudgeons at tho ends
to enable them TO be turned na'wiss or
edHewise upward. the whole 20 be oper-
attd by electric power 30 that an operator
by manipulating switches could make the
spot appear and disappear al will signals
could thus be flashed or "winked" Ia
Venus.
Figures show that 10 cover the 1900
square miles embraced in this spot would
use 9Oo, 100000 planes. plant Of 20 .
100000 horsepower would be- required
to handle the planes. An army of about
100000 men would be- needed TO operate
and attend to IL. The cost of constrlIc.
ton would be about $50. 000, 00O.O 900. while
the wages of the operatives and other .x.
penses would be about $4,000, 900 a day.
We cannot signal Mars at all We can
signal Venus, but rs the game worth tho
candleT EDWARD Rown
INDIANA. Pa. April 20.