The National tribune., 1908-12-03
NEVER A SUNRISE.
The Appearance Ii Optical Result OF the
Earfh's Eastward Revolution.

Editor National Tribune: In the issue
of June 4 appears a problem from B.
H. Tripp, entitled Does the Sun Rise
in the East?" which is eminently quail
fed to trip" the unwary. 1 do not
propose to explain why the tub of wa
ter weights the same, whether there Is
a fish in 1t or not, but to deny a whole
lot of premises which clouds the logic
of Mr.. Tripp.
First The sun does not go around the
earth at all, but the earth goes around
the sun once a year and around itself
once day. If Mr.. Trip was at the
equator of the earth on March 20, he
could put his left hand toward the
north star (Polaris). and see the sun
rise directly east of him. not because
the sun was rising In space, but because
by the earth's revolution upon its own
axis was lowering his eastern horizon
relative to a line drawn from him to
the sun.
Second. The apparent path of the
sun, then, as it rose would be vertical
and not horizontal Gas his diagram
shows), and at noon would be directly
over his head, and his north star would
be in the horizon and the center of the
ecliptic Cor "orbit of the earth," as he
explains it), the earth's equator carry
ing Mr.. Tripp with it by its diurnal
revolution. and the celestial equator ex-
tending into the heavens, and all of
them vertical to Mr.. Trip except the
North Star. Now if Mr.. Tripp will
imagine himself at home he has gone
practically halfway from the equator
to the north pole of the earth, and
conditions have changed; the north
star Is no longer in his horizon, but
halfway up to his zenith, and the "or-
bit of the earth" Is tipped over half
way toward the south pole of the earth
Then, suppose he goes to sleep and
wakes up June %, and, with the in
clination of the ecliptic at % 1-2 de-
greess the sun rising 23 1-2 degrees
north of east at the equator, would rise
80 degrees north of his east in Dakota.
Why? Because the curvature of the
earth drops his apparent level that diff
ference from what it would be were the
earth cube instead of a globe. Then
travel north, and this difference (called
the amplitude of the SUM increases un-
til at the Arctic Circle the sun would
rise directly north and at midnight,
and would not set until just ready to
rise again the next midnight, but at
noon would be south and only 23 1-2
degrees high; but keep on north to the
pole, and the sun does not set at all
until Sept. % (no allowance being
made for Fefraction, which is not under
discussion). Then the "orbit of the
earth" Is horizontal as in his diagram,
and the sun would go round and round
at his feet, except the inclination of the
ecliptic. which was from a vertical at
the equator, is from horizontal at the
pole, and his north star is directly
over his head, and he couldn't point to
it with his left hand without lying
down, and he couldn't look east, be-
cause there was no east even if he did
lie down. The same is as true of the
south pole. except in reverse order. and
within the Antarctic Circle the sun
would appear to rise in the south sim
ply because the "erd of the earth" no
longer intervened between the observer
and the sun, and directly toward the
pole is the first point to open straight
line.
Now, the sun at its distance has a
parallax of only eight seconds of arc.
and to the sun our earth is only a point.
Space has no north, south, east, west.
Up or down, those terms all being rela.
live to the earth. and are governed by
the position upon the earth's surface
held by the observer. If we were large
enough to look over the earth we could
see the sun at any time, or IL the earth
did not revolve upon its axis. and we
faced the sun, 1t would never set to