The Birmingham age-herald. [volume] (Birmingham, Ala.) 1902-1950, 1919-08-03

ing southwark among the stars, so that
it sets earlier on each successive evening.
The reader will remember how rapidly
this very bright planet ran eastward
among the stars, crossing the constella-
lions Cancer and Leo, and on July pass
ing very close to the planet Saturn. Its
eastward motion is growing continually
slower. and on August 20 it will entirely
cease After this date Venus will again
move westward among the stars. The OBJ
server should not fail from time to time
TO examine this beautiful world in the
telescope and to see how during the
month it's shape will rapidly change to
that of very narrow crescent.
Mars is in the morning sky, little to
the east of the summer solstice: its east
ward motion is so rapid that during the
month It will pass from Gemini into Can
Ger, and almost across the later constel-
lation. 1t consequently mounts upward
| in the eastern heavens but slowly On
| August / it rises / hour 40 minutes before
| sunrise, and this time is increased to
/ but 2 hours 10 minutes by August 81
| Jupiter which entered the morning
sky on July 20, rises Is minutes before
the sun on August and about hours
| before sunrise on August 81. Toward
the close of the month the observer may
notice how Mars and Jupiter are drawing
together in the morning sky, where they
| a
planet being far brighter than the other.
| The actual conjunction will not occur.
| However until the morning of September
IL, when Mars will pass Al minutes to
the north of Jupiter.
! Saturn sets / hour 10 minutes after
| sunset on August 1, but it is rapidly
becoming lost in the suns rays and viii
leave the evening sky on August Is. 1t
! cannot, therefore, be satisfactorily OBJ
| served during the present month.
| Uranus is slowly retrograding In
| Aquarius: it is in opposition to the sun,
| and so due south at midnight on August
| Neptune enters the morning sky August
L. Mars will overtake and pass this
planet on September T.
Thus the bright planets which have
! interested us for so many months Will
ALL excepting Venus, have disappeared
by the end of the month, and this last
planet will withdraw from our evening
heavens on September T. Until Novem-
Der we will have no bright planets with
us, but the slow changing OF the race
of the heavens will then again bring Jup-
tier into our evening sky.
THE PRINCIPLE OF RELATIVELY
Astronomers and other students of the
physical sciences have been much inter
ested during the last two or three years
in a new theory which has been de-
yelOped with very great elaDoTdtioH ain
which is wholly unlike the theories upor
which the whole of our physical science
rests. Our fundamental ideas and laws
regarding mass, acceleration, the mu
tual acton of bodies, etc, must be dis
carded if the new theory is true; Their
are no true units of mass, length, etc.
In the old sense, for the mass, or guam
titv of matter in body, and also tn
length of the body, depends upon IL
velocity in space and changes as tn
sreed of the BODY changes. Many strik
ing and apparently wholly impossible re
suits follow, according to the new theory
that rs. results which seem wholly impos
sible to us with our ingrained ideas con
corning matter and space; but it does no
follow that the new theory may not o.
true.
Incidentally, the theory of relatlv1t.
accounts for the action OF gravitation
and. very fortunately. the truth or raj
sitv of the theory admits of direct as
Economical test. Thus, where a ray
light passes through strong graVlta
tional field it should. according to tn
theory, be slightly DETECTED from II
course, its path should no longer
perfectly straight line. When sta
is seen in almost the same direction
the sun it's light is such ray, pursuln'
straight path for a very great dlstanc
through space. but finally passing clos
| to the ball of the sun and hence throug
the suns gravitational field. The neare
the star is seen to the edge of the DIS
| the stronger the gravitational neil
through which its light has passed, an
the greater should be the bending o