Arizona republican., 1903-11-13
CURRENT COMMENT
Observation-Disclosures:
Life on Other Worlds.

DR.. Alfred Russell Wallace seems still
to stand without company in the the
DRY that our little earth is the only in
habited planet in the universe Prof. +.
j. Allen discusses the question reason
ably in the November Popular Science
Monthly.
The chief characteristics of life, ac-
cording to Prof. Allen, is energy traf-
fic." Living substance absorbs radiant
energy, stores it, and later expend3 it
in active forms, such as motion, me-
chanical work. heat and electricity.
On the earth this energy traffic is car
ried on chiefly among the four ele-
ments, nitrogen, oxygen, y carbon and
hydrogen. For life as We know il to
exist there must be a supply of these
elements or of others like them, a mar
row gauge OF temperature and a supply
of intermittent or variable radiant en-
ergy. 1t is unlikely that these condi-
tions exist anywhere in our solar sys-
tenn except on the earth. The sun and
probably Jupiter and Saturn are too
hot.
Venus might answer the cond tions.
for she has about the same size and
graVitatiOn as the. earth, which implies
the probability that she has an atmcs-
phere similar in density and compost
ton. Her nearness to the sun might
make her equatorial regions too hot
fer earthly life. but other parts of her
surface might be of the right tempera-
ture. But there is a strong suspicion
that Venus keeps the same side always
turned toward the sun, in which casa
that side would always be sccrched
and dry and the other side casad in fc1.
Mars is probably so cold that wate'
cannot exist in a liquid form, and grav-
itation therefis too slight to hold an
atmosphere like ours.
The planet is so small that little heat
can be provided from within. and is so
far from the sun that little can be re-
ceiVcd from without. What little hea..
reaches the surface must radiata away
almost at once.
The gravitation of Mars is 50 small
that it is doubtful whether eve1 the
vapor of water could be held. 1t seems
impossible, therefore, that earthly life
could exist there.
The moon has neither air nor water,
although some think that geological ac-
ii witty has not ceased there, and the
extremes of temperature produced by
the alienation Of half a months sun
might awaken 10 vital activity ele-
ments which behave as dead on this
earth"
On the whole it is probable that we
are the only beings Of our kind In our
solar system. 1t may be, too, that the
conditions required for earthly life are
rare In other systems, although nobody
can say that they do not exist. We
know from the spectroscope that many
stars have the same elements and about
the same temperature as our sun, and
some Of those stars may have planets
situated like the earth.
But there is no reason to suppose that
the life we know is the only kind OF
life there is. Other elements than oxy-
gen, nitrogen, hydrogen and carbon
may carry on energy traffic" If we
die of sunstroke on d hot Gay. there
might conceivably be beings who could
live in the sun itself IF different
conditions can awaken a capacity for
exalted energy traffic among other ele-
ments than these just named, then the
universe seems to provide immense
possibilities of life whose variety and
nagnifcence may far exceed anything
that we can imagine