Omaha daily bee., 1916-08-08

Here's Proof of the Suns Heat.
Bellevue. Neb., Aug. ITO the Editor Of
The Bee: Elliot Loomis in the August issue
of The Bee argues against heated surface
for the sun. and gives several reasons for his
belief. shall try to convince him to the con-
trary. answering his reasons in their order.
l. "As we are 100000 miles nearer the
sun in january than in July, taking the
world over. we see no rise in temperature"
agree with him on this point; there is not
only raise in temperature but an actual low
ering. because January is a winter month.
But the cause is not as he supposes. As the
earth draws nearer the sun in January, there
is rise in temperature, but this is more than
counterbalanced by the fitting of the earth's
axis In such 4 way that the sunlight strikes
the northern hemisphere at greater slant
In January than In July. Now the more
obliquely the rays strike, the less heat they
bring to each square inch of surface. Also
the rays when oblique have TO travel through
. greater thickness of air, which robs them
Of still more heat. Thus we have winter
when we are nearest the sun.
2. Were the sun radiating heat as or
dinarily supposed, those inner planets (Ve-i
nus and Mercury would be burned to cin-
der. while the outer planets Jupiter, Saturn,
Uranus and Neptune) would be locked in
eternal frigidity."
' Mercury and Venus are indeed. figurative-
ly. burned to a cinder." Mercury always
turns the same face toward the sun, and We
nus is suspected of doing SO; therefore, the
face turned toward the sun would be at a
high temperature (above that of boiling wa
teri, while the dark hemisphere would be at
approximately the temperature Of interstellar
space t27S degrees below zero). The four
outer bodies are practically planets in the
making, and probably are still feeble suns,
not having developed solid crust Jupiter
is suspected to shine partly by its own light
8. His third reason las to the individuality
Of the planets) would like to take UP with
him in detail, but space will not permit. l
would advise him to read the last chapter
of Simon Newcomb's Astronomy University
edition., in which he treats Of the cos
mogomy.
I. He says in substance: Because burn
ing glass bringing ths<crays Of the electric
arc to focus produces heat effects identical
with those Of the sun. therefore the SUMS
light and heat are merely electrical mani
festations. and that ANY light or heat pro-
duced by combustion, no matter how In
tense" will produce no results II It Is TO-
cused with the burning glass.
He is mistaken in this. The acetylene
light lgas) gives very appreciable amount
OF heat at the focus Of the burning glass.
The reason the ordinary fire or oil light gives
no heat Is because Of the great disparity in
temperature between 1t and the arc, acety-
lene or sunlight. This difference is consid-
erably over 1000 degrees between arc and
oil.
s. The sun does not depend on combustion
for Its light and heat. ! agree with him
there. But neither does It depend on electri-
cal energy. Modern physicists and astrono-
mers are practically all agreed that the SUMS
light and heat are produced by its gradual
contraction upon itself due to the effect Of
gravitation. The sun on this hypothesis
needs only contract 1870 feet per year to keep
up its present energy for 100000 years to
come. The radioactive elements probably
have a good deal to do with the upkeep of
the suns energy, too.
8. The outermost lighting or heating
plant does not receive the same degree of
intensity" as those nearest the dynamo
There Is . progressive drop Of voltage all
along the line. as can be easily proven by
ohm's law. In the outlaying districts Of
large cities supplied with direct current
boosters" (smalI dynamos) are cut into the
line to help raise the voltage that has been
lowered by distance.
7. Sunspots are not holes in the photo
sphere showing the coal dark body Of the
SUM-" The darkest part 1.-THE umbra) Of a
sunspot is as hot and gives out as much
light as the aeetylene, and almost as much
as the electric arc. It is only by contrast
with the dazzling surface of the photosphere
around that they appear dark. They are
caused by vapors that have rushed up from
the body Of the sun. cooled. condensed and
fallen back on its surface again. In general,
their spectrum is like that of the rest of the
olar surface, yet it shows several interesting
differences. (See chapter II Of George FL
lery Hales book. 'The Study of Stellar Evo.
lution").
WILLIAM SMITH.