Honolulu star-bulletin. [volume] (Honolulu [Oahu, Hawaii]) 1912-2010, 1912-12-20
INTERESTING FACTS
CONCERNING LIGHT
Color vi Rays Depends Upon
Velocity; Eye Fails to Detect
Fast Moving Ones

Light travels at speed of $4,000
miles a second. The source of all
light, except the lignC from fireflies
and their kin, is a substance raised
to a temperature sufficient to set up
waves in the surrounding ether. Light
waves vary in length between 1-33400
and 1-650000 of an inch, the first be-
ing extreme red and the second being
extreme violet. Rays of white light
have length of 1-45000 Of an inch.
The sun is a great mass of white hot
matter.
In an arc lamp it is the white hot
particles of carbon floating between
the two electrodes which produce
light In the incandescent lamp it is
the hairpin filament inside the glass
globe which, when heated by electric
ity, gives off light waves. In gas and
oil lamps light is produced by the
heated particles of carbon in the
fame above the wick or mantle The
eye can stand without firing in a bril-
liancy of about five candle-power per
square inch or surface. The ordinary
candle fiamo gives from two to three
candlepower per square inch, while
the sun at zenith gives 10000 can
dlepower per square inch. The arc
light ranks next to sunlight, with TO-
00e eandlepower per square inch, and
the best tungsten ffilament incandes-
cents give about 100. candlepower.
The prism shows us that white
light is composed Of happy blend of
all the colors of the spectrum. The
sun gives the only pure white light,
with the arc lamp a close second and
the metal filament incandescents TAX
ing third place. Sky light, such as
comes from the nerth on q clear day,
is blush white: Gas mantles give
greenish light, open fame yellow
light and kerosene an orange light.
In the dark no color exists The
color of light depends upon the length
of the waves. The light source which
we know as red gives off only waves
| of a length to produce that particular
| color. A body appears red because
! it's surface absorbs all the other waves
and reflects the red waves back into
the eye A thing looks black when it
! is capable of absorbing all the colors
at once. Light rays, being in active
motion, produce heat when they meet
! with resistance in their path. That is
| why black clothing is warmer than
t white clothing, the resistance being
| 0 nthe surface Of the white clothing
! and nearer the skin when We wear
| black
The eyes have only a certain range
| AS we all know. there are times when
| all appears black to us. and yet ami
mails can see. The trouble is the faint
rays move too slowly to be registered
on the human retina. The X-ray has
| proved beyond a doubt that there are
! light rays which move too fast for hui
man eyes to register. This light pene-.
trates books, wood. paper and even
human flesh. With the Horoscope to
| assist our eyes we can see the bones
| in our arm without bothering to re-
move our shirt But man with x
ray eyes would be badly handicapped
in this world. for he could see moth
| ing but solids, such as earthS and
metals, and would be unable to see a
board fence at all To Us all is dark
ness beyond what our eyes will regis
| ter.
Light rays themselves are invisible.
When they move through the ether
alone Our eyes cannot see them; con-
sequently all is total darkness.-Ch
ca9o Inter Ocean