Science of light
Sound in Relation to Light
Sound is shown to be the most basic form of
vibration, and the study of sound has a place alongside the
science of light, due to many of the same characteristics
such as wavelength, reflection, refraction, scattering and
diffraction: but light is a finer and faster-vibrating form
of energy. The
science relating to sound is called acoustics, from the
Greek word “akoustikos”, relating to hearing.
Aristotle and other philosophers and mystics since
his time have believed that there was a definite correlation
between the color spectrum and that of sound – that sound
vibrations touched upon one’s inner color-consciousness,
and that colors aroused an inner attunement akin to music.
In more recent times definite charts have been set up
which match certain musical notes to corresponding color
hues. They do
not all use the same correspondences, therefore more
experimentation along these lines will be needed.
Two systems come to mind which seek to match the
octave of the musical keyboard to the color spectrum.
They agree on red, orange and yellow as corresponding
to musical notes C, D, and E, respectively.
But at F they diverge as follows:
F, green-yellow; G, green; A, blue; B, violet.
F, green; G, blue; A, indigo; and B, violet.
Science has described a scale of vibrations beginning
with two-per-second. When
the number of pulsations per second is repeatedly doubled, a
series of octaves results.
Sound has a lower rate of pulsation than light.
These energies move out from the Source in a series
of waves, the measurement of each wave being what we call a
The key of C, called “Middle C” in the musical
scale, occurs at 256 vibrations per second.
This produces a corresponding effect on the human ear
to that of the note. As
one can move up the musical scale, in a similar way one can
move up the rate of vibrations by 40 doublings of the
vibration of Middle C and arrive at the vibration which
produces the speed required for the appearance of the color
red. For at this
finer point, the vibrations are produced to which your
sight-center responds, receiving the sensation of “red”.
At the fifteenth octave of measurement, these waves
of vibration become inaudible to the human ear.
The octaves from twentieth to thirty-fifty are those
of electricity. The
thirty-sixth to forty-fifth, nerve currents in the body.
Forty-sixth through forty-eighth are octaves of heat
these are several octaves of light, of which visible light
and the whole range of the color spectrum cover only one
audible sound range by comparison comprises some 9 or 10
visible light are 5 octaves of ultra-violet light, 10
octaves of x-rays, and so on.
It goes without saying that some exist as yet
undiscovered by science, though hinted at by the old
Lesson Four, page 2
The Spectrum of Electromagnetic Waves
(Note: Boundaries are approximate.
Frequency Wave areas overlap from one
(Cycles per second) to another.)
A person emits sound stimuli when he speaks; the
listener experiences sound through hearing.
Man is surrounded on all sides by the sounds of
nature, but he has contrived to manufacture many more, which
can produce either pleasure or pain.
To simplify in the extreme, the
result of the process of speech is some motion of the air in
front of the mouth. And
a person hears because there is some motion of the air at
the entrance to his ear.
Sound is the result of motion in some medium.
The human voice operates by forcing air from the
trachea to vibrate the vocal cords.
This in turn sets into vibration the air in the
cavities of the throat and mouth, and the resulting
disturbance emerges from the lips.
Four, page 3
Four, page 4
There are many kinds of waves.
Light waves are very much shorter than either water
waves or sound waves. Sound
waves traveling through the air do not have humps and
hollows, as water waves do.
Instead, there are places where the air is slightly
squeezed together. In
between, the air is slightly thinned out.
The sound is carried by a set of these pushes and
pulls, moving along through the air.
The wave length is the distance between one push and
the next. Sounds
that we can hear have wave lengths from less than an inch to
as much as 70 feet.
The velocity of sound waves in air increases with
temperature; at room temperature it is about 344 meters
(1125 feet) per second, or roughly 767 miles per hour.
This is very much slower than the speed of light.
Therefore the sound of a crash of thunder is heard
after the lightning flash is seen.
You can measure the distance of a flash of lightning
from where you are standing by counting the number of
seconds between seeing it and hearing it.
The delay will be about five seconds per each mile
from the flash to you.
Sound waves, like those of light, are reflected when
they strike an appropriate surface.
An echo illustrates this: where a sound bounces off
the face of a cliff, for example, and returns toward the
direction from which it came.
Speaking in a closed room is easier than in an open
space, due to the gentle reflection of sound from the walls
and other surfaces, all blending simultaneously.
If reflection is too exaggerated due to hard or
metallic surfaces, the echoes may become noticeable, then
certain sound-absorbing materials such as cork, fabric, or
perforated materials should be introduced to absorb some of
of sound waves is more difficult to detect than that of
light, but it does occur.
Sound waves travel faster in warm air than in cold,
so that when encountering air layers of different
temperature, the sound slightly changes course, usually in
an upward direction. This
causes a sound mirage much like a visual mirage, in that the
sound will reach the ears as though it came from a different
Air currents also cause a variable factor, as sound
traveling with the wind moves more easily than against it.
An object waved back and forth with less frequency
than 15 cycles per second would not be audible.
An object moving any faster than that should become
audible if the intensity is sufficient, and it will remain
audible up to a movement of 20,000 cycles per second.
When the frequency is increased beyond that it
becomes inaudible to human ears.
These high frequency sounds are called ultrasonic
Ultrasonic waves tend to travel in beams like light,
whereas slow frequency audible sound waves tend to spread in
every direction from the source, radiating outward like
ripples on a pond into which a stone has been dropped.
But if the frequency is high enough, a beam of sound
can be produced. It
is more difficult to produce a beam of sound waves than a
beam of light, but it can be done.
Sound-wave propagation is basically a form of
transmission of energy through a medium.
The greater amount of energy transported per unit of
time, the greater will be the intensity of the sound wave.
All these things are of vital interest to those
working in the field of communications, such as radio,
television, telephone, or other media using sound.
four, page 5
The power in speech sound waves varies, being much
larger for vowels than for consonants.
Hearing with two ears rather than one leads to the
ability to detect the direction of sound waves.
Sound waves set the eardrum into vibration, and this
motion is communicated via the bony ossicles (a kind of
solid acoustic filter) to the oval window of the cochlea, a
spiral cavity. The
flexible basilar membrane in the cochlea can vibrate under
the impact of motions of the cochlear fluid.
Fine hairs in the adjacent organ of corti in the
cochlea communicate these vibrations to terminals of the
auditory nerve. The
system functions as a transducer, converting mechanical
energy to neural energy.
With all the sophisticated devices for both measuring
and transmitting sound, there are still two distinct
theories of hearing, of how the sound is communicated to the
brain. This is
still to be worked out.
Noise control is a vital need in life today.
If an employee must work close to an extremely noisy
machine, ear defenders (small acoustic filters inserted in
the ear canal) may be available.
The human ear is a vulnerable receiver, highly
attuned, and deserves a harmonious sound environment.
“Music hath charms to soothe the savage beast,”
and listening to the various types can easily induce
different moods or emotions.
Music thus has therapeutic value in treating those
with emotional disturbance, or inspiring interest in those
who have lapsed into apathy.
Light classical symphonic music gives the best
results generally. It
helps restore inner harmony to one who has gotten off
balance. For the
listless person who needs cheering, something a bit livelier
would help. But
avoid the hard beat of “rock” music and such.
It has a shattering and disruptive effect on the
nervous system, reducing persons to a jittery and unstable
condition, and upsetting the harmonies of nature. It can
tear down the spiritual work and growth you are attempting
Animals respond readily to light classical music,
when gently played. Even
goldfish seem to enjoy it.
In poultry houses or dairy barns, the output of eggs
and milk can be increased with the use of music.
It has been found that carefully selected music,
played with taste, not too loud or insistently, aids
employees in industry to maintain a better outlook and grow
less tired with their work.
Much discrimination is needed here, however.
The Egyptian hierophant taught that the universe is
called forth from chaos by ordered rhythmic sound.
In the beginning of any cycle of manifestation it is
the sound vibrations which come into expression before the
more rapid pulsations of light.
It is said by the Hindus that “through sound the
world stands.” They
classify sound as having two types, the unlettered and the
former is that which could be caused by striking two objects
latter is articulated sound, words and sentences, and
conveys intelligence. Such
sound is said to be eternal.
They reverse the order of our diagram, placing sound
as the first of the gunas, or principles, out of which
emanated the second principle, that of touch.
four, page 6
The secret of mantras has been carefully guarded by
the mystics, because “out of sound every form comes, and
in sound every form lives.”
They teach that sound is the quality of the Akasha.
It is the all-pervading fifth essence, having the
characteristic quality of pure space.
Out of it all things come, and into it all return.
Music therapy has been used by scientists to aid in
correcting mental and emotional conditions,
which respond well to sound.
Changing the mood of the music from sadness to joy,
or from vigorous to peaceful has a distinct effect on the
feelings of the listener.
Changes in color can produce a similar effect; both
music and color work on the psychic consciousness.
5) Concha 6)
Mastoid process 9)
Bony part of external auditory meatus
10) Facial nerve
11) Styloid process
13) Internal cartoid artery
14) Cartilaginous part of Eustachian tube
Membranous portion of Eustachian tube
16) Orifice of Eustachian tube in mouth
Tensor tympani muscle
18) Auditory nerve
21) Semicircular canals
22) Hammer 23) Anvil 24) Mastoid cells