privateline.com's Telephone History, Sound and Waves
at Western Electric)
What sound waves look like and how they
Here's what sound waves look like. The caption reads, "A
visible pattern of sound waves. This new technique of studying
sound demonstrates the focusing effect of an acoustical lens
on sound waves issuing from the horn at extreme left. Wave pattern
is produced by a scanning technique . . ." Bell Telephone Laboratories (external link) photograph, from the book The First
Book of Sound: A Basic Guide to the Science of Acoustics
by David C. Knight, Franklin Watts, Inc. New York (1960). p.
Sound waves are acoustic waves, with no electrical component.
They are simply vibrations in the air, a physical pressure made
by the utterance of the speaker.
In somewhat challenging yet elegant writing, A.T.&T. once
described sound in these terms, "Audible sound is thus defined
as a disturbance in the atmosphere whereby a form of wave motion
is propagated from some source at a velocity of 1,075 feet per
second, the transmission being accomplished by alternating condensations
and rarefacations of the atmosphere in cycles having a fundamental
frequency ranging somewhere between 16 per second and 32,000
per second." Principles of Electricity applied to Telephone
and Telegraph Work, American Telephone and Telegraph. C.F.
Myers, Supervisor of Instruction. Murray Hills, New Jersey? 1939.
I write a great deal about sound and radio waves at this site,
I've even discussed light waves
in passing. But did you know that all matter is a wave? A
never ending ocean of waves, one after the other, endlessly rolling
outward. We usually think of matter as particles; electrons,
photons, atoms, somewhat solid forms. But matter as a wave? Actually,
matter can be a particle and a wave at the same time. Prince
Louis de Broglie (external link) (1892-1987), postulated
in 1923 that atoms and their associates constituted solid form
and also acted as waves of radiated energy. Although the work
of Max Planck and Einstein helped Broglie develop his theory,
at the time he advanced his idea there was absolutely no physical
evidence to support it. Acceptance and confirmation by others
came quickly, however, and in 1929 he was awarded the Nobel Prize.
As Martin Mann explains the photograph below, "Electrons,
passing through a crystal, make a pattern almost exactly like
a light beam. Only waves can interact with each other to produce
such patterns; streams of individual solid [particles] cannot."
Editor's Note: The photograph below, believe it or not, is
authentic and accurately depicts the text that follows; it is
an official Navy photograph archived here: http://www.fly.faa.gov/carf/(external
link) The text itself is from the THE CGC COMMUNICATOR .
Here is a fabulous photo taken "by a military observer
from the deck of an aircraft carrier just as an F/A-18 jet broke
the sound barrier." Photo and information courtesy of Oscar
Medina, CE of KNSD(TV), San Diego. Oscar assures us that the
photo is authentic -- and not an e-artist's creation -- even
though the ocean's surface is obscured by haze. The photo was
first published about two years ago. About half way down the
text on the left side of the page, click on "Amazing Photo!"
Oscar adds: "One of my coworkers told me he has actually
witnessed the same thing happening when he was in the military.
The flares are there for a fraction of a second just as the sound
barrier is broken."
An end to telephony, Carl Sagan, and
the speed of light
The future might seem unlimited for telephony, with new technologies
invented every day. But even telephony has a limit, a barrier
it cannot cross: time. For years satellite phones have permitted
anyone at any location to call anyone else who has a phone. Going
further, a video telephone like the one envisioned by Arthur
C. Clarke in 2001: A Space Odyssey, could certainly work in Earth
orbit. But such a payphone on Mars would be impossible. Clarke
himself reminded us in 1977 that a call would take three minutes
to get to Mars and three more minutes to receive a reply. Telephony
requires a communication link providing an almost instanteous
response between both parties. Such a delay would eliminate telephony,
substituting for it a message service.
(As an aside, the latest
Britney Spear's video shows a Mars astronaut talking in real
time with mission control on earth. Not going to happen, Britney!)
Although unlimited information could be sent between both
parties, the feedback and instant response provided by telephony
would be lost. Anyone repairing a Mars orbiting space station
will have no quick help from Houston. Delays and confusion will
result, especially with problems needing immediate attention.
While telephony can overcome distance for us on earth, it itself
cannot overcome the distances it must travel; although radio
waves race at the speed of light in space, they cannot go any