Morse Code R.I.P.
(and what's that got to do with TCP/IP?)
... --- ... .-. .. .--. (SOS, RIP)
Morse code is being replaced by a
new satellite-based system for sending distress calls at sea. Its dots and
dashes have had a good run for their money "Calling all. This is our last cry
before our eternal silence."
Surprisingly this message, which flashed
over the airwaves in the dots and dashes of Morse code on January 31st 1997, was
not a desperate transmission by a radio operator on a sinking ship. Rather, it
was a message signalling the end of the use of Morse code for distress calls in
French waters. Since 1992 countries around the world have been decommissioning
their Morse equipment with similar (if less poetic) sign-offs, as the world's
shipping switches over to a new satellite- based arrangement, the Global
Maritime Distress and Safety System. The final deadline for the switch-over to
GMDSS is February 1st, a date that is widely seen as the end of an era.
For although dots and dashes will not die out altogether -- they will,
for example, continue to be used by amateur radio operators, spies, and some
members of the armed forces -- the switch to GMDSS marks the end of the last
significant international use of Morse. The code has, however, had a good
history. From its origins in 1832, when an American inventor called Samuel Morse
first started scribbling in his notebook, it grew to become the global standard
for sending messages along wires and, later, over the airwaves. Morse code was,
in effect, the network protocol for the world's first Internet: the
international telegraph network, whose cables trussed up the globe in the second
half of the 19th century.
The mother of all networks:
Appropriately for a technology commonly associated with radio operators
on sinking ships, the idea of Morse code is said to have occurred to Samuel
Morse while he was on board a ship crossing the Atlantic. At the time Morse was
a painter and occasional inventor, but when another of the ship's passengers
informed him of recent advances in electrical theory, Morse was suddenly taken
with the idea of building an electric telegraph.
Other inventors had
been trying to do just that for the best part of a century. Morse succeeded and
is now remembered as "the father of the telegraph" partly thanks to his
singlemindedness -- it was 12 years, for example, before he secured money from
Congress to build his first telegraph line -- but also for technical reasons.
Compared with rival electric telegraph designs, such as the needle telegraph
developed by William Cooke and Charles Wheatstone in Britain, Morse's design was
very simple: it required little more than a "key" (essentially, a spring-loaded
switch) to send messages, a clicking "sounder" to receive them, and a wire to
link the two. But although Morse's hardware was simple, there was a catch: in
order to use his equipment, operators had to learn the special code of dots and
dashes that still bears his name.
Originally, Morse had not intended to
use combinations of dots and dashes to represent individual letters. His first
code, sketched in his notebook during that transatlantic voyage, used dots and
dashes to represent the digits 0 to 9. Morse's idea was that messages would
consist of strings of numbers corresponding to words and phrases in a special
numbered dictionary. But Morse later abandoned this scheme and, with the help of
an associate, Alfred Vail, devised the Morse alphabet, which could be used to
spell out messages a letter at a time in dots and dashes.
At first, the
need to learn this complicated-looking code made Morse's telegraph seem
impossibly tricky compared with other, more user-friendly designs. Cooke's and
Wheatstone's telegraph, for example, used five needles to pick out letters on a
diamond-shaped grid. But although this meant that anyone could use it, it also
required five wires between telegraph stations. Morse's telegraph needed only
one. And some people, it soon transpired, had a natural facility for Morse code.
As electric telegraphy took off in the early 1850s, the Morse telegraph
quickly became dominant. It was adopted as the European standard in 1851,
allowing direct connections between the telegraph networks of different
countries. (Britain chose not to participate, sticking with needle telegraphs
for a few more years.) By this time Morse code had been revised to allow for
accents and other foreign characters, resulting in a split between American and
International Morse that continues to this day. On international submarine
cables, left and right swings of a light-beam reflected from a tiny rotating
mirror were used to represent dots and dashes.
Meanwhile a distinct
telegraphic subculture was emerging, with its own customs and vocabulary, and a
hierarchy based on the speed at which operators could send and receive Morse
code. First-class operators, who could send and receive at speeds of up to 45
words a minute, handled press traffic, securing the best-paid jobs in big
cities. At the bottom of the pile were slow, inexperienced rural operators, many
of whom worked the wires as part-timers. As their Morse code improved, however,
rural operators found that their new-found skill was a passport to better pay in
a city job. Telegraphers soon swelled the ranks of the emerging middle classes.
Telegraphy was also deemed suitable work for women. By 1870, a third of
the operators in the Western Union office in New York, the largest telegraph
office in America, were female. Just as skilled operators found that they could
recognise each other over the wires from their style of Morse code, many
operators claimed to be able to recognise women operators. Inevitably, romances
were initiated over the wires -- just as they are today by e-mail. There were
even a handful of weddings by telegraph.
In a dramatic ceremony in 1871,
Morse himself said goodbye to the global community of telegraphers he had
brought into being. After a lavish banquet and many adulatory speeches, Morse
sat down behind an operator's table and, placing his finger on a key connected
to every telegraph wire in America, tapped out his final farewell to a standing
ovation. By the time of his death in 1872, the world was well and truly wired:
more than 650,000 miles of telegraph line and 30,000 miles of submarine cable
were throbbing with Morse code; and 20,000 towns and villages were connected to
the global network. Just as the Internet is today often called an "information
superhighway", the telegraph was described in its day as an "instantaneous
highway of thought".
But by the 1890s the Morse telegraph's heyday as a
cutting-edge technology was coming to an end, with the invention of the
telephone and the rise of automatic telegraphs, precursors of the teleprinter,
neither of which required specialist skills to operate. Morse code, however, was
about to be given a new lease of life thanks to another new technology:
wireless.
Following the invention of radiotelegraphy by Guglielmo
Marconi in 1896, its potential for use at sea quickly became apparent. For the
first time, ships could communicate with each other, and with the shore,
whatever the weather and even when out of visual range. In 1897 Marconi
successfully sent Morse code messages between a shore station and an Italian
warship 19km (12 miles) away. The first sea rescue after a distress call sent by
radiotelegraph took place in 1899, when a lightship in the Dover Straits
reported the grounding of Elbe, a steamship. Two years later, Marconi sent the
first transatlantic radio signal: three dots, the letter "S" in Morse code. By
1910, Morse radio equipment was commonplace on ships.
The sinking of the
Titanic in 1912, however, highlighted the need for radio operators to listen at
all times for distress signals. After the disaster it emerged that the liner
Californian had been only a few miles away, and that hundreds of lives might
have been saved had the Californian's radio operator been on duty and so able to
receive the Titanic's "SOS" distress call. At the first International Convention
for Safety of Life at Sea (SOLAS), held in London in 1914, it was agreed that
large vessels should maintain 24-hour radio watch.
This rule has
remained ever since, with subsequent SOLAS conventions gradually introducing new
rules to keep pace with the development of technologies such as radiotelephony.
The advent of satellite technology led the International Maritime Organisation
to amend the SOLAS convention in 1988 to introduce GMDSS, an automated emergency
communications system based on satellite and radio links.
Optional since
1992, GMDSS equipment will be compulsory worldwide from February 1st on all
ships that exceed 300 tonnes, carry 12 or more passengers, or travel in
international waters. (Owners of smaller vessels can install the equipment if
they wish.) Under GMDSS, anyone on board a ship in distress merely has to press
a button to send a distress call containing the vessel's identification number
and its precise location -- there is no need for a skilled Morse operator. And
so, after nearly 170 years, Morse code will finally slip beneath the waves.
Over and out:
As communications protocols go, Morse has lasted a
surprisingly long time - -- admittedly with a few tweaks here and there. So how
might its modern descendant, the Internet Protocol (TCP/IP), fare in comparison?
TCP/IP was devised in 1973 by Robert Kahn and Vinton Cerf (a man with Morse-like
stature in the Internet world who is often known as the "father of the
Internet").
As with Morse code before it, TCP/IP is being improved to
respond to new challenges and technologies. Its addressing system is now being
overhauled to make room for billions of additional connections, to allow for the
wireless devices expected to proliferate over coming years and to enable even
household appliances to go online. Mr Cerf is also working on how to extend the
Internet to such other places as the moon and Mars, since the time delays as
radio signals travel through space make the current protocol unsuitable.
Further improvements will follow: indeed, since it is spoken by
computers, not humans, TCP/IP is easier to adapt than was Morse. Even so, in
today's fast-changing computer world, it seems unlikely that TCP/IP will remain
in continuous use for anything like as long as the century and a half managed by
Morse code, its distant digital ancestor.
From: The Economist, Jan. 23,
1999 SCIENCE AND TECHNOLOGY
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