The early rays of the Sun that mark the beginning of a day, the stars that guide travelers to the North, the burning fires of ancient lighthouses…all unspoken messages of light, changing the way we communicate.
Since ancient times, light has always been used as a guide for wandering ships. Whether in the form of wood fire, torches, or oil lamps, lighthouses stood by the seaside, proudly fulfilling their role by helping ships reach their destination safely. The signal of a lighthouse is clear; it is either take heed or simply you arrived safely. That was just the beginning of communication through light.
With the invention of telegraph, developing a coding system became a necessity; the purpose of the coding system was to translate language into pulses that will be sent through wires. In 1838, Samuel Morse, an American painter and inventor, created the Morse code; signals that transform into electric pulses, which move through a wire. Those pulses can deflect a magnet which subsequently moves a marker that produces written codes.
Morse transformed the alphabetical letters to codes consisting of dots and dashes; the most famous of these codes is SOS, the distress signal. The Morse code was not limited to transmitting signals through electric pulses; it developed from just dots and dashes into many other signals like sounds and flashes of light such as turning on and off a source of light to send pieces of information.
Light was used in the past to guide ships, and through the use of the Morse code it was also used to send different signals of help or guidance. Optical communication is a way of carrying information through light. This way of transferring information is very useful especially to ships at sea when no other form of communication is available.
One of the famous forms of transferring information through light is signal lamps, known as Aldis lamps. Those lamps are named after their inventor, and sometimes use Morse code; they are mainly used on naval vessels and airport control towers. Nowadays, they are used in airports just as backup devices, and they do not transfer complex messages; just basic messages like stop or land.
Officially, Morse code is no longer in use, whether in its written form (dots and dashes) or the flashes of light (signals), but it has been replaced by advanced and faster ways of communication.
Since Ancient Times, light was used for communication; traffic light is an example of how light is used for that purpose. Red light means stop, green light means go, and yellow light means caution. As light plays an important role and helps in organizing traffic, it is also important at sea. All ships abide by the rules of the International Regulations for Preventing Collisions at Sea.
The lights on a ship do not just indicate its size; they also show its direction. Lights on any ship are not haphazard; the left side is called the “port side”, while the right side is called the “starboard side”. The lights of the port side are red, and on the starboard side are green; thanks to these lights, you can easily tell which way a ship is heading.
Communication by light is not restricted to human beings only; other creatures also use light to communicate. Unlike human beings, they have not invented anything; however, they are gifted with powers to produce and emit light. The process of producing and emitting light is known as bioluminescence; it is used to find mates, for defense, for communication, and for camouflage. Some types of fish produce light to lure other types to attack.
References
omniglot.com
britannica.com
universetoday.com
todayifoundout.com
brighthubengineering.com
ns1763.ca/tele/morse01.html
inventors.about.com
earthsky.org
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