Preface
电信技术可追溯至古代的远距离“即时通信”(instantaneous commmunication)尝试。
In the early modern period and before, certain torch-coded communications, flags, and the development of cryptography and coding used in the military, together with the invention of the telescope in the 17th century, led to the development of many new "instant communication" technologies, laying the foundation for the formal emergence of telecommunications technology.
However, the continuous improvement of conventional communications such as the post system, the road revolution that began in the middle of the 18th century, the lack of demand for "instant communication" in military communications, the development of conventional military communications, and the shortcomings of many "long-range instant communication" systems themselves have seriously hindered the large-scale use of these technologies.
It was not until the end of the 18th century that the war situation caused by the French Revolution led to the large-scale application of the first telecommunications technology (video newspaper).
Remote "instant messaging" as a precursor to telecommunications technology
In a written society, the most common messenger of information was a messenger on foot or on horseback. This method of information exchange has appeared in the earliest civilizations, and gradually formed a stable post system.
In the late Middle Ages, the postal system first appeared in Paris and then spread to other European countries, and an institutionalized social communication system began. But with this conventional means of communication, the speed of communication does not exceed that of a galloping horse, or a sailing ship with a full wind.
In terms of the speed at which political orders were transmitted, the time of King Elizabeth I was no different from that of Pericles.
But there is another type of communication that uses non-material forms such as fire and sound, which also has a long history.
The use of beacon communication is recorded in many historical and religious books in ancient times, and even until the 16th century, simple beacon communication was still the usual (early warning) method in Europe.
In England, for example, the southern counties of England (especially along the coast) are strategically important and have a large number of beacon installations, with 31 beacon towers recorded in the 14th century.
The most famous example of this is the warning of beacon fire on the coast of England and Ireland as the Spanish "Armada" approached in 1588.
Although Fire Beacon communication has a long history and an important position, it can only transmit simple signals and cannot be regarded as the predecessor of telecommunications.
We believe that the predecessor of telecommunications is a kind of long-distance "instant communication" using coding principles, that is, what communication scholar James W. Carev called "transportation" and "communication" as a systematic communication technology.
In addition to simple communication methods such as beacon fire, "long-range instant communication systems" using coding have appeared in ancient Greece, and these communication methods can be regarded as the source of telecommunication coding technology from the perspective of coding.
The earliest record of this communication system can be found in the ancient Roman historian Polbius's "The Hislories", which is a communication system using multiple torches, originally invented about 150 B.C., the main principle is to divide the length of the character into five vertical and horizontal groups, and the position of the left and right groups of torches together to mark the letters to be transmitted.
At the beginning of the 20th century, students at the Technical University of Aachen in Germany experimented with the aforementioned 5<5 torch-coded communication method, which is said to be able to transmit 8 letters per minute, and the communication speed is already considerable.
The flag language is also an important way of long-distance instant communication: the flag assumed more of a military command and symbolic role in ancient times, and the "Sun Tzu" "Military Contention" quoted the "Military Politics" cloud: "Words do not hear each other, so it is a golden drum: if you don't see each other, you will accept it as the family flag".
And further pointed out that "the banner of the big golden drum tribe, so the ears of the people are also day." If the people learn, they must not advance alone, and the cowardly must not retreat alone.
This is a golden drum and flag as a symbol to command the convoy, and the flag can therefore also be used as a sign of morale.
In the early days, the flags used in the European wars were only used as instructions and symbols, and also for the communication of ships. There are not many records about the classical era in the West.
During the Byzantine Siege in the 9th century, Byzantine Leo VI (886-912) pointed out in his "Tactics" that the flags of each detachment in land battles were of different sizes and patterns, which could be used to indicate and assemble troops.
The flag was therefore so important that if it was "taken away by the enemy without justifiable reasons" during battle, the flag bearer would be "humiliated and demoted to the rank of an ordinary soldier".
In naval warfare, ships in the ocean are separated from each other, and the environment is noisy, making it difficult to use ordinary voices or heralds on horseback, so they can only resort to visual communication, "so the flag language is particularly important."
But at that time, the flag slogan seemed to only transmit simple command signals, "either erect, or swing to the left or right, or shake up and down, completely down, or turn around, change the color of the flag, and so on."
In the hundreds of years that followed, the progress of the flag language was also very limited. It is generally believed that the Duke of York (later known as Mus II) in the 17th century introduced the systematic flag language into the British Navy.
However, in the 1673 British Navy flag codebook, there were still 15 different flags representing a given message, which is obviously not much different from the ancient situation.
In ancient times, torch communication or flag language was regarded as secret communication at the same time as rapid communication, which is known as cryptography today, for the sake of communication security.
The history of cryptography is also very long. Julius Caesar's transposition cipher was well known at the time.
In the 13th century, the English Franciscan friar Roger Bacon discussed the use of ciphers in Europe and described several techniques for writing secretly, but with simple letter substitutions or omissions.
In the late 14th century, many cipher glossaries appeared in politically turbulent Italy, and cryptography gradually became a regular diplomatic tool.
At the end of the 16th century, there were many famous cryptographic methods or treatises, such as the "Vergenard Code" created by the French diplomat Blaise de Vigenere.
At the same time, Mary, Queen of Scots, the cousin of King Elizabeth I, was executed for plotting to assassinate Elizabeth and leaking the communication code.
In the 17th and 18th centuries, cryptography spread throughout Europe, and many regimes established institutionalized cryptanalysis institutions, known as "blackchambers," to intercept correspondence between enemies and diplomats, as well as domestic politicians.
New developments in the 17th and 18th centuries
From the classical era to the early modern period, a small number of elaborate torch or flag communication methods, as well as "cryptography" and "coding" applied to conventional communication, provided important references for more "long-distance instant communication" ideas or experiments in the 17th and 18th centuries.
The invention of the telescope in the 17th century led to new ideas for instant communication, which led to some important communication experiments and further advanced the development of related technologies.
The advent of telescopes is a key link in the evolution of long-range instant communication.
Telescopes, as an extension of the eye, have broken through the limitations of long-distance instant communication using visual signals and promoted the emergence of many communication ideas and experiments.
Invented by the Dutch in 1608, the telescope was soon used for long-distance instant communication after being improved by Galileo and others.
In 1616, the German Franz Kessler described the method of communication with a telescope: a large barrel with lead inside, a fire was lit in the barrel, and one side of the barrel was equipped with a blind that could control the switch, and the individual letters were encoded with the number of flashes to send a message to a distant place.
Similar ideas were followed, such as those of Wynantvan Westen of the Dutchman in 1636 and Marquis of Worcester in 1663.
In another 1664 letter, it was suggested that the ancient Greek 5x5 torch encoded communication at night should be replaced by daytime communication on the mountain, by hanging markers on two sets of five poles and transmitting signals by raising and lowering them.
In 1684, Robert Hooke, an Englishman, designed a communication device with the help of vision, which should be the first relatively complete remote "instant communication" device in modern times.
As laboratory director of the Royal Society, Hooke was "the most talented experimenter and the most ingenious and imaginative inventor of the Royal Society at that time".
Hooke's video design was first published in his lecture at the Royal Society. In his speech, he made it clear that "in order to achieve this method of communication, we must resort to a recent invention - an invention that the ancients apparently did not know, and the eye needs to see with the help of a telescope".
Hooke's design uses a screen as a backdrop to hang the symbol of the substitute school, and does not take into account the proportional relationship between distance and size, as well as the control symbols outside the letters, such as "start", "too fast", etc.: the device is not actually coded, but only replaces the letters with more obvious symbols for observation from a distance.
In 1690, the Frenchman Guillaume Amontons proposed a similar method, in which the human figure wrote letters on the blades of the wind and communicated with the help of a telescope, as if he himself admitted that this device was a novelty and would not be practical.
Hooke and Amonton's correspondence designs were well known in the 18th century, and their inventions were mentioned in the English magazine Genlemenshlagaine in 1794 and Dirk in 1796.
Edgeworth also noted in his 1797 essay that "all mechanical (communication) designers refer to Hooke
However, telescopes in the 17th and 18th centuries were undoubtedly rare and expensive, and the production of lenses required a certain amount of expertise. In addition, although the performance of the telescope is gradually improving, the chromatic aberration caused by the refraction of the lens degrades the observation quality of the telescope.
Lengthening the tube can reduce chromatic aberration, but it cannot eliminate it. Later, in 1668, he built a reflecting telescope, but it was difficult to make and was not widely available.
Thus, the use of telescopes for long-distance communication devices was apparently still unknown in the 17th century. It wasn't until the first half of the 18th century that an achromatic lens was created, which was later improved by John Dollond, who made it possible to see up to 10 kilometers away.
After Hooke's 1684 scheme, long-range instant communication designs such as the human pen also existed throughout the 18th century (at least the second half of the 18th century). As the telescope improves, so should its feasibility: but the design seems to have been used only as a pastime, not even documented.
There are many types of "novelties" in long-range instant messaging technology, and there are signs of discontinuity. In 1794, the Frenchman Claude Chappe's video was put into use, sparking a new design boom. But before that, many unfavorable factors prevented the large-scale application of these remote "instant messaging".