China
Africa
Explore chapters and articles related to this topic
Thought leadership pieces
Published in Nawal K. Taneja, Airimagination, 2023
The introduction of machine-assisted communication transformed human interaction. In the 19th century, the telegraph, Morse code, the telephone and the radio were all introduced/created, paving a new era of communication. From there on, how quickly and how effectively we communicate with one another has been influenced by the inputs and outputs between ourselves and machines.
The Telegraphic Interior
Published in Anca I. Lasc, Deborah Schneiderman, Keena Suh, Karin Tehve, Alexa Griffith Winton, Karyn Zieve, Interior Provocations, 2020
Telegraphy is a nineteenth-century point-to-point communication system that transmits coded pulses of electric current along dedicated wires. On either end, the wires are threaded through a receiving instrument, and the coded information is translated by a trained operator. First introduced in the 1830s and 1840s in the United States by Samuel Morse, by 1850 the technology was already being implemented for intercity and long-distance use. Like the railroad, the telegraphic interior collapsed time and space in an unprecedented way.11 Its uncanny impact on geography during the industrial era transformed commerce across the United States and around the world. It was rapidly adopted by traders, brokers, and bankers as a rapid and effective means of communication across the growing country.12 By the early 1860s companies like the Bankers and Brokers Telegraph Company, the Gold and Stock, the Atlantic and Pacific, and Western Union began to invest in the infrastructure that would link cities all along the East Coast down to New Orleans and through the Ohio Valley to Chicago.13 Lines were strung high on the top of wooden poles planted along railroad right of ways and the major streets of the nation’s central business districts. The wires entered buildings on upper levels, often through windows, and then were fed into tickers and special receivers in telegraph company headquarters, private offices, and on the floor of the nation’s newly built stock and commodities exchange buildings (Figure 10.3).14
Overview
Published in Carl Stephen Clifton, Data Communications, 2020
Telegraphy was used for long distance transmission because it was faster than the mail and permitted city to city, east to west, and coast to coast communication. By 1891, telephony was being used within cities to tie subscribers' business offices together, replacing messengers that formerly had run up and down the streets carrying information. Telephony at that time was a chaotic process and terribly inconvenient. Each telephone company could only connect its own subscribers together. The connection was made through a pair of wires dedicated to each subscriber which terminated in connectors in the central office. The wire pairs were then connected through a jumper cable inserted into the connectors by telephone operators at the request of the subscriber. These were the times of multiple phones on a manager's desk, one from each phone company. When A. S. Strowger invented his switch in 1891, he made possible the automatic connection of subscriber to subscriber, city to city, central office to central office—even competing telephone companies, and finally automatic connections nation to nation.
The Changing Face of Public Broadcasting in India
Published in IETE Journal of Education, 2023
Pioneering initial work by Heinrich Hertz and J C Bose was soon followed by the invention of wireless communication by Gugliemo Marconi and more development by Popov in Russia towards the end of nineteenth century. These events taken all together have paved the way for transmission of information at long distances by means of radio frequency (RF) electromagnetic waves, without the need for any physical connecting medium. In the beginning, information could only be transmitted in the presence or absence of RF signal, called keying. The long and short burst of RF energy was coded by the famous Morse code, already used in telegraphy, to represent alphabets and thereby intelligible sentences could be reconstructed at the receiving end. The possibility of continuous variation of the amplitude of the RF wave, called carrier, and subsequent extraction of the amplitude variation at the receiving end, made possible the transmission of voice signals over long distances by means of radio waves. The radio stations transmitting voice and music programs over the air came into being, heralding the birth of public broadcasting.
Engineering Laboratory Experiments – a Typology
Published in Engineering Studies, 2022
Due to the characterization above, intentions of researchers play a crucial role in the identification of experiments. Regarding artifacts, we usually distinguish between their physics, the material or molecular structures, and the purpose for which the artifact was conceived and developed. Only the molecular arrangements fail to characterize an artifact because of the lack of intentionality. The molecular arrangements of its stones, wood and glass does not make a construction a cathedral, which requires the intentions of its makers and users. In this article, the same is assumed for laboratory experiments. Consider Heinrich Hertz’ experiment with the Ruhmkorff coil designed to show the existence of Maxwell’s EM-waves. Hertz is claimed to have said about these experiments: ‘It's of no use whatsoever. This is just an experiment that proves Maestro Maxwell was right – we just have these mysterious electromagnetic waves that we cannot see with the naked eye. But they are there’.9 Some years later, also using the Ruhmkorff coil, Guglielmo Marconi carried out similar experiments to develop wireless telegraphy and radio emissions. Again somewhat later, Ruhmkorff coils were used in experiments to ignite internal combustion engines. Despite the physical similarity of these three types of experiments, they have to be classified differently because of their different purposes.
Rutherford and the Cavendish Laboratory
Published in Journal of the Royal Society of New Zealand, 2021
At the end of 1893 while still at Canterbury College, Rutherford began his physics research career with an investigation into the magnetisation of iron by high frequency discharges. He continued work in this area when he arrived in Cambridge and developed a magnetic detector for electromagnetic waves (Figure 2). In December 1895, he demonstrated the operation of the detector at a distance of 200 yards from a Hertzian spark transmitter. The first outdoor use of the detector occurred on 22 February 1896 when he set up a spark transmitter on Jesus Green and detected the radiated pulses at a distance of 350 yards in a house on Park Parade. On the following day, a successful transmission over a distance of nearly three quarters of a mile was achieved. Rutherford held the world record for the reception distance at the time. In the same year, however, Marconi came to England and developed a system for the transmission of Morse code signals by means of electromagnetic waves, the beginning of wireless telegraphy.