Telecommunication has truly gone a long way over the past 190 years. Today, we enjoy the privileges of having a cellphone, an Internet connection, and many other telecommunication devices. But did you know that physics and many different physicists played a major role in these developments?

Early Devices
Danish physicist and chemist Hans Christian Oersted’s discovery of magnetic fields induced by electric current in 1820 led to the invention of the earliest device known in telecommunication—the electrical telegraph. However, it still took 17 years after the discovery of electromagnetism before the first electrical telegraph was perfected by British gentleman Sir William Fothergill Cooke and scientist Charles Wheatstone in 1837. This was also the year when it was first commercially used.

A Morse telegraph (1912)

During the same year, a similar electrical telegraph was produced in the United States. Inventors Samuel Morse and Alfred Vail came up with an alternative design and a different set of telegraph codes. It was also during that year that the Morse code was born.

The Morse code is a character encoding alphabet composed of short and long elements of “dots” and “dashes”. These represent numbers and letters which can be used to send messages. Electrical contacts made by the telegraph keys produce audible signals which are transmitted through a telegraph wire. These are received and transcribed by interpreters on the other end of the telegraph transmission.

One of the earliest telephones designed by Alexander Graham Bell.

Nearly 40 years later, a young inventor who was interested in teaching deaf people how to speak came up with the idea of transmitting and receiving human voice instead of just electric pulses through an electronic device. In 1876, Alexander Graham Bell and Elisha Gray independently invented the telephone. However, Bell was credited for the invention. Two years later, the first commercial telephone service became available.

The original telephone transmission system was based on the telegraph technology. Following the concept of electromagnetism, it used a single iron wire to transmit sound. The telephone system back then was only for short distances. Soon after, physicists from different universities across the United States were laying the groundwork to make long-distance communication in a telephone network a possibility.

The Modern Era
Since the introduction of the telephone, the quest to improve telecommunication technology has never stopped. Between the late 19th century and the early 20th century, countless inventions, discoveries, and devices were made to make long-distance communication possible. The year was 1965 when a groundbreaking event happened, ushering in the era of modern telecommunication.

A bundle of fiber optics.

Charles K. Kao and George A. Hockham of the British company Standard Telephone and Cables worked on fiber optics technology as a medium for telecommunication. Their study was the first to theorize and propose the use of glass fibers instead of copper wires to transmit information.

In a further study, Kao and his team found out that the high purity of fused silica is ideal for long-distance transfer of information. Because of this study, Kao received half of the Nobel Prize for Physics in 2009.  He also became known as the “father of fiber optics”.

The use of fiber optics technology in data transmission works through the principle of total internal reflection. When light passes through an optical fiber, it will produce multiple reflections that do not refract until it comes out of the other end of the fiber. Optical fibers are now used in telephone and Internet technology.

The Future of Telecommunication
Today, scientists and engineers are no longer just using underground cables as media for telecommunication, they are also utilizing the airwaves. When radio was first invented during the late 19th century, radio signals were already in full swing. As early as the 1900s, physicists have already tried to improve analog radio frequency signals: amplitude modulation (AM) and frequency modulation (FM).

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Nowadays, satellites are also being used to relay radio signals. Artificial satellites orbiting Earth reflect radio signals being transmitted in space to different points on the ground where an antennae can receive the signals.

Satellite technology is the basis of a recent technological breakthrough. In some countries, transmission signals are being changed from analog to digital. Going digital promises a much clearer sound for radio transmission and a much sharper picture for television transmission. Cellular phones and wireless Internet also use this kind of technology.