Definition of the Concept:
Etymologically, the word ‘electricity’ is derived from the Greek word ‘electron’, meaning ‘amber’. According to the science of Physics, electricity is a form of energy generated by the movement of charged particles known as electrons and arising from a potential difference. Electricity is carried by negatively charged particles, whilst positively charged particles also exist in nature. An electrical potential is created by these electrical charges, where two different charges are present at the two ends of a conductor. When an electrical circuit is complete – that is, when the necessary conditions for conductivity are met – a potential difference arises due to the source (generator) containing these two different charges at its ends, and this is why the energy we refer to as ‘electricity’ in everyday life is produced.
Sources of current and potential difference, known as power sources, appear in various forms in our daily lives. For example, power sources may include galvanic cells, batteries and generators. The phenomenon caused by the movement of electrons is called electric current. In physics, there are two types of electric current. The first is Direct Current (DC), where the current intensity and direction remain constant over time; the second is Alternating Current (AC), where the current intensity and direction can change periodically and are subject to variation.
The History of Electricity:
The Ancient Period
When we look at the known history of electricity, we can see that it began with Thales, the natural philosopher from Miletus. In around 600 BC, during an experiment known as the ‘amber experiment’, Thales observed that when amber was rubbed against small objects such as wood shavings, it generated an attractive force. As the word ‘electricity’ is derived from the Greek word ‘Electronos’ – which itself means ‘amber’ – the story of the word ‘electricity’ begins here.
The observation of static electricity
By the year 1600 AD, the natural philosopher William Gilbert, in his book *De Magnete*, concluded that the interaction of amber with other small objects was a special phenomenon and became the first person to name this effect ‘electricus’. In the mid-18th century, Benjamin Franklin carried out a series of important experiments, which led him to classify charges into two types: positive and negative. He also independently discovered that glass is an insulator and, utilising this property, invented a glass battery.
The Observation of Electric Current and Electromagnetism
The concept of electric current in the history of electricity dates back to the late 18th century with Luigi Galvani. In his experiment with a dead frog, Galvani observed that when he touched various metals to the nerve-rich region of the frog’s leg, the leg moved; he believed this was caused by the frog’s leg itself and thus laid the foundations of electrophysiology. In 1800, Alessandro Volta, viewing this experiment from a different perspective, concluded that the movement originated from the metal itself. Capitalising on this insight, he invented the first battery capable of generating an electric current, known as the ‘Voltaic Pile’. In recognition of these contributions, the unit of voltage (potential difference) in physics was named the ‘Volt (V)’ in his honour. Another groundbreaking development took place in 1820. A teacher named Hans Oersted, during a school lesson, on a whim whilst the lesson was in progress, tried bringing a conductive wire parallel to a compass lying on the desk as current passed through the circuit. The moment the current passed, he observed that the compass needle deflected (turning towards the wire instead of pointing north). Oersted subsequently shut himself away in his laboratory to conduct experiments using more powerful batteries; by confirming his discovery, he established the concept of electromagnetism and drew attention to the relationship between electricity and magnetism, thereby both leaving a legacy for and guiding future physicists. Again, in the early 19th century, the French physicist André Marie Ampère, believing that electricity and magnetism originated from the same source, introduced Ampère’s law, introduced the concepts of electromagnetism and electrodynamics into the physics literature. Furthermore, by defining and formulating the magnetic force, he earned the title ‘the Newton of Electricity’, and in recognition of his work, the unit of electric current was named the ‘ampere (A)’ in his honour.
Formulation of the Electrostatic Force
During the same period, another French physicist, Charles Coulomb, formulated the relationship between the distance between two charges exerting an electrostatic force on one another and the magnitude of that force.
The Generation of Usable Electrical Energy
In 1831, Michael Faraday discovered concepts such as electromagnetic induction and electromagnetic self-induction. Furthermore, by constructing the first primitive electric motor in 1821, Faraday laid the foundations for many of the technologies we use today, making groundbreaking contributions to both world history and the history of physics. In the 1860s, another pioneering figure, James Clerk Maxwell, modified both Ampère’s Laws and Faraday’s Laws, drawing in particular on Faraday’s insight into the relationship between the concepts of electricity and magnetism, thereby laying the foundations of the Theory of Electromagnetism, and by explaining that light is also an electromagnetic wave, he theoretically proved the existence of electromagnetic waves.
The widespread adoption of electricity in human life
From 1847 onwards, Werner von Siemens pioneered the idea of transmitting electricity via power lines for distribution to towns; in recognition of his work on the concept of electrical conductivity and his development of the discipline of electrical engineering, the unit of electrical conductivity in physics was named ‘Siemens (S)’ in his honour. From 1882 onwards, following his development of the commercial, long-life light bulb, Thomas Edison played a leading role in the regular distribution of electricity to homes, first in New York and subsequently in many other parts of the world.
The Era of Alternating Current and Radio Technology
In the years that followed, the German physicist Heinrich Hertz practically proved Maxwell’s theory of electromagnetic waves in an experiment conducted in 1887 using an electric spark generator and an experimental setup comprising two metal rods. Although he did not live to see it, his work, combined with the efforts of scientists such as Marconi and Tesla, paved the way for the development of wireless communication technology. In recognition of his contributions, the unit of frequency in physics was named ‘Hertz (Hz)’ in his honour. Nikola Tesla developed polyphase alternating current between 1887 and 1888; as one of the pioneers of usable alternating current, he paved the way for the development of modern transformers and ensured their widespread adoption. In addition, Tesla – who is also known for his work on wireless energy transfer – drew upon Hertz’s research and even obtained a patent for a ‘remote-controlled boat’ in 1898. His work paved the way for the inception and development of modern radio technology. In 1904, John Ambrose Fleming, drawing on the developments he had long been contemplating —the Edison Effect—and the developments surrounding the discovery of the electron, to invent the diode, a component that enables the conversion of alternating current to direct current and, at the same time, a device that allows the unidirectional flow of electric current. This invention provided significant convenience, particularly in terms of the domestic use of electricity and its adaptation for household appliances. Furthermore, the invention of the diode, following the conversion of electromagnetic signals into electric current and their subsequent modulation to produce useful outputs such as sound and images, not only marked one of the most significant steps in the development of radio and communications technology but also paved the way for the emergence of the concept known as electronic technology.
The Modern Era
William Shockley, John Bardeen and Walter Brattain developed the transistor at Bell Laboratories in 1947. The invention of the transistor paved the way both for the development of modern computers operating on today’s principles and for computers to become progressively smaller, taking on their current form. Transistors have driven the advancement of both electrical and electronic technology, enabling electronic devices to be programmed and made ‘smart’. Following the invention of the transistor, the development of electrical technology has progressed collectively; influenced by electronic technology, this has shaped the modern world and led to further advancements in the fields of transport, communications, healthcare and engineering.
Understanding the history and working principles of electricity, and having a keen interest in this discipline, helps us to become experts in the field; the knowledge we gain also contributes to making us individuals who understand science and the world, and who are able to contribute to their betterment.
Author: Muhammed 76
Sources
U.S. Energy Information Administration (EIA), “Electricity Timeline.”
IEEE, “The History of Electromagnetics as Hertz Would Have Known It,” IEEE Transactions on Microwave Theory and Techniques, Vol. 36, No. 5, 1988.