In this blog post, we’ll explore how electricity was discovered and has evolved over time, as well as how these changes have influenced human life.
Today, it’s impossible to imagine our daily lives without electricity. Thanks to electricity, we can keep our lights on even on dark nights, and many of the devices we use—such as computers, televisions, radios, air conditioners, and cell phones—can exist. Furthermore, as demand grows year by year, the variety of electronic products is expanding, and their functions are rapidly advancing. Although modern people live in close connection with electricity, few actually know exactly what it is. Therefore, we will cover the basic concepts of electricity and its practical applications, and aim to learn them through simple hands-on exercises.
To understand electricity, we must first recognize that all matter is composed of two types of charge. Charge is the foundation of all electrical phenomena, and there are two types: positive and negative. Just like the poles of a magnet, opposite charges attract each other, while like charges repel each other. The basic unit of matter is the atom. An atom consists of a positively charged nucleus and negatively charged electrons. In their natural state, atoms are electrically neutral, but when electrons move to other atoms, causing them to become negatively charged, the original atom may become positively charged. Conversely, when electrons enter an atom, it becomes negatively charged.
Electricity is defined as “the various natural phenomena caused by positive and negative charges.” According to historical records, the first person to discover electricity was the ancient Greek philosopher Thales, around 600 BCE. He observed that when he rubbed a piece of cloth against amber, light objects would stick to the amber. This was the result of positive and negative charges being generated by the movement of electrons when the two objects were rubbed together. This phenomenon is called static electricity, and after Thales, the English physician William Gilbert confirmed in the late 16th century that the same phenomenon occurred in various other materials. The term “electricity” has been studied since then and is derived from the Greek word “elektron,” meaning amber.
The practical application of electricity began in 1800 when Alessandro Volta invented the battery. Electric current literally means the flow of electricity; when electrons move within a conductor, they collide with other electrons or atoms, generating heat. Today, electric appliances such as irons and heaters utilize this very heat-generating effect.
Motors, used in a wide variety of applications such as trams, electric fans, and elevators, are devices that convert electrical energy into rotational motion. Around 1820, the French physicist André-Marie Ampère discovered that a current-carrying wire produces an effect similar to that of a magnet placed around it. Based on this principle, electric motors generate rotational motion through the magnetic force acting between magnets and the wire.
For modern people, cell phones are essential. Thanks to advances in electricity, it is now possible to communicate in real time with people on the other side of the globe. Samuel Morse, the inventor of the telegraph, developed a method of signal transmission using changes in electric current in 1837, marking the beginning of telecommunications. In the late 19th century, the discovery of electromagnetic waves led to the practical application of wireless communication, and as communication technology continued to advance, radio and television broadcasting became possible. Recently, advancements in integrated circuits have made communication devices even smaller, and it is now possible to talk to more people simultaneously.
In this way, electricity has revolutionized our lives. Demand for electricity continues to grow, and as it can be applied to various fields, its potential for development is limitless. As research in electrical and electronic engineering continues, new materials and technologies will be developed, further advancing our way of life.
