From the invention of the light bulb to LED lighting, technological advancements have transformed our lives and the environment. From the inefficiency of incandescent bulbs to fluorescent and LED lighting, we’ve made strides in energy efficiency and environmental protection, and the future is expected to bring even greener and more efficient lighting technologies.
The invention of the incandescent light bulb is more than just a technological breakthrough. Invented by Thomas Edison in 1879, the incandescent light bulb was more than just a tool to illuminate the darkness; it was an innovation that fundamentally changed the way humans utilize electricity. The advent of the incandescent light bulb created a new social structure that allowed for nighttime activities across the globe, and along with the development of industry, it led to the acceleration of urbanization. For many years after its invention, the incandescent light bulb was an essential lighting device in homes and public spaces, and was widely used in South Korea until the 1980s.
The principle of incandescent bulbs is fairly simple. Any substance with an absolute temperature above 0 degrees Celsius emits electromagnetic waves, a phenomenon known as thermal radiation. Incandescent bulbs use this thermal radiation to produce light. The incandescent bulb has a thin tube called a filament made of tungsten in the center, and when electrical energy from a power plant is applied to the bulb, it heats up the filament and uses the light it emits to illuminate. However, incandescent bulbs have the disadvantage that only 5% of the electric energy supplied is converted into light energy, and the remaining 95% of the energy is dissipated in the form of heat, resulting in low efficiency, and the large amount of heat energy dissipated raises the temperature of the room unnecessarily. If you go to an old country house or building, you’ll often see incandescent bulbs, which is why you can feel hot if you sit under them for a long time.
As such, incandescent bulbs were an important invention in history, but their limitations soon led to the need for new technologies. Fluorescent light bulbs were created to overcome the problem of low energy efficiency. Unlike incandescent bulbs, fluorescent lamps do not produce light by heat, but by the discharge of vapor. The glass tube of a fluorescent lamp contains a small amount of mercury vapor and argon gas, which is easy to discharge. When a voltage is applied to the electrodes on either side of the fluorescent lamp, electrons are released and collide with the mercury atoms in the glass tube. Every atom has a nucleus with protons and neutrons at its center and electrons orbiting around it. When a particle hits it, the electrons orbiting around it are temporarily energized and become excited. In nature, all matter tends to stay as stable as possible, for example, water always flows from higher to lower levels. Excited electrons also want to return to their resting state, and in doing so, they give off the energy they received from the collision in the form of light. The light emitted is in the ultraviolet region, so it’s invisible to our eyes. However, the fluorescent material applied to the inside reacts with the ultraviolet radiation and emits light in the visible range, which we can use. Compared to incandescent bulbs, fluorescent bulbs emit brighter light, last twice as long, and consume only 25-35% of the electricity of incandescent bulbs, which can save you money on your electricity bill. However, the downside is that they consume a lot of energy to turn on and off, and flicker after turning on. We’ve all been to school under flickering fluorescent lights at one time or another. What’s more, if a fluorescent bulb breaks, the mercury vapor inside can be released, which can endanger our health and cause environmental problems later on.
LED lighting, also known as the next generation of lighting, has recently been introduced, and it stands for Light Emitting Diode. A semiconductor is a material that has the properties of a conductor that allows current to pass through it only under certain conditions. A semiconductor is a structure in which a positively charged substance and a negatively charged substance are bonded together, and when a voltage is applied to it, electrons move and friction generates energy, which is converted into light energy and emits light, which is what LEDs do. Depending on the material and structure of the semiconductor, the color of the light emitted by the LED can be adjusted. In fact, LEDs have been used in smartphones, TVs, traffic lights, monitors, etc. for a long time, and only recently have they been used for home lighting. LED lights are highly efficient, converting about 90% of their electrical energy into light, so they can save you money on your electricity bill, are low maintenance, and are semi-permanent, lasting about 20 years once installed. They are also environmentally friendly because they do not use heavy metals such as mercury, which is a major advantage over fluorescent lighting. However, LED lighting technology is not yet fully commercialized and can be expensive to install. There are also concerns that the blue color of LEDs may have an adverse effect on the optic nerve.
In South Korea, the production and import of incandescent bulbs has been banned since early 2014. You can still find incandescent bulbs in coffee shops, food stalls, and other places, but they will soon disappear. And in the near future, advances in LED technology will allow us to buy LED lights that overcome their current shortcomings at a cheaper price, and the world will be illuminated by the light of LED lights. The evolution of lighting technology isn’t just about becoming more energy efficient, it’s also evolving to take into account the impact it has on our daily lives and the environment. It’s not just a change of light bulb, but a process of constant challenge and innovation in humanity’s quest for a better quality of life.
