Introduction and Background
"God said, 'Let there be light,' and there was light. And God saw that the light was good, and He separated the light from the darkness." Most of us are familiar with these lines from Genesis, whether we believe in them or not. The reality is that our world is filled with both light and darkness. But what exactly is light? Where does it come from? How did it appear in the universe? And what might its future hold?
These questions are intriguing, but rather than answering them one by one, this article will take a different approach. Instead, I’ll explore the brief history of light—from the early moments of the universe up to the present day. Why start 14 billion years ago? Because according to data from NASA’s Wilkinson Microwave Anisotropy Probe (WMAP), that’s approximately the age of the universe. This instrument helped scientists detect the faint microwave background radiation left over from the Big Bang, revealing the cooling remnants of the initial fireball. Our solar system, including the Sun and Earth, is much younger—about 4.5 billion years old. As a result, the primary source of light on Earth is the Sun. Later, around 4 billion years ago, the Moon formed, though its origin remains uncertain. While several theories exist—such as the giant impact, fission, capture, and co-formation models—the exact process is still debated. Regardless of how it formed, the Moon reflects sunlight back to Earth, offering a secondary source of light during the night.
Humans, specifically early hominins, appeared on Earth about 1 million years ago—a mere blink in cosmic time. For most of that period, the Sun was the only source of illumination. It wasn’t until tens of thousands of years later that humans began to create artificial light. Evidence suggests that early humans controlled fire around 125,000 years ago, using torches as their first artificial light sources. Then, around 17,000 years ago, prehistoric people started using oil lamps made from shells, stones, or animal horns, filled with animal or plant oils and lit with wicks. Over time, the fuels used in these lamps evolved, including olive oil, nuts, sesame, and fish oil. By 500 BC, the study of light took a new turn when Pythagoras proposed the particle theory of light, suggesting that visible objects emit tiny particles that enter our eyes, allowing us to see.
In 400 AD, candles emerged as a major source of light, remaining popular for the next 1,400 years. A significant breakthrough came in 1666 when a young Isaac Newton conducted his famous prism experiment, proving that white light contains all the colors of the spectrum. In 1752, Benjamin Franklin famously flew a kite during a storm, demonstrating the electrical nature of lightning and laying the foundation for future innovations like the incandescent bulb. Around 1792, William Murdoch pioneered gas lighting by heating coal and using the resulting gas to illuminate his home in Cornwall, England. This marked the beginning of gas lighting, which became widespread in the 19th century after the discovery of natural gas.
In 1877, Thomas Edison turned his attention to electric lighting. With the help of a partner, he founded the Edison Electric Light Company, aiming to produce and distribute electric lighting devices. Although he didn’t invent the first incandescent lamp—Henry Woodward and Matthew Evans had filed a patent in 1874—Edison successfully commercialized the technology. Earlier, in 1865, German chemist Herman Sprengel had developed the vacuum bulb, an essential component for modern lighting. Through innovation and perseverance, Edison helped bring electric light into everyday life, marking a turning point in human history.
USB HUB
USB HUB,Thunderbolt Usb Hub,Satechi Usb C,Owc Thunderbolt 4 Hub
Pogo Technology International Ltd , https://www.wisesir.net