A Radiant History from Creation to the Quantum Age
Be enlightened by the wondrous world of light.
Light has been a source of wonder since the beginning of humanity. It appears in creation legends and is even worshiped as a god. Light also became a source of philosophical inquiry, artistic fuel, and scientific struggle, yielding magnificent art and significant discoveries.
In these summaries, you'll be taken on an interesting journey through the discovery of light and its uses, from illuminating cathedrals to becoming one of the focal points of the scientific revolution.
You will also learn.
This article explores the connection between light and vomit, egg, and the Book of Genesis. It also discusses how ordinary mirrors have been considered holy and how light is crucial to modern physics experiments.
1. Light has been an essential and influential phenomenon since humanity's dawn.
The early people did not study light; instead, they worshipped it. In fact, as light stole across a continent each day, it was always greeted with reverence and wonder.
So, it's no surprise that light plays a vital role in many origin myths. In the Finnish creation story, The Kalevala, an egg cracks open, revealing the sun and the moon.
Consider the Zuni Native American tale, which depicts the Earth's earliest people emerging from a dark abyssEarth'sright light. For example, the Bushongo people of Congo describe the God Bumba as having vomited up the sun. The eaEarth'srimordial waters dried up as sunlight grew, and land began Earth's she.
Finally, there is the Book of Genesis, when GGoddeclares, "Let there be light."
So, light is necessary for people worldwide, and it was one of the first themes investigated by ancient philosophers. Greek philosophers such as Empedocles wondered if light came from an item or the eye that saw it. And in the fifth century BC, the philosopher Leucippus claimed that all objects emitted razor-thin light particles.
Following this claim, Euclid and Ptolemy were among the first to investigate light in a laboratory, examining its reflection in flat and bent mirrors. Euclid observed that the angle at which light entered a mirrored plane was the same at which it was reflected. And Ptolemy discovered how curved mirrors interacted with light.
Despite these experiments, people needed to understand what light was.
Because light remained a complete mystery, it came to represent everything divine in various religions. For example, the Old Testament utilized light as a metaphor for God in two ways:
On Mount Sinai, Moses came upon a too-brightly blazing bush from which GGodspoke. Furthermore, every religious figure's biblical account is depicted with a luminous aura.
2. Light became a divine religious power and a location of artistic accomplishment.
If you know Arabic, you may know that manara means "lighthouse" or "place of light." The minaret, or tower from which a muezzin invites Muslims to prayer, is named after this word.
That's because light is considered a divine energy in Islam. The Qur'an states that God Godld guides believers "from darkness to good." The Bible further states that "He will bestow on you a light to walk in" and that "the man from whom God withholds His light shall find no light at all."
In fact, one of the suras, or chapters, of the Qur'an is exclusively dedicated to light. It is named al-nur, or The Light, and states, "God is the light of the heavens and earth."
However, Islam is not the only faith that places light on a heavenly pedestal. Christianity does, too.
During the Middle Ages, Thomas Aquinas was the most influential figure in Catholic theology. He felt that beyond the darkness of the night sky was a brilliantly lit paradise, which he dubbed the "brightness of glory."
As a result, gems, gold, and even ordinary mirrors were regarded as sacred because they reflected the light of God. Godurches were also built with God's Goddows to bring in light from above.
As a result, light became a central theme in theological discourse, but it was also essential to artistic accomplishment during the Renaissance. Around the 1500s, artists began to reinvent light on canvas as the Renaissance extended from Italy to the Netherlands.
Artists such as Brunelleschi, da Vinci, and Rembrandt researched perspective and shadow characteristics to capture light's nuance. This emphasis on light gave the paintings of the time their realism and served as the foundation for their genius.
3. Light was investigated in the laboratory and later used as inspiration for artists of all types.
As the Renaissance ended, European countries began to make substantial advances in the natural sciences. The empirical examination of light started in earnest during the scientific revolution, which occurred in the seventeenth and eighteenth centuries.
Johannes Kepler was among the first to conduct scientific research on light. In 1604, he published a dissertation on optics that described a fundamental law of light. He claimed that the intensity of light decreased with the square of the distance from which it was perceived. So, if you move a candle ten feet away, its light appears one-hundredth as bright as it did when standing right next to it.
René Descartes also began to ponder about light during this period, describing numerous of its qualities. He discovered that light travels in an instant and in straight lines. He compared these properties to a tennis ball because, as a beam of light travels through space, it collides with an object, reflecting it back at a specific angle corresponding to its angle of entrance, just like a ball bouncing.
Then, in the 1670s, while performing experiments with prisms, Isaac Newton discovered that light is made up of colors and that combining red and blue light produces purple.
Around the same period, the Italian scientist Francesco Grimaldi suggested that light could be a wave rather than a beam. These novel scientific concepts regarding light began to influence painters.
Light inspired musicians and writers during the Romantic era, which spanned the eighteenth and nineteenth centuries. This curiosity inspired musical performances in which light could be heard. Joseph Haydn, one of Europe's most beloved composers, created an oratorio called The Creation that set God'God'sds "Let There Be Light" to music.
WritersGod's eager to join the festivities. Consider the German poet Goethe, who released his Theory of Colors in 1810. In this work, he proposes that humans perceive and experience light. His theory is that each light color evokes an emotion. For example, yellow represents serenity, while red represents dignity.
4. The wave theory of light became widely accepted in the nineteenth century, and the first electric light was produced.
So, while light was attracting scientific attention and inspiring great works of art, it remained little understood at the start of the nineteenth century. In actuality, all that was known was how to determine the angle at which light deflected and its estimated speed, that it was divided into colors, and that it was made up of particles—or waves?
Fortunately, a new generation of students emerged to delve further. The wave hypothesis of light was supported by evidence discovered in the early nineteenth century. It was all thanks to Thomas Young, an English scientist who 1802 devised what is now known as "Young's experiment," a test that has been termed the single most influential experiment in modern physics.
This is how it worked.
Young would direct light through two slits, one next to the other. He reasoned that this "interference" would manifest in predictable patterns if the light was made up of crisscrossing and colliding waves.
That's because if two waves are in sync, with their crests parallel and boosting one another, the light should be brighter. Not only that but when the crest of one wave meets the trough of another, the waves should cancel each other out, resulting in darkness or at least low light.
And that is precisely the pattern Young discovered in his experiment.
Then, in the middle of the century, Scottish physicist James Clerk Maxwell discovered that light is electromagnetic, which means it is both electrical and magnetic. This resulted in the invention of the first electric light a few years later. This was a significant achievement for humanity. Previously, lighting included extracting fat from an animal or plant to make candles or oil, which were then burned.
5. Einstein altered the theory of light and used it to draw profound conclusions.
Albert A. Michelson, a German physicist, made the audacious remark toward the close of the nineteenth century that there was little chance of new discoveries in the physical sciences. However, we are all aware that tremendous discoveries continued to be made, many of which contributed to Einstein's definition of light as quanta.
In the early twentieth century, scientists debated whether light was made up of particles or waves when Albert Einstein proposed a new definition in 1905: quanta, or packets of energy.
It began three years earlier when another German physicist, Philipp Lenard, discovered that electrons are knocked off when ultraviolet light strikes a metal plate. The plate then emits electrons, a phenomenon known as the photoelectric effect.
But if light comprises waves, how does it knock off individual particles? And, if it's made up of particles, how can you explain why, no matter how intense the light, the released electrons always have the same amount of energy?
Einstein's solution was that light existed in a separate category, one of discrete wave packets known as quanta, which could act as both a particle and a wave.
From there, the scientific revolution continued. Einstein advocated that time be relative, basing his reasoning on the fact that light's speed remains constant. How does this work? So, when you go onto a moving walkway in an airport, your speed is added to that of the walkway. But that is not how light works; it always moves at the same pace.
With this information, Einstein determined that time can change. Light moves at a constant speed, yet it can cover different distances at the same time. So, if the light is steady, neither is time.
Final Summary
Humans have been fascinated by light since our origins on Earth. Earthave revered and examined it, which has emerged as an inspiration for painters, musicians, and poets alike. Light is now as simple as turning on a light switch, but it took hundreds of years to discover it.