A rainbow is one of the most beautiful natural phenomena that we can easily observe after heavy rain during the day.
The Rainbow and Its Color Significance
What is a Rainbow?
A rainbow is a natural optical phenomenon that nearly everyone has witnessed. Essentially, a rainbow is the dispersion of sunlight when it is refracted and reflected through raindrops. A rainbow actually contains many colors, with seven prominent ones being red, orange, yellow, green, blue, indigo, and violet.
Depending on the number of reflections, rainbows are categorized as first-order, second-order, etc. The first-order rainbow is the most distinct (only one reflection occurs, making it the brightest). Typically, the visible rainbow is a first-order rainbow. However, sometimes we can also observe a second-order rainbow, where the color order is reversed compared to the first-order rainbow and the brightness is weaker.
Because rainbows are viewed from the same angle (about 42 degrees for first-order and 53 degrees for second-order), where the intensity of sunlight through the raindrops is at its maximum, rainbows appear as a circular arc.
Understanding the Formation of Rainbows
In reality, a rainbow is not a defined object; it is a reflection of sunlight through raindrops in the air, a phenomenon known as light refraction.
In reality, a rainbow is not a defined object.
Sunlight is a mixture of colors blended together that our eyes cannot detect. Only when passing through a glass prism do the light rays bend, or refract, creating a continuous spectrum of colors known as the spectrum. Red light is bent the least, followed by orange, yellow, green, blue, and finally, violet light, which is bent the most.
Light Refraction.
Raindrops can also act as prisms. When sunlight passes through these droplets, the light rays bend and are then reflected back out at an angle of 42 degrees. This explains why we can only see a rainbow when our back is to the sun and we look at an angle of 42 degrees relative to the sunlight.
A rainbow is not unique, but we can only see one rainbow at a time
The refraction phenomenon occurs with millions of raindrops illuminated by the sun, so a rainbow is not unique. However, we can only see one rainbow at a time due to the 42-degree angle mentioned above. Our eyes can only see the refracted rays created by raindrops that have a 42-degree angle relative to the sunlight.
Thus, a rainbow is not unique; if viewed from a different location, we will see a completely different rainbow.
Is a Rainbow Just an Illusion?
Since a rainbow is merely an illusion, it does not have a real endpoint. The light that constitutes a rainbow forms at a specific distance and angle with the observer’s eye. This distance always exists between the viewer and the phenomenon. Instead, the position of the rainbow continuously shifts according to our viewpoint.
Sunlight refracted through certain raindrops creates the image of a rainbow in one person’s eyes, but simultaneously, those light rays also refract through different raindrops at another angle in someone else’s line of sight. This is why the visible colors of the rainbow differ for each person, even when standing in the same position and viewing the same rainbow.
Why Does a Rainbow Have 7 Colors?
A rainbow is a continuous band of colors, prominently featuring 7 colors: red, orange, yellow, green, blue, indigo, and violet. Infrared and ultraviolet rays lie outside the visible spectrum of light for the human eye, hence they are not visible.
The Significance of Rainbow Colors in Modern Philosophy
- Red – This is the first color of the rainbow from the top down. Red signifies passion, vitality, enthusiasm, and security. It has the longest wavelength.
- Orange – This color is a blend of yellow and red. It is a dynamic color representing creativity, practicality, cheerfulness, as well as balance or control.
- Yellow – This is the color of sunlight. It represents clarity of thought, intelligence, order, and energy.
- Green – This is the median color of the rainbow, symbolizing fertility, growth, balance, health, and wealth.
- Blue – This is the fifth color of the rainbow that evokes the unknown. The sky and vast oceans are this color, thus it is associated with spirituality and the divine.
- Indigo – It is believed that while Blue soothes, Indigo calms. Indigo is mystical as it narrows the gap between finite and infinite. Indigo gemstones are often used to achieve spirituality, psychic ability, self-awareness, and to enhance intuition.
- Violet – The final color of the rainbow is a blend of red and blue. It is considered the highest element of spirituality. It can evoke a person’s imagination and inspire artists. Darker shades of violet are associated with sadness. Deeper tones of violet or purple signify high spiritual mastery.
In different cultures, rainbows can also carry rich meanings: representing deities, the highest state of enlightenment, or even embodying evil.
Interesting Facts About Rainbows You Might Not Know
Double Rainbow.
Sometimes we see the phenomenon of a double rainbow, which is a secondary rainbow appearing above the primary rainbow. Its colors are reversed compared to the primary rainbow and it is fainter.
This phenomenon occurs very rarely, due to light diffraction allowing us to see both a 52-degree angle relative to sunlight. At this 52-degree angle, we can observe the light refraction occurring inside the raindrops before the light reflects and exits. This is why the secondary rainbow has reversed and fainter colors. This phenomenon occurs when we can simultaneously see both 42-degree and 52-degree angles relative to sunlight.
Moonbows
Moonbow.
Most of us see rainbows occur during the day, thanks to sunlight. However, sometimes rainbows appear at night, which astronomers call a Moonbow, created by the light of the moon. Moonbows typically occur on tropical islands like the Caribbean, where heavy rain falls at night. Images captured of Moonbows show that this rainbow appears white, likely due to the low intensity of moonlight compared to sunlight.
Waterfall Rainbows
If you visit large waterfalls, you have a high chance of encountering a rainbow.
Rainbows do not only appear when it rains; if you visit large waterfalls, you are also likely to encounter a rainbow. This is because the water vapor rising from the waterfall reflecting sunlight can create beautifully mesmerizing rainbows.
White Rainbows
“White Rainbow” is also known as a “ghost rainbow.”
You may have always thought that a rainbow has seven colors, but nature has a way of surprising us with its wonders. “White rainbow” or “fogbow” is an extremely rare phenomenon. While a traditional rainbow is formed by sunlight reflecting through raindrops, a white rainbow is created from tiny water droplets with a diameter of less than 0.05mm. Because these water droplets are so small, they cannot refract light into multiple colors like raindrops do, resulting in a rainbow that appears solely white.
- The famous physicist Isaac Newton identified seven colors that make up the spectrum of white light. These colors appear in the rainbow in the order of red, orange, yellow, green, blue, indigo, and violet. This is also the order of colors from the outer edge to the inner edge of the rainbow.
- “Fogbow” is formed by clouds and mist droplets, appearing almost white with other colors being barely visible. Fogbows are typically larger and wider than regular rainbows.
- It is very rare for light to reflect three or four times within a single droplet of water, resulting in third or fourth order rainbows appearing in the direction of the sun.
Below are some beautiful images of rainbows after the rain, inviting you to enjoy:
