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Mother Nature's Other Rainbow: The Science Behind Colorful Sunsets

Mother Nature's Other Rainbow: The Science Behind Colorful Sunsets

science behind sunsets

There is nothing quite like watching a sunset, especially on those evenings when the sky transforms into a beautiful spectrum of colors –– pinks and purples, yellows and oranges. Colorful sunsets are just another reminder that Mother Nature is an endlessly creative artist!

These awe-inspiring moments are a sight to behold –– but have you ever wondered about the science behind sunsets? Let’s take a look at what’s really going on during a sunset.

Why the Sun Sets

To understand the science behind sunsets, we first need to understand why the Sun “sets” in the first place. That, of course, means we need to revisit our basic astronomy!

We all remember that the Earth revolves around the Sun, but it also rotates on an axis. The reason the Sun appears to rise every morning and set every evening is due to the rotation of the Earth around its axis. A full rotation of the Earth takes 24 hours –– which is how we define a day.

As the part of the Earth on which you, the observer, is standing begins to rotate its face away from the Sun, the Sun appears to be sinking towards the surface of the planet –– or “setting” along the horizon. And voila, you’ve got a colorful sunset!

The Scattering of Sunlight

colorful sunset

As the sun sets along the horizon, the angle at which sunlight strikes enters the atmosphere lowers. As it lowers, it passes through a layer of the atmosphere crowded with particulate matter and various molecules that are suspended in the air.

When the sunlight strikes these particles and molecules, it causes the light to reflect, refract, and diffract. This breaks up the light into its spectrum of colors and –– depending on the shape of the molecule and the specific angle of the light –– causes the light to change. This process, known as scattering, is what creates those magnificent pinks and purples and oranges that we see when we’re observing a colorful sunset!

A more complicated piece of the science behind sunsets lies in determining the specific color and breadth of the event. They are nearly impossible to predict, as so much of the coloration you see depends on the volume of particles and molecules floating in your observable area of the sunset, as well as the wavelength of the light which passes through them.

Sunsets and Pollution

brilliant sunsets

It is an unfortunate truth that, in some cases, pollution is responsible for these colorful sunsets. Across the world, sunsets can be a sad side effect of an abundance of air pollution and a sign of low emissions standards. The smoke emitted from wildfires, too, can generate clouds of ashen particulates that contribute to brilliant sunsets.

In the United States, for example, Los Angeles, California, famously enjoys beautiful sunsets on an almost nightly basis. However, at least some of that beauty is related to the smog that LA’s millions of vehicles produce while crisscrossing the freeways each day.

(Fortunately, over the past several decades, Los Angeles has made progress on this front, reducing their smog pollution by nearly 85% since 1970. And the good news, Angelenos still get to enjoy amazing sunsets!)

The Symbolism of Sunsets

What any given sunset means to someone is deeply personal. Some people like to take sunsets as an opportunity to reflect on the day or meditate. In many cultures, a sunset marks the end of a journey, the passage of time, or a peaceful symbol of the end of a life.

Throughout history, sunsets have served as inspiration for paintings and poetry, works of literature, and captured on photographs and in films. In fact, in the film industry, sunset is referred to as ‘magic hour’ because the natural light creates an optimal condition for capturing beautiful footage.

Experience More of Mother Nature

From dazzling rainbows to colorful sunsets, Rainbow Symphony wants you to experience the best of what Mother Nature has to offer. That’s why we create products that help you discover these magical moments for yourself.

We carry a complete line of diffraction glasses to better explore the magic of light and color, eclipse shades to safely observe total solar eclipses, and suncatchers to celebrate the sun as part of your home decor. We offer bulk discounts for educators and customizable options for brands and events.

For any questions about our products, just shoot us a message by filling out our contact form.