Interference and Diffraction: How It Affects the Light Around Us

visible spectrum on hand

As you look at the horizon after a rainstorm, you see it in looming in the distance. It’s a rainbow. Of course, there’s no pot of gold at its end, but there is a wealth of knowledge that the rainbow can teach us about wave diffraction.

How about a more man-made phenomenon? As you spin a CD back and forth between your fingers, the back of the disc flashes a brilliant array of colors. Why does the CD react like this? It’s simple: the principles of interference and diffraction are at work, causing you to see these gleams of color.

Have you ever wondered how these kaleidoscopes of colors are produced? They are all around us. Not only do you see them in rainbows and CD’s but you can also observe them in bubbles, glass, and holographic stickers (just to name a few). So what exactly is this phenomenon?

Understanding the Science of Light

Before we consider interference and diffraction, we have to take a moment to consider what light is and how it travels. Waves are part of the electromagnetic spectrum, and they carry information from one place to another. Waves can carry different types of information, like light and sound. Some of these waves we are able to discern, but others are beyond our abilities to process.

Waves can be used many different ways. Radio stations transmit their signal via sound waves. Microwaves cook our food through the power of (unsurprisingly) microwaves. X-rays are harnessed by special machines that allow us to view inside our bodies. Waves are everywhere!

Right in the middle of the electromagnetic spectrum are light waves. These waves travel from a source and help us discern both light and color. So where does interference and diffraction come into this picture?

What Happens When Light Waves Bend

When light waves travel to our eyes on a straight and unimpeded path, we discern colors in a fairly straightforward fashion. However, it’s when light waves take a detour on the way to our eye that they react in unique and colorful ways. When waves are diverted by particles in the air or other light waves, their path and even their wavelength can change. This effect is called interference or diffraction.

rainbow over farmland

So, is there a difference between interference and diffraction? The scientific answer is this: not really. They are designations that don’t have a firm difference between the two. However, when most scientists talk about a small amount of sources diverting light waves, it’s usually called wave interference. When there are many different sources, it’s usually called wave diffraction. In the end, though, the two names describe the same concept.

The Effect of Interference and Diffraction

Let’s imagine for a moment that we’re looking at the evening sky after a pouring rain. As the sky starts to clear, a beautiful rainbow appears in the distance. How does interference and diffraction play into this beautiful natural phenomenon?

As you stand on your front lawn and see the clouds move away, the rain slows down and eventually comes to a stop. However, as you look to the horizon, you can likely see that, although it’s no longer raining where you are standing, there is still precipitation coming from the clouds. If these water droplets are in between your position and the sun, they represent an opportunity to see wave diffraction at work.

As light waves travel through the rain falling in the sky toward your eye, they can’t travel in a straight path. Imagine the light waves travelling through the rain like a pinball, bouncing around back and forth before they finally make their way back to your eye. What is the result of this? You end up seeing all seven colors of the visible spectrum in the natural wonder we call a rainbow. All of this is brought to you thanks to the work of interference and diffraction.

Everyday Observances of Interference and Diffraction

Of course, we don’t have the opportunity to see rainbows of a regular basis. Conditions in the atmosphere have to be perfect for us to witness one. But that doesn’t mean interference and diffraction are rare. In fact, we witness it so often that we probably don’t even realize it.

If you look at a piece of glass on your home, car, or even your smartphone, you can often see the array of colors that flash as your point of view changes. This is wave diffraction at work. Sometimes merchandise sold at stores have holographic stickers attached to them. These stickers are hard to duplicate, so they are a way to show that the item you are buying is authentic. As you turn the tag back and forth, you’ll see the variety of colors that pop and flash.

Even something as simple and beautiful as a suncatcher shows the practical use of interference and diffraction. As light waves travel through the opaque colored panels of the suncatcher, the light waves change and allow us to see a variety of colors. Stained glass windows work on the same principle as well. As light waves from the exterior of the building travel through the pieces of colored glass, the result on the interior of the building is a breathtaking display of colors and light.

stained glass cathedral

As you go about your day, can you find other examples in nature of interference and diffraction? When you look at your home, do you see ways that this phenomenon produces an array of colors? Once you begin to look, you’ll see it all around you.

However, if you always want to have access to the rainbow spectrum no matter where you are, or if you would simply like to give someone else the colors of the rainbow, then consider picking up a pair of our diffraction glasses, rave glasses, or our diffraction grating slides to bring the color spectrum to life!

Rave Shades For EDM Concerts: Add Some Fireworks to Your Next Festival

We all know that half of the fun of an EDM concert is dressing up for it. Furry boots, neon backpacks, and face paint are optional, but proper rave shades are an absolute must to complete the electronic dance experience.

Rave Shades For Every Occasion And Outfit

At Rainbow Symphony, you’ll find a wide array of EDM Glasses for your next big concert. Our Plastic Rainbow Fireworks Glasses® use the highest quality hard plastic holographic lenses to diffract every laser and light into a shower of magical rainbow starbursts. These stylish wayfarers are available in a multitude of colors, including red, pink, green, orange, white, blue, black, and clear.

Seeking a more futuristic aesthetic? Then you’ll want to check out our LaserSpex™ Plastic Rainbow Fireworks Glasses®, which come in a pack of four different glow in the dark colors and will give a distinctively sci-fi touch to your look.

If your future’s so bright that you gotta wear (extra) shades, you may want to pick up a pair of Double Rainbow Double Flip Up Diffraction Fireworks Glasses to give yourself a double dose of awesome color. Or, if you’d prefer to take a trip back to the 1980s instead, our four pack of Gems™ 3D Plastic Rainbow Fireworks Glasses may be more up your alley. These large glow in the dark rave shades are comfortable, lightweight, and guaranteed to help you stand out from the rest of the crowd.

A Club Experience That Can’t Be Beat

The gorgeous visual effects in clubs and EDM concerts are amplified ten-fold through the lenses of rave shades. Yes, rainbow sunglasses are a key component of EDM fashion, but they’re just as functional as they are stylish.’

Cheap neon-colored bracelets aren’t necessarily built to last all night long, but rave shades will stick with you even as you dance up a storm. They’re affixed to your face and they’re not going anywhere, unless you want to let another raver take them for a spin.

Turn up the color as you transform brilliant light displays into a kaleidoscope of magnificent rainbow wonder.

Rave Shades: Don’t Leave Home Without Them

No trip to Electric Daisy Carnival, Day Glow Festival, Burning Man, or Life in Color is complete without a proper pair of rave shades. Best of all, these glasses from Rainbow Symphony can also be used to take other fireworks displays, light shows, New Year’s Eve parties, and laser-intense events to the next level. These EDM glasses are more than just a fun party prop, they’re a must-have to illuminate good times and bring out the rainbow spectrum anywhere.

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Have a question about our rave shades and EDM glasses? Contact Rainbow Symphony by phone today at 818-708-8400, or by email at



How To Watch A Solar Eclipse: 5 Tips for an Unforgettable Experience

Few occurrences in nature can rival the jaw-dropping beauty of a solar eclipse. Solar eclipses should not be missed, but they should also not be viewed without the proper safety measures in mind. Here’s a guide on how to watch a solar eclipse from the experts here at Rainbow Symphony:

1. Protect Your Eyes

There are a number of ways to enjoy a solar eclipse (and we’ll get into those here), but the most important thing to remember is that you cannot view an eclipse without the proper equipment to protect your eyes. Watching a solar eclipse can cause irreparable damage to your vision if you are not wearing solar eclipse viewing glasses.

A solar eclipse will give off a hazardous amount of visible light along with harmful levels of ultraviolet and infrared waves. Before totality, the sun’s brilliant solar surface emerges, which can cause severe retinal damage. While our natural instinct would be to look away at this point, serious damage can occur in a matter of seconds. Simply put, there is no justification for viewing an eclipse without the proper protection for your eyes.

Fortunately, solar eclipse glasses are largely inexpensive, though not all of them are made equally. It’s imperative to only use solar eclipse viewing glasses that meet ISO (International Organization for Standardization) protocols. Lesser glasses cannot be counted upon to give you the proper safeguards against harmful rays, which could lead to a lifetime of unfortunate consequences.

All of the Eclipse Shades® sold by Rainbow Symphony meet ISO 12312-2 standards, meaning that you can view the marvel of a solar eclipse with complete peace of mind. The lenses of these specialty solar viewers are made from a patented scratch-resistant material with grade five optical density to guarantee ultimate protection from harmful solar radiation.

The lenses of the solar eclipse viewing glasses contain “Black Polymer,” a flexible resin infused with carbon particles, to filter out 99.999% of intense visible light and 100% of ultraviolet light and infrared light. The premium filters display an orange-colored image of the sun for the viewer that is both easier to see and sharper than the unfiltered view. Our dedication to quality ensures a safe and worry-free solar eclipse experience that will be remembered for a lifetime.

Our complete line includes a wide range of styles, designed to fit eclipse-chasers of any group or budget size. For a smaller bunch –– or one that is willing to share, we offer Plastic Eclipse Glasses in both traditional and wrap-around goggle variations. For a less expensive alternative, educators may want to look into our Eclipse Shades® Safe Solar Glasses. There are innumerable options to choose from the Rainbow Symphony website, starting as low as $0.45 per piece for large bulk orders.

Demand for glasses tends to spike in the days leading up to a solar eclipse, so be sure to stock up well in advance.

2. Find The Best Place To View The Eclipse

Solar eclipses don’t happen all that often and total solar eclipses are exceptionally rare. To take in this unique experience, you’ll want to view the eclipse from the best location possible.

In some instances, that may mean traveling. In July of 2019, a total solar eclipse will take place in the southern Pacific Ocean, just north of the Pitcairn Islands. Before the eclipse hits, locals and tourists will flock to Chile, Argentina, as well as ships in the nearby waters. Then, in December of 2020, another solar eclipse will return to the area around South America with visibility from select portions of Argentina and Chile. After that, there will be a total solar eclipse in Antarctica (good luck to those hoping to see that one) and a hybrid eclipse occuring in Indonesia and a tiny portion of Australia.

For those of you in North America who aren’t planning on traveling across the world for a total eclipse, we have wonderful news. On April 8, 2024, there will be a total eclipse crossing Mexico, several states stretching from Texas to Maine, and into eastern Canada. The expected duration is roughly four and a half minutes, which is longer than many total solar eclipses that we’ve seen in the past.

Of course, making the appropriate travel plans (if needed) and finding the best possible place for viewing is paramount when considering how to watch a solar eclipse. The quality of your eclipse viewing experience may vary from state to state, but there are other factors to keep in mind.

Ideally, you’ll want to view the eclipse where the width of the moon’s shadow is widest and the altitude of the sun in the sky is at or near its peak. That combination will help to provide the longest duration of totality possible. Those extra seconds made all the difference in 2017 for some as the eclipse’s longest run clocked in at about two minutes and forty seconds.

It's also wise to avoid areas with excessive light pollution. By looking at nighttime satellite images of specific areas, you can quickly determine which towns and cities give off the most light.

Locations with higher altitude can also provide better views of the shadow’s path. Being at higher altitude may also provide the advantage of being above valley fog, low clouds, or other air pollution. If a mountain location is a viable option, it’s something for eclipse chasers to heavily consider.

3. Pack A Lunch!

If you’re planning on viewing the eclipse from a more rustic locale, you’ll want to be well-stocked on the essentials. Obviously, that includes water and food for short-term visits and toiletries and other camping essentials for longer trips. You’re unlikely to find a hot dog or pretzel vendor nearby if you’re viewing the solar eclipse from high atop a mountain.

However, if you’re fortunate enough to view the eclipse from the comfort of your backyard, near your workplace, or your school’s blacktop, then you probably won’t need much more than solar eclipse viewing glasses and/or solar viewers.

4. Teach Your Kids Or Students About Eclipse Basics

Younger children might not fully realize the dangers of viewing an eclipse without solar eclipse viewing glasses, meaning that parents and educators must emphasize the risks involved and the proper protocol required. Of course, this doesn’t need to be entirely tedious or boring.

Moms, dads, and teachers can prepare students for the eclipse with fun lessons in the days leading up to it. For example, you can create your own “eclipse” at home or in the classroom. All you need is a flashlight in the dark and some props from Phys. Ed class or the garage, such a tennis ball and volleyball to represent the Earth, Sun, and Moon. This way, you can teach kids about the basic mechanics of the eclipse while underscoring the importance of eclipse glasses and other safety measures.

5. For An Extra-Special View, Pick Up The Proper Telescope

Quality telescopes tend to be expensive, but there are exceptions. The Galileoscope™, which was developed by a team of leading optical engineers, astronomers, and science educators, offers tremendous capability at a phenomenally affordable price. This telescope kit is easy to assemble and offers value for students and stargazers even beyond the solar eclipse.

Powered by a 25- to 50-power achromatic refractor, The Galileoscope™ allows for viewing of lunar craters and mountains, the four moons circling Jupiter, Saturn's rings, the phases of Venus, and incalculable stars that are impossible to view with the naked eye.

The Final Step: Relax And Enjoy!

Now that you know how to watch a solar eclipse, all that’s left to do is to sit back and marvel at one of nature’s most spectacular phenomenons. The dangers of viewing an eclipse without the proper safety measures may seem alarming, but there’s nothing to fear with the proper equipment in tow.

The temptation to take the perfect picture of the eclipse and share it on social media may be tempting, but it’s important to remember that there will be scores of other people - including professionals - also photographing the event. Instead of missing out on this miraculous occurrence, you would be well served to sit back and enjoy the moment. After all, the memory of this rare occasion will stay with you for a lifetime.

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Have a question about how to watch a solar eclipse or which style of solar eclipse viewing glasses is right for you? Contact the Rainbow Symphony customer service team by phone today at 818-708-8400, or by email at

The Science of Diffraction: What is the Diffraction of Light?

The Science of Diffraction

Light waves are known to behave in one of three ways when they reach the boundary of a medium. That is, the end of one medium and/or the beginning of another. They are either reflected, refracted, or diffracted.

  • Diffraction is the phenomenon in which a wave changes direction as it bends around an object in its path or passes through an opening.
  • Reflection occurs when a wave comes into contact with a surface, bounces off the surface, and is redirected back into its original medium.
  • Refraction is the change in direction a wave undergoes as it passes from one physical medium into another. For example, the direction change when a wave passes from water to air.

These phenomena are not unique to visible light waves. In fact, they can be observed for any wave, including sound waves, water waves, or any wave in the electromagnetic spectrum. However, this blog will focus on the wonders of diffraction of visible light waves.

Light Diffraction is a complex topic, but at Rainbow Symphony, we take great pride in being a gateway to the joys of science for learners at all levels. We’ll take you step-by-step through the basics and show you how you can do your own fun experiments and learn the science of diffraction.

Huygen’s Principle

Let’s start with Huygen’s Principle. Christiaan Huygens was a brilliant Dutch physicist, mathematician, inventor, and astronomer, known especially for his contributions to optics and mechanics. The explanations for all three phenomena of light wave behavior are rooted in Huygen’s principle, which states that every point on a wavefront is a source of wavelets, which spread forward at the same speed.

What is Visible Light?

All electromagnetic waves are light, but only light from a certain section of the electromagnetic spectrum is visible to the human eye. Electromagnetic radiation with a wavelength between 380 nm and 760 nm is visible to the human eye. This range is referred to as the visible light spectrum. On the electromagnetic spectrum, the visible light spectrum falls between infrared and ultraviolet waves. The visible effects of diffraction are most pronounced when the length of the opening through which the wave is passing is close to the light’s wavelength.

Examples of Light Diffraction in Nature

Examples of light diffraction can be seen in nature every day! Take, for instance, a cloud’s ‘silver lining’. This visual effect is a result of sunlight bending around the edge of the cloud. The various colors sometimes observed in clouds is another example of light being diffracted, this time by the clouds water droplets. This is called cloud iridescence and is most often observed in cirrocumulus, altocumulus, lenticular, and cirrus clouds. The different colors illustrate how waves of different wavelengths are diffracted differently and ‘scattered’.

Light Diffraction in Nature

Another great example of light diffraction in nature are the rings of light (corona) observed around the sun and other celestial bodies. This is caused by light wave diffraction by small particles in the atmosphere. Even the sky’s apparent blue color, is an example of light diffraction at work. When sunlight hits the earth’s atmosphere, colors of longer wavelengths simply pass through. However, blue, which has a relatively short wavelength, diffracts and scatters upon collision with the atmosphere’s molecules.

Diffraction Grating

You can observe light’s color spectrum by viewing a light source through a diffraction grating in a dark room. A diffraction grating is used to separate light into its constituent colors. It is an arrangement of a large number of equidistant parallel narrow scratches of equal width which are separated by equal opaque sections.

Just as Huygen’s principle states, when a light wave comes in contact with a diffraction grating, the light disperses, forming many point sources with their centers at each slit. Constructive and destructive interference between the ‘new’ light waves occur where their valleys and peaks meet or oppose each other, respectively.

Constructive interference occurs in different directions for different colors due to the differing wavelengths of the colors that make up the visible spectrum. Based on this, we can point a diffraction grating at a white light source and view the different colors in the spectrum.

Shop Our Store Today

Explore the selection of fun products at the Rainbow Symphony store to continue your exploration of light diffraction, including our diffraction glasses and rainbow suncatchers. We also carry three types of diffraction grating slides: the double axis 13,500 line/in diffraction grating slide, the linear 1000 line/mm diffraction grating slide, and the linear 500 line/mm diffraction grating slide.

Contact our team at Rainbow Symphony today for help adding splashes of color to your life and turning experiences from ordinary to extraordinary. Also, keep checking our blog for stimulating discussions on all things relating to light and color.

Exploring the Spectrum of Visible Light

 Spectrum of Visible Light

What is the Visible Light Spectrum?

The electromagnetic spectrum can be considered in terms of seven types of electromagnetic radiation, all corresponding to different wavelengths and frequencies: radio, microwave, infrared, visible light, ultraviolet, x-rays, and gamma rays. The visible light spectrum is the section of the electromagnetic spectrum which is visible to the human eye. The light in this section have wavelengths ranging from 380 nm and 760 nm.

Visible Light Spectrum

The visible light spectrum is often depicted as a scale of colors with different wavelengths. Sunlight, which is our primary source of visible light, and which is often referred to as white light, is actually the presence of all colors. Visible light travels at a speed of 300,000 km per second and can be broken down into seven colors. From longest to shortest wavelength, they are: red, orange, yellow, green, blue, indigo, and violet. To be clear, color is the eye’s perception of different wavelengths of electromagnetic light. Light, itself, does not possess color.

Properties of the Spectrum of Visible Light

Like any other form of electromagnetic radiation, visible light is subject to reflection, refraction, and diffraction.

  • Reflection is the process by which a light wave comes into contact with a surface and is thrown back towards its source.
  • Refraction is the change in direction a wave as a result of traveling from one medium to another.
  • Diffraction is the process by which a wave spreads out as a result of passing through a narrow opening.

Light, Energy, and Color Temperature of Visible Light

The color of a light is determined by the energy being radiated by the light’s source. The wavelength of the energy being radiated determines the color we perceive the source to be. Imagine a perfect black body, which absorbs and radiates all the energy that reaches it. The hotter the black body gets, the greater the energy it radiates and the shorter the wavelength of that radiation. Our eyes interpret this light as the colors associated with shorter wavelengths, such as blue and violet.

Temperature of Visible Light

Conversely, energy radiations with longer wavelengths are interpreted as the colors closer to red and orange. Incandescence is the phenomena when a body gets so hot that it begins to glow. The range of colors the eyes interprets from electromagnetic radiation of different wavelengths is commonly used to depict the visible light spectrum.

Experiments for Exploring the Visible Light Spectrum

There are lots of interesting and easy ways for you to explore the visible light spectrum. A great place to start is Newton’s prism experiment. With this experiment, Newton discovered that white light is a combination of all colors rather than a single color in itself.

Newton Prism Experiment

First, you’ll need a prism, a source of white light, and a white screen. On a flat surface, set up set up the prism and direct the white light through it. Position the white screen to receive the light as it exits the prism. On the white screen, you should see a rainbow. As we know, each color of the visible spectrum has a different wavelength and, therefore, is bent to a different degree as it passes through the prism. This property of light is what allows us to see the individual colors when the light exits the prism.

You can take this experiment a bit further. If you place a lens right in front of the screen and slowly move the screen away from the lens, the colors will combine back to a single white light. At this point, if you keep moving the screen away from the lens, the white light will separate back into the different colors but in the reverse order. If you move the screen back toward the lens, the colors will recombine to white, and then separate back into the constituent colors.

Optical Spectrometer

Another fun way to explore the visible light spectrum would be to make a simple spectrometer. An optical spectrometer is a scientific device used to split light into an array of its constituent colors. For this, you’ll need an old CD, a cereal box, a pair of scissors, aluminum foil, a 60 degree angle template, and tape.

  1. On the top of the box, use a straight edge to measure and mark off 1.5 inches along its length.
  2. Using the same straight edge, draw a guideline across the width of the box. Cut along the guideline, then unfold and cut off the flaps.
  3. From the corner of the box where the flaps were cut, draw a 3 inch line towards the center of the box on both sides.
  4. Using those lines as guides, cut two 3 inch slits on both sides of the cereal box.
  5. Insert the CD between the slits.
  6. Cut a rectangle on the opposite side of the box from where the CD was inserted. This rectangle should be half an inch from the top of the box, one inch high, and span the width of that side of the box.
  7. Cut enough aluminum for to cover the rectangle, then fold it in half. Align the crease with the center of the rectangular hole from the top and tape the other edge to the box.
  8. Cut another similar pieces of aluminum, fold and tape it from the bottom of the rectangle, leaving a 1mm slit between the two pieces of aluminum.
  9. Finally, tape the top of the box closed.
  10. Point the slit at any light source and look through the square hole. You should be able to see the rainbow colors.

Visible Light Spectrum and the Ecosystem

The visible light spectrum is a crucial part of the earth’s natural processes. The earth’s food chain depends heavily on it. Plants rely on visible light to power photosynthesis, the process by which they make food. Photosynthesis also produces oxygen and releases it to the atmosphere, making it available for human beings and other animals to breathe. Studies have also shown inadequate exposure to visible light causes brain damage and emotional illness in human beings.

Conversely, excessive exposure to the visible light can damage one’s eyes and skin. So, enjoy the wonders of visible light but, do so safely and responsibly.

Shop Rainbow Symphony Today

Need more ideas or equipment for creating an extraordinary light and color experience? Explore the collection of rainbow suncatchers, diffraction grating slides and diffraction glasses at Rainbow Symphony! Contact us today for any information on our products and services.


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