National Find a Rainbow Day is celebrated every year on April 3rd, and there’s no better way to spend a day in early spring.
Catching a glimpse of a magnificent rainbow in the sky is a beautiful sight to behold. It’s no surprise that rainbows have inspired poetry, mythology, and music throughout the centuries. It’s a symbol for hope, optimism, and nature’s beauty.
But did you know there are actually many different types of rainbows? Or that rainbows are actually full circles? Do you think that planet Earth is the only place where rainbows occur?
Read on to find out!
Here are 25 interesting and fun facts about rainbows that your kids will love:
25 Cool Rainbow Facts
1. A primary rainbow is formed when light shines through water droplets. It happens most often when the sun shines through the rain. This white light bends and reflects, causing all of the beautiful different colors to appear.
2. Earth is the only planet in the solar system where rainbows occur.
3. Some astronomers think it’s possible for rainbows to occur on Titan, one of Saturn’s moons. Titan has a wet surface and humid clouds. The sun is also visible from Titan, so it has all the ingredients necessary for rainbows to occur.
4. A rainbow is actually a complete circle, not an arc. From the ground, we only see a semi-circle.
5. From an airplane, you can see a completely circular rainbow.
6. Rainbows are made up of all seven colors that come from light. The colors of the rainbow are red, orange, yellow, green, blue, indigo, and violet. (You can remember the colors of a rainbow with the acronym Roy G. Biv.)
7. The state of Hawaii has the most rainbows on the planet.
8. The average rainbow is observable for less than an hour.
9. The world’s longest-observed rainbow was located high in the mountains of Taipei, Taiwan in 2017. It lasted for 8 hours and 58 minutes, 6:57 am until 3:55 pm.
10. The word “rainbow” comes from the Latin phrase arcus pluvius, meaning “rainy arch.”
11. In ancient times, Greeks and Romans believed that rainbows were paths created by the goddess of the rainbow, Iris. Greek mythology holds that rainbows linked humans to the Gods.
12. Ancient Japanese belief held that rainbows were the bridges that human ancestors took to descend to Earth.
13. Hindu culture teaches that the god Indra uses his rainbow bow to shoot arrows of lightning.
14. Irish legend says there is a pot of gold at the end of the rainbow. The gold is guarded by a tricky leprechaun, but no can ever find him!
15. Tribes throughout the Amazon basin associate rainbows with disease.
16. In the Epic of Gilgamesh and, later, the Bible, the rainbow is a symbol from a deity (the goddess Ishtar and the Hebrew God) to never again destroy the Earth with floods.
17. You can never touch a rainbow or reach the end of a rainbow because it’s appearance is based on your location and the light source. It’s a tricky optical phenomenon. When you move, the rainbow will move, too.
18. A double rainbow, or “secondary rainbow”, appears when light is reflected twice in a raindrop.
19. Rainbows normally appear from the rain, but can also be seen in other places water drops appear such mist, fog, spray, waterfalls, and dew.
20. A “fogbow” is formed by cloud and fog droplets. They appear almost complete white with very faint colors visible. Fogbows are larger and wider than a rainbow.
21. A “moonbow” is a rare lunar or nighttime rainbow that is produced by light from the moon. All of the colors are present, but our eyes see it as white.
22. “Red Rainbows” – also called monochrome rainbows – usually appear at sunrise or sunset. During this time, sunlight travels further in the atmosphere, and shorter wavelengths (blue and violet) have been scattered. Only the long-wavelength red colors are visible in this rainbow.
23. The visible arch of a rainbow is always a 42-degree angle.
24. Rainbow flags throughout history have long represented groups championing diversity, respect, and inclusiveness.
25. You can make your own rainbow! There’s an easy way to do it yourself.
All you need is a sunny day and a garden hose. Stand with your back against the sun. Turn on the water hose. These are your “rain droplets”. Put your other hand straight up in the air. Spray water about halfway between the ground and your other hand. As the sun’s light shines through, you should see a mini-rainbow and its beautiful colors.
We hope you loved these interesting facts about rainbows as much as we loved compiling them! The next time you see a beautiful rainbow, you can share your knowledge with others.
Frequently Asked Questions About Rainbows
How do rainbows form?
A primary rainbow is formed when light shines through water droplets. It happens most often when the sun shines through the rain. This white light bends and reflects, causing all of the beautiful different colors to appear.
Do rainbows touch the ground?
They looks like they do, but rainbows do not touch the ground. A rainbow is actually a complete circle, not an arc. From the ground, we only see a semi-circle. If you go high enough in a plane, you will see it is a full circle.
Can you touch a rainbow?
You can never touch a rainbow or reach the end of a rainbow because it’s appearance is based on your location and the light source. It’s a tricky optical phenomenon. When you move, the rainbow will move, too.
Is a rainbow a circle?
Yes, a rainbow is actually a complete circle, not an arc. From the ground, we only see a semi-circle. If you go high enough in a plane, you will see it is a full circle.
Rainbow Science Experiments
Now that you’ve learned these 25 interesting rainbow facts, here are more rainbow-inspired science experiments:
Sugar Water Rainbows
This science experiment is especially meant for young children, but it can me modified for kids of all ages. Your kids will love this colorful experience about density and buoyancy, and all you need are some common household ingredients.
What You Need:
food colorings (preferably in rainbow colors including red, orange, yellow, green, blue, purple)
a clear straw
First, fill each of the cups with the same amount of water.
Next, add the food coloring, one color in each cup, preferably in rainbow order.
Line the cups up next to each other.
In the first cup, do not add any sugar at all.
In the second cup, add one tablespoon of sugar.
In the third cup, add two tablespoon of sugar.
In the fourth cup, add three tablepoons of sugar, and so on.
Stir each mixture until all the sugar is dissolved in each glass.
The next step is to make a sugar rainbow by placing the end of the straw in the first cup (the cup with no sugar), only about a half of an inch.
Cover the top of the straw with your thumb before lifting it out of the water so that the water does not fall out of the straw.
Now dip the straw into the second cup (1 tablespoon sugar). This time, insert it deeper so that the end is one inch below the water level. In one quick move, release the thumb and recap again. Now you should have two layers of color.
Keep dipping the straw into each solution from the one with the least sugar to the one with five tablespoons of sugar. Each time, the straw is inserted half an inch deeper.
Density is the amount of substance (mass) within the volume occupied by the object. If two cups have the same amount of water (i.e. same volume), the one with more sugar is denser than the one with less sugar.
Buoyancy is determined by relative density. The solution with less density floats above the solution with higher density. That is why the color don’t mix.
Sugary water has higher density than plain water. The solution with more sugar has higher density than the one with less sugar. If you have inserted the straw in the solutions from the least sugar to the most sugar, then the color don’t mix and you have a sugar water rainbow.
This colorful experiement is a super simple way of demonstrating capillary action, water travel, and color mixing.
Kids of all ages will love watching the color move through the paper towel on its own, and they’ll have a better idea of how plants get their nutrients.
What You need:
6 glasses or jars
Food coloring (red, yellow, & blue)
First, fold six sheets of paper towel lengthwise. You may need to cut a few inches off so that it fits into the glasses well. They should go from the bottom of one mason jar to the next without sticking up too high in the air.
Next, fill the first glass with a generous squirt of red food coloring, the third with yellow, and the fifth with blue. Mix it up with a plastic spoon. Leave the other glasses empty.
Then, add water to the glasses with color until the colored water almost reaches the top.
Now add the paper towels. Starting with red, add once end of the paper towel and put the other end in the empty glass next to it.
After several minutes, the colored water will travel almost the whole length of each paper towel. You can watch the water do its magic for about 20 minutes!
The colored water travels up the paper towel by a process called capillary action. Capillary action is the ability of a liquid to flow upward, against gravity, in narrow spaces. This is the same thing that helps water climb from a plant’s roots to the leaves in the tree tops.
Paper towels (and all paper products) are made from fibers found in plants called cellulose. In this demonstration, the water flowed upwards through the tiny gaps between the cellulose fibers. The gaps in the towel acted like capillary tubes, pulling the water upwards.
The water is able to defy gravity as it travels upward due to the attractive forces between the water and the cellulose fibers. The water molecules tend to cling to the cellulose fibers in the paper towel. This is called adhesion. The water molecules are also attracted to each other and stick close together, a process called cohesion. So, as the water slowly moves up the tiny gaps in the paper towel fibers, the cohesive forces help to draw more water upwards.
Did you enjoy these fun rainbow facts and experiments? If you have others to share, email us at email@example.com.