Rainbows fascinate us. We find them in nature, and then expound upon and replicate them in our religions, mythologies, literature, art, and music. In this article we will talk about the science of rainbows, our cultural perception of rainbows, and we will learn how to make a rainbow.
How to Make a Rainbow: What Is A Rainbow?
The bright rainbows that we see in the sky are “primary rainbows,” which are red on the outside of their arcs and violet on the inside. They are caused by the light that is reflected from water droplets. Although we artificially subdivide rainbows into “bands,” the colors present in rainbows are not actually separate from each other. A rainbow is a continuous spectrum of colors. Infamous “double rainbows” appear as a color-inverted second arc above a primary rainbow. Rumored “triple rainbows” are scientifically impossible and cannot naturally occur.
How to Make a Rainbow: Where Do We Find Rainbows?
We can find rainbows wherever we find sunlight shining through airborne water droplets at a low angle. We can find rainbows around rainclouds, waterfalls, and fountains. We perceive rainbows to be brightest when half of the sky is still dark with rainclouds. Sometimes, when the moon is bright enough, we can even find moonbows, or nighttime rainbows. Interestingly, one cannot actually be “under” or “at the end of” a rainbow: even if you are looking at someone who appears to be at the end of a rainbow, from their vantage point, the person sees the rainbow as being still further off yet. This means that rainbows are not actual, physical objects that we can physically approach. So much for pots of gold.
How to Make a Rainbow: Rainbows in Science
Rainbows have fascinated scientists over the course of scientific history. Aristotle, the classical Greek scholar (384-322 BC), was the first major scholar to study the rainbow. Although his theories about the formation of the rainbow were largely incorrect, modern scholars still cite Aristotle’s work as the first serious scientific attempt to understand the rainbow. Aristotle’s work as followed by Seneca, who noticed that rainbows always appear in the opposite direction to the sun, and that rainbows always appear by water. Descartes later saw that the size of raindrops didn’t seem to affect the appearance of rainbows. Finally, Sir Isaac Newton worked with prisms to prove that white light was composed of the light of all the colors of the rainbow.
How to Make a Rainbow: Rainbows in Culture
People have explored the rainbow in every cultural form, from religious mythologies to hilariously incoherent YouTube videos. In the Bible, the rainbow was seen as a symbol of God’s promise to never flood the earth again. In Norse mythology, the rainbow was called the Bifrost Bridge, and was seen as the path between Asgard and Midgard, the realm of the gods and the realm of humans. Irish leprechauns are said to hide their pots of gold at the end of rainbows (a place that is, sadly, impossible to reach). Kermit the Frog and Dorothy from The Wizard of Oz sing about rainbows as symbols for hope. The rainbow has also used as a symbol for gay pride and a flag for the LGBT social movements since the 1970s.
Learn How to Make a Rainbow
You can learn how to make a rainbow by performing the following experiment. First, fill a glass of water almost to brimming and place it on the edge of a kitchen counter. Then place a sheet of plain white paper on the floor a few inches away from the counter. Turn off the lights. Cover the front of a flashlight with two strips of masking tape, leaving only a 1/8 inch aperture, and then shine the light down into the glass of water. This should shine a full spectrum onto the sheet of paper.
Access to water has always been an important factor in the location of settlements, whether primitive or modern, human or animal, and the need for water is a universal part of life. Unfortunately, billions of people around the world still lack access to potable water. Water shortages are usually defined as third-world phenomena, but shortages of clean water are also prevalent in the United States. As the world’s population grows, humanity must recognize that water access is becoming an increasingly global concern.
Access to Clean Water
Access to water is vital, but access to clean water is even more critical. Today, approximately one billion people do not have access to clean water, which has severely harmed the health and economic development of the most affected regions. Further, according to UNICEF, lack of safe water is the world’s single largest cause of illness. Lack of clean water can cause afflictions such as river blindness, cholera, diarrhea, dysentery, and a number of other diseases and infections. The global water crisis is not unsolvable, though. Countries around the world are actively pursuing solutions such as reduction of pollution, infrastructure building, desalinization, improved irrigation, and more.
In man’s effort to stay safe, he has found ways to treat water. Water treatment occurs before the water enters a house. Unfortunately, water treatment is so simplistic that many people are still concerned for population safety. Sewage treatment is done on used water before it re-enters the source, such as a river or under ground supply. Sewage treatment speeds the process of eutrophication, or the aging process of water, and creates favorable breeding grounds for disease that would not be as concentrated if nature took care of itself. Taking the larger particles from sewage water is acceptable, but the later-stage biological processes are what cause eutrophication.
Access to water and particularly, clean water will always present a major problem to the human race. Unfortunately, there are too many people needing too many resources from the planet.
It’s easy to not think about how much water is used to make things that we use everyday. However, besides implementing tips for water conservation, understanding how water is used to make things is important in our goal of reducing water consumption. It’s not just the water used to make stuff but also the water used for growing, processing and transporting. For example, cotton uses a tremendous amount of water to grow and to eventually become a pair of stylish jeans. Those morning lattes from the local coffeeshop use more water than is served in a given cup. And given the huge amounts of water used in manufacturing, many companies are looking for ways to reduce their water footprints.
How Much Water Does Agriculture Use?
It takes much more water to make things for the American dinner table than one would imagine. Obviously food crops need water to thrive, however, many people would be surprised to learn how much water is used to grow our food. It takes almost 20 gallons of water for one apple, 4,000 gallons for one bushel of corn and 11,000 gallons for one bushel of wheat. It takes over 15,000 gallons of water to raise a cow from birth to slaughter.
How Much Water Does It Take to Make Food?
It takes an amazing 53 gallons of water to make a latte. This figure may be hard to believe given that most lattes are just over a cup. Planet Green’s Brian Merchant states in a recent article that each latte requires water for the cane sugar’s growth, the plastic lid’s manufacture, the paper cup and sleeve’s manufacture, as wells as for the transportation costs for all of the above. Hamburgers take a whopping 634 gallons of water to make mostly given the cost of raising beef.
How Much Water Does It Take to Make Clothing?
According to OnEarth.org, it takes over 1,500 gallons of water to produce the cotton in one pair of jeans. And that’s just for growing the cotton, it doesn’t include the water used to dye jeans or to ‘weather’ them so that new jeans look and feel ‘broken in.’ It takes 400 gallons of water to grow the cotton to make one shirt. Water consumption for growing cotton crops is huge and cotton is the largest natural fiber textile in the world accounting for 40% of textile production.
How Much Water Does Our Corporate Footprint Reflect?
Most companies know how much water it takes to make things and are looking for ways to decrease water consumption for their products and for their supply chains. For example, Levi’s has recently introduced a new brand called Water less, that reduces water usage by an average of 28% and up to 96% for some products. Water Footprint Network recommends that companies complete their water footprint assessment manual to review their water usage. It provides for a global standard on definitions and calculations how how much water we’re using.
Many people wonder how good the water quality in their area is. When water contains contaminants, it leaves behind tiny particles that are dissolved in the water, particles that are called “total dissolved solids.” This map charts total dissolved solids in the water. Although this chart doesn’t show exactly which contaminants are present in your water and whether they’re bad for you, it’s still a good measure of water purity.
Click on the map to find out more about your local water quality.
