All About Water

The Science and Story of Rainbows 

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

The history of human civilization is enmeshed with the history of water. Water has guided civilization more than any other factor. Early civilizations were centered around water sources; the secure water supply of the Fertile Crescent enabled some of the first large-scale agricultural civilizations. Water allows people to sustain themselves and their animals and determines what can be grown and where. As civilizations learn how to better control water—to irrigate and to predict the weather, for instance—they learn how to grow. Even today we still center our civilizations around water. The Middle East is exploding with wars over clean water access. As the World Bank Vice President Serageldin famously stated, “Many of the wars of the twentieth century were about oil, but the wars of the next century will be about water.”

Reasons for the History of Water

Nowadays, after the growth of industries, clean drinking water doesn’t naturally occur. Scientists continually discover contaminants in fresh water sources and correlates between drinking contaminated water and health problems. Because we need water but it is impure, we have learned to treat water. However, the history of water filtration is not a recent one; water filtration began over 4000 years ago.

Milestones in the History of Water

Some milestones in the history of water include the invention of the microscope, the advent of municipal water treatment, the use of chlorine to purify water, and the Clean Water Act of 1972.

Early in the History of Water

The earliest recorded attempts to filter water date back to 2000 BC, to early Sanskrit writings of water purification methods. These methods include boiling water and filtering water through sand or charcoal filters. The Sanskrits’ biggest motive was to make water taste better, because they assumed that good-tasting water would also be clean. People didn’t yet realize that contaminated water caused disease, and they certainly couldn’t test for diseases in water.

Later Innovations in the History of Water

In 1590, the Dutch glasses-makers Zaccharias and Hans Janssen invented the forerunner to modern-day microscopes. A century later, Anton van Leeuwenhoek, “the father of microscopy,” advanced the Janssens’ invention to the extent that scientists could now view tiny living particles in water that had previously been thought clean. In nineteenth-century London, city officials first linked cholera to bad water quality. John Snow, a British scientist, confirmed cholera bacteria in the Broad Street Pump’s water, proving that taste and visual clarity doesn’t prove water’s pureness. After this event, the British government insisted upon filtering city water, a precedent for municipal water systems. The British municipal water system cleaned water partly by treating it with chlorine.

The History of Water Continues

In the 20^th century, people increasingly agreed that every person has the right to clean water. The Clean Water Act (CWA) of 1972 made it a law that every city in the United States must have a water treatment plant. The CWA forced industrial plants to become environmentally friendly and renewed interest in water filtration, making clean water a national goal. Today the history of water continues as we strive to bring clean water to places that still need it.

What Is Water?

The chemical formula for water is H₂O. This formula means that one molecule of water is made up of to two hydrogen atoms bonded with one oxygen atom. Oxygen is a negatively charged atom and hydrogen is positively charged, but when the electrons of these atoms combine to form a water molecule, the molecule’s charge is not evenly distributed: the molecule has a slight negative charge on its oxygen end and a slight positive on its hydrogen end. Because of this, water molecules are polar. This polarity causes water molecules to be electrostatically attracted to other water molecules, and also allows water molecules to dissolve other molecules.

What is Water: Polarity’s Effects

Polarity makes water molecules special. For instance, it causes water’s solid form, ice, to float atop its liquid form, water—and unusual chemical property. This happens because water molecules’ hydrogen bonds repulse other water molecules’ hydrogen bonds, which makes the solid water molecules be spaced further apart from each other than they were as liquid water molecules. This causes ice to be less dense than water, thereby causing ice to float.

What Is Water: Other Unusual Properties

When we wonder what is water, need to understand water’s also possesses some other interesting physical properties.

• Water has strong surface tension, high heat of vaporization, and high specific heat.
• Water dissolves more substances than any other liquid, and has therefore been nicknamed “the universal solvent.”
• Water is the only chemical compound on Earth’s surface that is naturally present as liquid, gas and solid.

What is Water: Water Is Necessary for Life

All of life’s biochemical reactions rely upon liquid water to occur. Without water, the world as we know it would not exist. The world’s temperature systems would be wildly different, chemical reactions would not occur, and organisms would not be able to maintain their cell membranes. In chemical reactions, water pushes non-polar compounds together. This hydrophobia is the basis for the creation and maintenance of cell membranes, which are necessary for all living organisms. Additionally, only water can bend enzymes into the proper shape for catalyzing the chemical reactions that we need to stay alive. What is water? Necessary for life. Us folks of Operation Hydros understand how important water is, and that’s why we’re fighting so hard to conserve it.