St. Patrick’s day is a lot of fun. Setting leprechaun traps and talking about pots of gold at the end of the rainbow. It is fun to pretend and eat a bowl of Lucky Charms but…..in the end…..what is a rainbow? How does it work? And what are some fun facts about rainbows????? Let us tell you. Today we are taking a vacation to the top of a rainbow, not in search of gold but in search of facts.
I don’t know about you, but I have a mental countdown going until the first day of spring. With spring comes warmer weather, more time spent outdoors, the sweet perfume of new flowers blooming and…. rain. Lots of rain. After all, April showers bring May flowers…but with these April showers also come the elusive and often sought after rainbow.
But what is a rainbow exactly? Where do its miraculous colors come from? Is there a specific order to a rainbow’s colors, and if so, why? Let’s get rainbow connected, just in time for Spring- and afterwards a sweet surprise!
Let’s start off easy. What is a rainbow? In short, a rainbow is an optical (sight) and meteorological (weather) miracle. It is a brief moment in time where at just the perfect moment, the Sun’s rays shine through water droplets in the sky at just the right angle (well, to be honest it’s less than a right angle-since a right angle is 90 degrees and a rainbow’s viewing angle is 42 degrees….um, never mind, lol) to refract (bend) the light upon entering a single droplet of water, reflecting inside the back of the droplet then refracting itself once again upon exiting it. In laymen’s terms, it’s a light-bending water show of colors.
But what are the colors, where do these they come from and in what order do they appear?
The 7 colors of the rainbow (kinda neat how God snuck the number 7 into something he has blatantly called a sign of his promise) can be easily remembered using the following acronym:
These radiant colors come from the visible light spectrum (aka the optical spectrum of light) of the electromagnetic radiation spectrum. This spectrum has many wavelengths made up of frequencies and energy, and each wavelength determines what color we see. (Added fact- the red or blue you see may not be the same brightness, intensity or saturation of red and blue your friend sees! Colors are apparently “perceived”!)
Colors that can be produced by visible light of a narrow band of wavelengths (monochromatic light) are called pure spectral colors. The various color ranges indicated in the diagram below are an estimate: the spectrum is continuous, with no clear boundaries between one color and the next.
violet 380–450 nm
indigo 476–495 nm
blue 450–475 nm
green 495–570 nm
yellow 570–590 nm
orange 570–590 nm
red 620–750 nm
The color order we are so used to seeing (with red on the outside and ending with violet on the inside) is called a primary rainbow; in this type of rainbow the highest wavelength comes first. In the extremely rare double rainbow, a second arc is seen outside the primary rainbow and the color order is reversed, with violet on top and red on the inside. This second rainbow is caused by light reflecting twice inside the water droplets. The area between a double rainbow is dark, and is known as “Alexander’s band” or “Alexander’s dark band”.
Now that we know the ins and outs of the beautiful rainbow time for some fun facts and that sweet treat!
- Sir Isaac Newton discovered the seven distinct colors of the visible spectrum
- What we see, feel, hear, taste and smell exists between the frequencies of red and violet
- Rainbows are Gods promise – Genesis 9:12-17
- Rainbows and music are made of the same things, just vibrating at a different frequency
- The true shape of a rainbow is a complete circle