How are rainbows formed. I know it’s about refraction from water droplets, but shouldn’t you see many tiny rainbows instead of one big one.
In: Physics
I would really recommend looking on youtube for “Walter Lewin Rainbow”, he was a professor at MIT and he’s lectures on introductory physics are amazing. I would recommend watching all his lectures but you know… I’m a nerd.
Imagine the sky is a Giant LCD display.
Each water droplet is a pixel on the display. Its transparent when light passes straight thru it.
But if the light passes thru at an angle, it gets a colour/hue when you view it.
The droplets are stationary, but your perspective is different with respect to different droplets. Droplets at a certain area give off a certain color, to you. Droplets in another area, another color.
You can also see this effect when you view your LCD display at extreme angles. I think the phenomenon is called colorshift.
Good question, no answers. Water is at a “farther angle”…water droplets near each other all “send the same color”…nonsense. I have no doubt that people actually understand the physics, but I’m not sure that they understood the question, and certainly no one answered it.
The pokémon called Ho-Oh has wings that are prismatic, causing it to trail a rainbow behind it. It is said that when it flies its huge wings create bright, colorful rainbows.
So what you’re actually looking at is a big ball of mist in the sky?
Sunlight is what is called polychromatic light. This means it contains all visible wavelengths (red, orange, yellow, blue, green, indigo, violet) as well as wavelengths of light we cannot see (infrared, ultraviolet, x-ray, gamma-ray and so on). When this light from the sun refracts through a water molecule, all the light is separated. The longer wavelengths (red) will refract at a smaller angle then the shorter wavelengths (blue, violet). This is why we see red at the top of a rainbow and the blue colors at the bottom of a rainbow.
Now to address your question. Technically there are tiny rainbows from one water molecule, but we wouldn’t be able to see this refraction through a single water molecule just because there is not enough light to be received by our eye. It is a sum of all these that produces what we call a rainbow. Rainbows only occur when there are enough water molecules refracting light to be perceived by the human eye.
So, everyone gets their own rainbow?
Well, I once saw three rainbows in a row. One really bright one. One slightly less bright one just underneath and one barely discernible one underneath that one.
Was pretty cool. Doesn’t really meet the definition of “many” though.
For me, it’s helpful to remember that a rainbow is a circle. You usually just can’t see the other half. In the inner parts of a circle the spectrum continues. The ultra violet and higher frequencies keep going. Outside the circle, the infra red and lower frequencies continue. A rainbow only appears like it does to us because we can only see a small segment of the spectrum.
I can’t explain why you don’t see teeny ones, BUT when you see a rainbow, you only see one of what’s actually an endless formation of concentric rainbows.
The primary rainbow is the brightest, and if you see purple in it, you are actually witnessing a whole new bow.
Have you ever noticed that sometimes in perfect conditions a primary rainbow seems as though there are “extra” shiney bands below it?
This is called a supernumerary rainbow, and it’s the beginning of the second “disk” in the concentric bands. The blue of the primary one overlaps with the red of the next, and it shows up as purple or violet.
So, you are kind of right. There are many different rainbows. Our eyes are only capable of seeing the brightest of them.
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