Why is the Sky Blue?

Ever been asked the question, "Why is the sky blue?" Better yet, ever asked that question yourself?

If you were to walk alongside me, in the comings and goings of life, there would likely follow a moment where someone, somewhere would walk up to me and offer their help and assistance. Maybe they're a sales clerk at Best Buy or a worker at Cracker Barrel; perhaps a bank teller or a guitar technician. They all ask a similar thing: "Do you have any questions?" or "Is there anything I can help you with?" They're giving me a courteous opportunity to ask them a question. They think it's going to be about a product or service that they can provide. And how do I respond? Usually with a question of my own: "Could you tell me, 'Why is the sky blue?'"

Yeah, I know, it comes at them from left field, but, it's just so much fun! The expressions I get sometimes - amazing! Probably because the sky blue inquiry is the last question that someone is expecting!

Over the years, I've had a lot of fun with this question. Some laugh, some go silent, some look up toward the sky and shrug their shoulders. Some look confused (which usually makes me quickly apologize and move on to more "official" questions.) Some stop what they're doing and appear to give my sky question much thought. Overall, most attempt to answer in some way.

What kind of answers do I get to, "Why is the sky blue?"

"Air molecules are that color? Right?"
"Water molecules are that color? Right?"
"I don't know."
"Because it just is. It's blue."
"That question hurts my brain."
"Because God made it that way."
"I think it has something to do with the ocean."

Home Depot to the rescue!

My wife and I were doing some evening shopping for home supplies at our local Home Depot, when I spotted a store worker approaching. I readied my response to what I knew was coming.

"Is there anything you are looking for? Do you have any questions?" the polite Home Depot worker, with a name tag of Shawn, asked.

"I do!" I said with a grin. "Can you tell me why the sky is blue?"

Shawn gave me a sideways glance. "So. You're one of those kind of guys, huh?"

That got me laughing, so I moved on to asking an 'official' question of where a particular bolt was located. My wife asked about paint, and we all three went our separate ways.

Twenty minutes passed, and by then I'd visited all kinds of different departments before heading toward the checkout registers. I was looking around for my wife, when I saw Shawn walking straight at me. With little to no expression (or was that just his poker face?) he presented a folded piece of paper to me, and simply said, "Here you go." Then, without another word he turned and began helping another customer.

Stock still in the middle of the main aisle, I unfolded the paper and began reading:

"The blue color of the sky is due to Rayleigh scattering. As light moves through the atmosphere, most of the longer wavelengths pass straight through. Little of the red, orange and yellow light is affected by the air.

However, much of the shorter wavelength light is absorbed by the gas molecules. The absorbed blue light is then radiated in different directions. It gets scattered all around the sky. Whichever direction you look, some of this scattered blue light reaches you. Since you see the blue light from everywhere overhead, the sky looks blue." (I later found this on the ScienceMadeSimple's website)

After literally laughing out loud, I joined my wife in the check-out line. The cashier looked over at the paper I was holding.

With a look of recognition she said, "Oh, so you're the 'why is the sky blue' guy."

I gave her a second glance. "Uh, yeah," I said chuckling. "I guess I am."

She laughed. "The whole store knows about you now," she added cheerfully.

I chuckled all the way to the car, marveling at how much fun it can be to ask people a simple, unexpected, off-the-wall question.

Under God's blue sky I've been afforded many enjoyable responses from the different people I've encountered over the years. And Shawn's answer easily ranks at the top of the "most scientific" of all the responses I've ever received.

Well done, Shawn of Home Depot. Well done.