Sky, sky, blue and black…

Jackson Browne was talking about how true love hangs in through thick and thin, whether you have sunny blue skies or ugly black ones.  Black skies are not too tough to figure out, they result from the absence of light…night.  But what makes the sky blue?  To answer that question, you have to know something about the nature of light.  Sunlight is composed of different colors (wavelengths) of light…maybe you’ve seen this when the morning sun shines through a piece of crystal, breaking the light into that pretty array (spectrum) of red, orange, yellow, green, blue and violet.  Moving from the red toward the blue end of the lineup, those wave forms become shorter, smaller.  It turns out the little blue waves scatter more easily than the reds when they encounter bits of dust, water vapor, political ads and other trash on their journey from the sun to our eyes.  So we look up, and all those crazy blue particles of light are bouncing around willy-nilly, while the reds and oranges are marching on locked in on target.  Our eyes see blue, blue, blue…hey, it’s all blue up there, apparently!  But what about sunset?  It’s usually some form of red, right?  Well, the sunlight coming to our eyes at sunset is really low down there on the horizon, which means the light has to travel through even more of our messy atmosphere, down low where the dust particles are bigger, water molecules more rampant, and politician yap more intense.  By this time the blue particles of light are pretty much beaten into submission, out of the game, and even the big boys…the reds and yellows and golds…are getting kicked around and scattered about.  To our eyes, the blue bits are gone and we we see the colors that are still there bouncing around, and we grab the camera because it’s just so pretty.  So the next time you get The Blues from too many Tequila Sunrises, you can just blame all the Dust In The Wind!  (16 September, 2011  Firenze, Italy)