Why is the sky boo!
Just kidding, why is the sky glue? No, no
Why does the sky mooooo?
Oh dear. Why does the sky wear shoes?
That's not it.
Ah yes, I remember- why is the sky blue?
Hey Squints! So what does make the sky
blue? Did Big Foot really color outside the
lines with his blue crayon and
accidentally color the sky?
Well first it's important to remember
that the sky isn't always blue. At night
we can actually see straight through the
sky, that's how we can see the stars in
outer space. Or at sunrise or sunset the
sky is full of reds oranges and yellows.
But during the day the sky is almost
always blue and that's because during
the day there's a lot of light.
I've talked previously about how we get
colors from light or more specifically
photons of light. A faster photon looks
blue or violet and a slower photon looks
more orange or red. And when photons of
all speeds are moving together the light
will look white. Knowing that we can get
down to the nitty-gritty of what makes
the sky blue. Even though we usually draw
the Sun yellow, it's actually closer to
white because it shoots out photons of all
speeds. This white light from the Sun
travels through space in all directions
but some heads straight for earth. Right
as it gets just above the earth it hits
something called "The Atmosphere". The
atmosphere is a protective blanket that
covers the earth made out of little
particles and gases like the air we
breathe. The atmosphere is really good at
bouncing photons, kind of like how you
can bounce a photon off a CD, except the
atmosphere mostly bounces the faster
colors like blue. The slower photons like
yellows and reds go straight through
the gases in the atmosphere, only
bouncing a little bit. But the faster
photons like blue and violet bounce off
them pretty hard.
It's like bouncing a ball off a wall, the
faster the ball is going,
the more it bounces. So as the sun's
white light hits our atmosphere, the
slower photons like yellow, orange, and
red go through the particles in our
atmosphere and shine straight down to
the ground. That's why the Sun does
sometimes look more yellow or orange
because those yellow and orange photons
shine at us through the atmosphere.
Straight from the Sun, express delivery!
The faster photons full of energy,
however, like blue and violet, bounce off
the gas in the atmosphere. The blue and
violet lights just bounce around the sky
from one particle in the sky to the
other until it finally gets bounced down
to us on earth. This makes it look like
blue light is coming down from all
around us instead of just straight line
from the Sun. And that's what makes the
sky blue- it's just blue and violet light
getting bounced around the sky before
coming down to our eyes forming kind
of a blue light blanket. So keep seeing
colors, keep asking questions, and keep on
squinting!
