1. Why is the sky blue?

2. The shades of the sky
Looking at the Eath's surface, the sky
on different colors depending on the
time. If day, displays a blue; if at the
end of the afternoon, reds win; if
night, turns black.

3. We see the sky
Astronauts always see the dark sky. So
why do we get to see blues, reds and
oranges? Have you ever stopped to
think about it?

4. History
Because all this happens because of the
way the light scatters through the
atmosphere! It may seem strange, but
the light is a form of energy that
travels through space like a wave. This
same: a wave! That only a very small
wave: to find the length of a wave of
sunlight, for example one millimeter
would need to divide into a thousand
equal parts.

5. A popular saying curious
The proverb says: that size does not
matter does not apply to light. You know
why? For the size of the wave
described by this form of energy
determines exactly the color she has.
The smaller waves are blue; the longest
waves are red.

6. Experience
Have done an experiment with a prism?
The prism is na object made of glass or
crystal used to decompose sunlight. I've
Certainly heard of that white light is
the union of all colors, is not it? For
white sunlight just being formed by
waves of different sizes. With the help
of a prism, we can see the colored
beams that form.

7. The sunlight
When sunlight reaches Earth, it
encounters na obstacle: the
atmosphere, ie, the large mass of air
that envelops the planet. By bumping
into air molecules, waves of different
sizes begin to spread each one way.
Waves of short length spread. And what
color the smallest light wave? Exactly:
blue!

8. The waves
This mechanism also explains the color
variations in the sky. In addition to the
air molecules are suspended in the
atmosphere, dust particles. When these
particles are smaller than the
waves, causing an even greater spread
of light. The blue waves spread far, you
end up diluting, allowing us to see the
longest waves as red and yellow.

9. We hope you enjoyed!
Work done by:
Luís Torre;
Inês Veríssimo;
Alexandra Pinto;
Eduardo Cruz;
Rui Guimarães.