The answer to your question involves energy.
Energy comes in a lot of forms, including light
and heat. Energy can change forms. The energy
from the sun comes to us as light, but it can
Light can be reflected or
bounced back to where it came from. That's
reflection and mirrors can do it.
can pass right through things like glass. That's
Light can be bent by
things it passes through. Have you ever reached
into a fish tank and noticed that things weren't
where you expected them to be? That's because the
light is being bent (refracted).
be absorbed. If you put an object in front of a
strong light,it will heat up. That's because the
light energy has changed into heat energy. Heat
is basically a form of light, but it has less
energy than the light we can see. NASA has a site
about heat at:about_heat
It may be a little hard to understand, but has
great heat pictures.
Back to your question,
getting through our atmosphere requires
energy.Light, which has a lot of energy, so lots
of it passes through our atmosphere. Then some of
the light may be bounced back out (reflected). But
some of it is absorbed by many things, such as the
ground, water,trees, buildings, even you. It
becomes heat. Heat has less energy than light, so
it has a harder time getting back through the
atmosphere.Some of it is trapped here.
site has a nice picture of what happens to light
as it enters and leaves our atmosphere:click_here
you don't believe that light can turn into heat,
don't take my word for it. Have an adult help you
with an experiment.
Fill 3 clear cups with
water. Wrap one in foil, shiny side out. Wrap
one in black paper.Leave one unwrapped or wrap it
in clear plastic. Now shine a strong lamp on all
three (it may take a while, depending on the
light). Which water will get warmer? Hint: Which
one is absorbing energy? Which one is throwing
energy back where it came from? Which one is
letting energy pass through it? Make sure you get
help with this so that you don't get hurt by the
hot lamp or start a fire.Thanks for asking,