What causes shadows?
Do you remember the work you did last year?
A post in the ground with a shadow.
What causes the shadow?
Yep it's the sun.
The object in the middle of the
picture gets in the way of the sun's rays and the thing we call a shadow
is formed. The sun's light cannot reach the piece of ground that is in
the shadow of the object.
Do shadows stay the same during the day?
Have you ever drawn a shadow picture to show
the
different lengths and positions of the
shadows during the day?
You should try it.
But what does this tell us about the
movement of
the sun and the earth?
Take a look at the animation on this page.
How would you explain the changing position of the sun and shape of the shadow?
Is it the sun moving or the earth rotating?
The sun rises, the sun sets, the sun rises high in the sky,
all these sayings suggest it is the sun moving around the earth.
Can we trust the direct evidence?
In fact it's the earth rotating that causes it to
look
as if the sun is rising and setting.
You just can't trust the evidence
in
front of your eyes sometimes.
Investigating Shadows
From the Children's University of Manchester
