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Author Topic: How and why does the length of a shadow change from day to night?  (Read 2094 times)


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junwei asked the Naked Scientists:
How and why does the length of a shadow change from day to night?

What do you think?
« Last Edit: 11/10/2010 15:30:02 by _system »


Offline Soul Surfer

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Other than obvious projective geometry answer related to the elevation of the sun compared with the height of the object  see below.  I see nothing else in this question.  Junewi could you please try to explain in a little more detail why you asked this question.

The length of the shadow cast by vertical pole on the ground is a right angled triangle  with its angle with the (assumed flat) ground equal to the elevation of that object in the sky.  This means that the length of the shadow is equal to the height of the object when the sun is 45 degrees  if the sun is lower the shadow is longer and if it is higher the shadow is shorter becoming zero when the sun is overhead.
« Last Edit: 12/10/2010 19:05:13 by Soul Surfer »

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