Why do shadows change shape when light is shone on them?

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In summary, the conversation discusses the observation of shadows and light spreading. The speaker asks whether the light spreads or not and how it affects the shape of the shadow. The discussion also touches on how light can be observed from different angles and mentions the concepts of Umbra and Penumbra.
  • #1
danielhaish
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if you put a light on object you will see shadow in the shape of the object . it would looks like the following picture
ss.png

the blue part is the object.
but if you point a laser or light on specific object you will be able to observe it from differences angles like in the following picture
ss2.png

the black circles are quemen eyes and the red point is leaser .
so my question is whether the light spreading or not because if it does spread i would expect the shadow shape to looks like that
ss3.png

but if it doesn't the light would return only to one angle
 
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  • #2
danielhaish said:
my question is whether the light spreading or not because if it does spread i would expect the shadow shape to looks like that
Harsh-Light-iPhone-Street-Photos-39.jpg
 
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  • #3
Dale said:
Harsh-Light-iPhone-Street-Photos-39.jpg
this exactly my point we can see that the light stay in sharp shape but we can observe it from other angles how the lights get to other angles
 
  • #4
danielhaish said:
this exactly my point we can see that the light stay in sharp shape but we can observe it from other angles how the lights get to other angles
The light gets to other angles by reflection.
 
  • #5
danielhaish said:
so my question is whether the light spreading or not
Sometimes it does, and sometimes the rays are almost parallel.
 
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  • #6
Not many natural light sources are points so the light does not all come from exactly the same direction. So the shadow will get more and more blurred as you get closer. Look up Umbra and Penumbra to see things like shadow softening and what you can really see during an eclipse.
Edit: BEG your pardon - the fuzz gets worse as you get further away. If the Moon went way beyond its present distance, (from us) our umbra would be so small that we would never get a total lunar eclipse. The Sun is so much bigger than us.
 
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1. Why do shadows appear to change shape?

Shadows appear to change shape because they are created when an object blocks light from reaching a surface. As the position and angle of the light source changes, the shadow will also change shape.

2. What causes shadows to change shape when light is shone on them?

The shape of a shadow changes when light is shone on it because the light source is no longer directly behind the object. This causes the shadow to stretch or shrink depending on the angle of the light.

3. How does the distance between the light source and object affect the shape of a shadow?

The distance between the light source and object can greatly affect the shape of a shadow. The closer the light source is to the object, the sharper and more defined the shadow will be. As the distance increases, the shadow will become larger and more diffuse.

4. Can the shape of a shadow be manipulated?

Yes, the shape of a shadow can be manipulated by changing the position or angle of the light source, or by altering the object blocking the light. For example, using a different object or changing the shape of the object can result in a different shadow shape.

5. Why do shadows change size and shape throughout the day?

Shadows change size and shape throughout the day because the position and angle of the sun changes as it moves across the sky. This causes the direction of the light to change, resulting in different shadow shapes and sizes at different times of the day.

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