A friend of mine sent me these pictures showing multiple shadows

  • Context: High School 
  • Thread starter Thread starter merlyn
  • Start date Start date
  • Tags Tags
    Multiple Pictures
Click For Summary

Discussion Overview

The discussion revolves around the phenomenon of multiple shadows observed in pictures taken during an overcast day. Participants explore potential explanations for the presence of three distinct shadows, considering factors such as light diffusion and reflection.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • Drforbin hypothesizes that the overcast conditions diffuse light, causing scattering and resulting in multiple shadows due to non-parallel photons.
  • Another participant suggests that one shadow may be due to sunlight shining more brightly through the clouds, while a second shadow could be caused by light being scattered or reflected by the clouds in the opposite direction from the Sun.
  • Some participants agree with the idea that one shadow is from the Sun and another from a discrete cloud reflecting sunlight, noting the well-defined edges of the shadows.
  • There is a consideration that the appearance of the shadows may be influenced by the perspective of the camera, which could make edges appear sharper than they are.

Areas of Agreement / Disagreement

Participants express various hypotheses regarding the cause of the multiple shadows, with some agreeing on certain points while others propose alternative explanations. The discussion remains unresolved as multiple competing views are presented.

Contextual Notes

Participants note the importance of camera angle and perspective in interpreting the shadows, suggesting that additional information could clarify the situation.

merlyn
Messages
23
Reaction score
4
TL;DR
A friend of mine sent me these pictures showing multiple shadows
A friend of mine send me these pictures showing three shadows during the day.
The time of day was approx 11:45 and it was overcast. He asked me what was causing this effect.
Basically you see three shadows. My hypothesis is that the overcast is diffusing the light causing scattering and the photons are not all parallel, due to this there are multiple shadows. What do you all think?

Drforbin.
 

Attachments

  • IMG_0249.jpg
    IMG_0249.jpg
    38.2 KB · Views: 165
  • IMG_0249.jpg
    IMG_0249.jpg
    38.2 KB · Views: 153
  • vlcsnap-2022-07-08-11h12m32s932.png
    vlcsnap-2022-07-08-11h12m32s932.png
    7.6 KB · Views: 140
Last edited:
Science news on Phys.org
To guess, I'd say that one shadow is caused by the Sun shining somewhat more brightly through the overcast clouds than the scattered light. The 2nd is probably caused by light being scattered/reflected by the clouds preferentially back in the opposite direction from the Sun.
 
Agree with Drakkith.

At first I thought perhaps it was just one big diffuse-edged shadow with the whole sky as the light source. But the edges of the shadows in the pic are quite well-defined, not diffuse.

So I'd say one shadow is for the sun and the other shadow is from a large, discrete cloud that is efficiently reflecting the sun back.

It's kind of a pity that merlyn's friend didn't just angle the camera upward, and then he wouldn't be guessing - and neither would we.
 
I agree... especially as the vehicles are not in direct sunlight. This is indicated by the shadow-line on the grass median near the bridge.
 
DaveC426913 said:
At first I thought perhaps it was just one big diffuse-edged shadow with the whole sky as the light source. But the edges of the shadows in the pic are quite well-defined, not diffuse.
They look well-defined. But we are looking an extremely fore-shortened image of a long object. This would naturally make a fuzzy edge appear sharper.
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 40 ·
2
Replies
40
Views
5K
  • · Replies 0 ·
Replies
0
Views
3K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 25 ·
Replies
25
Views
5K
  • · Replies 5 ·
Replies
5
Views
4K
  • · Replies 22 ·
Replies
22
Views
4K
Replies
3
Views
2K