Seeing Merging Shadows in the Sunlight

[Vibhu]

Today when I was standing beside a container in sunlight I observed that the shadow of my hand merged at a certain distance with of the container even though their was enough distance between my hand and container for light to pass is there a reason?

 

[sysprog]

Yes, there's a reason. If you consider a sundial, you'll recognize that the shadow cast by the gnomon depends on the angle of the gnomon relative to the light source, i.e. the sun, which depends on the time of day.

If a small bird were to alight on the III in the illustration, none of its shadow would be merged with that of the gnomon, but if it were to alight on the IX, almost all of its shadow would be merged with that of the gnomon, and the distance from the gnomon of the III and the IX is about the same.

 

[DrClaude]

Or it may be the shadow blister effect.

 

[Vibhu]

Yes, there's a reason. If you consider a sundial, you'll recognize that the shadow cast by the gnomon depends on the angle of the gnomon relative to the light source, i.e. the sun, which depends on the time of day.

View attachment 241378

If a small bird were to alight on the III in the illustration, none of its shadow would be merged with that of the gnomon, but if it were to alight on the IX, almost all of its shadow would be merged with that of the gnomon, and the distance from the gnomon of the III and the IX is about the same.

It looked like the Shadows were attracting each other after a certain distance each time I did it. Thank you for this explanation but I don't think it is correctly defining it.

 

[Vibhu]

Or it may be the shadow blister effect.

Also not this one, I read this one and was very knowledgeable.

 

[sysprog]

It looked like the Shadows were attracting each other after a certain distance each time I did it. Thank you for this explanation but I don't think it is correctly defining it.

That seems more like the shadow blister effect phenomenon to which @DrClaude alluded, but given that you disclaim that, perhaps you could provide a more detailed description.