SearchResearch Challenge (4/3/24): Solar eclipses and shadows?
Dan Russell
Wednesday, April 3, 2024
I'm sure you've noticed...
... that when you're walking through a group of trees, they cast shadows on the ground, dappling the surface with a lovely pattern of light and shadow.
When I look up into the trees, I can see where the sunlight is coming from, and I'm struck by something: Why are some of the spots of light round when what I see in the trees is not round?
Here's another view of light through trees:
See those gaps? The patches of light projected onto the forest floor are shaped like the openings in the tree canopy... mostly.
But when the holes are small, the projected light is always circular. In the image above, you can see that the large patches of light are soft rectangles, irregular blobs, and triangles with fuzzy edges. When I look up into the tree, I see those rectangles, triangles, and irregular gaps in the tree cover.
But when the hole is small, it always creates a small circular pool of light.
Why?
That's our Challenge for this week. Since there's a solar eclipse that's passing over the center of North America on Monday, April 8, I thought I should understand why the shadows are like that.
 |
| Path of eclipse on April 8, 2024. P/C NASA. I will be standing at the tip of the red arrow on April 8. |
To prepare for the eclipse and the avalanche of shadows, I have a couple of Challenges:
1. Why ARE the dapples of sunlight round in shape? Why isn't the shape of the sun light exactly like the shape of the hole in the tree canopy? Related: Why are only the small patches of light round while the bigger ones are other shapes? Super related: Will the round sun patches change shape during the eclipse?
2. What other solar light phenomena should I be looking for? Are there any other extraordinary shadow and light things I should be looking for?
Of course, all this will happen next Monday--so I hope you post your answers to the blog before then so I'll know what to look for! Tell us how you found your answers.
Keep searching!
(And wear eye protection if you're going to watch the eclipse.)
