The Doodles and Jots gang had a big night out at the 99 the other night and as we were walking through the parking lot headed into the restaurant the sky looked like this…
Then we had our fill of food and fun (including seconds and thirds on popcorn to start and ending with our petite treats) and as we were leaving the sky looked like this.
It gets so dark so early now but what really caught my interest was that the second sky was like a negative image of the first.
It reminded me of afterimages. Do you want to know what a color’s compliment is? To find out you can look at a color wheel OR you can stare at a large swatch of it then look at something white and the compliment will appear as an after image. Pretty neat! Here, try this one. Stare at this crazy sky (focus on the gray dot) for about 30 seconds and then see what appears in the white square…
Do you see a pretty pink sunset? Fun right?!
These images are also called ghost images. So, try this one…
What causes a negative afterimage?
A simple way to explain it is like this. As you are looking at a large area of color for a long time your eye’s photoreceptors for that color get over stimulated. So if you then look at a white area those tired receptors send out a very weak signal while the receptors for the opposite color are ready to go and send out a regular strength signal. For more from Wikipedia click here.
Not done with afterimages yet? Check this fun book by Eric Carle!
It’s Little Frog’s birthday, and Mama Frog gets a big surprise when the guests show up for his party — all the animals are the wrong color! Little Frog tells her she’s not looking long enough, and he’s right (Amazon description).
And for more on how the eye works check out the “Brain and Senses” section at the Children’s University of Manchester site, a super cool sciency site!
Today’s question… I am very fascinated by eyesight! In an other life I think I would like to be an Optomotrist. What would you be? Please share!