A few weeks ago, Keri participated in her first ever Science Fair which was hosted by her elementary school.
This project was to be done entirely at home and the students had two months to work on it. The main requirement was the experiment needed to be an investigative one as opposed to a project that would merely yield a yes or no answer. I know how time consuming things like this can be, but thankfully Keri managed her time relatively well (with some reminders and gentle prodding from her parents) so things never got too ominous.
I must admit I was pretty excited for Keri to learn and better understand (and appreciate!) the steps of the scientific method. Yes, the former Biology Teacher in me was coming out. Interestingly enough, I did a blog post on the Steps of the Scientific Method back in May of 2007. That post has had nearly 12,000 hits and it is the 5th most popular post on my blog. Who would have known?!
Randy, with his science and engineering background, was also looking forward to helping Keri with her project. They spent some quality time together … and had fun in the process … while researching a lot of topics. She finally settled on the topic of eye cone cells and afterimages.
Perhaps the highlights of this whole process were: 1) seeing how satisfied she felt with the finished project and all the hard work she put into it and 2) seeing her at the actual Science Fair interacting with students and parents, explaining what her project was all about and answering their questions. She seemed to be completely in her element. She is definitely a people person. We are very proud of her!
And because some people were asking for more details, here are some excerpts from the write up of her experiment:
Chaotic and Confusing Cone Cells
Purpose and Background
I once looked up at a new light bulb in the kitchen for about two seconds. I then looked up at the white ceiling and blinked. On the ceiling I saw a bluish, purplish color in the same shape as the light bulb. Every time this happens to me I wonder how and why the color of a white surface changes when I look at a light. After doing some research with my Dad, I found out that eye cone cells can get fatigued and then they can’t give a proper signal to the brain. Instead, you see an afterimage of a different color. You won’t see the real color again until your cone cells regain their strength.
Will the color of the afterimage change to blue, red, green, or a combination depending on which of your three cone cells is fatigued?
I predict that if the blue cone cells are fatigued, then the afterimage will be red, green, or a combination of the two colors on a white surface. If red cone cells are fatigued, then the afterimage will be blue, green or a combination on a white surface. If the green cone cells are fatigued, then the afterimage will be blue, red, or a combination of the colors on a white surface.
My hypothesis was partly supported. The color I saw when I fatigued the blue cone cells was a pinkish, salmon color. When I fatigued the red cells I saw a sky blue. I saw a purplish, magenta color when I fatigued the green cone cells.
My hypothesis was supported because the color that I stared at had an intensity on the RGB Color Model of at least 110 (average) less than the other cone cells I didn’t fatigue. However, my hypothesis wasn’t completely supported because the color I fatigued wasn’t entirely tired out. There was still a little bit of the fatigued color in the afterimage. Only five times during the twenty seven trials was the intensity of the fatigued cone cell exactly zero.
The results of my experiment weren’t entirely accurate because our cone cells seem to regain strength pretty quickly. When you look at a white surface to see the afterimage, you blink, which makes the cells regain strength, which affects the results. To make the results more accurate we need a robot or a computer to do the experiment because they wouldn’t blink. Another reason why the results weren’t completely accurate is because I couldn’t always remember the exact color I saw when trying to find its match on the color palette.
Now that I have done my experiment, I have even more questions about light and cone cells. For example, how long does it take for cone cells to regain strength? Another question is what would the afterimage be if you looked at a yellow surface afterwards instead of a white surface? I also wonder what it would be like if we had different colors for our cone cells.