I used to be a champion of the science fair. Here's how they went in grammar school:
Third Grade: "How Electricity Gets to your House." Excellent display of Legos, LEDs, and a large dry cell. First place. Girl next to me got so jealous, she put my 1st place ribbon in her exhibit: "The Hamster." The hamster crewed up the edges of my ribbon, which pissed me off.
Fourth Grade: "The Effects of Noise on Plant Life." This was my "Mythbusters" sort of attempt at debunking how noise affected plant life, because at the time (1970s) people were all about talking to plants. My plants were subjected to voice, classical music, rock music, and nothing at all. Discovery: Nothing at all did the best. To be fair, this was not very accurate since each plant grew in a different area of my house, which probably affected light and water, but I didn't think back on that until I was an adult. First place. I recall that this was the year that a girl named Kate (a foreign student from Britain) did one on the Bernoulli effect (what makes airplane wings work with air pressure). Her set up was museum-quality, but she got disqualified because it was really obvious her father helped her. I recall her father arguing with the judges about it, but they stayed firm, and Kate had a crying fit. They still didn't let her win.
Fifth Grade: "The Solar System and the Life of Stars." This was one of those lessons in flaky people. I had a friend named Eric at the time. Eric was my partner, and this was my first foray into doing the fair with a second person. He showed up the first few times to the library, and then the rest of the time, he didn't show, and eventually, I had to do the whole thing myself. He didn't show up to the science fair, either. Apparently he forgot to tell his mom, despite numerous reminders about the fair and library visits. We got first place only because we were the ONLY "pair" that showed up in that category, even though I was the only one there. I told the judges Eric was running late, but they didn't seem to care too much. I liked my black hole, which was a 10 cent superball painted black. The Red Giant was a large foam ball a little larger than a basketball. Obviously, scale was not an issue I paid much attention to. I'll never forget telling him we won first place by default the next day, and he said, "First place in what?" My mother said Eric didn't deserve the second ribbon, but I gave it to him anyway.
Sixth Grade: "Crime Detection: Ballistics and Arson Investigation." Done with my best friend Neal. First place. He showed up to library AND the science fair. Thank you, Neal. I got the burnt log from Neal's fireplace, too. But I was kind of a pyro at the time...
Seventh Grade: "Tachyonic and Tardionic Particles: Theories of Missing Matter and FTL Travel." I remember this bitterly. When I signed up for the fair, I saw what I was up against, and it was very sophisticated. You had people doing huge-scale soil sampling, sine wave analysis on voice harmonics, and predictability on cross-breeding via pollination. Heady stuff. So I decided to tackle the question, "Is FTL (faster than light) travel possible?" In the study, I found that most scientists had recently found that the universe's mass was not wholly accounted for. So I bridged on this by showing what I thought was possible with tachyonic (faster than light) particles, and showed how my theory worked, using various graphs of mass and energy (part of the theory involved going backwards in time). I was disqualified at the submittal for fair approval, and told to "stay away from comic books." My mother said I should have fought this one, but I was pretty unmotivated by the school atmosphere at the time. I never entered a science fair again, although I used the very same thesis (and most of the data, since I saved the bibliography) for my astronomy class many years later, and got a A, which counted toward my final grade. One of the few classes I ever aced an A average.
I wonder why adults don't do science fairs? We really should. It would be kind of fun to see what people would test in the name of science... "Beer: The Effects of Drunkeness on Social Confidence."
What science project would you do?