I dont think a minecraft forum is the greatest place in the world to be seeking science fair project ideas
I dunno. I think it's a good starting point. Like, how about redstone circuitry? You can create a circuit in game that lights up different redstone lamps depending on which combination of switches are used. That would translate into a rl circuit where you can use multiple switches to power different lights.
All depends on the grade level, tho.
might be good for 4th grade, but not 9th. XD