Science Fair ideas

Yea... science fair topics are due pretty soon, i have no idea what i want to do, i plan to major in civil engineering so thats the category id like to do, if anyone has any cool ideas plz bring them up...

all except for the damn mentos and diet coke and a penis volcano

>>4
I thought the braincells just died due to lack of oxygen. I suppose maybe they shrink and the neurons detach or something.