Answer:
You can do many easy science projects.
You could test which cleaner works best by getting filthy water, looking at it through a microscope, then putting each cleaner in different drops of the water, and look through the microscope again.
If you have pets, you can find where they like to mark their territory.
You can test how people perform in sports with different light settings on.
You can see how different colors affect one's mood.
Just try anything, because anything works.