It is all about experimenting but using the scientific process. It is more original to think of your own question than to take something that has been done. In one of my classes I was explaining that plants don't need soil to grow. They can grow in just water. Then one of my students asked if a plant would grow in coke. So we put one plant in water and one in coke. It took several weeks. At first they both grew but after a couple of weeks the plant in coke began to die.