Test the effectiveness of various fertilizers and try to pinpoint which chemicals may be responsible for the different results. Buy several different types of fertilizer and analyze their chemical content. Write down the elements of each chemical. Plant seeds in individual containers. Water each container every day at the same time with the same amount. Watch the growth of your plants. Examine the different chemicals in the fertilizer and note which chemicals are most common in the most effective fertilizers.
Study sociological patterns with this simple experiment. Place two unlabeled plates of food or drink on the table. State that one of the foods is fat free while the other is normal. Use the exact same food on each plate. Make sure that taste testers know which is the supposed fat free food. Let the first person do the taste test and make her decision. Make sure that everybody around the experiment can hear which sample she prefers. Take note of how many people agree with her and how many disagree. See if the sample chosen first becomes the most popular sample. Keep track of who prefers the supposed regular version as well as people may choose it simply because they think its the non-fat free food.
Test how different colors effect the growth of plants. Pick a few flowers of the same type and let them grow using the same conditions. Take them out of the dirt, including the roots and place them in a glass of dyed water. The water will be absorbed into the plant, changing its color. Replant the plants and place them in sunlight. Chart their growth speed from day to day. Re-color the plants if their colors begin to fade.
Test the immediate effects that smoking has on different aspects of the human body. Write a hypothesis stating how you think a person's vital signs change after smoking. Pay five smokers not to smoke for at least six hours before the experiment. Use a thermometer to take their temperature. Use a blood pressure monitor to get their pulse rate and blood pressure. Let the smokers smoke a cigarette. Immediately retake their vital signs. Repeat this process every day for a month or longer. Create a large chart that illustrates the way their vital signs change after each cigarette smoked. Use information from your textbooks or from research articles to write a paper discussing how these altered vital signs could impact the body over a long period of time.