Political science studies forms of government, political parties, pressure groups, elections and other aspects of politics. Psychology involves investigation of mental processes and behavior. Physiological psychologists study how the nerves and the brain work. They use systematic methods to examine people's thoughts, feelings and personality traits. Science is needed by everyone in some way and that is why science is important.
Science is important because of predictions.
If someone knows that something bad will happen, like an earthquake, they could save a lot of lives. There were a lot of predictions about space. Some of them were right and some were wrong. But they tried and they found out about space and the basic planets and how far away they are from earth. Science is all about predictions.