The term science comes from the Latin word scientia, which means “knowing.” It is used to describe a huge group of subjects that deal with the search for knowledge about the universe and all that is in it. Each of these subjects is also separately referred to as a science—for example, the science of physics or the science of chemistry. People involved in science are called scientists. Some scientists study science solely to learn more about a particular subject. These scientists are studying basic, or pure, science. The knowledge they get from their projects may or may not be used in everyday life. Other scientists apply the information from their projects, as well as from pure science, to solve specific problems. These scientists are involved in applied science. Applied science is used in business, industry, and medicine. The branches of scienceScientific subjects can be grouped into three branches: the physical sciences, the life sciences, and the social sciences. Each separate subject can be thought of as belonging to a particular branch, though some sciences may belong to two or more branches at the same time. Physical sciencesThe physical sciences deal with nonliving things—from the tiny particles that make up an atom to the universe itself. They include physics, the study of matter and energy; chemistry, the study of the properties and behavior of substances; astronomy, the study of stars, planets, and other objects in outer space; metallurgy, the study of metals; and engineering, the most important of the applied sciences. Engineering can be broken down into a whole range of related subjects, all of which deal with the application of scientific principles to industry. The Earth sciences form a category within the physical sciences. Their goal is to understand the present features and the past development of the Earth. They include geology, meteorology, mineralogy, oceanography, and paleontology. Geology covers the study of the Earth's structure and includes the study of rocks and rock formation. Meteorology is the study of the Earth's atmosphere and weather. Mineralogy is the study of all aspects of minerals, including their properties, composition, structure, occurrence, and origin. Oceanography is the study of the sea and its currents, waves, and tides. Paleontology is the study of fossils. Mathematics is also considered to be a physical science. Mathematics can be studied for its own sake, but it is also a tool. The mathematical sciences, which include statistics and computing, are constantly used in almost every branch of science. Life sciencesThe life, or biological, sciences deal with living things and their environments. They include biology and medicine. Biology, the study of all living things and their vital processes, is itself broken down into botany, the study of plants, and zoology, the study of animals. Medicine is concerned with the maintenance of health and the prevention and cure of disease. Its different fields include anatomy, pathology, and psychiatry. Anatomy deals with the structure of the human body. Pathology is the study of diseases and the changes they produce in bodily tissues. Psychiatry concerns the diagnosis, treatment, and prevention of mental disorders. Social sciencesThe social sciences deal with aspects of human society and culture. They include sociology, the study of the form or structure of societies; history and archaeology, the studies of human communities in the past; political science, the study of government; geography, the study of the Earth's surface and the relationship of the human race to it; and economics, the study of how a society or country manages its resources and finances. Anthropology is the general study of human beings and the way in which they live and act. Other social sciences include linguistics, the study of language and communications among human beings, and philosophy, the subject dealing with the ways in which human beings try to understand the universe and their experience of it. Overlapping branchesSciences that overlap more than one field often have names that indicate this overlapping. For example, astrophysics is the study of the physical behavior of objects in outer space. Another way of looking at it is to say that astrophysics is the application of physics to the subject of astronomy. In the same way, biochemistry combines biology and chemistry; geophysics combines geology and physics; and socioeconomics combines sociology with economics. The scientific methodScientists believe there is a cause and effect relationship that explains most things. For any problem they encounter they therefore seek to understand the cause in order to be able to come up with a solution. By learning what causes a disease, for example, scientists can work to control its spread. The process that scientists use to find this cause and effect relationship is called the scientific method. The scientific method begins with a problem. Scientists can become interested in a particular problem from reading about it or simply by observing something in nature. They ask questions that begin with “Why does…?”, “How does…?”, or “What determines…?”. Then they read scientific journals and books to find out as much as possible about the problem. They try to find out what other scientists have learned about it. This step is called searching the literature. After learning about the problem, scientists make a hypothesis, or an educated guess, to explain it. They test whether the hypothesis is correct by designing an experiment. The experiment gives the scientist measurements and observations, which are then analyzed. The analysis tells the scientist if the hypothesis was correct. If the hypothesis was incorrect, the scientist can revise it and test it again. If the hypothesis was correct, scientists in other laboratories repeat the experiment to make sure that they get the same results. Scientific results must be repeatable. This means that scientists must get the same results every time they do the experiment. If the results of the other scientists' tests are the same, the scientific community will accept the hypothesis. The hypothesis then becomes a theory—an explanation for why something happens. Theories can be revised if scientists discover new information about the subject. |