Natural sciences are one of the three major divisions of science, the other two being the social sciences and the formal sciences. Chemistry, biology, earth science, astronomy, and physics are all part of natural sciences. There are also cross-disciplines, such as biophysics, which integrate different aspects of multiple subjects. Prior to the 17th century, these disciplines were often referred to as "natural philosophy" and lacked the types of experiments and procedures used today.
Much of what defines modern civilization comes from advances in knowledge and technology caused by investigations in the natural sciences and chemistry. For instance, the modern production of food can be traced back to the Haber-Bosch process which was developed during World War I. This chemical process allows the creation of fertilizer nitrates from atmospheric nitrogen, rather than relying on biologically fixed sources of nitrogen such as cow dung, significantly increasing the amount of food various countries produce.
Biology and Medicine
Thanks to developments in biology, especially those in the 20th Century, doctors can use advanced medicines to cure or treat many diseases that were previously fatal. Through research in biology and medicine, scourges of the 19th century and before, such as plague and smallpox, have come largely under control. Perhaps more importantly, mortality rates for infants and mothers in industrialized nations have drastically decreased. The biological subfield of genetics has even allowed scientists to understand the very code of life itself, and recognize the way it expresses itself within each person.
Advances in earth science have allowed mankind to extract huge amounts of minerals and petroleum from the Earth’s crust, powering the engines of modern civilization and industry. Paleontology, a subfield of earth science, provides a window into the Earth’s distant past, long before humans even existed. Through discoveries in geology and similar fields within the natural sciences, scientists are better able to understand the history of the planet and predict changes it may go through in the future.
Astronomy and Physics
Physics is, in many respects, the science that underlies all other natural sciences, and offered some of the most unexpected revelations of the 20th century. Among the most notable of these was the discovery that matter and energy are constant, and merely transfer from one state to the other. Through astronomy, scientists have discovered an enormous amount of information about the universe. In previous centuries, it was thought that the entire universe was just the Milky Way galaxy, until a series of debates and observations in the 20th Century revealed that the universe is literally millions of times bigger than previously imagined.
Different Types of Science
The establishment of the scientific method in the 1600s, and the ensuing scientific revolution, helped create modern science. Natural sciences are often referred to as “hard science” because of the heavy use of objective data and quantitative methods that rely on numbers and mathematics. In contrast, the social sciences, such as psychology, sociology and anthropology, rely more on qualitative, or non-numeric, evaluations and tend to have less-certain conclusions. The formal sciences, including mathematics and statistics, are heavily quantitative in nature, but do not typically involve the study of natural phenomenon or experimentation.