Natural science

The natural sciences are those branches of science that seek to elucidate the rules that govern the natural world through scientific methods.[1] The term "natural science" is used to distinguish the subject from the social sciences, which apply the scientific method to study human behavior and social patterns; the humanities, which use a critical or analytical approach to study the human condition; and the formal sciences such as mathematics and logic, which use an a priori, as opposed to factual methodology to study formal systems. Overview There are five branches of natural science: astronomy, biology, chemistry, the Earth sciences and physics.[2][3] This distinguishes sciences that cover inquiry into the world of nature from human sciences such as anthropology, sociology and linguistics, and from formal sciences such as mathematics and logic.[2] Despite their differences, these sciences sometimes overlap; the social sciences and biology both study human beings as organisms, for example, and mathematics is used regularly in all the natural sciences.[2] The natural sciences are among the basic sciences, or scientific fields where study is motivated purely by curiosity.[4] They also form the basis for applied sciences, however, which find real-world, practical applications for concepts and methods developed in basic science.[5] In academic contexts, the natural and applied sciences are distinguished from the social sciences on the one hand, and the humanities on the other.[6] Not all institutions and scientists are in agreement, however, about the classification of sciences and other academic disciplines.[7] Alongside its traditional usage, natural science may encompass natural history, which emerged in the 16th century and focused on the description and classification of plants, animals, minerals and other natural objects.[8] Today, natural history refers to observational descriptions of the natural world aimed at popular audiences rather than an academic ones.[9] The natural sciences are sometimes referred to colloquially as hard science, or fields seen as relying on experimental, quantifiable data or the scientific method and focusing on accuracy and objectivity.[10] These usually include physics, chemistry and biology.[10] By contrast, soft science is used a as a pejorative term to describe fields more reliant on qualitative research, including the social sciences. Some scholars trace the origins of natural science as far back as pre-literate human societies, where understanding the natural world was necessary for survival.[11] People observed and built up knowledge about the behavior of animals and the usefulness of plants as food and medicine, which was passed down from generation to generation.[11] These primitive understandings gave way to mo

e formalized inquiry around 3,500 to 3,000 B.C. in Mesopotamian and Ancient Egyptian cultures, which produced the first known written evidence of natural philosophy, the precursor of natural science.[12] While the writings show an interest in astronomy, mathematics and other aspects of the physical world, the ultimate aim of inquiry about nature's workings was in all cases religious or mythological, not scientific.[13] A tradition of scientific inquiry also emerged in Ancient China, where Taoist alchemists and philosophers experimented with elixirs to extend life and cure ailments.[14] They focused on the yin and yang, or contrasting elements in nature; the yin was associated with femininity and coldness, while yang was associated with masculinity and warmth.[15] The five phases fire, earth, metal, wood and water described a cycle of transformations in nature. Water turned into wood, which turned into fire when it burned. The ashes left by fire were earth.[16] Using these principles, Chinese philosophers and doctors explored human anatomy, characterizing organs as predominantly yin or yang; they understood the relationship between the pulse, the heart and the flow of blood in the body centuries before it became accepted in the West.[17] Little evidence survives of how Ancient Indian cultures around the Indus River understood nature, but some of their perspectives may be reflected in the Vedas, a set of sacred Hindu texts.[17] They reveal a conception of the universe as ever-expanding and constantly being recycled and reformed.[17] Surgeons in the Ayurvedic tradition saw health and illness as a combination of three humors: wind, bile and phlegm.[17] A healthy life was the result of a balance between these humors.[17] In Ayurvedic thought, the body consisted of five elements: earth, water, fire, wind and empty space.[17] Ayurvedic surgeons performed complex surgeries and developed a detailed understanding of human anatomy.[17] Pre-Socratic philosophers in Ancient Greek culture brought natural philosophy a step closer to direct inquiry about cause and effect in nature between 600 and 400 B.C., although an element of magic and mythology remained.[18] Natural phenomena such as earthquakes and eclipses were explained increasingly in the context of nature itself instead of being attributed to angry gods.[18] Thales of Miletus, an early philosopher who lived from 625 to 546 B.C., explained earthquakes by theorizing that the world floated on water and that water was the fundamental element in nature.[19] In the fifth century B.C., Leucippus was an early exponent of atomism, the idea that the world is made up of fundamental indivisible particles.[20] Pythagoras applied Greek innovations in mathematics to astronomy, and suggested that the earth was spherical.