Science (from the Latin word scientia, meaning "knowledge") is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe.
The earliest roots of science can be traced to Ancient Egypt and Mesopotamia in around 3500 to 3000 BCE. Their contributions to mathematics, astronomy, and medicine entered and shaped Greek natural philosophy of classical antiquity, whereby formal attempts were made to provide explanations of events in the physical world based on natural causes. After the fall of the Western Roman Empire, knowledge of Greek conceptions of the world deteriorated in Western Europe during the early centuries (400 to 1000 CE) of the Middle Ages but was preserved in the Muslim world during the Islamic Golden Age. The recovery and assimilation of Greek works and Islamic inquiries into Western Europe from the 10th to 13th century revived "natural philosophy", which was later transformed by the Scientific Revolution that began in the 16th century as new ideas and discoveries departed from previous Greek conceptions and traditions. The scientific method soon played a greater role in knowledge creation and it was not until the 19th century that many of the institutional and professional features of science began to take shape; along with the changing from "natural philosophy" to the "natural sciences".
Modern science is typically divided into three major branches that consist of the natural sciences (e.g., biology, chemistry, and physics), which study nature in the broadest sense; the social sciences (e.g., economics, psychology, and sociology), which study individuals and societies; and the formal sciences (e.g., logic, mathematics, and theoretical computer science), which study abstract concepts. There is disagreement, however, on whether the formal sciences actually constitute a science as they do not rely on empirical evidence. Disciplines that use existing scientific knowledge for practical purposes, such as engineering and medicine, are described as applied sciences.
Science is based on research, which is commonly conducted in academic and research institutions as well as in government agencies and companies. The practical impact of scientific research has led to the emergence of science policies that seek to influence the scientific enterprise by prioritizing the development of commercial products, armaments, health care, and environmental protection.
is the study of the rates
of chemical reactions
that are catalysed
. The study of an enzyme's kinetics
provides insights into the catalytic mechanism of this enzyme, its role in metabolism
, how its activity is controlled in the cell
and how drugs
Enzymes are molecules that manipulate other molecules — the enzymes' substrates. These target molecules bind to an enzyme's active site and are transformed into products through a series of steps known as the enzymatic mechanism. Some enzymes bind multiple substrates and/or release multiple products, such as a protease cleaving one protein substrate into two polypeptide products. Others join substrates together, such as DNA polymerase linking a nucleotide to DNA. Although these mechanisms are often a complex series of steps, there is typically one rate-determining step that determines the overall kinetics. This rate-determining step may be a chemical reaction or a conformational change of the enzyme or substrates, such as those involved in the release of product(s) from the enzyme.
Richard Phillips Feynman
(May 11, 1918 – February 15, 1988) was one of the most influential American physicists of the 20th century, expanding greatly upon the theory of quantum electrodynamics
. As well as being an inspiring lecturer and amateur musician, also later he became a member of the panel which investigated the Space Shuttle Challenger disaster
. For his work on quantum electrodynamics, Feynman was one of the recipients of the Nobel Prize in Physics
in 1965, along with Julian Schwinger
and Shin-Ichiro Tomonaga
Feynman was a keen and influential popularizer of physics in both his books and lectures. He is famous for his many adventures, detailed in the books Surely You're Joking, Mr. Feynman!, What Do You Care What Other People Think? and Tuva or Bust!. Posthumously, Feynman is often credited with helping catalyze the field of nanotechnology through his December 1959 talk called There's Plenty of Room at the Bottom. Richard Feynman was, in many respects, an eccentric and a free spirit.
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