Mechanics (Greek Μηχανική) is the branch of physics related to the behavior of physical bodies when subjected to forces or displacements, and the aftereffects of the bodies of their environment. The discipline has its roots in several ancient civilizations (see History of classical mechanics and the timeline of classical mechanics). During the modern era, scientists like Galileo, Kepler, Newton and above all, laid the foundation for what is now known as classical mechanics. It is a branch of classical physics that deals with particles that move either with less speed or at rest.
Classical versus quantum
The major division of the mechanics discipline separates classical mechanics from quantum mechanics.
Historically, classical mechanics was first, while quantum mechanics is a relatively recent invention. Classical mechanics originated with Isaac Newton's laws of motion in Principia Mathematica, while quantum mechanics did not appear until 1900. Both are common knowledge to be safer than exists about physical nature. Classical mechanics has often been viewed primarily as a model for other so-called exact sciences. Essential in this regard is the ruthless use of mathematics in the theories and the role played by experience in creating and testing them.
Quantum mechanics is a broader scope, covering classical mechanics as a sub-discipline that applies under certain limited circumstances. According to the correspondence principle, there is no contradiction or conflict between two individuals, each one simply refers to specific situations. The correspondence principle that the behavior of systems described by quantum theories of classical physics plays in the limit of large quantum numbers. Quantum mechanics has replaced classical mechanics at the basic and essential to the explanation and prediction of processes at the atomic and molecular (sub). However, for macroscopic processes classical mechanics is able to solve difficult problems that are unmanageable in quantum mechanics and therefore still useful and well used. Modern descriptions of behavior to begin with a careful definition of quantities such as displacement (distance traveled), time, speed, acceleration, mass and strength. Until about 400 years, however, the movement is explained from a different perspective. For example, following the ideas of Aristotle, Greek philosopher and scientist, scientists reasoned that a cannonball falls because its natural position in the earth, sun, moon and stars travel in circles around the earth, because is the nature of celestial objects to travel in perfect circles.
The Italian physicist and astronomer Galileo brought the ideas of other great thinkers of his time and began to analyze the motion in terms of distance traveled from a starting position and the time it took. Showed that the speed of falling objects increases continuously during the time of his fall. This acceleration is the same for heavy and for light, provided that the air friction (air resistance) is deducted. The English mathematician and physicist Sir Isaac Newton improved this analysis to define the strength and mass and the relative acceleration of these. For objects traveling at speeds approaching the speed of light, Newton's laws have been replaced by Albert Einstein's theory of relativity. For atomic and subatomic particles, Newton's laws have been superseded by quantum theory. Of everyday phenomena, however, Newton's three laws of motion remain the cornerstone of the dynamics, which is the study of what