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Johannes Kepler

Galileo Galilei

Nicolaus Copernicus

Tycho Brahe

Niels Bohr

Lagrange, Joseph Louis

Gottfried von Leibniz

Max Planck

Isaac Newton

History

The Greeks, and Aristotle in particular, were the first to propose that there are abstract principles governing nature.

One of the first scientists who suggested abstract laws was Galileo Galilei who may have performed the famous experiment of dropping two cannon balls from the tower of Pisa. (The theory and the practice showed that they both hit the ground at the same time.) Though the reality of this experiment is disputed, he did carry out quantitative experiments by rolling balls on an inclined plane; his correct theory of accelerated motion was apparently derived from the results of the experiments.

Sir Isaac Newton was the first to propose the three laws of motion (the law of inertia, his second law mentioned above, and the law of action and reaction), and to prove that these laws govern both everyday objects and celestial objects.

Newton also developed the calculus which is necessary to perform the mathematical calculations involved in classical mechanics. However it was Gottfried Leibniz who developed the notation of the derivative and integral which are used to this day.

Timeline of classical mechanics

• 260 BC - Archimedes mathematically works out the principle of the lever and discovers the principle of buoyancy
• 60 - Hero of Alexandria writes Metrica, Mechanics, and Pneumatics
• 1490 - Leonardo da Vinci describes capillary action
• 1581 - Galileo Galilei notices the timekeeping property of the pendulum
• 1589 - Galileo Galilei uses balls rolling on inclined planes to show that different weights fall with the same acceleration
• 1638 - Galileo Galilei publishes Dialogues Concerning Two New Sciences
• 1658 - Christian Huygens experimentally discovers that balls placed anywhere in side an inverted cycloid reach the lowest
• point of the cycloid in the same time and thereby experimentally shows that the cycloid is the isochrone
• 1668 - John Wallis suggests the law of conservation of momentum
• 1687 - Isaac Newton publishes his Principia Mathematica
• 1690 - James Bernoulli shows that the cycloid is the solution to the isochrone problem
• 1691 - Johann Bernoulli shows that a chain freely suspended from two points will form a catenary
• 1691 - James Bernoulli shows that the catenary curve has the lowest center of gravity that any chain hung from two fixed points can have
• 1696 - Johann Bernoulli shows that the cycloid is the solution to the brachistochrone problem
• 1714 - Brook Taylor derives the fundamental frequency of a stretched vibrating string in terms of its tension and mass per unit length by solving an ordinary differential equation
• 1733 - Daniel Bernoulli derives the fundamental frequency and harmonics of a hanging chain by solving an ordinary differential equation
• 1734 - Daniel Bernoulli solves the ordinary differental equation for the vibrations of an elastic bar clamped at one end 1738 - Daniel Bernoulli examines fluid flow in Hydrodynamica
• 1739 - Leonhard Euler solves the ordinary differential equation for a forced harmonic oscillator and notices the resonance phenomenon
• 1742 - Colin Maclaurin discovers his uniformly rotating self-gravitating spheroids
• 1747 - Pierre Louis Maupertuis applies minimum principles to mechanics
• 1759 - Leonhard Euler solves the partial differential equation for the vibration of a rectangular drum
• 1764 - Leonhard Euler examines the partial differential equation for the vibration of a circular drum and finds one of the Bessel function solutions
• 1788- Joseph Louis Lagrange presents Lagrange's equations of motion in Mecanique Analytique
• 1789 - Antoine Lavoisier states the law of conservation of mass
• 1821 - William Hamilton begins his analysis of Hamilton's characteristic function
• 1834 - Carl Jacobi discovers his uniformly rotating self-gravitating ellipsoids
• 1834 - John Russell observes a nondecaying solitary water wave (soliton) in the Union Canal near Edinburgh and uses a water tank to study the dependence of solitary water wave velocities on wave amplitude and water depth
• 1835 - William Hamilton states Hamilton's canonical equations of motion
• 1835 - Gaspard Coriolis examines motion on a spinning surface deduces the Coriolis effect
• 1842 - Christian Doppler examines the Doppler shift of sound
• 1847 - Hermann von Helmholtz formally states the law of conservation of energy
• 1851 - Leon Foucault shows the Earth's rotation with a huge pendulum (Foucault pendulum)
• 1902 - James Jeans finds the length scale required for gravitational perturbations to grow in a static nearly homogeneous medium

Overview

In physics, Classical mechanics is one of the two major sub-fields of study in the science of mechanics, which is concerned with the motions of bodies, and the forces that cause them. The other sub-field is quantum mechanics. Roughly speaking, classical mechanics was developed in the 400 years since the groundbreaking works of Brahe, Kepler, and Galilei, while quantum mechanics developed within the last 100 years, starting with similarly decisive discoveries by Planck, Einstein, and Bohr.

The notion of “classical“ may be somewhat confusing, insofar as this term usually refers to the era of classical antiquity in European history. While many discoveries within the mathematics of that period remain in full force today, and of the greatest use, the same cannot be said about its "science". This in no way belittles the many important developments, especially within technology, which took place in antiquity and during the Middle Ages in Europe and elsewhere.

However, the emergence of classical mechanics was a decisive stage in the development of science, in the modern sense of the term. What characterizes it, above all, is its insistence on mathematics (rather than speculation), and its reliance on experiment (rather than observation). With classical mechanics it was established how to formulate quantitative predictions in theory, and how to test them by carefully designed measurement. The emerging globally cooperative endeavor increasingly provided for much closer scrutiny and testing, both of theory and experiment. This was, and remains, a key factor in establishing certain knowledge, and in bringing it to the service of society. History shows how closely the health and wealth of a society depends on nurturing this investigative and critical approach.

The initial stage in the development of classical mechanics is often referred to as Newtonian mechanics, and is characterized by the mathematical methods invented by Newton himself, in parallel with Leibniz, and others. This is further described in the following sections. More abstract, and general methods include Lagrangean mechanics and Hamiltonian mechanics.

Classical mechanics produces very accurate results within the domain of everyday experience. It is enhanced by special relativity for objects moving with large velocity, near the speed of light. Classical mechanics is used to describe the motion of human-sized objects, from projectiles to parts of machinery, as well as astronomical objects, such as spacecraft, planets, stars, and galaxies, and even microscopic objects such as large molecules. Besides this, many specialties exist, dealing with gases, liquids, and solids, and so on. It is one of the largest subjects in science and technology.

Although classical mechanics is largely compatible with other "classical" theories such as classical electrodynamics and thermodynamics, some difficulties were discovered in the late 19th century that can only be resolved by more modern physics. When combined with classical thermodynamics, classical mechanics leads to the Gibbs paradox in which entropy is not a well-defined quantity and to the ultraviolet catastrophe in which a black body is predicted to emit infinite amounts of energy. The effort at resolving these problems led to the development of quantum mechanics.