Mechanics

Lore & Background

The ancient Greek philosophers were among the first to propose that abstract principles govern nature. The main theory of mechanics in antiquity was Aristotelian mechanics, though an alternative theory is exposed in the pseudo-Aristotelian Mechanical Problems. Another tradition used mathematics to analyze bodies statically or dynamically, with examples including Archimedes (On the Equilibrium of Planes, On Floating Bodies) and Hero (Mechanica). In the Middle Ages, Aristotle's theories were criticized and modified by figures beginning with John Philoponus in the 6th century. The 12th-century Jewish scholar Hibat Allah Abu'l-Barakat al-Baghdaadi said that acceleration of a falling body was a consequence of continuous action of the body's natural inclination. Influenced by these writers, the 14th-century French priest Jean Buridan developed the theory of impetus, which later developed into modern theories of inertia, velocity, acceleration and momentum. Two central figures in the early modern age are Galileo Galilei and Isaac Newton. There is dispute over priority of various ideas, as many concepts had been developed by prior scholars such as Christiaan Huygens and medieval predecessors.

Reader's Guide

Mechanics is foundational to physics, originating in ancient Greek thought and evolving through medieval critiques and early modern mathematical formulations. Its significance lies in providing the framework for understanding motion, forces, and energy, which underpin engineering, astronomy, and much of modern technology. The shift from Aristotelian mechanics to Newtonian mechanics marked a pivotal change, introducing concepts like inertia and acceleration that remain central. In the 20th century, classical mechanics was challenged by relativistic mechanics and quantum mechanics, leading to fundamentally new approaches. The sub-disciplines of mechanics—including Newtonian, analytical, celestial, fluid, solid, and quantum mechanics—cover a vast range of phenomena from planetary orbits to atomic behavior. The development of continuum mechanics in the second half of the 20th century further expanded the field into areas like elasticity, plasticity, and fluid dynamics. Mechanics continues to be essential for both theoretical understanding and practical application, with its principles applied in fields as diverse as biomechanics, astrodynamics, and acoustics.

Did You Know?

• The term 'mechanics' comes from Ancient Greek μηχανική (mēkhanikḗ) meaning 'of machines'.
• Ibn Sīnā argued that a projectile in a vacuum would not stop unless acted upon, consistent with Newton's first law of motion.
• The 14th-century Oxford Calculators studied and formulated various laws regarding falling bodies.
• In quantum mechanics, particles themselves are fields, as described theoretically by the wave function.