Classical Mechanics

A branch of physics that deals with the effects of energy and forces on the motion of physical objects, based on the work of Isaac Newton and on three-dimensional Euclidean geometry, also called Newtonian mechanics.

Recall that in classical physics, nature is described as a closed causal system of ‘matter in motion’ and governed by Newton ’s deterministic equations of motion. This means that the future is, in principle, entirely predictable as long as we know all the forces acting on a system and if we obtain an exact knowledge of its initial conditions. This view, rooted in classical physics, was carried over and applied to all macroscopic systems in nature, including those described by thermodynamics, geology, meteorology, evolutionary biology, and even those now studied using chaos theory. Chance events occur in all these fields, but the notion of chance here is purely epistemic, the ignorance of underlying causes. There are two distinct kinds of ‘epistemic chance’: i) Random walk: Individual events can occur along a given trajectory, from the motion of microscopic plankton to tossing a coin. ii) Crossed trajectories: Epistemic chance also denotes the juxtaposition of two apparently unrelated causal trajectories, such as a car crash or the combination of a genetic mutation expressed in a phenotype and the adaptivity of that phenotype to a changing environment. In either case, even when statistical methods are used, they are used for practical purposes and do not indicate ontological indeterminism; indeed the ubiquitous role of the Gaussian distribution (the ‘bell curve’) in classical science underscores this fact. As Murphy depicts it, the combination of determinism in physics, epistemic and causal reduction in philosophy, and an ontology of atomism, completed the case for the mechanistic world view by the nineteenth century.

Related Topics:

Physics

Contributed by: Robert Russell - CTNS