Notes

------------------------------------------------------------World of Physics-------------------------------------------------------------
Acceleration- increase in speed or velocity

Entropy- (on a macroscopic scale) a function of thermodynamic variables, as temperature, pressure, or composition, that is a measure of the energy that is not available for work during a thermodynamic process. A closed system evolves toward a state of maximum entropy.

Magnetism- the properties of attraction possessed by magnets; the molecular properties common to magnets.

Density- the state or quality of being dense; compactness; closely set or crowded condition.

Superconductivity- the phenomenon of almost perfect conductivity shown by certain substances at temperatures approaching absolute zero. The recent discovery of materials that are superconductive at temperatures hundreds of degrees above absolute zero raises the possibility of revolutionary developments in the production and transmission of electrical energy.

Quantum Theory- any theory predating quantum mechanics that encompassed Planck's radiation formula and a scheme for obtaining discrete energy states for atoms, as Bohr theory.

Electric charge- one of the basic properties of the elementary particles of matter giving rise to all electric and magnetic forces and interactions. The two kinds of charge are given negative and positive algebraic signs: measured in coulombs.
Spectrum- an array of entities, as light waves or particles, ordered in accordance with the magnitudes of a common physical property, as wavelength or mass: often the band of colors produced when sunlight is passed through a prism, comprising red, orange, yellow, green, blue, indigo, and violet.

Relativity- a theory, formulated essentially by Albert Einstein, that all motion must be defined relative to a frame of reference and that space and time are relative, rather than absolute concepts: it consists of two principal parts. The theory dealing with uniform motion (special theory of relativity or special relativity) is based on the two postulates that physical laws have the same mathematical form when expressed in any inertial system, and the velocity of light is independent of the motion of its source and will have the same value when measured by observers moving with constant velocity with respect to each other. Derivable from these postulates are the conclusions that there can be no motion at a speed greater than that of light in a vacuum, mass increases as velocity increases, mass and energy are equivalent, and time is dependent on the relative motion of an observer measuring the time. The theory dealing with gravity (general theory of relativity or general relativity) is based on the postulate that the local effects of a gravitational field and of acceleration of an inertial system are identical.

Force- physical power or strength possessed by a living being
---------------------------------------------------------------Time Periods-------------------------------------------------------------
Stone Age- the period in the history of humankind, preceding the Bronze Age and the Iron Age, and marked by the use of stone implements and weapons: subdivided into the Paleolithic, Mesolithic, and Neolithic periods.

Bronze Age- a period in the history of humankind, following the Stone Age and preceding the Iron Age, during which bronze weapons and implements were used.

Iron Age-the period in the history of humankind, following the Stone Age and the Bronze Age, marked by the use of implements and weapons made of iron.

Ice Age- typically defined as the time period that began about 1.8 million years ago and lasted until about 11,700 years ago. The most recent Ice Age occurred then, as glaciers covered huge parts of the planet Earth

Cambrian- noting or pertaining to a period of the Paleozoic Era, occurring from 570 million to 500 million years ago, when algae and marine invertebrates were the predominant form of life.

Cosmology- the branch of philosophy dealing with the origin and general structure of the universe, with its parts, elements, and laws, and especially with such of its characteristics as space, time, causality, and freedom.

Cretaceous- noting or pertaining to a period of the Mesozoic Era, from 140 million to 65 million years ago, characterized by the greatest development and subsequent extinction of dinosaurs and the advent of flowering plants and modern insects.

Devonian- noting or pertaining to a period of the Paleozoic Era, 405 to 345 million years ago, characterized by the dominance of fishes and the advent of amphibians and ammonites.

Eocene- noting or pertaining to an epoch of the Tertiary Period, occurring from 55 to 40 million years ago and characterized by the advent of the modern mammalian orders.