oscillation period
121Pacific Ocean — an ocean bordered by the American continents, Asia, and Australia: largest ocean in the world; divided by the equator into the North Pacific and the South Pacific. 70,000,000 sq. mi. (181,300,000 sq. km); greatest known depth, 35,433 ft. (10,800… …
122geomagnetic field — Magnetic field associated with the Earth. It is essentially dipolar (i.e., it has two poles, the northern and southern magnetic poles) on the Earth s surface. Away from the surface, the field becomes distorted. Most geomagnetists explain the… …
123History of Physics — History of Physics † Catholic Encyclopedia ► History of Physics The subject will be treated under the following heads: I. A Glance at Ancient Physics; II. Science and Early Christian Scholars; III. A Glance at Arabian Physics; IV.… …
124United States rainfall climatology — The characteristics of United States rainfall climatology differ significantly across the United States and its possessions. Late summer and fall extratropical cyclones bring a majority of the precipitation which falls across western, southern,… …
125Drought in the United States — A farmer and his two sons during a dust storm in Cimarron County, Oklahoma, 1936. Photo: Arthur Rothstein. Drought in the United States is similar to that of other portions of the globe. Below normal precipitation leads to drought, which is… …
126Simple harmonic motion — is the motion of a simple harmonic oscillator, a motion that is neither driven nor damped. The motion is periodic, as it repeats itself at standard intervals in a specific manner described as being sinusoidal, with constant amplitude. It is… …
127Hirnantian — The Hirnantian is the seventh and final internationally recognized stage of the Ordovician Period of the Paleozoic Era. It was of short duration, lasting about 1.9 million years, from 445.6 ± 1.5 to 443.7 ± 1.5 Ma (million years ago). The early… …
128earth — /errth/, n. 1. (often cap.) the planet third in order from the sun, having an equatorial diameter of 7926 mi. (12,755 km) and a polar diameter of 7900 mi. (12,714 km), a mean distance from the sun of 92.9 million mi. (149.6 million km), and a… …
