initial radiation
91particle accelerator — accelerator (def. 7). [1945 50] * * * Device that accelerates a beam of fast moving, electrically charged atoms (ions) or subatomic particles. Accelerators are used to study the structure of atomic nuclei (see atom) and the nature of subatomic… …
92Main sequence — A Hertzsprung Russell diagram plots the actual brightness (or absolute magnitude) of a star against its color index (represented as B V). The main sequence is visible as a prominent diagonal band that runs from the upper left to the lower right.… …
93Milky Way Galaxy — Large spiral galaxy (roughly 150,000 light years in diameter) that contains Earth s solar system. It includes the multitude of stars whose light is seen as the Milky Way, the irregular luminous band that encircles the sky defining the plane of… …
94geomagnetic 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… …
95climate change — Introduction periodic modification of Earth s climate brought about as a result of changes in the atmosphere as well as interactions between the atmosphere and various other geologic, chemical, biological, and geographic factors within the Earth …
96dose — 1. The quantity of a drug or other remedy to be taken or applied all at one time or in fractional amounts within a given period. Cf.:dosage (2). 2. In nuclear medicine, amount of energy absorbed per unit mass of irradiated material (absorbed d.) …
97Cold fusion — This article is about the Fleischmann–Pons claims of nuclear fusion at room temperature. For the original use of the term cold fusion , see Muon catalyzed fusion. For all other definitions, see Cold fusion (disambiguation). Diagram of an open… …
98Half-life — This article is about the scientific and mathematical term. For other uses, see Half life (disambiguation). Number of half lives elapsed Fraction remaining Percentage remaining 0 1/1 100 1 1/2 50 2 …
99Radiosurgery — This article is about the medical procedure. For the album by American rock band New Found Glory, see Radiosurgery (album). Radiosurgery Intervention CLINAC: a model of steerable linear accelerator commonly used in radiosurgery …
100History of radar — The history of radar starts with experiments by Heinrich Hertz in the late 19th century that showed that radio waves were reflected by metallic objects. This possibility was suggested in James Clerk Maxwell s seminal work on electromagnetism.… …
