dating — I In geology and archaeology, the process of determining an object s or event s place within a chronological scheme. Scientists may use either relative dating, in which items are sequenced on the basis of stratigraphic clues (see stratigraphy) or … Universalium
fission-track dating — Method of determining the age of a mineral that utilizes the damage done by the spontaneous fission of uranium 238, the most abundant isotope of uranium. The fission results in radiation damage, or fission tracks, that can be made visible by… … Universalium
Optical dating — is a method of determining how long ago minerals were last exposed to daylight. It is useful to geologists and archaeologists who want to know when such an event occurred. Alternate names sometimes used are optically stimulated luminescence… … Wikipedia
Uranium-lead dating — Uranium lead is one of the oldest and most refined radiometric dating schemes, with a routine age range of about 1 million years to over 4.5 billion years, and with routine precisions in the 0.1 1 percent range. [Parrish, Randall R.; Noble,… … Wikipedia
List of civilian radiation accidents — This article lists notable civilian accidents involving radioactive materials or involving ionizing radiation from artificial sources such as x ray tubes and particle accelerators. Accidents related to nuclear power that involve fissile materials … Wikipedia
Neutron radiation — is a kind of ionizing radiation which consists of free neutrons. A result of nuclear fission or nuclear fusion, it consists of the release of free neutrons from atoms, and these free neutrons react with nuclei of other atoms to form new isotopes … Wikipedia
Zircon — Not to be confused with zirconia or cubic zirconia. This article is about the mineral. For other uses, see Zircon (disambiguation). Zircon Zircon crystal from Tocantins, Brazil (2×2 cm) … Wikipedia
space exploration — Investigation of the universe beyond Earth s atmosphere by means of manned and unmanned spacecraft. Study of the use of rockets for spaceflight began early in the 20th century. Germany s research on rocket propulsion in the 1930s led to… … Universalium
Human spaceflight — Orbital Human spaceflight Name Debut Launches Vostok 1961 6 Mercury 1962 4 Voskhod 1964 2 Gemini 1965 … Wikipedia
Electron paramagnetic resonance — (EPR) or electron spin resonance (ESR) spectroscopy is a technique for studying chemical species that have one or more unpaired electrons, such as organic and inorganic free radicals or inorganic complexes possessing a transition metal ion. The… … Wikipedia
