Context: Dark matter is an unidentified type of matter distinct from dark energy, baryonic matter (ordinary matter), and neutrinos. The name refers to the fact that it does not emit or interact with electromagnetic radiation, such as light, and is thus invisible to the entire electromagnetic spectrum. Although dark matter has not been directly observed, its existence and properties are inferred from its gravitational effects such as the motions of visible matter, gravitational lensing, its influence on the universe's large-scale structure, on galaxies, and its effects in the cosmic microwave background., The Universe is all of time and space and its contents. It includes planets, moons, minor planets, stars, galaxies, the contents of intergalactic space, and all matter and energy. The size of the entire Universe is unknown., Hydrogen is a chemical element with chemical symbol H and atomic number 1. With an atomic weight of , hydrogen is the lightest element on the periodic table. Its monatomic form (H) is the most abundant chemical substance in the Universe, constituting roughly 75% of all baryonic mass. Non-remnant stars are mainly composed of hydrogen in the plasma state. The most common isotope of hydrogen, termed "protium" (name rarely used, symbol H), has one proton and no neutrons., Atom is a home computer game published by Tandy in 1983 for the TRS - 80 . The game educates the player about the first few elements of the periodic table ( Hydrogen through Xenon ) ., The TRS-80 Micro Computer System (TRS-80; later known as the Model I to distinguish it from successors) is a desktop microcomputer launched in 1977 and sold by Tandy Corporation through their Radio Shack stores. The name is an abbreviation of "Tandy/Radio Shack, Z-80 microprocessor". It was one of the earliest mass-produced personal computers., Tandy Corporation, was an American family-owned leather goods company based in Fort Worth, Texas. Tandy Leather was founded in 1919 as a leather supply store, and acquired a number of craft retail companies, including RadioShack in 1963. In 2000, the Tandy Corporation name was dropped and entity became the RadioShack Corporation., A microcomputer is a small, relatively inexpensive computer with a microprocessor as its central processing unit (CPU). It includes a microprocessor, memory, and minimal input/output (I/O) circuitry mounted on a single printed circuit board. Microcomputers became popular in the 1970s and 1980s with the advent of increasingly powerful microprocessors. The predecessors to these computers, mainframes and minicomputers, were comparatively much larger and more expensive (though indeed present-day mainframes such as the IBM System z machines use one or more custom microprocessors as their CPUs). Many microcomputers (when equipped with a keyboard and screen for input and output) are also personal computers (in the generic sense)., Weakly interacting massive particles (WIMPs) are hypothetical particles that are thought to constitute dark matter. There exists no clear definition of a WIMP, but broadly a WIMP is a new elementary particle which interacts via gravity and any other force (or forces), potentially not part of the standard model itself, which is as weak as or weaker than the weak nuclear force, but also non-vanishing in its strength. A WIMP must also have been produced thermally in the early Universe, similarly to the particles of the standard model according to Big Bang cosmology, and usually will constitute cold dark matter.
Obtaining the correct abundance of dark matter today via thermal production requires a self-annihilation cross section of formula_1, which is roughly what is expected for a new particle in the 100 GeV mass range that interacts via the electroweak force. Because supersymmetric extensions of the standard model of particle physics readily predict a new particle with these properties, this apparent coincidence is known as the WIMP miracle, and a stable supersymmetric partner has long been a prime WIMP candidate. However, recent null results from direct detection experiments including LUX and SuperCDMS, along with the failure to produce evidence of supersymmetry in the Large Hadron Collider (LHC) experiment has cast doubt on the simplest WIMP hypothesis. Experimental efforts to detect WIMPs include the search for products of WIMP annihilation, including gamma rays, neutrinos and cosmic rays in nearby galaxies and galaxy clusters; direct detection experiments designed to measure the collision of WIMPs with nuclei in the laboratory, as well as attempts to directly produce WIMPs in colliders, such as the LHC., The XENON dark matter research project operated at the Italian Gran Sasso laboratory is a deep underground research facility featuring increasingly ambitious experiments aiming to finally detect long sought after dark matter particles. These particles in the form of Weakly interacting massive particles (WIMPs) are believed to be found by looking for rare interactions via nuclear recoils in a liquid xenon target chamber. The current detector consists of a dual phase Time projection chamber (TPC)., Subject: atom , Relation: publisher, Options: (A) definition (B) ibm (C) rare (D) spectrum (E) tandy corporation (F) unknown
Output: tandy corporation