Astrophysics for People in a Hurry – Flashcards
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Einstein's General Theory of Relativity
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The presence of matter and energy curves the fabric of space and time around it.
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Molecules
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A group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.
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Atoms
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A unit of matter; the smallest unit of a chemical element.
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Subatomic Particles
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A particle smaller than an atom (e.g., a neutron) or a cluster of such particles (e.g., an alpha particle).
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Quantum Gravity
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Field of theoretical physics that seeks to describe gravity according to the principles of quantum mechanics
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Planck Era
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Earliest stage of the Big Bang
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Photons
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A particle representing a quantum of light or other electromagnetic radiation. A photon carries energy proportional to the radiation frequency but has zero rest mass.
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Antimatter
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Molecules formed by atoms consisting of antiprotons, antineutrons, and positrons. Stable antimatter does not appear to exist in our universe.
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Quarks
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Any of a number of subatomic particles carrying a fractional electric charge, postulated as building blocks of the hadrons. Quarks have not been directly observed, but theoretical predictions based on their existence have been confirmed experimentally.
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Bosons
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A subatomic particle, such as a photon, that has zero or integral spin and follows the statistical description given by S. N. Bose and Einstein.
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Leptons
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A subatomic particle, such as an electron, muon, or neutrino, that does not take part in the strong interaction.
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Electrons
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A stable subatomic particle with a charge of negative electricity, found in all atoms and acting as the primary carrier of electricity in solids.
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Antielectrons
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The antimatter counterpart of the electron.
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Antiquarks
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The antiparticle of a quark.
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Hadrons
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A subatomic particle of a type including the baryons and mesons that can take part in the strong interaction.
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Light Year
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Unit of astronomical distance equivalent to the distance that light travels in one year, which is 9.4607 × 1012 km (nearly 6 trillion miles).
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Kelvin
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The SI base unit of thermodynamic temperature, equal in magnitude to the degree Celsius.
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Ozone Layer
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A layer in the earth's stratosphere at an altitude of about 6.2 miles (10 km) containing a high concentration of ozone, which absorbs most of the ultraviolet radiation reaching the earth from the sun.
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Newton's Law of Gravity
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A particle attracts every other power particle in the universe using a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.
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Dark Matter
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Nonluminous material that is postulated to exist in space and that could take any of several forms including weakly interacting particles
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George Gamow
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A theoretical physicist and cosmologist. He was an early advocate and developer of Lemaître's Big Bang theory.
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Ralph Alpher
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An American cosmologist, who carried out pioneering work in the early 1950s on the Big Bang model
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Robert Herman
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A United States scientist, best known for his work with Ralph Alpher in 1948-50, on estimating the temperature of cosmic microwave background radiation from the Big Bang explosion.
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Arno Penzias
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German-American astrophysicist who shared one-half of the 1978 Nobel Prize for Physics with Robert Woodrow Wilson for their discovery of a faint electromagnetic radiation throughout the universe.
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Robert Dicke
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An American physicist who made important contributions to the fields of astrophysics, atomic physics, cosmology and gravity.
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John C. Mather
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He showed that the cosmic microwave background radiation has a blackbody spectrum within 50 ppm
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George F. Smoot
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an American astrophysicist, cosmologist, Nobel laureate. He won the Nobel Prize in Physics in 2006 for his work on the Cosmic Background Explorer with John C. Mather
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Dark Energy
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A theoretical repulsive force that counteracts gravity and causes the universe to expand at an accelerating rate.
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Cosmologist
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A branch of astronomy that involves the origin and evolution of the universe, from the Big Bang to today and on into the future.
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Milky Way
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The galaxy of which the sun and the solar system are a part and which contains the myriads of stars
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Magellanic Clouds
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Two irregular dwarf galaxies visible in the Southern Celestial Hemisphere
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Andromeda Nebula
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The brightest galaxy in the northern sky and one of the closest to our galaxy
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Supernovas
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A star that suddenly increases greatly in brightness because of a catastrophic explosion that ejects most of its mass.
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Quasars
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A massive and extremely remote celestial object, emitting exceptionally large amounts of energy, and typically having a starlike image in a telescope. It has been suggested that quasars contain massive black holes and may represent a stage in the evolution of some galaxies.
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Issac Newton
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An English mathematician and physicist; remembered for developing the calculus and for his law of gravitation and his three laws of motion
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Albert Einstein
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A German who formulated the special theory of relativity and the general theory of relativity
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Fritz Zwicky
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Zwicky was the first to use the virial theorem to infer the existence of unseen dark matter
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Vera Rubin
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American astronomer who pioneered work on galaxy rotation rates
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Under-luminous
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Insufficiently luminous
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Nicolaus Copernicus
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Renaissance- and Reformation-era mathematician and astronomer who formulated a model of the universe that placed the Sun rather than the Earth at the center of the universe
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Edwin P. Hubble
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He played a crucial role in establishing the fields of extragalactic astronomy and observational cosmology and is regarded as one of the most important astronomers of all time.
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Saul Perlmutter
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U.S. astrophysicist selected for the Breakthrough Prize in Fundamental Physics with Brian P. Schmidt and Adam Riess for providing evidence that the expansion of the universe is accelerating.
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Nuclear Fission
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The splitting of the nuclei of atoms into two fragments of approximately equal mass, accompanied by conversion of part of the mass into energy: the principle of the atomic bomb
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Spectrometer
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An instrument used for measuring spectral wavelengths
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Coma Cluster
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Large cluster of galaxies that contains over 1,000 identified galaxies.
