theoretical density
51Cosmological constant — Physical cosmology Universe · Big Bang …
52High-temperature superconductivity — Unsolved problems in physics What causes superconductivity at temperatures above 50 kelvin? High temperature superconductors (abbreviated high Tc or HTS) are materials that have a superconducting transition temperature (Tc) above 30 K… …
53geoid — geoidal, adj. /jee oyd/, n. 1. an imaginary surface that coincides with mean sea level in the ocean and its extension through the continents. 2. the geometric figure formed by this surface, an ellipsoid flattened at the poles. [1880 85; < Gk… …
54star — starless, adj. /stahr/, n., adj., v., starred, starring. n. 1. any of the heavenly bodies, except the moon, appearing as fixed luminous points in the sky at night. 2. Astron. any of the large, self luminous, heavenly bodies, as the sun, Polaris,… …
55Alan Guth — Infobox Scientist name = Alan Harvey Guth caption = Alan Guth at Harvard University birth date = Birth date and age|1947|2|27|df=y birth place = New Brunswick, New Jersey death date = death place = residence = United States nationality = American …
56Multijunction photovoltaic cell — Multi junction solar cells or tandem cells are solar cells containing several p n junctions. Each junction is tuned to a different wavelength of light, reducing one of the largest inherent sources of losses, and thereby increasing efficiency.… …
57nebula — nebular, adj. /neb yeuh leuh/, n., pl. nebulae / lee , luy /, nebulas. 1. Astron. a. Also called diffuse nebula. a cloud of interstellar gas and dust. Cf. dark nebula, emission nebula, reflection nebula …
58physics — /fiz iks/, n. (used with a sing. v.) the science that deals with matter, energy, motion, and force. [1580 90; see PHYSIC, ICS] * * * I Science that deals with the structure of matter and the interactions between the fundamental constituents of… …
59Albert Einstein — Einstein redirects here. For other uses, see Einstein (disambiguation) …
60physical science — physical scientist. 1. any of the natural sciences dealing with inanimate matter or with energy, as physics, chemistry, and astronomy. 2. these sciences collectively. [1835 45] * * * Introduction the systematic study of the inorganic world …
