short-period measurements
51Variable star — A star is classified as variable if its apparent brightness as seen from Earth changes over time, whether the changes are due to variations in the star s actual luminosity, or to variations in the amount of the star s light that is blocked from… …
52celestial mechanics — the branch of astronomy that deals with the application of the laws of dynamics and Newton s law of gravitation to the motions of heavenly bodies. [1815 25] * * * Branch of astronomy that deals with the mathematical theory of the motions of… …
53human disease — Introduction an impairment of the normal state of a human being that interrupts or modifies its vital functions. health versus disease Before human disease can be discussed, the meanings of the terms health, physical fitness, illness …
54agricultural technology — Introduction application of techniques to control the growth and harvesting of animal and vegetable products. Soil preparation Mechanical processing of soil so that it is in the proper physical condition for planting is usually… …
55undersea exploration — Introduction the investigation and description of the ocean waters and the seafloor and of the Earth beneath. Primary objectives and accomplishments Included in the scope of undersea exploration are the physical and chemical… …
56Binary star — For the hip hop group, see Binary Star (band). Hubble image of the …
57Development of Jehovah's Witnesses doctrine — Part of a series on Jehovah s Witnesses Overview …
58Prediction of volcanic activity — (also: volcanic eruption forecasting ) is an interdisciplinary scientific and engineering approach to natural catastrophic event forecasting. Volcanic activity prediction has not been perfected, but significant progress has been made in recent… …
59135 Hertha — Infobox Planet width = 25em name = 135 Hertha symbol = background = #FFFFC0 caption = discovery ref = Cite journal | title = Observations of the Planet Hertha (135), made at the Litchfield Observatory of Hamilton College | last = Peters | first …
60Secular variations of the planetary orbits — The Secular Variations of the Planetary Orbits (French: Variations Séculaires des Orbites Planétaires, abbreviated as VSOP) is a semi analytic theory describing the long term changes (secular variation) in the orbits of the planets Mercury to… …
