initial radiation
71space 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… …
72Space colonization — Artist Les Bossinas 1989 concept of Mars mission Space colonization (also called space settlement, space humanization, or space habitation) is the concept of permanent human habitation outside of Earth. Although hypothetical at the present time,… …
73X-ray crystallography — can locate every atom in a zeolite, an aluminosilicate with many important applications, such as water purification. X ray crystallography is a method of determining the arrangement of atoms within a crystal, in which a beam of X rays strikes a… …
74Management of prostate cancer — Treatment for prostate cancer may involve active surveillance, surgery, radiation therapy including brachytherapy (prostate brachytherapy) and external beam radiation therapy, High intensity focused ultrasound (HIFU), chemotherapy, cryosurgery,… …
75Nuclear weapon design — The first nuclear weapons, though large, cumbersome and inefficient, provided the basic design building blocks of all future weapons. Here the Gadget device is prepared for the first nuclear test: Trinity. Nuclear weapon designs are physical,… …
76Nobel Prizes — ▪ 2009 Introduction Prize for Peace The 2008 Nobel Prize for Peace was awarded to Martti Ahtisaari, former president (1994–2000) of Finland, for his work over more than 30 years in settling international disputes, many involving ethnic,… …
77ice in lakes and rivers — Introduction a sheet or stretch of ice forming on the surface of lakes and rivers when the temperature drops below freezing (0° C [32° F]). The nature of the ice formations may be as simple as a floating layer that gradually thickens, or it …
78Numerical weather prediction — Weather models use systems of differential equations based on the laws of …
79radioactivity — /ray dee oh ak tiv i tee/, n. Physics, Chem. the phenomenon, exhibited by and being a property of certain elements, of spontaneously emitting radiation resulting from changes in the nuclei of atoms of the element. Also called activity. [1895… …
80Effects of nuclear explosions on human health — See also Effects of Nuclear Explosions Nuclear weapons History Warfare Arms race Design Testing Effects …
