Science 2.0 Quick reference
A Dictionary of the Internet (4 ed.)
... 2.0 A term used to describe the transformation of scientific research that has come about through the extensive use of computers both for the analysis and for the capture of...
Prussian horse-kicks
A set of data introduced by Bortkiewicz. It illustrates the fact that the frequencies of occurrence of unlikely events follow a Poisson distribution even when there may be variations in the ...
river water, major constituents
The average composition of river water is very different from that of sea water. The pH varies greatly from areas of high organic activity, e.g. the equatorial rain forests, to zones of little ...
birthday problem
A well-known, but intriguing probability problem. There are n people in a room. Assume that none is born on 29 February and that the remaining 365 days are all equally likely as birthdays. What is ...
Amazonian
A division of areological time, lasting from 1.80 Gy to the present in the Hartmann–Tanaka Model and 3.55 Gy to the present in the Neukum–Wise Model, and divided into three epochs: Lower Amazonian ...
brackish
Applied to water that is saline, but less so than sea water. According to the Venice system, brackish waters are classified by the chlorine they contain and divided into zones. The zones, with their ...
sea state
A system for the classification of average wave height, with a scale that ranges from 0 to 9.wave height (m)statedefinition00calm, glassy0–0.11calm, ...
four squares theorem
Any positive integer can be expressed as the sum of not more that four positive integers. Alternatively it can be expressed as the sum of squares of exactly four non-negative integers, see Lagrange ...
Lagrange theorem
(sum of four squares)Every natural number can be written as the sum of four squares of integers. This expression is not necessarily unique. For example,1=12+02+02+02,10=32+12+02+02 or 22+22+12+12.
chrysocolla
A hydrated silicate of copper, with the formula CuSiO2.2H2O; sp. gr. 2.0; hardness variable; greenish-blue; variable lustre; normally forms from the weathering of copper-rich mineral deposits, and ...
kaersutite
A member of the alkali amphiboles with the composition (Na,K)Ca2(Mg,Fe)4Ti[Si6Al2O22](OH)2 in a group which includes katophorite Na(Na,Ca)(Mg,Fe2+)4Fe3+[Si7AlO22] (OH)2 and oxyhornblende NaCa2(Mg,Fe, ...
water velocity
The velocity (v m/s) of sound waves in water is dependent on temperature (T °C) and salinity (S parts per thousand), and can be calculated for any depth (Z) using the formula v = 1449 + 4.6T - ...
International Gravity Formula
Formula used to determine the gravitational acceleration at a given latitude (gϕ) for a model of the Earth that comprises a rotating, oblate spheroid. gϕ= g0(1 + α sin2 ϕ + β sin2 ϕ), where g0 is the ...
Gregory–Newton forward difference formula
Let x 0, x 1, x 2,…, x n be equally spaced values, so that x i=x 0+ih, for i=1, 2,…, n. Suppose that the values f 0, f 1, f 2,…, f n are known, where f i=f(x i), for some function f. The ...
mean body temperature
An average body temperature, which takes into account temperature variations throughout the body. It is not a mathematical mean, but is a weighted average often estimated using the equation: mean ...
stilpnomelane
A phyllosilicate (sheet silicate) similar to biotite with the formula (K,Na,Ca)0–1.4 (Fe2+,Fe3+,Mg,Al,Mn)5.9–8.2 [Si8O20] (OH)4(OH,F)3.6–8.5; sp. gr. 2.59–2.96; hardness 3.0–4.0; properties similar ...
vector norm
For an n-dimensional vector x a vector norm is a non-negative function which satisfies:|x|>0 when x ≠ 0 and |x|=0 when x=0,|k x|=k×|x| for any scalar k,|x+y|≤|x|+|y|.
Langevin distribution
A distribution used to model spherical data. The probability density function f in the direction (θ, ϕ) (See spherical data) is given byf(θ, ϕ)=c exp[κ{cosθ0 cosθ+sinθ0 sinθ cos(ϕ-ϕ0)}], 0≤θ≤π, -π≤ϕ ...
