four-point probe
41Physical Sciences — ▪ 2009 Introduction Scientists discovered a new family of superconducting materials and obtained unique images of individual hydrogen atoms and of a multiple exoplanet system. Europe completed the Large Hadron Collider, and China and India took… …
42Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity. Computer scientist Manindra Agrawal of the… …
43United States — a republic in the N Western Hemisphere comprising 48 conterminous states, the District of Columbia, and Alaska in North America, and Hawaii in the N Pacific. 267,954,767; conterminous United States, 3,022,387 sq. mi. (7,827,982 sq. km); with… …
44space 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… …
45Venus — This article is about the planet. For other uses, see Venus (disambiguation). Venus   …
46Jupiter — This article is about the planet. For other uses, see Jupiter (disambiguation). Jupiter   …
47General relativity — For a generally accessible and less technical introduction to the topic, see Introduction to general relativity. General relativity Introduction Mathematical formulation Resources …
48Atmospheric reentry — refers to the movement of human made or natural objects as they enter the atmosphere of a planet from outer space, in the case of Earth from an altitude above the edge of space. This article primarily addresses the process of controlled reentry… …
49Plame affair — (CIA leak) investigation Related topics and issues 2003 invasion of Iraq ( Operation Iraqi Freedom ) Contempt / Obstruction / Perjury Grand jury Intelligence Identities Protection Act of 1982 (full text) …
50Oscilloscope — This article is about current oscilloscopes, providing general information. For history of oscilloscopes, see Oscilloscope history. For detailed information about various types of oscilloscopes, see Oscilloscope types. Illustration showing the… …
