... The choice of which type of electricity is called "positive" and which "negative" was made around 1750 by Ben Franklin, early American scientist and man of many talents (the stamp on the left commemorates his role as first US postmaster--and colonial postmaster before that). ... Franklin knew of two types of electric charge, depending on the material one rubbed. ... Later, when electric batteries were discovered, scientists naturally assigned the direction of the flow of current to be from (+) to (-...
... CURRENT ASPECTS OF REMOTE SENSING OF EARTH FROM SPACE . ... For developing of the scientific concept and the programs of global monitoring of the Earth from space and pursuant to the disposal of Presidium of Russian Academy of Sciences # 10310-717 (August 11, 2004 ) Space Research Institute RAS and Center of Space Observations of the Russian Space Agency during November 16-18, 2004 conduct the Second Opened All-Russia conference ' Current Aspects of Remote ...
Ice Volcanoes Reshape Europa's Chaotic Surface . Ice-spewing volcanoes and the grinding and tearing of tectonic plates have reshaped the chaotic surface of Jupiter's frozen moon Europa, images from NASA's Galileo spacecraft reveal. ... Although the images do not show currently active ice volcanoes or geysers, they do reveal flows of material on the surface that probably originated from them, said Galileo imaging team member Dr. Ronald Greeley of Arizona State University, Tempe. ... Europa . ...