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. Franklin studied static electricity, produced by rubbing glass, amber, sulfur etc. with fur or dry cloth. ... Later, when electric batteries were discovered, scientists naturally assigned the direction of the flow of current to be from (+) to (-). ... Exploration" home page (index) Glossary . Official GSFC Home Page .. ...
... Faraday's Lines of Force (field lines) . Faraday's Disk Dynamo . ... The Earth's Dynamo . ... Magnetic Storms and Ring Currents . The Magnetosphere . ... Chronology of Geomagnetism . ... 1581 Robert Norman publishes "The Newe Attractive," . ... 1832 Faraday tries to detect a dynamo current in water flowing in the Earth's field. ... magnetic storm. ... 1903 Birkeland proposes the existence of "polar magnetic storms," He also . ... 1919 Joseph Larmor proposes that magnetic fields of sunspots . ...
... Kuiper belt objects are icy bodies in the outer solar system. ... Views of Kuiper Belt Objects . Object 1993 SC . This image shows a small part of the discovery frames of 1993 SC, one of the brightest Kuiper-Belt objects so far discovered. ... Assuming that Object 1993 SC reflects light much like other primitive asteroids and comets in the out solar system, the diameter is around 300 kilometers (186 miles), or just a quarter the size of Pluto's moon Charon. ... Comet Shoemaker-Levy 9 Impact . ...