... 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 . ...
... 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 (-...
... NASA's Hubble Space Telescope has detected a long-sought population of comets dwelling at the icy fringe of the solar system . The observation, which is the astronomical equivalent to finding the proverbial needle-in-a-haystack, bolsters proof for a primordial comet reservoir just beyond Neptune , currently the farthest planet from the Sun . ... The comet-disk lies just beyond Neptune and might stretch 500 times farther from the Sun than Earth . ... Comet Introduction Kuiper Belt Objects . ...