Talk:Magnetic dip

Discovery
The information about the discovery by Abu Rayhan Biruni and Shen Kuo is doubtful or irrelevant. The Abu Rayhan Biruni article mentions a dip angle, but that is the angle between the true horizon and astronomical horizon, and it is not related to the Earth's magnetic field. The Shen Kuo article mentions magnetism, but not dip. JonH (talk) 14:17, 21 March 2010 (UTC)

Sign conventions
The sign conventions in Magnetic dip have changed so often that it gets confusing, and even I got it wrong in a recent revision. For the record, this version is correct: "the north end of a compass needle will point downward in the northern hemisphere (positive dip) or upward in the southern hemisphere (negative dip). The range of dip is from +90 degrees (at the North Magnetic Pole) to -90 degrees (at the South Magnetic Pole)." RockMagnetist(talk) 16:24, 1 June 2019 (UTC)