Search results
Results from the WOW.Com Content Network
This model truncates at degree 12 (168 coefficients) with an approximate spatial resolution of 3,000 kilometers. It is the model used by the United States Department of Defense , the Ministry of Defence (United Kingdom) , the United States Federal Aviation Administration (FAA), the North Atlantic Treaty Organization (NATO), and the ...
The earliest ideas on the nature of magnetism are attributed to Thales (c. 624 BC – c. 546 BC). [1] [2] In classical antiquity, little was known about the nature of magnetism. No sources mention the two poles of a magnet or its tendency to point northward. There were two main theories about the origins of magnetism.
By analogy with Earth's magnetic field, these are called the magnet's "north" and "south" poles. Before magnetism was well understood, the north-seeking pole of a magnet was defined to have the north designation, according to their use in early compasses. However, opposite poles attract, which means that as a physical magnet, the magnetic north ...
Two pairs of gauge transformed potentials (φ, A) and (φ′, A′) are called gauge equivalent, and the freedom to select any pair of potentials in its gauge equivalence class is called gauge freedom. Again by the Poincaré lemma (and under its assumptions), gauge freedom is the only source of indeterminacy, so the field formulation is ...
Walter M. Elsasser, considered a "father" of the presently accepted dynamo theory as an explanation of the Earth's magnetism, proposed that this magnetic field resulted from electric currents induced in the fluid outer core of the Earth. He revealed the history of the Earth's magnetic field through pioneering the study of the magnetic ...
On July 12, a rematch of the first MLS Cup between the Galaxy and D.C. United will take place. Austin FC will host this coming season's All-Star Game on Wednesday, July 23. The day before will see ...
Poisson's electrical and magnetical investigations were generalized and extended in 1828 by George Green. Green's treatment is based on the properties of the function already used by Lagrange, Laplace, and Poisson, which represents the sum of all the electric or magnetic charges in the field, divided by their respective distances from some given point: to this function Green gave the name ...
12. You're weighing yourself at different times of day. If you're discouraged by daily ups and downs on the scale, you should know it's normal for body weight to fluctuate throughout the day ...