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Recently the terrella experiments have been further developed by a team of physicists at the
Institute of Planetology and Astrophysics in Grenoble, France to create the "planeterrella" which uses two magnetised spheres which can be manipulated to recreate several different auroral phenomena.
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conducted more realistic experiments around 1990. All such experiments are difficult to interpret, and are never able to scale all the parameters needed to properly simulate the Earth's magnetosphere, which is why such experiments have now been completely replaced by
170:) at a terrella in a vacuum tank, and found they indeed produced a glow in regions around the poles of the terrella. Because of residual gas in the chamber, the glow also outlined the path of the particles. Neither he nor his associate
132:, balanced on a horizontal axis perpendicular to the magnetic one, indicated the proper "magnetic inclination" between the magnetic force and the horizontal direction. Gilbert later reported his findings in
205:(1788–1869) also experimented with a terrella. He used an electromagnet, placed within a large hollow iron sphere, and this was examined in the darkroom under varying degrees of electrification.
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William
Gilbert's explanation was that the Earth itself was a giant magnet, and he demonstrated this by creating a scale model of the magnetic Earth, a "terrella", a sphere formed out of a
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Kristian
Birkeland and his magnetized terrella experiment, which led him to surmise that charged particles interacting with the Earth's magnetic field were the cause of the aurora.
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174:(who calculated such paths) could understand why the actual aurora avoided the area directly above the poles themselves. Birkeland believed the electrons came from the
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Kristian
Birkeland's magnetised terrella. In this experiment, he noted two spirals which he considered may be similar to that of
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Birkeland constructed several terrellas. One large terrella experiment was reconstructed in
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Terrellas have been used until the late 20th century to attempt to simulate the Earth's
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was a
Norwegian physicist who, around 1895, tried to explain why the lights of the
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showed the force on the needle was not horizontal but slanted into the Earth.
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De
Magnete, Magneticisque Corporibus, et de Magno Magnete Tellure
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was directed, simulating the solar wind. Hafiz-Ur Rahman at the
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appeared only in regions centered at the magnetic poles.
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needle pointed north. Earlier investigators (including
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16:Device that simulates Earth's magnetic field
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344:NASA Educational Website on the Terrella
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47:for 'little earth') is a small
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162:He simulated the effect by directing
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222:University of California, Riverside
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273:Birkeland, Kristian (1908–1913).
35:An example of an active terrella
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289:out-of-print, full text online
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249:Section 2, Chapter VI, p. 678
140:Kristian Birkeland's terrella
51:model ball representing the
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327:"Planeteterrella - English"
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90:William Gilbert's terrella
82:William Gilbert's terrella
67:, while investigating the
301:"The Birkeland Terrella"
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208:Brunberg and Dattner in
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283:& Co – via
166:(later identified as
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136:, published in 1600.
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227:computer simulations
115:Christopher Columbus
59:while investigating
359:Physics experiments
299:Terje Brundtland.
153:Kristian Birkeland
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65:Kristian Birkeland
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201:The German Baron
107:Earth's magnetism
103:Queen Elizabeth I
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57:William Gilbert
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309:. Retrieved
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172:Carl Størmer
164:cathode rays
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157:polar aurora
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285:archive.org
257:References
182:activity.
130:dip needle
49:magnetised
281:Aschehoug
168:electrons
126:lodestone
61:magnetism
353:Category
41:terrella
180:sunspot
111:compass
311:24 May
305:Sphæra
218:plasma
210:Sweden
191:Norway
187:Tromsø
97:, the
69:aurora
237:Notes
53:Earth
45:Latin
313:2012
307:(7)
176:Sun
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39:A
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