Speaker
Description
In 1899, the Norwegian physicist Kristian Birkeland designed an experiment called Terrella, to show the formation of the polar lights. Electrons were shot on a magnetised sphere in a vacuum chamber. The electron gun represented the sun, and the magnetized sphere was naturally the Earth. This experience allowed him to see (without identifying them) also ring current later discovered by James Van Allen. We now know that the sun-earth system is more complex than Birkeland imagined. However, this experience was already fascinating. The Planeterrella was created a few years ago, inspired by Birkeland's work, It remains an auroral simulator. But its great flexibility allows to simulate a much larger amount of sun - planets interaction: the solar corona may be pictured as well as the magnetopause, the specific cases of Uranus and Neptune, the interaction between Ganymede and Jupiter, or even the interaction between a magnetized exoplanet and a nearby star. With the most recent version, one can also see the dynamics of the magnetosphere and its dependency to the interplanetary magnetic field direction. The experience is wonderful. On sees above the sphere circles of purple auroras around the magnetic poles. More reddish iridescence allow to literally map the magnetic field configurations. You can also highlight a ring of particles around the sphere by the radiation that it produces, that Birkeland had interpreted like the rings of Saturn. The experience is very well suited to let the public dream on the magnificence of cosmic phenomena while explaining astrophysics. It was decided not to put any patent on it but to give the plans to any public service. There are now 40 copies throughout the world. However, two groups tried to steal the plans in order to sell the Planeterrella, in a totally opposite spirit than ours, which was sharing the wonders of science. Therefore, the owning institute (CNRS) forbid to share the plans anymore. Instead, CNRS funded a new, more powerfull Planeterrella adapted to developing countries difficult conditions. In parallel, a non for profit association was set in order to assemble the Planeterrellas in France and to sell them a the real cost price. The association is called AurorAlpes. AurorAlpes also provides training for the educators, and services when a group only requests to get a series of demos for a given event.
This economic new model allowed to consider new developments. Indeed, it is well suited for receiving funds from Foundations. In France, La Fondation Dassault Systèmes, supporting projects using 3D as a way to better educate and discover, allowed to develop a 3D model to run scientific 3D numerical Simulations of the Planeterrella, as well as to use this 3D model for mounting/dismounting sequences. La Fondation also considers running the Planeterrella in a Planetarium at a special event in their facilities in Vélizy-Villacoublay, near Paris, so that the visitors can feel both inside and outside the aurorae.
The Planeterrella will be briefly presented through movies and photographs, and this economic model will be discussed, including the future extensions.
| Do you plan to attend in-person or online? | In-person |
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