THE PLASMA UNIVERSE

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It is known that 99 % of visible matter in the Universe is in the plasma state. Only us have the luck of living in our Earth, which belongs to the one percent of the other states of the matter. But even in our Earth we find plasma: within the channels of the lightnings, in the ionosphere, in the auroras or Northern and Southern Lights and in the Earth’s magnetosphere. In the Solar System the plasma is found in the solar wind, in the planet’s magnetospheres and the comets. Around Jupiter and Saturn we even have plasma that forms gigantic plasma toroids. The Sun itself and the rest of the stars are enormous plasma balls and such phenomena as the Sun spots, spicules, chromosphere eruptions, coronal mass ejections and protuberances belong to the typical plasma manifestations. Not only the stars, but also a good deal of the nebulae within the galaxies is composed of plasma. In the nebulae again we observe plasma manifestations: filamentation product of the electric and magnetic fields, particle acceleration up to a remarkable high energy and luminous radiation (in different wavelengths) result of different mechanisms. Near the centre of our Galaxy it has been observed extensive plasma filaments, with lengths of around 250 light years, perpendicular to the plane of our Galaxy. In the rest of the galaxies are found similar formations, namely, those tracked within the nuclei of the active galaxies (AGN - Active Galactic Nuclei). Neighbor galaxies are bound by plasma bridges, which are conductors of electric current (for example our Milky Way with the Magellanic Clouds). The jets and two radio spots near the quasars, the active galactic nuclei and others are again plasma formations, and have its origin in the plasma properties. The numerical simulations of the last years show that probably the plasma phenomena should have a dominant role in the star formation from the creation of the protostellar cloud, making possible the creation of the primary globules without having to accomplish the Jean’s criterion regarding the minimum size of the nebula and even without a “starter” shock wave from a neighbor supernova. In the same manner the numerical simulations show that the arms of the galactic spirals can be the result of the electromagnetic interaction of global magnetic fields and need not to be only gravitational manifestations. Nowadays it also seems that the most energetic particles, which are observed in the cosmic rays, were accelerated in the plasma spatial filaments inside an electric double layer. Therefore the possible picture that we can make of our Universe changes, since the Universe is not only gravitational interaction, as we have thought until recently. In the formation of the Universe has contributed in the same manner the electromagnetic interaction and its diverse manifestations. With the introduction of the X-ray studies we have come literally with an attack from plasma physics to the study of our Universe.

Sun
Solar protuberance: plasma expulsion from the solar surface controlled by a magnetic field.

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For a human, the most known example of plasma might be the conducting channel of the lightnings. The typical parameters of lightings are:

  • Diameter of conducting channel ~ 5 cm
  • Length of channel ~ 3 km
  • Current ~ 200 kA
  • Temperature ~ 30 000 K
  • Duration ~ 10−4 s
  • Speed of movement ~ 0,1 c  (that is 30 000 km·s−1)
  • Energy ~ 6×108 J
  • Volume of charge condensation ~ 3 000 km3

In other planets we may find even larger thunderbolts: in Venus the lightnings have a total energy of 2×1010 J and in Jupiter even 3×1012 J.

Lightings
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Translation: Arturo Ortiz Tapia, 2005