section_heading: Plazmatična kozmologija i proučavanje galaksija
paragraph_text: Hannes Alfvén od 1960-ih do 1980-ih tvrdio je da je plazma igrala važnu, ako ne i dominantnu ulogu u svemiru, jer su elektromagnetske sile daleko važnije od gravitacije kada djeluju na međuplanetarne i međuzvjezdane nabijene čestice.<ref>H. Alfvén and C.-G. Falthammar, Cosmic electrodynamics(2nd edition, Clarendon press, Oxford, 1963). "The basic reason why electromagnetic phenomena are so important in cosmical physics is that there exist celestial magnetic fields which affect the motion of charged particles in space ... The strength of the interplanetary magnetic field is of the order of 10<sup>−4</sup> gauss (10 nanoteslas), which gives the [ratio of the magnetic force to the force of gravity] ≈ 10<sup>7</sup>. This illustrates the enormous importance of interplanetary and interstellar magnetic fields, compared to gravitation, as long as the matter is ionized." (p.2-3) Dalje je hipotezirao da oni mogu potaknuti stezanje međuzvjezdanih oblaka i mogu čak predstavljati glavni mehanizam za kontrakciju, pokretajući stvaranje zvijezda.