Three years before the present lecture, in 1979, Hannes Alfvén gave a talk on ”Observations and Cosmology” at the Lindau Meeting. In his talk, he rejected the Big Bang theory and instead advocated a model of the Universe symmetric in matter and anti-matter. In 1982 he came back to Lindau, this time with a more general lecture title about space research and its results. In particular he wanted to describe the implications for cosmology of the discoveries made in 25 years of space research. In his introduction, Alfvén quotes the Chairman of the session, Bengt Nagel, at that time the Scientific Secretary to the Nobel Committee for Physics, as saying ”one should not believe in what is believed today, because that may very well change rapidly”. Even though I was not present at the lecture, I think that I can warrant that this is a correct quotation. Nagel was my predecessor as secretary to the Nobel Committee and it is true that he used to say things like that. After the introduction, as a true plasma physicist, Alfvén then spends most of his lecture describing and explaining electric currents and magnetic fields in space. In particular the emphasis is on the then recently discovered electric double layers. These were well known from laboratory plasma physics, but had only recently been discovered by spacecrafts exploring our solar system. He then makes a rather large extrapolation from these interplanetary discoveries to space in general and in particular to a hierarchically structured universe, with stars, galaxies, galactic clusters and superclusters, etc., etc. If this extrapolation is accepted, there is a mechanism that would give rise to a cellular structure in space, where the matter content of each cell would be separated from that in the surrounding cells by double layers. So the main result for Alfvén turns out to be a physical mechanism that would allow a universe symmetric in matter and anti-matter, as described by him in 1979. Always somewhat of a showman, at the very end of his lecture, Alfvén again quotes the Chairman and ends by giving as advise to the young 500 students in the audience: Don’t go for a curriculum of General Relativity but chose Plasma Physics instead! Anders Bárány