Birkeland was among the first to speculate that the Northern Lights were charged particles ejected from the Sun, captured by the Earth's magnetic field, and directed towards the polar atmosphere. To prove this theory, Birkeland performed his famous 'Terella' experiments where he artificially created the aurora in the laboratory. His theories were initially laughed at, and it is only now in the space age that measurements from satellites are proving him correct. After a controversy that raged for one quarther of a century, the electric currents that flow through space are named after him – Birkeland currents.

"It seems to be a natural consequence of our point of view to assume that the whole of space is filled with electrons and flying electric ions of all kinds, and we have assumed that each solar system in evolution throws off electric corpuscles into space. It does not seem unreasonable therefore to think that the greater part of the material masses in the universe are not in the solar sytems or nebulae but in empty space."
Kristian Birkeland

Significantly, his approach to science was broad, comprising observation and laboratory experimentation in addition to mathematical modelling. He was not content with a merely theoretical approach, despite having trained as a mathematician himself.

He is probably Norway's greatest ever scientist, and many of his works are still used as reference materials. He is recognised for bringing plasma and electromagnetism into cosmology, but while many of his ideas are widely accepted, his cosmological theories are less well known. He died aged 49 just when a working committee was in the process of nominating him for the Nobel Prize in Physics.

Birkeland has been called the first 'space scientist'. He was a full professor of physics at the University of Oslo aged just 31.

Langmuir (1881-1957) was the first to use the term 'Plasma' in 1927, borrowing it from Blood Plasma to describe the almost life-like and self-organising behaviours of a plasma when in the presence of electrical currents and magnetic fields.

He discovered Plasma Sheathes, now called Double Layers, having observed the electrons and ions of a plasma separating during experimentation. DLs are one of the most important features of plasma behaviour. He also defined and explained the term 'valence' as part of his description of the atom. Few textbooks, however, recognise the influence that Langmuir had on the development of our understanding of the nature of the atom.

He became the first 'non-academic' chemist to receive the Nobel Prize, an accomplishment he realised in 1932. Langmuir probes, which can be used in space, are named after him.

[There] are cases where there is no dishonesty involved but where people are tricked into false results by a lack of understanding about what human beings can do to themselves in the way of being led astray by subjective effects, wishful thinking or threshold interactions. These are examples of pathological science. These are things that attracted a great deal of attention. Usually hundreds of papers have been published upon them. Sometimes they have lasted for fifteen or twenty years and then they gradually die away.
Irving Langmuir

Alfvén (1908-1995) is generally regarded as the Father of modern Plasma Physics. He continued the work of Birkeland, feeling very much in spirit with him, and eventually won a Nobel Laureate for his ground-breaking contributions. He was not always highly regarded by the scientific establishment because of his controversial ideas, however, and suffered no little condescension and ridicule in his lifetime.

In fact, it now seems bizarre that he wasn't awarded the Nobel Prize until 1970, especially considering his many fundamental accomplishments. For some time he was forced to publish in journals that did not enjoy international readership. His ideas finally became known to the general scientific community through his ground-breaking book, Cosmical Electrodynamics, published by Oxford University Press in 1950.

Alfvén took a practical and intuitive approach to science, insisting that theories of cosmological phenomena must agree with laboratory experiments. (The definition of 'laboratory' being broadened to include experiments in space.) Having started out as an engineer, his methods were in direct opposition to the approach generally favoured by Big Bangers, that of starting-out from idealised mathematical principles.

In 1937 Alfvén proposed that our galaxy contained a large-scale magnetic field and that charged particles moved in spiral orbits within it, owing to forces exerted by the field. Plasma carried the electrical currents which create the magnetic field.

"In order to understand the phenomena in a certain plasma region, it is necessary to map not only the magnetic but also the electric field and the electric currents."
Hannes Alfvén

While many of Alfvén's theories are now well known, like those of Birkeland, the cosmological implications of his work also remain to be fully recognised. Ironically, some have put this down to the very simplicity of many of these ideas.

"The peer review system is satisfactory during quiescent times, but not during a revolution in a discipline such as astrophysics, when the establishment seeks to preserve the status quo."
Hannes Alfvén

"The universe is an unending transformation in flux whose previous states we are not privileged to know." David Bohm

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