Pink Noise - Leonid Korogodski [50]
Every single so-called “proof” of dark matter’s existence to date is just like that: dark matter must exist because there would have been a gap between theory and observation otherwise. Duh!
Since then, dark matter was conveniently sprinkled anywhere it was needed to close yet another gap between theory and observation—and the number of such gaps kept mounting. New surprises, contradicting the generally accepted wisdom, were popping up like mushrooms almost anywhere one aimed a telescope. Naturally, the same kind of dark matter could not explain them all. So the variety kept growing. Soon we had cold dark matter, hot dark matter, warm dark matter, weakly interacting dark matter, strongly interacting dark matter, repulsive dark matter, self-annihilating dark matter, even fuzzy dark matter. . . none of which was ever observed, and not for the lack of trying. Moreover, the total amount of dark matter called upon dwarfed the visible matter many times over.
Contrary to a common misconception, Occam’s Razor principle does not say that a simpler explanation is more credible.
Somewhere along the way, scientists must have forgotten the venerable Occam’s Razor principle: Do not invent new entities in vain!
The world hadn’t seen the like of it since the infamous epicycles.
ENTER HANNES ALFVéN (1908–1995). AN EXPERIMENTALIST with incredibly strong intuition, he would have felt himself at home in the 19th century, the time of hands-on experimental science and passionate inventors. Instead, he lived and worked during the era when theory dominated over experiment in certain fields, the era of an increasing compartmentalization of science and the rise of scientific bureaucracy. One of the pioneers of plasma physics, he crossed into the space sciences with new ideas, going against the established wisdom. Even after he received the Nobel Prize in Physics in 1970, he continued to be ignored by the astrophysical establishment.
His sin was to maintain that the universe was made mostly not of dark matter but of plasma, a state of matter that contained charged particles (electrons and ions) instead of, or in addition to, neutral atoms—and consequently that the electromagnetic force played an equal or greater part than gravity at the galactic and supra-galactic scales.
Already in 1937, he predicted the existence of a galactic magnetic field. Before the space age, nothing seemed to portend such a discovery. Space was considered to be a vacuum, which obviously couldn’t conduct electric currents, and so no magnetic field on such a scale was possible.
Of course, as soon as we went into space, we discovered that it was filled with plasma, electric currents, and magnetic fields. But even though the existence of electric currents in the solar system soon became common knowledge, galactic-scale electric currents continued to be denied.
The (in)famous Alfvén–Chapman controversy lasted for decades; it’s symptomatic of the relationship between theory and experiment in the 20th century space sciences. The argument between Hannes Alfvén and Sydney Chapman (1888–1970) was about the nature of auroras. Chapman thought that the electric currents creating auroras existed entirely within the Earth’s magnetosphere. Alfvén believed that there was an explicit Sun–Earth connection, continuing the tradition that began with Kristian Birkeland (1867–1917), a Norwegian scientist, inventor, and polar explorer, whose name Chapman had been systematically trying to erase from history of science.
Alfvén’s is quoted in [9] on Chapman’s approach to Birkeland’s scientific legacy.
Chapman’s theory