Dark matter represents 85% content of our cosmos and is essential in making the Universe function. The fact that dark matter does not reflect, absorb or emit light makes it harder to study. Yet, there are few leading scientists who have helped us understand dark matter.
In May 1922, Dutch astronomer Jacobus Kapteyn’s Astrophysical Journal paper was the early one to mention the term, ‘Dark Matter’. In his last paper, Kapteyn presented his model, ‘Kapteyn Universe’, a comparatively small Milky Way with the Sun close to its center, and nothing outside its outer edge. Although the model turned out to be incorrect, it indicated that it will be possible to define the amount of dark matter from the gravitational effect. Kapteyn’s work led to the birth of the ‘riddle of dark matter.
Zwicky was examining individual galaxies in the Coma Cluster when he found that the Coma galaxies were moving much faster than anticipated given the cluster’s visible content. Zwicky wrote in a 1933 Swiss magazine paper that to stop the cluster from flying apart, it needed an enormous amount of invisible mass known as ‘dunkleMaterie’ or dark matter. For the time when the dark matter riddle was largely neglected, this was a significant observation.
In 1973, Peebles while working with fellow Princeton astrophysicistsrevealed that disc galaxies like Milky Way or Andromeda cannot be stable until they are embedded in enormous halos of dark matter. Peebles suggested that dark matter is cold and should not experience any interaction with ‘normal’ matter beyond gravitational relation. This proved to be a key observation in explaining the structured universe we see.
While at the University of California, Faber along with John Gallagher authored a well-received review article on dark matter for Annual Reviews of Astronomy and Astrophysics which was published in 1979. They successfully convinced the scientific community that dark matter is not imagination but a major component of the universe.Five years later, Faber co-authored another remarkable paper that described the evolution of a cold, dark matter-dominated Universe.
Israeli particle physicist Mordehai Milgrom presented his MOND theory (Modified Newtonian Dynamics) in 1983 which explains the flat rotation curves found by Rubin, Ford, and their colleagues, without any need for enigmatic dark matter.If his findings are true, the century-old search for dark matter may have been idealistic. This could challenge the old understanding of the Universe and proposal new thinking.
Only time will tell the truth behind dark matter.
