An international group of astronomers, including Dr. Behnam Javanmardi from the astronomy school of IPM Iran, has revived a previously debunked theory of gravity, arguing that motions within dwarf galaxies would be slower if close to a massive galaxy.
The research team examined a theory previously published in the journal Nature which claimed that modified Newtonian dynamics (MOND) couldn’t be true because the internal motions were too slow within dwarf galaxy NGC1052-DF2, a small galaxy comprising about 200 million stars. MOND is a controversial alternative to general relativity, the prevailing Einstein-inspired understanding of the phenomenon of gravity, that requires dark matter to exist, but this has never been proved. MOND does not require dark matter. Such theories are essential in understanding our universe, as galaxies rotate so quickly they should fly apart, according to known physics.
Various theories have been put forward to explain what holds them together, and debate rages over which is right. The now debunked study claimed MOND was dead. However, this latest study – printed in Nature – shows that the earlier work neglected a subtle environmental effect.
The new research argues that the previous work did not consider that the influence of the gravitational environment around the dwarf could affect motions within it. In other words, if the dwarf galaxy were close to a massive galaxy – which is the case here – then the motions within the dwarf would be slower.
Source: University of St. Andrews