An international team of scientists was able to revive a previously debunked theory of gravity, arguing that movement in dwarf galaxies will slow down if they are close to a massive galactic neighbor. The theory mentioned is the modified Newtonian dynamics (MOND). It had to be abandoned because the movement of the dwarf galaxy NGC1052-DF2 (200 million stars) studied was too slow.
MOND is an alternative to the general theory of relativity. The latter describes Einstein's understanding of gravity, which needs the existence of mysterious dark matter. However, no one was able to prove its veracity. MOND is attractive because it does not need a mysterious substance.
Similar theories are needed to understand the Universe, since galaxies rotate so fast that they must fly apart. Scientists have long argued about various theories. Recently, MOND decided to return to the fight, believing that it was written off too early. The fact is that in the previous work did not take into account the fact that the influence of the gravitational environment around the dwarf can affect its internal movements. That is, if a dwarf galaxy was located near a massive neighbor, then the movements inside the first should slow down and this is normal. Dark matter is considered an important element of the modern vision of space, because it is believed that it holds back galaxies from decay due to fast rotation. However, no one has yet managed to find its particles, although more than a decade of intensive research has been conducted with powerful detectors.
MOND is able to explain a huge amount of data on the speeds of galactic rotation, using only gas and visible stars. It applies a mathematical principle that enhances the gravity of visible matter, but only where it becomes too weak. Otherwise, gravity will follow the standard Newton's law (in the solar system or in proximity to a massive galaxy).
MOND still manages to make successful predictions using equations written 35 years ago. Future research will show which theory will be true. Perhaps all of our searches for dark matter are completely meaningless, because it simply does not exist.
