More than 50 years have passed since astronomers first recommended “dark matter,” which is believed to be the most popular form of substance in the universe. However, we have no idea what it is, and no one has seen it or generated it in the lab directly.
According to our promising gravitational theory for these scales, Newton’s law states that stars and gas in a galaxy should rotate slower and slower the more distant they are from the galaxy’s center. That’s because the maximum of the stars will be near the center, developing a solid gravitational pressure.
Regarding the strange rotation in galaxies, the data alone cannot explain if the observed velocities are due to additional unobservable matter or because our existing gravitational laws are inaccurate.
Scientists thus look for more data in other contexts that will ultimately settle the question. One such example of dark matter appears from the observations of how matter is circulated in the Bullet cluster of galaxies, composed of two colliding galaxies roughly 3.8 billion light-years away from Earth. Another is based on measurements of how light is diverted by matter in the cosmic microwave environment and the light left over from the big bang. These are always recognized as indisputable evidence in favor of dark matter because Milgrom’s initial theory can’t decipher them.
One strategy to understand it is to utilize the philosophical tools of Bayesian confirmation theory. This is a probabilistic framework for calculating the degree to which the available information assists assumptions in various contexts.