The Bullet Cluster has, for practically 20 years, been hailed as an empirical “proof” of darkish matter. Can their detractors clarify it away?
It’s one of the well-accepted concepts within the Universe, and but one of the controversial: the notion of darkish matter. Right here within the Photo voltaic System, the Solar and planets are sufficient to clarify all the gravitational results that we see: merely use the regulation of Normal Relativity and what you expect matches what you observe precisely. However on bigger scales — the scales of galaxies, teams and clusters of galaxies, and even the grand cosmic net — the traditional matter that we all know of, together with every thing made from protons, neutrons, and electrons, merely isn’t adequate to clarify what we observe. Another huge ingredient, i.e., darkish matter, is required to convey issues again into alignment.
On the size of a single galaxy and under, different explanations, similar to modifications to gravity, are simply as profitable as darkish matter, with MOND being a primary instance. In truth, exams of huge binary stars might quickly be capable to take a look at these concepts in opposition to the notion of darkish matter instantly. However on bigger cosmic scales, such because the scales on which clusters of galaxies collide, those self same modifications of gravity are not any…
