The Elephant in the Universe: 100-year search for dark matter Author: Govert Schilling Challenging Dogma: MOND and the Exclusion of MACHO

The John Batchelor Show

The Elephant in the Universe: 100-year search for dark matter Author: Govert Schilling
Challenging Dogma: MOND and the Exclusion of MACHO
Headline: Alternative Gravity, MOND, Contests Dark Matter Theory as MACHOs are Ruled Out
Amidst the elusive search for dark matter, alternative theories have emerged. Mordehai Milgrom and his colleagues developed Modified Newtonian Dynamics (MOND), proposing that our understanding of gravity is flawed at galactic scales, thereby explaining rotational curves without needing dark matter. While some like Jeremiah Ostriker dismiss it, others such as Stacy McGaugh acknowledge its surprising success in fitting observational data. Gravitational lensing, as demonstrated by the Bullet Cluster, offers strong evidence for dark matter by showing separate distributions of mass and gas during galaxy collisions, challenging MOND. Meanwhile, another dark matter candidate, Massive Compact Halo Objects (MACHOs)—very massive, compact objects in galactic halos—was extensively searched for in the 1990s using gravitational microlensing. Despite significant effort, these searches yielded no detections, effectively ruling out MACHOs as the primary form of dark matter.
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