There are many independent lines of evidence: https://en.wikipedia.org/wiki/Dark_matter#Observational_evidence https://en.wikipedia.org/wiki/Dark_matter#Observa

There are many independent lines of evidence: https://en.wikipedia.org/wiki/Dark_matter#Observational_evidence https://en.wikipedia.org/wiki/Dark_matter#Observational_evid... Contrarian theories have outsized popularity here on hnews, and this tends to get fed by garbage articles from the usual sources (glances at quanta with mild disdain). Modified gravity theories are not some alternate path we just didn't explore. We explored them. They fail to explain the observational evidence. In particular the way stuff moves in galactic collisions makes very clear there's dark matter distinct from some modified version of gravity interacting with visible matter. It ends up that the consensus view of thousands of Phds that study this stuff is actually not trivially mistaken.