Most scientists also thought it was crazy at first--surely there must be some simpler explanation than just conjuring up a new type of matter. But at this point

Most scientists also thought it was crazy at first--surely there must be some simpler explanation than just conjuring up a new type of matter. But at this point, the dark matter theory is by far the most popular. There are a lot of reasons we know that dark matter is (almost certainly) non-baryonic. For one, we know how much baryonic matter there is (based on models of the big bang, etc.) And while no one has seen dark matter in a laboratory, we have observed it indirectly (eg by gravitational lensing). [1] https://www.nasa.gov/vision/universe/starsgalaxies/dark_matter_proven.html https://www.nasa.gov/vision/universe/starsgalaxies/dark_matt...