manythings said:
Flight was regarded as a fever dream until there was a plan. The idea of dark matter is born of arrogance. According to the equations the universe hasn't enough mass to account for the gravity it would take to keep it from firing off into eternity so instead of trying to figure out what was wrong with their hypothesis they invented an unverifiable X-factor to show that they were right all along. It's non-sense, they might aswell have blamed goblins for it. Dark Matter is just a new version of Phlogiston.
Actually, Einstein conceived Dark Matter in order to fix a problem he had with his Theory of Special Relativity. Then he regretted it and called it the greatest blunder of his career.
Annnnnd around fifty years later, when they pulled the equations and realized that SOMETHING had to fill the damn void, Dark Matter actually made sense.
It isn't proven, but it's a damn better hypothesis than Phlogiston (though Phlogiston is awesome).