https://en.wikipedia.org/wiki/Bullet_Cluster https://en.wikipedia.org/wiki/Bullet_Cluster We know there's a bunch of mass we can't see: https://en.wikipedia.or

https://en.wikipedia.org/wiki/Bullet_Cluster https://en.wikipedia.org/wiki/Bullet_Cluster We know there's a bunch of mass we can't see: https://en.wikipedia.org/wiki/MACS_J0025.4-1222 https://en.wikipedia.org/wiki/MACS_J0025.4-1222 https://en.wikipedia.org/wiki/Dragonfly_44 https://en.wikipedia.org/wiki/Dragonfly_44 We have had direct detection of dark matter since the 50s https://en.wikipedia.org/wiki/Neutrino https://en.wikipedia.org/wiki/Neutrino And the generally successful standard model predicts several possible additional forms of dark matter e.g. https://en.wikipedia.org/wiki/Neutralino https://en.wikipedia.org/wiki/Neutralino I mean no shit there are in answered questions. We aren't omniscient. this is how it works.