-Scientists thought the earth was flat for a long time. It was a given. It was undisputed. Then, all of a sudden, it wasn't.
-Scientists said there were canals on Mars and that meant there had to be life. This spawned many more "facts" about Mars. Well, once a better telescope came out, turns out they were just dust being blown across the lens of the old telescope.
-Scientists said all people were born with a blank slate personality. Parents and outside influences caused all behavior pros and cons. Well, the discovery of DNA debunked that. Heck, we discovered DNA in 1869 but scientists still ignored it until 1953.
Geologists and historians now just accept that carbon dating is accurate. They don't dispute it. So naturally, when you are using a flawed measuring unit, the dating is going to be off.