For example, there's the "theory of evolution." But "scientists" act like it's absolutely proven fact. Untrue. Even Darwin wrote that if anything in life was shown to be impossible to develop over time, then his "theory" would be blown out of the water. And things like that have been found that have what is called "irreducible complexity," such as the single cell organisms that have tiny motors and propellers for locomotion. It's a complete assembly that wouldn't work without all those part simultaneously.

The "theory of relativity" is just a theory, but I think it has more going for it in the way of experiments.