What Is Scientific Uncertainty?

Inspired by this infuriating piece in the NYT, I want to go over the concept of scientific uncertainty.

Scientific uncertainty is a concept meant to remove bias and prevent scientific findings from becoming misleading. It means that, in any given experiment, there may be variables that the scientist can't see or can't control. Those variables could affect the experiment or the findings. Or, they may have nothing to do with it. Whatever an experiment or an observational study found, uncertainty...