What? Was everyone blind before the discovery of quantum mechanics? If we can't measure things we don't understand, how the heck would we come to understand them? Through their affects on the world? "No, you say, "we can not perceive things whose causes we don't understand." Where did you get your epistemology? Was it The Secret?

Karl Popper.

>If we can't measure things we don't understand, how the heck would we come to understand them?

We get new ideas, such as the concept of distance, by guessing them in response to problems.