# 8. Not all Theories on Earth are True

## First Proof

A quick search on Google tells you that factories employ a lot of workers.

Since man must eat, a factory boss might not have enough resources for his research and thus publishes half true results.

## Second Proof

This occurs in mathematics exams: a student solved a mathematical problem and was sure of his answer. But when the teacher marks the studentâ€™s answer, he finds something wrong from the reference books the teacher used.

Furthermore, it is usually common for a student to have gotten three steps right while missing a single step. And this single step would make his final result wrong.