Earth Science

Principles of Science

Development of Theories

Study Tip
Although a theory is often trusted and reputable, theories must be constantly tested and revised. Gravity is a law because it applies in every situation in the same way (but perhaps in different quantities).

Theories and Laws

  • A scientific theory is a strongly supported hypothesis with no significant evidence to disprove it.
  • If conflicting data is discovered, theories can be revised or discarded.
  • A law is something that always applies the same way, regardless of the conditions.
  • Laws explain simpler things than theories: laws state that things happen, but theories explain why they occur.












Theories are very comprehensive, and thus scientists spend
a lot of time trying to reinforce and develop their theories.
Study Tip
Although a theory is often trusted and reputable, theories must be constantly tested and revised. Gravity is a law because it applies in every situation in the same way (but perhaps in different quantities).
Open note book
Open note book
Theories are very comprehensive, and thus scientists spend
a lot of time trying to reinforce and develop their theories.
Concept Check
  • Can a law become a theory? Can a theory become a law?
  • Which one is the most important: hypothesis, theory, or law?