1. Laws vs. Theories

2. What is a Scientific Law? A scientific law is a description of an observed phenomenon. It offers no explanation to why they are that way. A scientific law can often be reduced to a mathematical statement, such as E = mc²

4.  Newton’s Laws of Motion  Law of Universal Gravitation  Kepler’s Law of Planetary Motion  The Laws of Thermodynamics  Law of Bouyancey (Archimedes' Buoyancy Principle)

5. What is a Scientific Theory? A scientific theory is a well-supported, well-documented explanation of an observation. THIS IS NOT A GUESS!!!

6.  The Big Bang Theory  Theory of Evolution  Theory of Natural Selection  Theory of Plate Tectonics  Cell Theory

7.  Scientific theories DO NOT become laws with more evidence.  Laws describe WHAT happens and theories explain WHY it happens.

8.  The theory of plate tectonics was introduced in the 1960s to explain how the Earth's plates move and to provide some understanding as to how volcanoes, earthquakes and tidal waves occur. The theory of plate tectonics also explains mountain range formation, ocean ridges and undersea trenches.  Why is plate tectonics a theory?

9. Theories are rarely discarded. Theories can change as more evidence is collected and new technology becomes available. FOR EXAMPLE….

10. People did once believe that the Earth was flat……

11. and the center of the Universe.

13. Explain why theories may be modified but are rarely discarded.

14. Scientific LawsScientific Theories  Hubble’s Law of Cosmic Expansion  Kepler’s Law of Planetary Motion  Universal Law of Gravitation  Newton’s Laws of Motion  Law of Thermodynamics  Hooke’s Law of Elasticity  Ideal Gas Law  The Big Bang Theory  Theory of Evolution  Theory of Natural Selection  Theory of Plate Tectonics  Cell Theory

15. 1. Why is the Law of Conservation of Energy a law instead of a theory? 2. Why is the scientific theory of evolution a theory instead of a law?