SC.7.N.3.1Laws vs. Theories

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

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)

Examples of Scientific Laws

What is a Scientific Theory?A scientific theory is a

well-supported, well-documented explanation of an observation.

THIS IS NOT A GUESS!!!

Examples of Scientific Theories

The Big Bang TheoryTheory of EvolutionTheory of Natural SelectionTheory of Plate TectonicsCell Theory

Scientific theories DO NOT become laws with more evidence.

Laws describe WHAT happens and theories explain WHY it happens.

Relationship between theories and laws

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?

Theories are rarely discarded.

Theories can change as more evidence is collected and new technology becomes

available.

Are theories forever?

FOR EXAMPLE….

People did once believe

that the Earth was

flat……

and the center of

the Universe

.

Describe what is represented in this image.

Explain why theories may be modified but are rarely discarded.

Scientific Laws Scientific 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

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?