Bellringer 09/11/14

Differentiate between a test variable and an outcome variable

Bellringer

Differentiate between repetition and replication. Why are both important?

Topic: Theories and Laws

EQ: What are theories and laws?

If you see a movie in which early humans fight giant dinosaurs, how would you judge the scientific accuracy of that movie? Give

reasons for your judgment.

Scientific Laws, Hypotheses, and Theories

In layman’s terms, if something is said to be “just a theory,” it usually means that it is a mere guess, or is unproved. It might even lack credibility.

EXAMPLES OF LAWS AND THEORIES

Scientific Laws vs. Theories

The difference between a hypothesis, law and theory is the amount of confirmed experimental evidence.

What is a Scientific Law?a. A scientific law is a description of an observed phenomenon.

b. Explains what will happen does not explain why it happened…Ex. Gravity….

Scientific Law

◦Based on direct evidence, and can be reproduced many times with the same result.

◦Example: The Law of Gravity.. What goes up must come down…

WHAT IS A THEORY?

What is a Scientific Theory?

A scientific theory is a well-supported, well-documented explanation of an observation. In other words an accepted hypothesis

Tells us how something happens..

In scientific terms, a theory implies that something has been proven and is generally accepted as being true.

Flexible enough to be modified if new data/evidence is discovered

                     

How Theories are made…

records

Examples: Theories

Plate Tectonics

Plate tectonics is the study of the processes that have formed the features of the earth.

Mid Ocean Ridges

Mountains

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?

Plate TectonicsIn the 1800’s

Alfred Wegener developed the Theory of Continental Drift.

His theory simply stated that the continents were moving.

But no one believed him.

Why didn’t anyone believe Wegener?

A) He didn’t have enough evidence.B) People thought a weatherman should

stick to forecasting the weather.C) Because Wegener wasn’t looking at the

fossil evidence.D) Because Wegener couldn’t explain HOW

the continents were moving.

Plate Tectonics

Harry Hess began mapping the ocean floor during World War II.

He discovered a chain of mountains in the middle of the ocean!

255 Million Years Ago

255 Million Years Ago

Present Day Position

Present Day Position

250 Million Years From Now

250 Million Years From Now

Describe what is represented in this image.

People did once believe

that the Earth was

flat……

and the center of

the Universe

.

Fall 2005, Pflugerville ISDChapter 1 Section 3

Let’s Review

What is the difference between a scientific theory and a scientific law?

Fall 2005, Pflugerville ISDChapter 1 Section 3

Answer

Theories are unifying explanations for broad range of hypotheses and observations.

Laws are summaries of experimental results and observations.

Hypothesis

Closing Activity: ISN 38 Directions:Complete a double bubble map comparing

theories and laws….

Theories Laws

similarities

differencesdifferences