Theories, Models, and Laws – Oh, my!

What is a scientific theory?

• a well-supported

explanation about

the natural world.

What does it really mean?•A scientific theory

EXPLAINS WHY or

HOW something

happens.

Example 1:• The Big Bang Theory

– more than just a TV show.

– it is the idea that the universe

started as a very dense ball of

matter and exploded outward

and formed the universe as we

know it.

• Edwin Hubble and others proved the

universe is still expanding today!

Example 2:

• Darwin’s Theory of

Evolution: the theory that

all life came from a common

ancestor, with specific traits

becoming different species.

– Natural selection – only the

organisms with the best

characteristics for survival will

survive.

Example 3

• Plate Tectonics

• The theory that the

Earth’s outer layer is

divided into plates

which move and carry

the continents with

them.

What is a scientific law?

• - describes a basic

principle of nature that

always occurs under

certain conditions.

What does it really mean?

•- DESCRIBES WHAT

you can expect to

happen.

Example 1• Law of

superposition

(geology) – states

that each layer of rock is

younger than the layer

underneath it.

• Kind of like your laundry

hamper

Example 2• Kepler’s Laws of Planetary Motion

– – 1 . All planets orbit the sun in elliptical orbits.

Example 3

• Newton’s Laws

of Motion: – 1st Law – an object

in motion stays in

motion until

another force acts

on it.

Models

• Not the skinny kind!

• Illustrate something

too big or too small for

humans to study easily.

Models – what it really means

•SHOWS how

something looks or

behaves

Example 1

Example 2

Example 3

EXIT TICKET!

• Using sign language, you’re going to

show me you know what we just

covered!

A.

an untested idea

B.

an educated guess

C.

an accepted description

D.

a well-supported explanation

2. Which phrase defines a scientific theory?

A.

Hurricanes get bigger over warm water.

B.

The eye is the calmest part of the storm.

C.

Hurricanes have wind speeds greater than 119 km/h.

D.

Rotating thunderstorms gain energy over warm tropical waters.

3. Which statement belongs in a scientific theory about how hurricanes form?

A.

In theory, the experiment will work as planned.

B.

She has a theory about why the storm arrived later than predicted.

C.

The atomic theory explains that material objects are made up of atoms.

D.

The doctor’s prescription for curing a cold is based on his best theory or guess.

4. In which statement does the word theory mean scientific theory?

A.

a hypothesis

B.

an observation

C.

a scientific law

D.

a scientific theory

5. The fact that atoms and molecules are always in motion helps scientists explain how solids turn into liquids. What is this explanation an example of?

A.

data model

B.

visual model

C.

conceptual model

D.

mathematical model

6. The following map shows how likely it is for a storm to develop winds that are fast enough to become a tropical storm. The map was made with a computer program that uses weather data and mathematical equations to make predictions about the storm.What type of model is shown in the diagram?

A.

a model

B.

an observation

C.

a scientific law

D.

a scientific theory

17. Scientists need to know how gravity acts on a space shuttle so they can put the space shuttle into orbit. They use an equation that describes how gravity relates to the mass of two objects and the distance between the two objects. Which term describes this equation?

A.

The sun rises in the east.

B.

Why does the sun rise in the east?

C.

The sun appears in the east because of Earth’s rotation pattern.

D.

If the sun appears in the east, then I am in the Western Hemisphere.

18. Bryce observes that the sun always seems to rise in the east. He talks with others and finds that everyone has the same observation. Which statement is a scientific law?