Ch. 1 - The Nature of Science

Section 1: The Methods of Science

What is Science?

Science is a process that uses observation and investigation to gain knowledge about events in nature

Major Categories of Science

Life Science the study of living organisms

Earth Science the study of Earth and space

Physical Science the study of matter and energy chemistry & physics

Science Explains Nature Sometimes explanations must

be modified New information or technology

New Information through Investigation Observation Setting up experiments Build a representative model

B. Scientific Methods An organized set of investigation procedures.

How do we build a vehicle that can carry people to outer space?They needed a material that could withstand heat and force of re-entry

B. Scientific Methods An organized set of investigation procedures.

•Information on melting points of materials•What tests could they do?•Materials used in similar situations

B. Scientific Methods An organized set of investigation procedures.

Hypothesis: a possible explanation using what you know and observe.Ceramic coating used for guided missiles might also work for space shuttle.

Test the hypothesis using an experiment

Experimental Design

Experiment - organized procedure for testing a hypothesis

Key Components: Control - standard for comparison Single variable - keep other factors

constant Repeated trials - for reliability

Experimental Design

Types of Variables Independent Variable

adjusted by the experimenter what you vary

Dependent Variable changes in response to the indep.

variable what you measure

Experimental Design

Constants and Controls Constant

A factor that doesn’t change when other variables change.

Control The standard by which the test

results can be compared.

B. Scientific Methods Analysis Conclusions

C. Scientific Theories and Laws

Hypothesis - testable prediction

Theory - explanation of “why”. based on many observations &

experimental results

Scientific Law - prediction of “what” happens in nature.

Theories can explain a law

Scientific Theories and Laws

Theories and laws are well-accepted by scientists, but...

They are revised when new information is discovered.

THEY ARE NOT SET IN STONE!

Practice: Scientific Method

1. Determine the problem. When the Titanic sank, what happened to

the water level on shore?

2. Make a hypothesis. The water level rose. The water level dropped. The water level stayed the same.

3. Test your hypothesis. How could we test our hypothesis?

4. Analyze the results. What happened during our test?

5. Draw conclusions. Was our hypothesis correct? Is further testing necessary?

Practice: Scientific Method

Hypothesis: Storing popcorn in the freezer makes it

pop better.

Control: Popcorn stored at room temp.

Single variable: Storage temperature

Constants: Popcorn brand Freshness Storage time Popper

Independent Variable: Storage temperature

Dependent Variable: Number of unpopped kernels

Using Science-Technology

Pure Science research that adds to the body of

scientific knowledge Observing blood flow through heart

Applied Science (Technology) the practical application of scientific

knowledge to help people Creating replacement valves

Defining Science

PURE human genetics

polymer science

atomic theory

study of the human ear

APPLIED DNA fingerprinting

Lycra® spandex

nuclear weapons

hearing aids