The Scientific MethodThe Scientific Method

……and the Nature of Scienceand the Nature of Science

What is science?What is science?

Science is the total collection of knowledge Science is the total collection of knowledge gained by observation of the physical gained by observation of the physical universe. universe.

It tries to answer the questions "how" and It tries to answer the questions "how" and "why." "why."

It is a logical way of problem solving. It is a logical way of problem solving.

It is basically common sense.It is basically common sense.

The Scientific World View

The world is understandable - truth exists

Scientific theories are subject to change

Science cannot provide answers to all questions

Characteristics of Science

Science is a process

Scientific theories must be falsifiable

Scientific theories must be able to predict

Scientific experiments must be repeatable

Confidence in theories is not absolute

The Limitations of ScienceThe Limitations of Science

Cannot make value judgments. Cannot make value judgments.

Cannot prove something doesn't exist Cannot prove something doesn't exist (universal negative). (universal negative).

Scientific investigation is as limited as the Scientific investigation is as limited as the instruments we use. instruments we use.

Inductive and Deductive ApproachesInductive and Deductive Approaches Inductive ApproachInductive Approach

Empirical data leads to generalizationEmpirical data leads to generalization Experiments or observations lead to predictions about Experiments or observations lead to predictions about

the futurethe future Used by scientists trying to discover or explain Used by scientists trying to discover or explain

phenomenaphenomena

Deductive ApproachDeductive Approach Observations lead to explanations about past events Observations lead to explanations about past events

or observed phenomenaor observed phenomena Post-dictions can be tested with experimentsPost-dictions can be tested with experiments Used by Police and CSI specialistsUsed by Police and CSI specialists

Inductive Approach ExampleInductive Approach Example

Empirical DataEmpirical DataThe more times I water my grass during the The more times I water my grass during the

week, the greener the grass becomesweek, the greener the grass becomes

GeneralizationGeneralizationMore water equals greener grassMore water equals greener grass

This yields correlation only This yields correlation only not cause and effect not cause and effect

Deductive Approach ExampleDeductive Approach ExampleGeneral ideaGeneral idea

More water equals greener grassMore water equals greener grass

PredictionPredictionThe more I water, the greener the grass will The more I water, the greener the grass will becomebecome

ExperimentExperimentVary the amount of water and measure how Vary the amount of water and measure how green the grass becomesgreen the grass becomes

Scientific StatementsScientific Statements FactsFacts - things that are observable and indisputable. - things that are observable and indisputable.

DataData - any piece of information; usually gained - any piece of information; usually gained through experimentation. through experimentation.

TheoriesTheories - explanations usually based on evidence - explanations usually based on evidence (may be wrong). (may be wrong).

ModelsModels - man-made ideas to help us visualize - man-made ideas to help us visualize scientific concepts. scientific concepts.

LawsLaws - statements that describe patterns in nature - statements that describe patterns in nature with no known exceptions. with no known exceptions.

The Scientific MethodThe Scientific Method

Observe the situation Observe the situation Ask a question Ask a question Turn that question into a testable idea Turn that question into a testable idea Predict the outcome of your experiment Predict the outcome of your experiment Perform your experiment Perform your experiment Analyze the results Analyze the results Evaluate your idea or Evaluate your idea or hypothesishypothesis

Systems of MeasurementSystems of Measurement English System of MeasurementEnglish System of Measurement: : is the one you use is the one you use

commonly, and includes pounds, feet, and gallons. commonly, and includes pounds, feet, and gallons.

International System of Measurement or SI:International System of Measurement or SI: is called is called the metric system in the US. It’s based on units of ten, the metric system in the US. It’s based on units of ten, and all science measurements use this system. and all science measurements use this system.

Know these SI units: Know these SI units:

MeterMeter - unit of length (about a yard) - unit of length (about a yard) KilogramKilogram - unit of mass (about ½ a pound) - unit of mass (about ½ a pound) LiterLiter - unit of volume (about a quart) - unit of volume (about a quart) Celsius DegreesCelsius Degrees - temperature unit (about ½ degree F°) - temperature unit (about ½ degree F°) SecondSecond - unit of time ( - unit of time (same unit in metric, subdivides by tenthssame unit in metric, subdivides by tenths))

It’s All Greek to Me!It’s All Greek to Me!

• Mono - 1 Mono - 1 • Duo/Di - 2 Duo/Di - 2 • Tri - 3 Tri - 3 • Tetra - 4 Tetra - 4 • Penta - 5Penta - 5

• Hex/Hexa - 6 Hex/Hexa - 6 • Hepta - 7 Hepta - 7 • Octa - 8 Octa - 8 • Deca - 10 Deca - 10 • Hecaton 100Hecaton 100

Friends, Romans, Countrymen!Friends, Romans, Countrymen!

1 - una1 - una2 - duo 2 - duo 3 - tres, tria 3 - tres, tria 4 - quattuor 4 - quattuor 5 - quinque 5 - quinque 6 - sex6 - sex

•7 - septem 7 - septem •8 - octo 8 - octo •9 - novem 9 - novem •10 - decem 10 - decem •100 - centum 100 - centum •1000 - mille1000 - mille