Science and the Scientific Method

An Introduction for Paramedic Students

What is Science?

Science =

A set of facts and the theories that explain the facts.Whatever’s being done by institutions carrying on “scientific” activity.A particular approach, the scientific method.

Popular Fictions

The goal of science is to accumulate facts

Science distorts reality and can’t do justice to the fullness of human experience.

Scientific knowledge is truth.Science is concerned primarily with

solving practical and social problems.

“Science is neither a philosophy nor a belief system. It is a combination of mental operations that has become increasingly the habit of educated peoples, a culture of illuminations hit upon by a fortunate turn of history that yielded the most effective way of learning about the real world ever conceived.”

Edward O. Wilson

Consilience: The Unity of Knowledge

So then, what is Science?

The Heart of the Matter

Why do we see what we do and not something

else?

Explanation

Mythos “The Word”

An authoritative account of the facts that is not to be questioned.

Thales of MiletusThe Father of Greek

Science, Philosophy, and Mathematics

Man is capable of understanding nature.

Natural phenomena have natural explanations.

Logos“The

Word”An account

of the facts whose truth can be demonstrated and debated

AristotleDeveloped “logos”

into “logic”Advocated

deductive reasoning as a tool for understanding nature

Dominated scientific thinking for the next 2000 years

Deduction

Reasoning from the general to the specific “All men are mortal.” (major premise) “Socrates is a man.” (minor premise) “Therefore, Socrates is mortal.”

(conclusion)Always produces correct answers if

the premises are correct.

The Problems of Deduction

The conclusions are only as good as the premises.

Because it moves from general to specific cases, deduction does not generate new knowledge.

The Problem with Aristotle

He didn’t advocate the use of experiments or observations to check the validity of premises.

He was a pure rationalist.“Thinking about it is good enough.”

Francis Bacon If you want to know

how the world works, begin with the facts. Not prejudices about what the facts are.

Infer general instances from specific observations.

Draw conclusions about future events from past observations.

Induction

Reasons from the specific to the generalCan generate new knowledgeHowever, the accuracy of that new

knowledge can NEVER be proven with 100% certainty

WHY?

Because we can never be 100% certain about what our next observation will show

Galileo

If you have a theory about how a phenomenon works, test it with an experiment.

During an experiment, try to control all of the variables except the one you are interested in.

Isaac NewtonMathematics is the

language of nature.The world of

observation can be encoded into mathematical form.

Mathematical forms can be decoded into new statements about reality.

The Scientific Method

Observation

Hypothesis

Experiment

Empirical LawEmpirical Law

Are about kinds of events, not any single event

Show relationships between two or more kinds of events

Are supported by a large amount of experimental data

Are applicable to a variety of different events

Empirical LawsEmpirical Laws

An Example: Boyle’s LawAn Example: Boyle’s Law

In 1662, Irish chemist Robert Boyle studied the effects of pressure changes on the volume of gases.

An Example: Boyle’s LawAn Example: Boyle’s Law

His experimental results showed that as pressure increases, the volume of a gas decreases proportionately.

PV = constant So, if we decrease the

volume of a container, we can predict how much the pressure of the gas inside will increase.

An Example: Boyle’s LawAn Example: Boyle’s Law

Boyle’s work was later combined with that of Jacques Charles and Joseph Gay-Lussac to produce the Ideal Gas Law.

PV = nRT The Ideal Gas Law predicts the behavior of gases

over a wide range of temperatures, pressures, and volumes.

There’s just one problem:

It doesn’t explain how this stuff works!

We need a theory!!!

A means of relating the laws describing a class of events to a framework and a set of principles described in terms differing from those used for the laws.

The observations predicted by the Ideal Gas Law are explained by the Kinetic Theory of Gases.

The Kinetic Theory of GasesThe Kinetic Theory of Gases

Let’s assume that the molecules making up a gas are like little billiard balls...

Wouldn’t that make the gas pressure equivalent to the number of impacts by the billiard balls with the sides of the container?

So, if we decrease the size of the container, what happens to the number of impacts?

What would happen to the number of collisions if we increased the velocity of the billiard balls?

Isn’t increasing the velocity of the billiard balls equivalent to increasing the temperature of the gas?

The Kinetic Theory of GasesThe Kinetic Theory of Gases

Theory of Billiard

Balls

Observations on Billiard

Balls

MODEL(Tiny elastic

spheres)

Kinetic Theory

Observations on Gases

Analogy?

Analogy?

A Good Theory Is...

Accurate

Fruitful

Simple Broad

Consistent

Why there are no scientific “truths”The Problem of Induction

Hypotheses, laws, and theories are

products of inductive reasoning

Products of inductive reasoning are only as good as

the next observation

So, no amount of data will ever

confirm a hypothesis, law, or

theory

But it only takes one negative piece of data to refute it

Falsifiability

“The scientific mentality may be roughly characterized as the tendency to suspend belief until evidence of the appropriate kind is produced. And then to believe the proposition in question to the degree that the available evidence warrants it, without excluding the possibility of a further disconfirmation.”

Sir Karl Popper

Norms of Science

Accessibility

SkepticismUniversalit

y

Detachment

Originality

The Hallmarks of Pseudoscience

Anachronistic Thinking

Seeking Mysterie

sAppeals to Myths

Casual Approach to Evidence

Irrefutable Hypotheses

The Hallmarks of Pseudoscience

Spurious Similarities

Explanation by Scenario

Research by Literary Interpretation

Refusal to

Revise

Eight Important Points

Anecdotes do NOT make scienceScientific language does NOT make

scienceBold statements do NOT make claims

trueHeresy does NOT equal correctness

Eight Important Points

Rumors do NOT equal realityUnexplained is NOT inexplicableCorrelation does NOT mean

causationCoincidence does NOT mean

connection

Always remember...

“A wise man proportions his belief to the evidence.”David Hume