Concept Summary

Batesville High School Physics

Natural PhilosophySocrates, Plato, Aristotle

Were the “authorities” in Western thought from about 500 BCE to 1600 AD

Believed that there was a perfect world, but this world isn’t it

Natural PhilosophyAristotle’s “perfect world” was

accessible only through thought and contemplation.

Observation or experiment on this dirty, nasty imperfect world was useless in understanding “timeless truth.”

Beginnings of ScienceScience, as we know it, evolved from

“natural philosophy” (literally “thinking about nature”) starting about the year 1600 due to the work of Galileo, Bacon, and many others.

Scientific Progress In the last 400 years, scientists have

made incredible strides in their efforts to understand our universe (although there

is still much to know).Scientific progress has brought about

technological progress that Galileo could not have imagined.

Scientific Methods

The progress of science has not been due to adherence to a simple-minded step-by-step process, as many elementary texts would have you believe.

Scientific MethodsTo quote our text (p. 2): “The success of science has more to do

with an attitude common to scientists than with a particular method. This attitude is one of inquiry, experimentation, and humility before the facts.”

Scientific MethodsSomething to keep in mind:

Since science is such a huge and complex enterprise with no central governing body, just about any generalization about science and scientific methods is not going to be strictly true.

Many people naively expect certainty and absolute truth from science - science doesn’t have any of that.

Science TerminologyWe need a common science vocabulary

in order to communicate effectively with one another.

Keep in mind that the scientific meaning of a word is often different than its everyday meaning.

Observation An observation is something you

notice. May be casual or even accidental May be formal - experimental data are

observations.Not all observations are correct - people

make mistakes.

Scientific ObservationsThe primary way we have to tell if an

observation is correct is to repeat it, and have other competent people repeat it.

Therefore, scientific observations must be repeatable.

Non-repeatable observations are called “anecdotal evidence”.

Scientific FactsAn observation that many competent

observers agree is correct is a fact.All scientific facts are not correct -

people make mistakes.

Facts are NOT Immortal If further observations show that a fact

is not correct, it must be replaced.This often happens when new

technology becomes available to make observations that could not be made before.

Aren’t Facts True?Often people naively assume that

“facts” must be absolutely true - but how can we know this?

Facts are true to the best of our current ability to tell - but that is all we can really say about them.

ConclusionsA conclusion is a decision based on

observations, facts, or experimental data.

Scientific LawsA scientific law is a powerful summary

of many facts. Laws describe what happens, they don’t

generally explain why they happen. Laws can often be expressed very

conveniently and concisely in mathematical form.

HypothesesA hypothesis is an educated guess

about why something happens. A scientific hypothesis must be testable by

observation - there must be observations that we can make to tell whether the hypothesis is correct or not.

A hypothesis that is not testable is called “speculation”.

“Falsifiability”An experimental test that could show

that a hypothesis is wrong (if it’s wrong) is a much more useful test than a test that can only confirm the hypothesis.

Some scientists insist that scientific hypotheses have such tests - they must be “falsifiable”.

Scientific TheoriesAs experimental evidence

(observations) accumulates, we can become more confident that a hypothesis is true.

A theory is a synthesis (powerful combination) of well-tested hypotheses.

TheoryScientific theories tend to explain why

scientific laws operate the way they do - theories are often called “models”.

Physical theories tend to be highly mathematical in nature.

TheoryThe word “theory” is probably the most

misused science term - certainly by laymen, but even by scientists!

The Process of Science In science, evidence for the truth of

any idea is experimental observation - not tradition, authority, or anything else.

The Process of ScienceThis process of testing facts,

conclusions, laws, and theories with

experimental observations NEVER ENDS.

The Process of Science In science NOTHING (well, hardly

anything) is ever “proven once and for all”.

Science & TechnologyScience is about discovering new

things about nature, and about how nature works.

Technology is about using scientific discoveries to make (hopefully) practical structures and devices for society.

Science & TechnologyScience uses technology, and

technology uses science.Although science and technology are

not the same, neither could exist for long without the other.

The End