WHAT IS THE NATURE OF SCIENCE?

Transcription

WHAT IS THE NATURE OF SCIENCE?
WHAT IS THE
NATURE OF
SCIENCE?
WHAT IS THE NATURE OF SCIENCE?
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THIS IS THE
SCIENTIFIC WORLD VIEW
1. The Universe Is Understandable.
2. The Universe Is a Vast Single System In
Which the Basic Rules Are Everywhere
the Same.
3. Scientific Ideas Are Subject To Change.
4. Scientific Knowledge Is Durable.
5. Science Cannot Provide Complete
Answers to All Questions.
WHAT IS THE NATURE OF
SCIENTIFIC INQUIRY?
• Certain features of science make it
distinctive as a means of
understanding the world/universe
• Those features are especially
characteristic of the work of
professional scientists, but anyone can
use them to think scientifically about
many aspects of everyday life
Science Demands Evidence
• The validity of scientific claims is
settled by referring to observations of
phenomena
• Therefore, scientists concentrate on
getting accurate data
THE SCIENTIFIC METHOD
1. Observe and describe a phenomenon or group of
phenomena.
2. Formulate hypotheses to explain the phenomena;
hypotheses often take the form of a proposed causal
mechanism or mathematical relationship.
3. Use the hypotheses to predict the existence or
actions of other phenomena, or to predict
quantitatively the results of new observations.
4. Perform additional data collection or repeat
experimental tests of the predictions by several
independent experimenters using properly performed
techniques or experiments.
THE SCIENTIFIC METHOD
• Observations/Data ➔ Hypotheses ➔ Hypothesis
Testing ➔ Models ➔ Laws ➔ Theories
• At some point in time, each stage must be reported to
the larger scientific community by presentations or
publications.
THE SCIENTIFIC METHOD
• The scientific method does not allow any
hypothesis to be proven true
• Hypotheses can be disproven, in which case
those hypothesis are rejected as false
• A hypothesis which withstands a test designed
to falsify it establishes a level of probability that
the hypothesis accurately explains data and
can be used for further predictions, subject to
further tests
Hypothesis Testing
SCIENTIFIC LAWS AND THEORIES
• A Scientific Theory is an explanation of a set or
system of related observations or events based
upon proven hypotheses and verified multiple
times by detached groups of unbiased
researchers
• (One scientist cannot create a theory; s/he can only
create hypotheses)
SCIENTIFIC LAWS AND THEORIES
• As a result of our confidence in the
Scientific method, both scientific laws and
broader scientific theories are accepted to
be “true” (accurate) by the scientific
community as a whole
• A scientific law or a scientific theory is
used to make predictions of events or
relationships among data sets
SCIENTIFIC LAWS AND THEORIES
• The biggest difference between a law and a
theory is that a theory is much more complex
and dynamic
• A law governs a single action or situation,
whereas a theory explains an entire group of
related phenomena (Mendel’s Laws versus
Darwin’s Theory of Evolution by Natural
Selection)
• [Note: Evolution is a Fact; Darwin’s Theory is
the scientifically accepted explanation for the
fact(s) of evolution.]
SCIENTIFIC LAWS AND THEORIES
• Genuine scientific theories must be falsifiable
by applying the scientific method (data
collection and hypothesis testing)
• If one cannot imagine a specific investigation or
experiment, based on predictions from the
theory, leading to results which can further
verify or refute the predictions, then the theory,
as an explanation, is not scientific
SCIENTIFIC LAWS AND THEORIES
• When the scientific community accepts a Law
or Theory, it represents the best understanding
of the explanations for the properties of a given
system at that point in time
• A Scientific Theory represents our best
understanding of the “truth” about some aspect
of the universe, even though it is not proven as
absolute and is still understood to be subject to
future revision, or even to rejection
THE EXPERIMENTAL METHOD
• The Experimental Method is usually considered
the most scientific of all methods, the “method
of choice”
• The main problem with all other nonexperimental methods is less control over the
situation and its components
• The Experimental Method exerts the most
control on data collection and interpretation
THE EXPERIMENTAL METHOD
• An experiment is a study of cause and effect
• It differs from non-experimental methods in that
it involves the deliberate manipulation of one
variable, while trying to keep all other variables
constant
• Experiments must be properly designed and
include controls
HYPOTHESIS GENERATION
• The use of logic and the close examination of
evidence are necessary but not usually
sufficient for the advancement of science
• Scientific concepts do not emerge automatically
from data or from any amount of analysis alone
• Inventing hypotheses or theories to imagine
how the world works and then figuring out how
they can be put to the test of reality is a
creative thought process
SCIENCE EXPLAINS AND PREDICTS
• Scientists try to make sense of observations by
constructing explanations for observations that
are consistent with currently accepted scientific
principles
• Such explanations—theories—may be either
sweeping or restricted, but they must be
logically sound and incorporate a significant
body of scientifically valid observations
• The credibility of scientific theories often comes
from their ability to show relationships among
phenomena that previously seemed unrelated
SCIENCE EXPLAINS AND PREDICTS
• It is not enough for scientific theories
to explain the observations that are
already known
• Theories should also explain
additional observations that were not
used in formulating the theories in the
first place; that is, theories should
have predictive power
SCIENTISTS TRY TO
IDENTIFY AND TO AVOID BIAS
• When faced with a claim that something is true,
scientists respond by asking what evidence
supports it
• But scientific evidence can be biased in how the
data are interpreted, recorded or reported, or
even in the choice of what data are considered
in the first place
• A scientist’s nationality, culture, sex, ethnic
origin, age, political convictions, etc., may
incline him or her to look for or emphasize one
kind of evidence or interpretation or another
SCIENCE IS NOT AUTHORITARIAN
• In science, it is
appropriate to turn to
knowledgeable sources of
information and opinion,
usually specialists in
relevant disciplines
• But respected authorities
have been wrong many
times in the history of
science
Aristotle
SCIENCE IS SELF CORRECTING
AND PROGRESSIVE
• In the short run, new ideas that do not agree
well with mainstream ideas may encounter
vigorous criticism, and scientists investigating
such ideas may have difficulty obtaining support
for their research
• Challenges to new ideas are the legitimate
business of science in building valid knowledge
SCIENCE IS SELF CORRECTING
AND PROGRESSIVE
• SF Author Sir Arthur C.
Clarke’s First Law:
“When a distinguished
but elderly scientist
states that something is
possible, he is almost
certainly right. When he
states that something is
impossible, he is very
probably wrong.”
SCIENCE AS A WAY OF KNOWING
1.
2.
3.
4.
5.
The Universe Is Understandable
The Universe Is a Vast Single System In Which the Basic
Rules Are Everywhere the Same
Scientific Ideas Are Subject To Change
Scientific Knowledge Is Durable
Science Cannot Provide Complete Answers to All Questions
Scientific ideas are developed by particular ways of
observing, thinking, experimenting, and validating
Observations/Data ➔ Hypotheses ➔ Hypothesis
Testing ➔ Models ➔ Laws ➔ Theories
Principles and Processes
of Evolution
• For the rest of the semester, we will
examine the fact(s) of Evolution and
the evidence that supports
Darwin’s/Biology’s Theory of
Evolution by Natural Selection
WHAT IS THE NATURE OF
SCIENCE?
END