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Week 4: Complete Chapter 3
The Science of Astronomy
How do humans employ
scientific thinking?
• Scientific thinking is based on everyday
ideas of observation and trial
trial-and-error
and error
experiments.
• But science adds the requirement for an
explanation of mechanisms
– Observation alone is not enough
3.4 The Nature of Science
Our goals for learning:
• How can we distinguish science
from nonscience?
• What is a scientific theory?
Idealized scientific
method
• Based on proposing
and
d ttesting
ti
hypotheses
• hypothesis =
educated guess
Caveat
• We see what we are
looking for
• e.g. Where are your keys
when you finally find
them?
Science rarely proceeds in this
idealized way…
• Sometimes we start by “just looking” then
coming up with possible explanations.
• Sometimes we follow our intuition rather
than a particular line of evidence.
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Hallmarks of Science: #1
Hallmarks of Science: #2
Modern science seeks explanations for
observed phenomena that rely solely
on natural causes.
Science progresses through the
creation and testing of models of
nature that explain
p
the observations as
simply as possible.
(A scientific model cannot include divine
intervention)
Hallmarks of Science: #3
A scientific model must make testable
predictions about natural phenomena
that would force us to revise or
abandon the model if the predictions
do not agree with observations.
3.5 Astrology
Our goals for learning:


How is astrology different from
Astronomy?
Does astrology have any scientific
validity?
(Is “Occam’s razor” our own “perfect spheres”?)
Scientific theory?



The word theory has a different meaning in
science than in everyday life.
In science, a theory is NOT the same as a
hypothesis rather:
hypothesis,
A scientific theory must:
—Explain a wide variety of observations with a few
simple principles, AND
—Must be supported by a large, compelling body
of evidence.
—Must NOT have failed any crucial test of its
validity.
How is astrology different
from Astronomy?
Astronomy is a science focused on
learning about how stars, planets,
and other celestial objects
j
work.
 astrology is a search for hidden
influences on human lives based
on the positions of planets and
stars in the sky.

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Does astrology have any
scientific validity?
What have we learned?


Scientific tests have
shown that
astrological
predictions are no
more accurate than
we should expect
from pure chance.
Science or Technology?





Science is the process of inquiry
Science seeks to understand HOW nature
operates by using observation, reasoning, theory.
Science can use technology (better
thermometers), but does not require it.
Technology is the process of tooltool-making and
invention.
Technology performs empirically to reach a goal
(e.g. perfect machines). Often, but not always
using theory and prediction derived from science.
Science and Objectivity




The Uncontrolled Experiment:
 Typical of journalism (e.g., “40% of children improved”)
 Which children; over what time; compared to whom?
The Controlled Experiment:
 states how much better (1%, 10%, 200%) than a control.
In any set of observations, the dependent variable will change
in response to the independent or manipulated variable (e.g.,
growth of corn in soil receiving different levels of fertilizer).
 Growth of corn is dependent upon the level of fertilizer
applied
Failing to isolate variables for cause and effect is the single
biggest difference between Science and Pseudoscience.

How is astrology different from astronomy?
– Astronomy is the scientific study of the
universe and the celestial objects within it.
– Astrology assumes that the positions of
celestial objects influence human events.
Does astrology have any scientific validity?
– Scientific tests show that the predictions of
astrology are no more accurate than pure
chance.
So what were the Greeks?
Science use empirical methods? Yes, but
only as part of the process.
 Science uses technology? Yes
Yes, but only
for testing hypotheses.
 Are science and technology synonymous?
No, technology is an application of science
 Technology is the practical application of
knowledge in an area (e.g. engineering)

Science and Pseudoscience




Pseudoscience: discarded
scientific ideas, unfounded
ideas about the world
world—
—also
called fringe science.
Cannot be tested
Often presented with a siege
or conspiracy theory
mentality
Poor or nonexistent use of
statistics
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Characteristics of Pseudoscience
•
•
•
•
•
•
•
•
Appears to be scientific
Often commingled with a political or religious
agenda—
agenda
—example: Nazi theories of blood purity.
Makes assertions it is scientific, but rejects rigorous
scientific testing
Quickly accepted by nonnon-scientists
Often represented as the grand solution
Fatally flawed in content, method, or both
Fails to differentiate between cause and effect
Cannot be tested (can’t test, can’t prove wrong!)
Dinosaurs on Venus
The Theory of Natural Selection
•
What lives in jungles?
•
•
•
Al & Chuck’s Excellent
Scientific Adventure
Charles Darwin were
Naturalists.
 19th Century Naturalists
amassed huge
collections of anything
natural.
 They practiced inductive
reasoning by examining
the range of variations in
these collections.
Venus is
V
i 100% cloud
l d covered.
covered
d.
Where do we see lots of clouds?
•
The more extraordinary the claim, the more extraordinary
the evidence needs to be. –Carl Sagan
 Alfred Wallace &
•
•
Jungles
Dinosaurs
Observation: Can’t see a thing.
Conclusion: Dinosaurs on Venus
This was their Hypothesis:
•
That variation in
plants and animals is
a result of random
mutations.
•
Independently; they
proposed Natural
Selection (from
mutations) as the
driving force of
Evolution (1850’s).
But what made it work?
•
•
•
•
Random Mutations can be good or bad
depending on the environment.
Stated that nature was implicitly easier
for one individual or group over another
if there was an inherited trait which made
the offspring more successful.
There is no explicit force implied.
•
•
•
Gregor Mendel demonstrated that inherited
traits & mutations were passed from one
generation to the next (1860’s).
Genetic Mutations may be related to
environmental incidents in the life of a
single parent.
Learned attributes are not passed along!
None of this was news to Farmers or
Ranchers. It was just BREEDING.
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Muddy Thinking +
PseudoScience =
And if Humans are animals too...
•
•
•
Sir Francis Galton coins the term Eugenics
(well--born)
(well
born).. Advocates controlling the birthbirthrate of the unfit
(1900
1900)).
T.X. Huxley introduces the term Survival
of the Fittest which eventually led to
the concept of Social Darwinism.
Darwinism.
Oneida Communities and controlled breeding
of humans becomes widespread in the U.S.
Dinosaurs on Venus and Aryan Supremacy
•
•
Original Hypothesis:
That variation in
plants and animals
is a result of
random mutations.
Social Response:
World War II
-and
and-Ethnic Cleansing
•
National Socialists use
Eugenics arguments to
defend racial policies.
•
Nazi’s
Nazi
s envisioned a Master
Race (themselves).
•
10 million+ Jews, Slavs, &
Catholics are executed (to
avoid “contaminating” the
Aryan Gene Pool).
Chapter 3 Redux
• Understanding the simple observations of
Chapter 2 took humans thousands of years.
• Achieved that understanding through a
rigorous process of scientific inquiry.
• Science itself is a way of making sense of
observations
• Science, by definition, must be flawed; but
it works!
Term Exam #1
• Chapters 1-3 and notes from Weeks 1-4.
• 45 objective @ 2 points each and 1 essay
(selected from 3 choices) @ 10 points.
• Particular emphasis on Lunar Phases.
• Backwards definitions common.
• Just like real life – open book and open
notes….but be careful not to trip on this.
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