Transcript The Scientific Method - Dr. Shepard`s Science Home

The Scientific Method
2/18/1996
…lots and lots and lots of math.
Goal
•
•
•
•
What is the scientific method?
What does the scientific method assume?
Does the scientific method work?
What is not a scientific argument.
The Scientific Method
• Science is not subjective
• Results are statements
based on observations
• Results must be
reproducible and
thoroughly tested
• Scientific discovery is the
results of human efforts…
people just like you!
• Science proves nothing, but
does test ideas!
The Scientific Method
1. Observe an event.
2. Develop an hypothesis (or model) which makes
a prediction.
model
3. Test the hypothesis.
4. Analyze the result.
5. Revise the hypothesis.
test
6. Repeat as needed.
7. A hypothesis that has support from many
scientists may become a Scientific Theory.
Everyday Science
Scientific Method
Car Repair
Observation
Engine won’t turn over.
Hypothesis (prediction)
Predict battery is dead.
Test
Replace battery.
Observe result
Engine now turns over.
Revise hypothesis?
Not needed.
New test?
Not needed.
Scientific Theory
Cars won’t work without a
charged battery.
Everyday Science
Scientific Method
Making Spaghetti Sauce
Observation
Spaghetti sauce should be red.
Hypothesis (prediction)
Try a tomato sauce.
Test
Heat pot of tomato sauce.
Observe result
Taste the sauce - bland.
Revise hypothesis?
Use tomato sauce and garlic!
New test?
Add garlic, taste - not so bland.
Scientific Theory
The Final Recipe.
Scientific Method Modern Example:
Upheaval Dome, UT
• Step 1 – Identify the problem/question
– What formed this bizarre geologic structure?
Collect Data
• Circular shape
• Dome structure
• Lots of Faults
Make A Hypothesis
• Meteor Impact!
– Consistent with
dome structure
and lots of faults
Great Hypothesis?
Hypothesis Testing
• After you submit your findings, someone else
reviews your work and points out that
• Salt deposits can also make circular domes!!
• Uh Oh! 
Solved!
• In 2008, Researchers
from the University of
Vienna:
– Found Shocked Quartz
– Demonstrated that the
impact hypothesis was the
only idea that was
consistent with all of the
data
– Now if the community
verifies and reproduces
these results…
• we will have a theory to
explain upheaval dome!
Repeatability
• A successful theory is repeatable.
– By you.
– By anyone.
• Examples:
– Cold Fusion (Pons and Fleischmann1989)
– Ecstasy (Science Retraction, 2003)
Assumptions
• Objective reality
– We all see the same world.
• Constant Laws of Nature
– What happens here, happens there.
– What happened yesterday will happen tomorrow.
• The Cosmos is knowable.
Hypotheses, Theories, and Laws,
Oh My!
• Hypothesis
consistent with your data
other researchers test it
• Theory
consistent with all verified data
may be modified if new data is
presented
• Scientific Model
Combines many theories and
hypotheses to explain a complex
system
• Law
considered correct throughout the
natural universe (e.g. gravity)
The Moral…
Its not easy to become a theory.
Non-scientific Theories
•
•
•
Make no predictions
Un-testable
Can’t be disproven
Examples of Non-scientific
Theories
• Car won’t work? 
– Aliens drained the battery.
• Spaghetti is bland? 
– You were meant to eat bland food.
• Car won’t work? 
– Gods must be angry.
• Spaghetti is bland? 
– At the instant of tasting, tongue is transported to
alternate dimension where all flavors are rendered
nullified.
Non-scientific Theories
• The chain of events needed for life to arise is
too complicated to have happened by
chance, a divine intelligence must therefore
have caused life to arise (Intelligent Design).
• Face on Mars.
Viking Orbiter (1976)
Mars Global Surveyor (1998)
Astrology and the President
(TIME, May
16, 1988)
-- Chief of Staff, Donald] Regan and
“[Former
White
House
“The First
Lady
dabbled in astrology
others
make
a compelling
case thatas
in far
1986 and 1987
back as 1967.
In 1981 [Joan]
Quigleyreduced
made the
astrological
influence
dramatically
Nancy a believer …. And from then on, no
presidency's
effectiveness, at least partly, by keeping
presidential public appearance was slated
Ronald
under
wraps
without Reagan
the Friend's
say-so.
Tofor
thismuch
day, of the time.
Nancy's
in the to
scheduling
process, Regan said
Nancy's intrusions
Friend continues
influence the
schedule.
For thelast
ReaganinPresident's
an interview
with TIME
week, ‘began to interfere
Gorbachev
Washington
cast
with
the normal
conductsummit,
of the she
presidency.’”
the charts of both men and determined
that 2 p.m. on Dec. 8, 1987, was the most propitious moment
(TIME,
16,the1988)
for themMay
to sign
intermediate-range nuclear forces treaty.
At Nancy's behest, the entire summit was built around that
hour. For the upcoming Moscow summit, Gorbachev's chart
(he is a Pisces) has been recast alongside Reagan's
(Aquarius).”
Astrology Tests
• What test would disprove astrology?
Home Work
• Devise a scientific test for some
pseudoscience (astrology, tarot, dowsing,
faith healing, scientific racism, vitalism, etc.).
– What claim are you testing?
– How will you test it?
• Due Thursday Sept. 5.