Transcript The Scientific Method

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.
Does astrology follow the scientific method?
esearch and observation.
Astronomy
• Astronomy is a science that studies
everything outside of the earth's atmosphere,
such as planets, stars, asteroids, galaxies;
and the properties and relationships of those
celestial bodies.
• Astronomers base their studies on research
and observation.
Astrology
Astrology on the other hand, is the belief that the
positioning of the stars and planets affect the
way events occur on earth.
Horoscope for ?
You feel totally focused on ambition todayAnd there's nothing wrong with that! You know
you'll get back to your family or spiritual
search when the time is right. For now keep
pushing.
Like this year's bold logo prints, you want things
spelled out in black and white today, If you
can't find your answers by reading the fine
print, call a meeting. You might have to push
What is science?
• Science is a tool.
• Medicine: “I have high cholesterol, what should I
do?”
– Take cholesterol lowering medication.
– Consult your astrologer.
– Pray to the god Baal and sacrifice a goat.
The Scientific Method
1. Observe an event.
2. Develop a model (or hypothesis) which makes a
prediction.
model
3. Test the prediction.
4. Observe the result.
5. Revise the hypothesis.
test
6. Repeat as needed.
7. A successful hypothesis becomes a Scientific
Theory.
Medical Science
Scientific
Method
High Cholesterol
Observation
Patient has high cholesterol
Hypothesis
(prediction)
Certain chemicals may
dissolve cholesterol deposits.
Test
Give 100 patients these
chemicals, give 100 patients
placebo.
Observe result
Same number lower their
cholesterol as placebo
patients.
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
fully 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.
Food Science
• Throwing something together  Hypothesis
• Your grandmother’s time-tested recipe 
Scientific Theory.
Repeatability
• A successful theory is repeatable.
– By you.
– By anyone.
• Examples:
– AID cure in MS
Requirements
• 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.
Does it work?
• Scientific Method is a tool.
• Does this tool work?
– Life expectancy
– Mortality rates
• Are there better tools?
Recap: Theories, Guesses,
Laws
• What does the word “Theory” mean to you?
“A conjecture; guess”
• Does it mean the same to a scientist?
“A model which has been born out by repeated
tests and observation.”
• Is a Theory less than a Law?
“Evolution is just a theory, it is not a fact.”
(What is wrong with this statement.)
• Do Theories “grow up” to be Laws?
“Einstein’s Theory of Relativity”
Theories
• So: a theory is a highly successful
hypothesis.
• All hypotheses make predictions.
• All theories make predictions.
• All theories can be tested.
• Result: Any scientific theory is subject to
change as our ability to make tests, or make
observations of a test’s results, improves with
time.
Non-scientific Theories
•
•
•
Make no predictions
Un-testable
Can’t be falsified
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. Happens instantaneously.
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)
Falsification
• A real Scientific Theory tells you what
observations are necessary to falsify it.
– Not so proponents of:
• Face on Mars
• Moon Hoax
• Astrologers
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
infar
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).”
HW
• Devise a scientific test for some
pseudoscience (astrology, tarot, etc).
– What claim are you testing?
– How will you test it?
Virtual Lab
http://glencoe.mheducation.com/sites/007877806
9/student_view0/unit1/chapter1/virtual_lab.html