Development of a Theory
Now that I’ve shown that adults
cannot hear certain ringtones, did I
just make a new scientific theory?
1. Yes
2. No
0%
1
0%
2
Hypotheses vs Theories vs Laws
Hypothesis
• An educated
guess based on
observations
• A rational
explanation of a
single event
• Usually can be
supported or
refuted by
continued
experimentation
or observation
Theory
• What one or more
hypotheses
become when they
have been verified
and accepted to be
true
• It explains a set of
related observation
or proven events
• Verified multiple
times by separate
groups of
researchers
Law
• Describes a single
action (usually a
mathematical
relationship)
• Accepted to be
true by the
scientific
community
• Much less complex
compared to a
theory
How is a scientific theory developed?
1.) Start with the scientific method
observe
hypothesis
experiment
analyze
conclusion
2.) Publish findings in a peer reviewed journal
publication
3.) Other scientists read and try to duplicate it using
different methods
4.) IN TIME, if many other scientists verify and
agree then it may become a theory.
Theories vs Laws
Theory: A well tested explanation for a set of
observations or experimental results (subject to
revision)
Law: A statement that summarizes a pattern
found in nature (typically generate a
mathematical relationship)
Laws
Theories
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Atomic theory
Cell theory
Big Bang Theory
Theory of Evolution
String Theory
Theory of relativity
Kinetic Molecular Theory
Theory of Gravity
Germ Theory of Disease
Quantum Mechanic Theory
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Law of Conservation of ________
Law of universal gravitation
Newton’s Law
Gas Laws
Law of Thermodynamics
Hubbles Law
Kepler Laws of planetary motion
Theories
Laws
The dynamic theory
• Tested - A procedure for critical evaluation; a
means of determining the presence, quality,
or truth of something
• Validated - To establish the soundness of;
corroborate or confirm
• Revised - To reconsider and change or modify
What causes theories to be changed??
Example: Ringtones results
1.) Tested: Repeat the experiment many times
by many different people.
2.) Validated: Mr. Rasmussen tries the
experiment only he tests the movement of the
eardrum of people of various ages in response
to higher frequencies.
3.) Revised: As new technology is engineered,
we may get more specific as to the general
relationship between age and frequency.
Pre-plate Tectonic Plate ideas
• Belief that all earthly changes were sudden and
caused by a series of catastrophes
(Catastrophism)
• "Contraction theory" which suggested that the
planet was once a molten ball and in the process
of cooling the surface cracked and folded up on
itself. The big problem with this idea was that all
mountain ranges should be approximately the
same age, and this was known not to be true.
Project Details
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Group 1: Magnetic Fields – Sea Floor spreading
Group 2: Fossil Records
Group 3: Seismic Activity
Group 4: Continental Drift
Group 5: Layers of the Earth
Group 6: Convection in Mantle
What am I going to do?
1.) Research information about the evidence or theory
that led to the theory of plate tectonics
2.) Create a poster including the following:
a.) Summarize your topic
b.) Justify & defend how your piece provided
evidence that support the Plate tectonic theory
b.) Time in history
c.) Any historical connections
d.) Anything else relevant to their evidence of theory
3.) As a class put together poster as one big flow map
and do a gallery walk taking notes on each
4.) Reflection questions for essay
Poster Highlights
• Justify - To demonstrate or prove to be just,
right, or valid
• Defend - To support or maintain, as by
argument or action