Scientific Models
Scientists create
models to help them
to visualize complex
properties,
structures or
behaviors. Scientists
must gather Indirect
Evidence to develop
their models.
This is a model of a very
complex molecule made of
many different kinds of atoms.
Each colored ball represents an
atom of a different element.
Indirect Evidence
Indirect Evidence is
evidence gathered
without being able to
directly observe the
object. Just like
pieces being added
to a puzzle, each
new bit of
information gives us
a better
understanding of the
model.
How can Indirect Evidence
be Gathered?
Indirect evidence is
gathered through
experimentation.
It’s like navigating
through a maze
blindfolded, each
experiment allows the
scientist to move one
step closer to the
solution.
Model Should Start Off
Simple and Be Additive
Scientists build their
models using only
the data that they
have collected. As
more indirect
evidence is added by
experimentation, the
model expands to fit
that evidence.
What should a Model look like?
This is a painting of a young woman
by Pablo Picasso. Does it actually
look like a young woman?
Scientific models
may not always
look like the
actual object. A
model is an
attempt to use
familiar ideas to
describe
unfamiliar things
in a visual way.
Is this really an Atom?
Many of the models that you have
seen may look like the one below. It
shows the parts and structure of the
atom. Even though we do not know
what an atom looks like, scientific
models must be based on evidence.
The model above represents
the most modern version of
the atom.
(Artist drawing)
drawing
Can a Model be Changed?
A model can be changed as new
information is collected.
From the early Greek concept to
the modern atomic theory,
scientists have built upon and
modified existing models of the
atom.
Black Holes
Scientists have
collected indirect
evidence on black
holes through
experimentation.
Over the years,
models of black
holes have been
modified to match
new evidence.
Biological Models
Watson and Crick’s
Model of DNA
revolutionized the
study of genetics.
Let’s Make a Model
We will practice
making a model by
developing a mental
picture of something
we cannot directly
see. We will gather
indirect evidence
through simulated
experiments.
The Black Box Dilemma
Imagine that a
strange black box
suddenly appears
hanging from the
ceiling of your
classroom. You
cannot see inside
the box nor can
you open it.
Experiment #1
Your first
experiment
determines that
the object
inside the box
rolls.
Experiment #2
Your second
experiment
determines that
the object inside
the box has
wheels.
Experiment #3
The third
experiment that
you do
determines that
the object inside
the box has
mechanical gears.
Experiment #4
The next
experiment that
you do
determines that
the object inside
the box is
motorized.
Experiment #5
The fifth
experiment
determines that
the object can
hold over 10
individuals.
Experiment #6
The next
experiment
indicates that the
object inside the
box travels over
set routes.
Experiment #7
The seventh
experiment indicates
that at certain times
the box is empty and
at other times it
contains something,
even though it has
never been opened!
Are Models Ever Complete?
Scientific Models
are never really
finished. As new
technology is
discovered,
models can be
modified or
changed.