Transcript Science Communication 2

Science Communication
LOLO.00.037
www.ut.ee/BG/scom
Session 2
The Nature of Science
Jack Holbrook
University of Tartu
The Overall Goal
Developing an understanding of :
• What science is and what it is not.
• What science can do and what it cannot do.
• How science contributes to culture.
Some Assumptions about
Scientific Knowledge
THE WORLD IS REAL
In other words, the physical universe really does
exists, apart from our sensory perception of it.
Another Assumption
HUMANS CAN PERCEIVE AND
UNDERSTAND THE PHYSICAL
UNIVERSE.
In other words, we can learn about
how the natural world (as opposed
to the supernatural world) works and
operates.
A Third Assumption
NATURAL PROCESSES are SUFFICIENT
to explain, or account for natural
phenomena or events.
In other words, scientists must explain the
natural in terms of the natural.
Last Assumption
Scientists ASSUME THAT NATURE
"OPERATES" UNIFORMLY
in both space and time
(unless we have evidence to the contrary).
This is known as the
PRINCIPLE OF UNIFORMITY.
The Scientific Process
Would you support the idea that ‘scientific’
means involvement of Observations followed
Inferences
?
Observations
followedbyby
Inferences
Observations are important as they lead us on
the path to being a successful scientist, or to
gain an understanding of the real world.
Comment on observations made in the
natural world.
• Would you be willing to accept that
scientific observations are unambiguous
and give the ‘real’ picture?
• If so, take a look at the following -
Does A or B
form the
straight line
extension of
line C ?
Could we make
a mistake in our
observations
without realising
it ?
Are the lines at the top of the
trapezia of different lengths ?
Could we
inadvertently
give false
information ?
How many f’s ?
Answer within 5 seconds
Finished files are the result
of years of scientific study
combined with the experience
of years...
Are we good at making complete observations ?
Observing scientifically
You may have difficulty in observing
correctly, but scientists have no problem.
Or do they ??
Let us observe more.
A rabbit or a duck?
An Illusion
• Do you see a
face?
• Or an Eskimo?
Can you see the three faces?
Can you
see 3
faces ?
How
many
faces or
people do
you see ?
How many hidden faces?
Can you find the 13 hidden faces?
Buy a poster!
The picture
shows a
waterfall to
the side of
the house.
But are you
sure ??
I have another clip similar to
the previous one
Take a look
Is this physically possible?
Going up or down ?
Maybe neither !
Just a
slice of
bread !
Can you see a man ?
What do you
see – man or
woman?
May I invite
everyone to
leave their
seat and
observe from
closer to the
screen. Then
move to the
back of the
room.
Additional sources of illusions
•
www.eyetricks.com
Observations
• Scientific observation needs to be objective.
• But is this always possible ?
• It would seem there is a human element that
interferes with absolute objectivity.
• Could it be that scientific observations are
subjective ?
Observation and Inference
Science is based on both observation and
inference.
Observations are gathered through human senses or
extensions of those senses.
Inferences are interpretations of those
observations.
But is there more to being ‘scientific’?
For example, what about being inquisitive?
(Inquisitiveness may be shown by asking questions)
Try the following ACTIVITIES
Examining a cube
Create a group of 3/4 persons.
Sit around a table facing each other in the group.
Examine (but do not touch/move) a cube which is
placed on top of a plastic cup on the table.
Being inquisitive !
• Can you (individually) put forward a question
to ask about the cube ?
• Please record the diversity of questions
coming from the persons in the group.
What is written on the bottom, i.e. on
the hidden side of the cube?
• In your group, discuss this question.
• Record your group prediction(s).
Now – try to justify your predictions.
• If you feel it is useful, your group may give
more than one justification.
And, if you have more than one prediction, identify
the one your group considers to be dominant.
Examining another cube
The previous exercise was (I hope) simple.
(school students find it easy)
• NOW, in your groups, examine (but do not
touch/move) a new cube placed on the
plastic cup.
• AGAIN put forward your predicted
response to what is on the hidden, bottom
face of the cube.
• AGAIN record your prediction(s).
Cube 3 - A further stage
• Carefully raise one corner of the cube so
that, with the use of a mirror, you can see the
number recorded in the top right corner, OR
the bottom left corner (but not both !!)
• Modify (add to) your prediction as to what is
written on the bottom of the cube.
• TRY TO GIVE A FULL PREDICTION
COVERING ALL THAT IS WRITTEN.
Cube 3 and degree of observation
Does cube 3 give us any insight into the scientific
approach ?
Does it suggest that we do not necessarily need to
observe everything and that we can make calculated
guesses from other observations ?
Make inferences on incomplete observations .
• If a gas is colourless and lighter than air, can we infer it is
probably hydrogen ?
• Or if a gas is known to be hydrogen, then can we infer a
balloon containing hydrogen will …..
The Importance of Inference
Try reading the passage below
Aoccdrnig to rscheearch at Cmabrigde
Uinervtisy, it deosn't mttaer in waht oredr the
ltteers in a wrod are, the olny iprmoatnt tihng is
taht the frist and lsat ltteer be at the rghit pclae.
The rset can be a toatl mses and you can sitll
raed it wouthit a porbelm. Tihs is bcuseae the
huamn mnid deos not raed ervey lteter by istlef,
but the wrod as a wlohe.
Acting the scientific way
If inference skill is a key to being ‘scientific’,
even if observation is incomplete,
what about making predictions ?
Observe what does actually
happen.
What explanation do you have for what happened?
You should be able to put forward at least one
explanation. Explanations from the group may not all
be the same.
Select one explanation which you like. Now
based on that possible explanation, predict
what will happen when the second hole is
uncovered.
Observe what actually did
happen.
Did the result match your prediction ?
If so, do you feel your prediction is good?
If NOT, it seems your prediction is not good.
Can you put forward another Prediction?
Now we have one more hole. Let us again
make a prediction about the outcome if we
uncover all 3 holes.
Summarising
• Science is limited to operations within certain
boundaries (assumptions).
• Observations are scientific, but not always easy.
• Inferences are scientific and often can be made
with incomplete observation.
• Making predictions is an important scientific
attribute, as are putting forward explanations.
• So why is school (university) science so much
about knowing facts ?
Session 3
Individual presentation
Taking whatever optical illusion you wish, please
present this to the group (from powerpoint or from
the internet, or as a live demonstration).
The challenge
In doing this, please pay attention to the need to
present to the audience (not the screen or the
ceiling/floor) and please note the audience needs
to understand the point of your presentation.