What do we know about science? - University of Southern California

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Transcript What do we know about science? - University of Southern California

What is Science?

What is science?

Science is that activity, the underlying aim of which is to further our understanding of why things happen as they do in the natural world. It accomplishes this goal by applications of scientific method—the process of observing nature, isolating a facet that is not well understood, and then proposing and testing possible explanations.

-S. Carey, 2004

What is science?

Way of knowing

Study of natural world (process)

Involves observing, proposing explanations, testing explanations

Evidence-based

CURIOSITY! ASK WHY.

What is science?

Know, use and interpret scientific explanations of the natural world

scientific knowledge (content)

Generate and evaluate evidence and explanations

scientific reasoning, using evidence (process)

(National Research Council, 2007,

Taking Science to School

)

What is science?

Understand the nature and development of scientific knowledge

how science works (nature of science)

Participate productively in scientific practices and discourse

how to talk/think about science, how to use scientific knowledge, engage in scientific practice

(National Research Council, 2007,

Taking Science to School

)

Be careful…

Sometimes we think science can do things it can’t OR does more than we think--there are science about

Common Science Myths

When exposed to the vacuum of space, the human body pops.

a human can survive for 15 – 30 seconds in outer space as long as they breathe out before the exposure Food that drops on the floor is safe to eat if you pick it up within five seconds Um, no..

but eating germs and dirt is not always a bad thing as it helps us to develop a robust immune system

Common Science Myths

Brain cells can’t regenerate – if you kill a brain cell, it is never replaced.

In 1998, scientists at the Sweden and the Salk Institute in La Jolla, California humans

can

discovered that brain cells in mature regenerate. An old dog CAN learn new tricks!

A penny dropped from a very high building can kill a pedestrian below the aerodynamics of a penny are not sufficient to make it dangerous. What would happen in reality is that the person who gets hit would feel a sting

Public Views of Science

U.S. science is tops, but most Americans don't think it is, a new survey finds.

By Mandy Kendrick | Jul 9, 2009 04:15 PM 

84% of the public felt that “science’s effect on society” has been mostly positive, with only 6% considering it mostly negative

Posted on July 15, 2009 by speakingofresearch 

Study finds public relatively unconcerned about nanotechnology risks

Health & Medicine Published: Tuesday, April 12, 2011 - 09:36 in

Dangers of Science

That which we don’t understand can be looked at as good or evil – science illiteracy The “magic” of science with little understanding of how it works can be a dangerous state of affairs.

The Nature of Science

Content, process, nature

How does science lead to new knowledge?

What can science do?

What

can’t

it do?

a Nature of Science quiz… What do you know about science? (Answer True or False) 1) Science is a system of beliefs.

2) Scientists are totally objective in their work 3) The scientific method is the basic, 5-step guide for conducting scientific research.

4) Doing science involves creativity.

5) Scientific ideas are tentative and can be modified or disproved, but never proved.

1. Science is a system of beliefs

FALSE

Many students, science teachers, and the general public often believe that science is a system of beliefs

Scientific ideas are established only after compelling evidence has accumulated from observations of nature.

Scientists use reasoning and imagination, study the work of other scientists, and collaborate with other professionals, always looking for evidence to support or disprove their ideas.

2. Scientists are totally objective in their work.

FALSE

Science involves some subjectivity.

Humans do science

humans are subjective

SO…science involves subjectivity

Personal experience and expectations influence observations

How do we "get around" this?

   

Controlled settings Repeat tests Confirmation from other observers Large sample sizes

Perceptions and Bias

Work in groups of 4.....

* Keep the 'checks' (evidence) hidden in the envelope.....

* Pull out ONLY 3 checks, and discuss with your group what situation the checks imply

* Record the implied scenario.....

*Now, pull 3 more checks and modify the scenario........

* Now, pull 3 more checks and further modify the scenario.......

* Publish your results by describing your analysis to the group

http://www.indiana.edu/~ensiweb/lessons/chec.lab.html

Perceptions and Bias

This is an excellent way to experience the very real fact that even in science, cultural biases and experiences DO influence interpretations (and even perceptions).

Scientists typically collaborate, share ideas through conventions, meetings, and publications, much as you were doing as you discussed the checks.

What do you see?

What do you see?

What do you see?

Inference is when observations are influenced by prior knowledge and beliefs

Being able to infer is a survival mechanism, so it is positive.

Inference doesn’t make science weak, but rather forces us to be careful in our observations and interpretation of evidence

What happened here?

What do you OBSERVE?

Now what do you think

?

Infer what happened based on your observations.

Observation

Any information collected with the senses.

The skill of describing scientific events.

__________

Inference

______________

Conclusions or deductions based on observations .

The process of drawing a conclusion from given evidence.

What happened here?

Be sure to distinguish

observation

and

inference

.

Prior knowledge affects observation!

Not all evidence leads to one answer.

Not all scientific knowledge is gained through

controlled experiments

. (Paleontology for instance)

3. The

scientific method

is the basic, 5-step guide for conducting scientific research.

FALSE

There is no universal scientific method

.

There are methods, but not a

single pathway

  

Observations (before, during, after) Proposing explanations based on observation Testing explanations or predictions

Observations

Definition Using senses to gather information Observations lead to questions

How does sand grain size affect the size and abundance of crabs?

Two types of Observations

Qualitative:

Uses senses to describe

Ex : color and consistency of sand, minerals present etc.

Quantitative:

Uses tools to take a numerical measurement

Ex: actual size of grains, actual size and number of crabs at various sites.

Hypothesis

Predicts the answer to a question Hypothesis are based on: Past experience Observations Research

Test your prediction by designing an experiment Collect data and and analyze Conclusion

www.understandingscience.org

4. Doing science involves creativity

TRUE

Scientific explanations and data interpretation involve creativity and imagination.

Science involves ‘ making leaps ’ and ‘ thinking outside the box .’

Inquiry Cubes

2. Arrange in groups of 2 or 3 at each table. You will be provided with a cube that will be placed in the center of your table.

Do not touch, turn, lift, or open the cube.

Inquiry Cubes

3. Your group will focus on the question: WHAT IS ON THE BOTTOM OF THE CUBE?

  

You will have to answer the question by proposing an explanation, and must convince other colleagues that your answer is BASED ON EVIDENCE.

Use your observations to propose an answer to the question: What is on the bottom of the cube? Be ready to present your reasoning for this conclusion

.

Inquiry Cubes

Use your observations to make a prediction of the number in the upper right corner of the bottom.

   -

Your team needs to decide which corner of the bottom you wish to inspect and why you wish to inspect it.

Lift the designated corner LESS THAN ONE INCH and look under the corner.

Describe the data gained by the “experiment.” Be ready to share a summary of your investigation.

Inquiry Cubes

6. In your same groups, create a cube that will be used as the evaluation exercise for other groups. The focus question for evaluation will be: What is on the bottom of the cube?

Exchange your cube with another group. All procedural directions are the same as for Cube 2.

What is on the bottom face of this cube?

You made observations of the other sides in order to provide a prediction and a hypothesis

You used the scientific process of

inferring

to come to a conclusion about what is on the bottom of the cube

As in ‘real science’ you needed to be organized and systematic

As in ‘real science’ you needed to recognize patterns

Recognizing patterns in science involves the important process skill of

categorizing

(although this activity is mainly about inferring)

5. Scientific ideas are tentative and can be modified or disproved, but never proved.

TRUE

Tentative but durable

--an important characteristic (strength) of science

  

We can't look at ALL possible cases or combinations, past present or future.

One bit of evidence that contradicts an explanation requires us to come up with a new explanation.

Doesn't mean scientific explanations are bad or inadequate—we know that based on the evidence at hand, this explanation is

durable

Dead words, caution words

Prove or proof

Avoid these: use

support

or

evidence

Word to avoid: ‘

PROVE’

Science can’t really PROVE absolutely.

anything

Scientific knowledge is based on evidence -lots and lots of tests, observations, etc.

But none of the methods of science allow us to examine every possible case--past, present and future. We can’t presume to know this (not part of natural world)

Word to avoid: ‘

PROVE’

We can

DISPROVE

an explanation or generalization by finding conflicting evidence.

A strength of science is the fact that it is falsifiable (can be disproved)--it is

not dogma.

Science can correct itself--new theories replace old theories when the evidence fits better with a new explanation.

As researchers, it’s better to talk about “supporting your case” or “providing evidence” than “proving” something.

The case of the oviraptor…

Egg-stealer or good parent?

The case of the oviraptor…

The oviraptorid Ingenia on a nest. Photo © Rob Gay 

A recent study found an oviraptorid embryo inside one of those eggs, so actually the oviraptor was by its own nest! More expeditions have found oviraptor skeletons on top of nests — these devoted parents apparently died in sudden sandstorms while guarding their nests! Just recently, one of the most amazing fossils ever found was announced — an

Oviraptor

skeleton brooding a clutch of eggs, just like a bird does.

What is a scientific theory?

An explanation based on repeated observations, and/or repeated testing.

They can be used to explain numerous observations and patterns

They may change, however, given new contradictory evidence.

A well-substantiated explanation of some aspect of the natural world. (Backhus

)

What is a scientific theory?

Example: Atomic theory Atoms consist of protons, neutrons, electrons. Electrons are negatively charged, protons are positively charged, neutrons have no charge.

This explains LOTS of observations, patterns Chemical reactions (entire branch of science based on this!) Even things like electrical circuits!

There is no “guessing” here—scientists use this theory to predict outcomes and make other explanations.

The problem with ‘theory’

In everyday language, ‘theory’ refers to something untested or very tentative

‘ She had a theory as to why her boyfriend was always late.

The word has a different meaning depending on the

context

.

We must be aware of how we use terms that have different meanings in different situations.

What is a scientific law?

Scientific Laws describe patterns, predict outcomes (description) Law of gravity

There is an attractive force between any two bodies. This force depends on the size of the objects and the distance between them.

There is no explanation for this. No answer to ‘Why?’

 

Can be used to predict future observations Laws can sometimes be expressed as mathematical expressions too.

Be careful…

Scientific theories become scientific laws when they are proven.

Law vs. Theory

Laws describe Theories explain Two DIFFERENT things

Scientific Theories

don’t become

Laws Scientific

A theory might explain a law, but it can NEVER become one.

Six Criteria of Science :

C

onsistent

O

bservable

N

atural

P

redictable

T

estable

T

entative

Consistency : The results of observations and/or experiments are reasonably the same when repeated.

1. Green plants will grow towards a light source.

2. Walking under a ladder will cause bad luck.

Observability : The event or evidence of the event, can be observed and explained. The observations are limited to the basic human senses or to extensions of the senses.

1. Some plants eat meat.

2. Extraterrestrial beings have visited Earth.

List the differences you see

Natural : A natural cause (mechanism) must be used to explain why or how the event happens.

1.

Green plants convert sunlight into energy.

2. With a rod, Moses parted the sea so his people could cross to the other side.

Predictability

:

Specific predictions can be used to foretell an event. Each prediction can be tested to determine if the prediction is true of false.

1.

Without sunlight (or artificial light), green plants will die.

2. If you are a "Scorpio", your horoscope for today is "You'll be saying 'I feel rich !' Lunar position highlights back pay, refunds, correction of accounting error."

Testability : the event must be testable through the processes of science, and controlled experi mentation.

1. The Bermuda Triangle causes ships and planes to sink and disappear.

2. Life comes from life and cannot come from non-life.

Tentativeness : Scientific theories are changeable and correctable, even to the point of the theory being proven wrong. Scientific theories have been modified and will continue to be modified

1. The number of human chromosomes was once "known" to be 48, but is now considered to be 46.

2. We know that the world began about 6000 years ago.

Emerging Science

Also called protoscience, a “near science”

Tends to conform to CONPTT, but falls short in one or two criteria

Consistent observations and predictions limited by knowledge and/or technology

Ex: mental telepathy

Non-Science

Does not meet criteria of CONPTT

Topic that can be very logical but not fall within realm of science

Ex: belief systems, philosophy, ethics

False Science

Also known as pseudoscience

Non-science portrayed as a legitimate science

Ex: astrology, creation science

The last observation!

Moon over North Carolina….. Can you see Santa?

Resources

Checks Lab can be found at: http://www.indiana.edu/~ensiweb/lessons/chec.lab.html

Inquiry Cubes – variations https://skydrive.live.com/?cid=e9d326cb60bb8791#!/?cid= e9d326cb60bb8791&sc=documents&uc=1&id=E9D326C B60BB8791!126

(my temporary website!) http://brainu.org/inquiry-cubes