Hypothesis●Hypothesis is possible explanation about

the cause of an event or relationship among things. It is frequently formulated as an “If/then” statement.

●Must be testable and falsifiable ○Falsifiable = must be able to be shown to be untrue.

Theory

Theory- an extremely well supported explanation of how some aspect of the natural world works.

A theory incorporates: facts, laws, inferences and tested hypotheses

Theory is a unifying explanation for MANY observations, inferences, and tested hypotheses.

Theory

Scientific theories are the ideas about which scientists are most certain.

Theories are the bedrock of our understanding of nature.

EXAMPLES Anyone?

TheoryWell tested ideas supported by diverse lines of evidence and capable of explaining observations and predicting new ones.

Examples:Cell TheoryTheory of RelativityGravitational TheoryGerm TheoryQuantum TheoryElectromagnetic TheoryChaos TheoryTheory of Plate TectonicsAtomic Theory

Theories explain how nature works.

Is anything wrong with the following sentence? Explain why or why not.

Bert: “I think a lot of people have missed school lately because the flu is going around. What’s your theory?”

Science⦿Is uncertain⦿Is always changing⦿Is Collaborative⦿Is about Questioning and Observing

Uncertainty⦿Scientists make observations of

nature. A hypothesis is a possible explanation for an event or set of observations.

⦿One can never be sure that they have observed all evidence, and it is often possible to interpret evidence in different ways

Uncertainty⦿Therefore, a scientist can never be

certain that a hypothesis is correct.⦿BUT, a hypothesis can always be

tested

Science is Always Changing

⦿Science does not create absolute fact⦿A hypothesis is only as strong as the

evidence that backs it up. ⦿A hypothesis must be rejected if new

evidence does not support it

⦿A scientist's job is to “falsify” hypotheses.

Science is Always Changing

The scientist’s number one priority is to find evidence that contradicts a hypothesis.

A scientist seeks to reject hypotheses.

What happens to a hypothesis when the evidence disagrees with it?

Science is Always Changing

FalsificationA hypothesis that is inconsistent with the evidence has been shown to be false.

Thus, that hypothesis is REJECTED or modified and re-tested.

This is HOW we learn about the world around us.

This is how science moves forward.

Science is Collaborative⦿The power of thinking is

strengthened by including as many perspectives as possible.

Observing and Questioning ⦿Science can only study things that

can be observed and tested.⦿Observations can be made directly

with the senses or with help from things like microscopes

Observing and Questioning⦿A hypothesis is an attempt to explain

observations.⦿One must be able to test a

hypothesis.

Provisional Assent ➢Scientific Ideas Can Only Be Proven

Wrong➢A theory stands because

observations or experimentation never proves its tenets wrong.

➢This doesn’t prove the theory is correct – only that its never been proved wrong.

➢ In this sense, scientific knowledge is provisional.

The Scope and Limitations of Science Are More Than An Academic Issue

Summary points of the December 20, 2005 Kitzmiller v. Dover Area School District ruling:

Is this the final word on evolution and alternatives in the classroom? Hardly.

The Scope of Biology

all of this

some of this

Biology and its study are arranged hierarchically. New properties (emergent properties) arise at each level of organization.

Evolution Is Biology’s Unifying Principle

⦿Is anything wrong with the following situation?

⦿There is a law that requires that science classes in Louisiana teach that supernatural forces may have created the world and the life in it.

Science is Uncertainty⦿Many of the things that scientists

observe cannot be experienced directly

⦿Scientists must put together pieces of evidence. They use indirect evidence.

⦿They make a guess called a hypothesis

How's that?⦿Did you know geese grow on trees?

You are now less d$#&*