Scientists believe that the universe follows a set of rules called natural laws.

The primary goal of science is to discover these natural laws and what they mean.

The Scientific Method Always starts with an observation and a question!!

InquiryInquiry – Learning about science by asking questions.

Inquiry is like a crime investigation with a mystery to solve.

What things do you know for sure? How do you know what you know for sure?

EVIDENCE !!!

What counts as good and reliable evidence?? Must accurately describe what happens in the real world Must be reported without bias or opinion Must be repeatable Must be communicated clearly with no room for

misunderstanding Scientific evidence MUST be objective

What does this mean?

“Objective” means that the evidence should describe only what actually happened as exactly as possible.

Scientific evidence may include numbers, tables, graphs, words, pictures, sound recordings, etc.

From all this inquiry, we can form a hypothesis. Hypothesis – a possible explanation that can be

tested by comparison with scientific evidence. We use the evidence that we have gathered in

order to support or not support our hypothesis.

If we gather a lot of evidence from repeated investigations, our hypothesis may become a theory. Theory – a scientific theory is a human attempt

to describe a natural law.

Let’s look at an example of the Scientific Method being used: A long time ago, understanding heat

puzzled people for a long time.

Scientists thought it was a fluid that flowedfrom hotter to colderobjects.

Then, weight was ableto be measured.

What happens when new evidence is found?

1) The current theory correctly explains the new evidence OR …

2) The current theory does not explain the new evidence so a new (or improved) theory is waiting to be discovered.

A hot cup of coffee has more heat energy than a cold cup of coffee.

As coffee cools its heat energy is transferred to the room

As a result, air in the room is warmed, but no change in weight or mass can be detected in the two cups.

Review of how scientists use the scientific method:

1. Scientists observe nature, then develop or revise hypotheses about how things work.

2. The hypotheses are tested against evidence collected from observations and experiments.

3. Any hypothesis that correctly accounts for all of the evidence from the observations and experiments is a potentially correct theory.

4. A theory is continually tested by collecting new and different evidence. Even one piece of evidence that does not agree with a theory forces scientists to return to step one.

Before 1843, scientists believed that heat was a kind of fluid that flowed from hotter objects to colder objects (called the Caloric Theory).

However, a big problem came about when people learned to measure weight accurately (the mass of the two coffee cups were the same). If heat was a fluid then one cup should weigh more than

the other. This new evidence caused the Caloric Theory to be

discarded. Now, a new hypothesis needed to be developed: Maybe

heat is a form of energy??