1. Unit 1 Lesson 3 Scientific Knowledge

2. … From the Beginning What is science?
Unit 1 Lesson 3 Scientific Knowledge
… From the Beginning
What is science?
Science is the study of the natural world.
Scientists study many different things, living and nonliving, from the deepest parts of the ocean to the objects in outer space.
The natural sciences are divided into three areas: biology or life science, geology or Earth science, and physics or physical science. Chemistry is often included in physical science.
Copyright © Houghton Mifflin Harcourt Publishing Company

3. Unit 1 Lesson 3 Scientific Knowledge
What is science?
Biology, or life science, is the study of living things.
Copyright © Houghton Mifflin Harcourt Publishing Company

4. Unit 1 Lesson 3 Scientific Knowledge
What is science?
Geology, or Earth science, is the study of Earth and the processes that shape Earth.
Copyright © Houghton Mifflin Harcourt Publishing Company

5. Unit 1 Lesson 3 Scientific Knowledge
What is science?
Physical science is the study of nonliving matter and energy.
Copyright © Houghton Mifflin Harcourt Publishing Company

6. What does science tell us?
Unit 1 Lesson 3 Scientific Knowledge
What does science tell us?
Scientific knowledge is constantly changing.
Many things that people consider scientific “facts” are actually the most widely accepted explanations.
What we learn in science are what most scientists agree are the best explanations about how things happen. They are theories scientists have about the world.
Copyright © Houghton Mifflin Harcourt Publishing Company

7. What does science tell us?
Unit 1 Lesson 3 Scientific Knowledge
What does science tell us?
A scientific theory is an explanation supported by a large amount of evidence.
Theories are what most scientists agree to be the best explanations based upon what we now know.
Copyright © Houghton Mifflin Harcourt Publishing Company

8. Not a Theory—It’s a Law! How do scientific theories differ from laws?
Unit 1 Lesson 3 Scientific Knowledge
Not a Theory—It’s a Law!
How do scientific theories differ from laws?
The words law and theory have specific meanings in science.
A scientific law is a description of a specific relationship under given conditions in the natural world.
Scientific laws describe the way the world works. They hold anywhere in the universe.
Copyright © Houghton Mifflin Harcourt Publishing Company

9. What does Boyle’s Law describe?
Unit 1 Lesson 3 Scientific Knowledge
What does Boyle’s Law describe?
Boyle’s law describes the relationship between the volume and pressure of a gas that is kept at a constant temperature.
Boyle’s law states that at a constant temperature, when the pressure of a gas is increased, its volume decreases. When the pressure of a gas decreases at a constant temperature, its volume increases.
Copyright © Houghton Mifflin Harcourt Publishing Company

10. What does Boyle’s Law describe?
Unit 1 Lesson 3 Scientific Knowledge
What does Boyle’s Law describe?
Copyright © Houghton Mifflin Harcourt Publishing Company

11. How can Boyle’s Law be graphed?
Unit 1 Lesson 3 Scientific Knowledge
How can Boyle’s Law be graphed?
A graph for Boyle’s Law shows that a pressure of a gas varies inversely with its volume at constant temperature (curved line)
Copyright © Houghton Mifflin Harcourt Publishing Company

12. How do scientific theories differ from laws?
Unit 1 Lesson 3 Scientific Knowledge
How do scientific theories differ from laws?
A scientific theory is a well-supported explanation of nature.
Scientific theories are supported by many pieces of evidence.
Theories help us understand and explain the laws we observe.
Copyright © Houghton Mifflin Harcourt Publishing Company

13. Unit 1 Lesson 3 Scientific Knowledge
What is the Cell Theory?
The cell theory states that living things are made up of cells that perform the basic functions of life.
Copyright © Houghton Mifflin Harcourt Publishing Company

14. What’s Your Evidence? Where do scientists get their evidence?
Unit 1 Lesson 3 Scientific Knowledge
What’s Your Evidence?
Where do scientists get their evidence?
Scientists are curious. They look at everything going on around them, ask questions, and collect information to answer these questions.
Scientific knowledge is based on empirical evidence.
Empirical evidence is all the measurements and data scientists gather in support of a scientific explanation.
Copyright © Houghton Mifflin Harcourt Publishing Company

15. Where do scientists get their evidence?
Unit 1 Lesson 3 Scientific Knowledge
Where do scientists get their evidence?
Scientists gather evidence in many places. Some do fieldwork, and others do laboratory work.
Fieldwork is work done outdoors or where conditions cannot be controlled.
Fieldwork gives scientists the opportunity to collect data in an original setting. Biologists and geologists do fieldwork.
Copyright © Houghton Mifflin Harcourt Publishing Company

16. Where do scientists get their evidence?
Unit 1 Lesson 3 Scientific Knowledge
Where do scientists get their evidence?
In a laboratory, scientists have the opportunity to collect data in a controlled environment.
Most experiments are conducted in laboratories. In an experiment, scientists try to see what happens under certain conditions.
Laboratories come in many varieties. They can be in the ocean or in the sky.
Copyright © Houghton Mifflin Harcourt Publishing Company

17. The Debate Continues How do scientific ideas change?
Unit 1 Lesson 3 Scientific Knowledge
The Debate Continues
How do scientific ideas change?
Scientific knowledge is what scientists think are the most-likely explanations for what we see. Over time, these explanations can change.
Scientific ideas and explanations change when new evidence is found or when someone gives a better explanation of the old evidence.
Copyright © Houghton Mifflin Harcourt Publishing Company

18. The Debate Continues How has the model of the atom changed?
Unit 1 Lesson 3 Scientific Knowledge
The Debate Continues
How has the model of the atom changed?
The theory of atoms is a good example of how new evidence can modify an established theory.
Copyright © Houghton Mifflin Harcourt Publishing Company

19. How do scientific ideas change?
Unit 1 Lesson 3 Scientific Knowledge
How do scientific ideas change?
Scientists collaborate and share ideas. Often, many brains are better than one when solving a puzzle.
Scientists regularly gather at meetings to discuss and debate ideas. Many ideas are not accepted at first.
This rigorous evaluation ensures that scientific knowledge is solidly supported.
Copyright © Houghton Mifflin Harcourt Publishing Company