Unit 1 Lesson 1 What Is Science? Copyright © Houghton Mifflin Harcourt Publishing Company 1

Unit 1 Lesson 1 What Is Science? What All Scientists Do Science is the study of the natural world through careful observation and investigation. There are many branches of science. Scientists use investigations to try to explain how and why things in the natural world happen. Investigations are procedures carried out to observe, study, or test something. Copyright © Houghton Mifflin Harcourt Publishing Company 2

Unit 1 Lesson 1 What Is Science? What All Scientists Do All scientists observe by using their five senses to collect information. All scientists compare by finding ways objects and events are similar and different. Scientists must think critically about the results of their investigations to learn more about the natural world. Copyright © Houghton Mifflin Harcourt Publishing Company 3

Unit 1 Lesson 1 What Is Science? Prove It! Scientists collect evidence, or information, to explain observations during a scientific investigation. Evidence can be direct. A fossil of a dinosaur skull is direct evidence that dinosaurs once lived. Evidence can be indirect. A fossil of a dinosaur footprint is indirect evidence of dinosaurs. Copyright © Houghton Mifflin Harcourt Publishing Company 4

Prove It! Here is an example of a scientist collecting evidence: Unit 1 Lesson 1 What Is Science? Prove It! Here is an example of a scientist collecting evidence: In the 1660s, a scientist named Dr. Francesco Redi designed an experiment on maggots. At that time, most people thought maggots grew out of rotting meat. Copyright © Houghton Mifflin Harcourt Publishing Company 5

Unit 1 Lesson 1 What Is Science? Prove It! Redi put fresh meat in two jars. He covered one jar with cloth and left the other jar uncovered. Copyright © Houghton Mifflin Harcourt Publishing Company 6

Prove It! He observed the meat over many days. Unit 1 Lesson 1 What Is Science? Prove It! He observed the meat over many days. He saw that flies landed on the meat in the uncovered jar. No flies landed on the meat in the covered jar. Copyright © Houghton Mifflin Harcourt Publishing Company 7

Unit 1 Lesson 1 What Is Science? Prove It! Soon, there were maggots on the meat in the uncovered jar. There were no maggots on the meat in the covered jar. Copyright © Houghton Mifflin Harcourt Publishing Company 8

Prove It! Redi repeated the experiment many times. Unit 1 Lesson 1 What Is Science? Prove It! Redi repeated the experiment many times. Each time, he observed the same thing: Maggots grew on meat that flies landed on, but no maggots appeared on meat with no flies. He concluded that maggots come from eggs that flies lay. Copyright © Houghton Mifflin Harcourt Publishing Company 9

Prove It! Which jar would the meat in the image below have been in? Unit 1 Lesson 1 What Is Science? Prove It! Which jar would the meat in the image below have been in? Copyright © Houghton Mifflin Harcourt Publishing Company 10

A Sticky Trap How to Draw Conclusions Unit 1 Lesson 1 What Is Science? A Sticky Trap How to Draw Conclusions Scientists repeat investigations over and over to draw conclusions. The conclusions are always based on evidence. A scientist uses inferences to draw conclusions based on evidence. Scientists do not use feelings or opinions to draw conclusions. Copyright © Houghton Mifflin Harcourt Publishing Company 11

Unit 1 Lesson 1 What Is Science? Opinion or Evidence? Opinions are beliefs or judgments. Scientists do not use opinions to draw conclusions. Personal feelings and opinions should not affect how you do investigations or your conclusions. You should not ignore evidence, even if you do not like what it means. Copyright © Houghton Mifflin Harcourt Publishing Company 12

Unit 1 Lesson 1 What Is Science? Knowledge Grows Scientists communicate, or share, the results of investigations. Other scientists can repeat the investigations and compare the results. Scientific knowledge grows as scientists expand on one another’s ideas. Copyright © Houghton Mifflin Harcourt Publishing Company 13

Unit 1 Lesson 1 What Is Science? Meet Scientists Many people work as many different types of scientists. Astronomers: study how the universe works, using time and space relationships to investigate it Botanists: investigate questions about plants, such as how environmental conditions impact the plant cycle Taxonomists: identify and classify living things into categories based on specific characteristics Copyright © Houghton Mifflin Harcourt Publishing Company 14

Unit 1 Lesson 1 What Is Science? Meet Scientists Scientists may need to place objects or events in order. They may also need to classify objects or events based on specific characteristics. How do you know the order, or correct sequence, for the images below? Copyright © Houghton Mifflin Harcourt Publishing Company 15