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Unit 1: Nature of Science

Lesson 1- What is Science?


Engage your brain

Tell whether the statement is true or false. Science can determine what book you will enjoy. Scientists can often be creative when designing experiments. Because they are well educated, scientists do not need to make many observations before coming to a conclusion. Scientific results can be proven incorrect.

What is science?
Science is the systemic study of natural events and

conditions. It is a logical, structured way of thinking about the world.

What scientists do?

Scientists ask questions about nature. They try to give explanations to describe what they

observe. Any explanation a scientist gives must rely on information available to everyone.

The natural world

Science is subdivided into different branches. Each

branch studies the world in the same logical and structural way. Biology, or life science is the study of all living things, from the smallest, one-celled organisms to mammals. Geology, or earth science, studies Earth, from the materials that make it up to the processes that shape it.

The Natural World cont.

Astronomy, the study of objects in outer space. Physical science is the study of energy and all

nonliving matter. Physical science includes both physics and chemistry.

What are types of questions scientists ask?

Scientists ask questions that can be tested; questions

that have answers they can measure in some way. An explanation in science is usually agreed upon by many people and not just someones opinion. This is what distinguishes scientific questions from other kinds.

What is a scientific explanation?

A scientific explanation describes a natural process.

It relies on evidence gained from direct observation and testing. It is an explanation that others can test and refute. Evidence gained from observations is empirical evidence. It includes observations, measurements, and other types of data scientists gather. Personal feelings and opinions are not empirical evidence.

What is a scientific explanation? Cont.

A scientists should never hide any evidence he or she

claims support a scientific explanation, if they want to be taken seriously. If one scientist does an experiment, other scientists must be able to do the same experiment and get the same results. This openness is what makes scientific explanations strong.

How do scientists show creativity?

Scientists must rely on what they can observe. They

must always try to think logically. Scientists can be creative in the experiments they design and explanations they draw from them.

How might creativity help in designing experiments?

In one case, environmental scientists

in Washington, DC, were looking for a method to detect harmful substances in drinking water. Since it would be too dangerous to have people drink the water directly, they had to be creative.

How might creativity help in designing experiments? Cont.

Scientists knew that bluegills are very sensitive to

some contaminants. The fish cough to expel dirty water from their gills. They set bluegills in tanks at different locations and have a sensor hooked into the tank to detect the fishes coughing and alerted monitors to potential harm.

Explaining Observations
New explanations can

often be as important as new observations. Isaac Newton claimed the law of gravity came to him when he saw an apple fall. He reasoned that some force, gravity, pulled the apple to the ground.

Newtons explanation change the understanding of motion forever. He had taken something many had seen, and explained it in a new way.

Summary - page 12
The natural sciences are normally divided into the

life, earth, and _________ branches. Science _____ explain why you think a particular sculpture looks good. Empirical evidence includes ________. Scientific explanations ______ able to be proven false. Scientists are often creative in ______ experiments.

Now that you understand the material, check your

answers in the true or false activity. Copy and answer the questions on page 13 Make index cards with the word and definition for each of the vocabulary terms in unit 1.

Lesson 2: Scientific Knowledge


What are some types of scientific explanations?

Examples of scientific Theories and models are

explanations are theories, models and laws. A scientific theory is a well-supported explanation about the natural world. A scientific model is a representation of something in the natural world.

modified as we learn more about the natural world. A scientific law describes a basic principle of nature that always occurs under certain conditions.

Scientific theory
Theories explain the observations scientists have

made. Scientists also use theories to make predictions about what they may not have seen yet. Theories are powerful things in science and are often explaining why things happen.

Scientific Theory cont.

Plate tectonics is an example of a scientific theory, it

states that Earths outer layer is divided into individual plates. The plates move over Earths surface and carry the landmasses with them. This theory changed the study of Earth science greatly.

Scientific Laws
Laws describe principles of nature that always occurs

under certain conditions. Laws can be expressed as statement or mathematical equation.

Scientific Laws (cont.)

Newtons law of inertia- and object at rest will stay at

rest unless an unbalanced force acts on it.

Scientific Laws cont.

Every branch of

science has its scientific laws. In Geology, the law of superposition states that younger layers of rocks will always overlie older layers.

Scientific Models
Models allow scientists to study things

that may be too large, too small or in some way too difficult to study. Models do not need to be a physical thing, a model can be a computer program or a mathematical equation.

Scientific Models cont.

Scientists use

models to help them understand the past, present, and even future events. Maps are one example of a scientific model.

The model of Pangea has its limitations, it doesnt allow scientists to study the real thing but it can give them a better sense of what Pangea was like.

What makes good scientific knowledge?

The best scientists are those that are open to change,

based on new discoveries. The theory of light is a good example on how scientists knowledge can adapt and change. At one time scientists saw light as particles, and later as waves. Today scientists view light as having both a particle nature and a wave nature.

What makes a good source of scientific knowledge?

You can trust
You should be cautious

information that comes from a government or university source. Nationally recognized research institutions such as NASA, the Mayo Clinic, or Salk Institute.

with old publications, remember scientific knowledge changes. You should also be cautious of information made by those trying to sell products, they use science to make money.

Evaluate whether it is a reliable, somewhat reliable or not very reliable source of information
Government science agency Advertising agency Science textbook from 1985

University (.edu site)

Personal webpage

Visual Summary
Tell whether each statement is true or false
Any hunch you have is as good as a scientific theory. Models can represent things that are too far away or too small to see. Scientific laws can be thought of as general descriptions of what we see happening around us. Scientific theories can change when new evidence is found. You can trust scientific information from advertisers, because they are selling a product.

Laws can be explained by theories, if a theory

changes, does it mean the law must change? Explain. No. A law is just a statement of what you see. Just because the explanation of why something happens changes, doesnt mean that it stops happening.

Work with a partner or on your own Page 23- Copy and answer 1-7 Choose one of the following to analyze
Law of universal gravitation Uses of scientific models Development of the atomic theory Relationship between Boyles law and Charles law

Make a cartoon sequence, story, song, or poem with supporting details.

Lesson 3:Scientific Investigations


Vocabulary Terms
Experiment Observation Hypothesis


Engage your brain!

Tell whether each statement is true or false. Every scientific investigation is an experiment. You could do an experiment to see if eating breakfast helps students raise their grades. Scientist need fancy instruments to do experiments. Scientists must repeat an experiment for it to be useful.

What are some types of scientific investigations?

The two main types of scientific investigations are

experiments and observations.

Characteristics of good scientific investigations

A good scientific investigation it is carefully planned

and able to replicate.

Scientific investigations
Observation is the process of obtaining information

by using the senses. It may give a better description of what is actually happening in nature.

Scientific investigations cont.

Another type of scientific investigation is the

creation of models, which are representations of an object or system. Models are useful to study things that are very small, large, or complex.

What are some parts of scientific investigations?

A hypothesis is a Scientists were removing

testable idea or explanation that leads to scientific investigation. A hypothesis can be tested by experiment or observation.

mummies in Peru and some were well preserved. Because Perus climate is so dry, some DNA is preserved.

Elements of Investigations
A variable is any factor that can change in an

experiment, observation, or model. When scientists plan experiments they try to change only one variable and keep the other variables constant.

Elements of investigations cont.


Information gathered

by observation or experimentation that can be used in calculating or reasoning. Everything a scientist observes in an investigation must be recorded.

Scientific Method

Defining a Problem

After making observations scientists come up with questions. The problem must be well-defined, or precisely stated, so that it can be investigated.

Forming a Hypothesis and Making Predictions

A hypothesis is an educated guess about a problem. Before testing the hypothesis scientists make predictions about what will happen in the investigation

Planning an investigation

Decide whether the investigation should be done in the field or in a laboratory. Determine the equipment and technology required for the investigation.

Identifying Variables

Scientists identify all the variables that can affect the results, then decide which variable should change and which ones should stay constant.

Collecting and Organizing Data

The data must be recorded and properly organized so that it can be analyzed. (tables, Interpreting Data and graphs, Analyzing Information spreadsheets) Scientists may have different interpretations of the same data because they analyze it using different methods.

Defending Conclusions

If the hypothesis is not supported, scientists come up with a new hypothesis to test. Scientists must be prepared to defend the conclusion if they are challenged by other scientists.

Problem: Scientists wonder how do geckos stick to walls and ceilings?

They came up with two hypotheses that either the weak forces of hairs on the geckos feet hold the gecko to the surface, or the hairs interact with a film of water on a surface.

Data: The force of a geckos hair against a surface was the same whether or not the surface was wet. Conclusion: The gecko sticks to the wall because of the combined forces of the hairs on its feet.

What are some ways to confirm an investigation is valid?

Peer Review
Before a study is

It is very important that

published, it is read by scientists who were not involved in the investigation. A reviewer can decide whether an experiment was properly controlled.

scientists replicate or repeat the investigation and obtain the same findings. If a study cannot be supported by the results of similar investigations, it will not be accepted by the scientific community.

How can you evaluate the quality of scientific information?

Although the lab reports For example

that you prepare for school might not be published, you should try to meet the same standards of published studies.

State the problem Hypothesis Independent variables Constant variables Materials Procedure Data table Conclusion

Summary p.36
Scientific investigations that involve testing a single

variable are called _________. __________ are often made before other types of investigations are done. A ________ must be tested to see if it is supported. Scientists must decide which _______ will stay constant in an experiment. The findings of experiments are generally not accepted until they are _________. The most reliable scientific information comes from ________ working in a particular field.

Lesson Review
A _______ determines what will be tested in a

scientific experiment. All of the ________ gathered in an investigation must be recorded. A good scientific _______ can be repeated by someone else and the same results will be found.

Lesson Review cont.

Example Scientific method

Scientists use instruments to record the strength of earthquakes in an area.

Scientists decide that in an experiment on fish, all the fish will be fed the same amount of food.

Lesson Review cont.

What are two key characteristics of a good scientific

investigation? Why is it important for scientists to share information from their investigations? Which is less likely to be a reliable source of information, the webpage of a university or the webpage of a scientist who is trying to sell a new invention? Explain.

Lesson 4: Representing Data


Engage your Brain!

Tell whether each statement is true or false. Scientific models have been used to show results of scientific experiments. Certain types of graphs are better than others for displaying specific types of data. Most graphs are confusing and unnecessary. If something can be shown in a table, then it should not be shown in a graph.

How do scientists make sense of data?

Before scientist begin an

experiment, they often create a data table for recording their data. Information that might be recorded in a data table are times, amounts, and frequencies. When creating a data table, scientists must decide how to organize the table into columns and rows. Finally a title must be added to describe the data in the table.

Scientist graph and analyze the data

A circle graph is an ideal way to display data that is

part of a whole.

Scientists graph and analyze data

Graphs show data in a visual way. Data

displayed in a graph is easier to understand than data displayed in a table. Circle graphs or pie chart is used when showing how each group of data relates to all of the data. A bar graph is used to display and compare data in a number of categories. A line graph is used to show continuous change. Line graphs are useful for showing changes in variables over time.

What do graphs show?

Graphs are visual

representations of data. They show information in a way that is easier to understand. All graphs should have a title explaining the graph.

What do graphs show? Cont.

The data displayed

on the horizontal axis are the values of the independent variable. The data displayed on the vertical axis are the values of the dependent variable.

How are graphs constructed?


Draw a horizontal axis and a vertical axis. Write the names of the categories to be graphed along the horizontal axis. Include an overall label for the axis as well. Label the vertical axis with the name of the dependent variable. Be sure to include the units of measurements. Create a scale along the axis by marking off equally spaced numbers that cover the range of the data collected. Draw a solid bar using the scale on the vertical axis to determine height. Make all bars the same width. Add a title that describes the graph.

How do scientists evaluate models?

A scientific model can be visual or mathematical

representation of an object or system. Models are useful for showing things that are too small, too large, or too complex to see easily. Scientists use models to make predictions before an investigation as well as to represent the results of an investigation.

Types of Models

Are models that you

Is made up of

can touch. Toy cars, models of buildings, maps, and globes are all physical models. Physical models look like the things they represent.

mathematical equations and data. This models allow you to calculate things as how far a car travel in an hour.

What are some benefits and limitations of models?

Models allow scientist to change variables without

affecting or harming the subject that they are studying. For example, crash-test dummies to study the effects of car accidents on people. All models are limited because they are simplified versions of the system they try to explain. Models can change, technology may help create new models that allow us to understand the world differently.

Lesson Review
A(n)______ can be a visual or mathematical

representation of an object or a process. After data are collected they are often arranged in a ______. Data can be arranged in visual displays called ______ to make identifying trends easier. How is a physical model different from a mathematical model?