Unit 1: The Nature of Science Lesson 1: What is Science?

“Perception is not always reality” World is full of illusions and simple common sense doesn’t always work to explain them. SCIENCE is an especially reliable tool that can help us see past the illusion and form an accurate explanation for what we see. BUT science is not perfect and can be fooled too.

Illusions in Nature Where was the SUN earlier this morning? Where will it be in the afternoon? How did it get from the morning point to afternoon point? Compare the size of a full moon just above the horizon to the size straight overhead.

Other Illusions in Nature Rainbows Stars are on the surface of a dome…our sky Lightning Earthquakes The earth is not moving and flat Eclipses We are the center of the universe

How many legs?

Growing Pyramid

If your eyes follow the movement of the rotating pink dot, The dots will remain only one color, pink.  Stare at the black '+' in the center - moving dot turns to green. Now, concentrate on the black '+ ' in the center of the picture. After a short period, all the pink dots will slowly disappear. You will see only a single green dot rotating.

Which line LOOKS longer?

Science Questions what we see: Why is this an illusion? OR What feature about this figure is responsible for the illusion?

How could we test this idea, to see if it does indeed have any effect on the illusion? How could you measure this?

Interactive T-illusion

What is science? Science - A way of explaining the natural world by asking questions and finding answers Scientist – someone who asks questions and finds answers about the world around them

2 Types of Science 1. Physical study of nonliving things Biological Examples: Chemistry Physics Geology Astronomy Biological study of living things Examples: Botany Marine Entomology Cytology

How do you know what is NOT science and what IS science?

Characteristics of Science Consistent Experimental results and observations are the same every time. Example: Every time you release an object from a height, it falls towards the earth.

Characteristics of Science Observable- The event or evidence for the event can be observed by the human senses. Example: We can see the sun.

Characteristics of Science Natural –A natural cause is used to explain how or why an event happens. (NOT Supernatural) Example: Gravity is what causes an object to fall, not a supernatural being.

Characteristics of Science Predictable –Accurate predictions and conclusions are based on natural causes and NOT on assumed information Example: If a new object is found, we can predict that if it is dropped, it will fall.

Characteristics of Science Testable –Controlled experiments can be designed to test the natural cause of the event or question. Example: We can preform tests on the force of gravity.

Characteristics of Science Tentative – Explanations of the cause for the event are subject to change as new evidence is collected. Example: We use to believe that the earth was flat until we discovered that it was actually round!

6 Characteristics of Science Consistent – same results Observable – 5 senses Natural – not supernatural Predictable – explanations based on natural causes Testable - experiment can be performed Tentative - changeable CONPTT

Science vs Nonscience Irisology - the study of the colored part of the eye (iris) to determine potential health problems. Irisologists believe changing patterns and markings in the iris reveal emerging conditions in every part of the body and identify inherited weaknesses that may lead to physical and emotional disorders.

Science vs Nonscience Biology – study of living things Consistent – plants grow toward light Observe - living things (plants and animals) Natural – green plants convert sunlight to chemical energy Predictable – drugs kill your brain cells Testability – experiment if caffeine increases activity level Tentativeness – Redi’s experiment pg 261

Pseudoscience Pseudo= false A false science ("pseudoscience") is a non-science which is portrayed and advertised as a real science by its followers and supporters. Examples: "astrology“ “Palmistry” “Phrenology”

In order for an area of study to be considered science it must have all 6 characteristics of science.

REALITY CHECK #1 2. Walking under a ladder will cause bad luck. 1. Green plants will grow towards a light source. 2. Walking under a ladder will cause bad luck.

REALITY CHECK #2: 1. Some plants eat meat. 2. Extraterrestrial beings have visited Earth.

REALITY CHECK #3: 1. Green plants convert sunlight into energy. 2. Supernatural beings are the ones that created crop circles.

REALITY CHECK #4: Without sunlight (or comparable artificial light), green plants will die. If you are a "Scorpio", your horoscope for today is "You'll be saying 'I feel rich !' Lunar position highlights back pay, refunds, correction of accounting error.“

REALITY CHECK #5: 1. The Bermuda Triangle causes ships and planes to sink and disappear. 2. Life comes from life and cannot come from non-life.

REALITY CHECK #6: 1. The number of human chromosomes was once "known" to be 48, but is now considered to be 46. 2. Living things were once grouped into 2 major groups, then 3, then 4, and now 5, because the criteria used for classifying living things have changed. 3. We know that the world began about 6000 years ago, and nothing will change that.

How Scientific is it? Activity Each group will “rate” a statement based on how scientific they think it is. Groups will then check each other's answers and see if they disagree or agree.

Unit 1: The Nature of Science Lesson 2: How do Scientists find answers?

How do scientists find answers? Scientists make OBSERVATIONS – using 5 senses to learn about world around you Example: He is wearing a red shirt

Use Your Senses!

Inferences Inferences – interpretation of an observation Example: He is wearing a red shirt because he is happy.

How do scientists make good inferences? Information previously known New Observations

Make a list of observations about the picture.

Make a few more observations… Pic #2

Make a few more observations… Now go back through your previous observations & put an “ I “ beside inferences that you made, then, make a few more!

Types of Observations Qualitative Quantitative Deals with descriptions. Data can be observed but not measured. Colors, textures, smells, tastes, appearance, beauty, etc. Qualitative → Quality Deals with numbers. Data which can be measured. Length, height, area, volume, weight, speed, time, temperature, humidity, sound levels, cost, members, ages, etc. Quantitative → Quantity 

Lesson 3: Designing a Good Experiment

What is the scientific process? The Scientific Process is a plan used by scientists to learn about the world around us. Goal: solve a problem or understand an event NO SINGLE Scientific Method

What is the purpose of doing an experiment? To search for cause and effect relationships in nature. A good experiment is set up so that changes to one item causes something else to change in a predictable way. In order to determine the cause and effect relationship, you must identify all the variables.

What is a Variable? Any factor, trait or condition that can change in a scientific investigation or experiment

Types of Variables An experiment has three kinds of variables: independent, dependent and controlled.  In order for a good experiment to take place all of these variables must be identified and observed!

Independent variable the variable that the experimenter intentionally changes to see the effect it has on the dependent variable. There can only be one independent variable in an experiment. Also known as the manipulated variable  

Dependent variable The variable that responds to the change made to the independent variable. This is the variable(s) that are measured by the experimenter, there can be more than one! The scientist focuses his or her observations on the dependent variable Also known as the responding variable

Control variable The variables that must remain unchanged during an experiment These must be held constant or the relationship between the dependent and independent variables can not be determined. There are many controlled variables in every experiment Also known as constant variables

Types of Variables Understanding Check Does changing the temperature affect the height that a ball will bounce? Does changing the color of the light affect the amount that a pea plant will grow? How does the size of a parachute affect the time it will take a hippo to fall 10 ft? How does sound affect the human reaction time? Does salt affect the temperature of water when it is heated?

Setting up the experiment: A good test includes at least 2 groups. One that does not contain the independent variable. This is called the control group. A control group serves as a way to compare data between the experimental group and the control group.

Setting Up An Experiment After you have identified your variables . .  . . . A good experiment includes at least two groups. One that does not contain the independent variable and another one that does get/contain the independent variable

Test Groups: Experimental Group The test group in a scientific experiment where the group is exposed to the independent variable being tested . Control Group The group that does NOT get what is being tested Provide a base line or comparison to the experimental group

Important- Every good experimenter MUST have: properly identified all variables keep control variables constant at least 3 trials large enough test groups collected qualitative and quantitative observations (data) Started with a testable question and hypothesis

What is a good scientific question? Have real answers. Are testable (This means you could design an experiment or take measurements to find the answer) Have a hypothesis that is falsifiable. (This means that your experiment could show that your hypothesis is false (and that’s okay!)) Are interesting! You should want to know the answer!

Scientific or Not Questions Understanding Check Why is basketball a boring sport? Does Pepsi have more carbonation than Coke? What is the effect of cigarette smoke on lung cancer? Is cigarette smoke pretty? Did Abraham Lincoln think blue was a terrible color? What is the effect of adding fertilizer to grass have on the greenness of the grass?

Predictions and Hypotheses: What’s the difference? A prediction or hypothesis is a possible explanation for a set of observations or an answer to a scientific question. A hypothesis and a prediction are similar to each other. Just like a scientific question, a prediction or hypothesis must be testable. Both are statements that can be tested by doing an experiment.

Prediction A guess of what is going to happen based on your observations. It specifically tells how one variable (IV) might affect another variable (DV). Example: If the surface area of a fan blade increases, then the speed of air will increase.

Hypothesis A possible explanation for an observation or problem that can be further tested by experimentation. Sometimes called an “educated guess”- prediction with an explanation added. Example: If the surface area of a fan blade increases, then the speed of air will increase because the increased surface area will be able to move more air at one time

Hypothesis Song: https://www.youtube.com/watch?v=giC6ZYBIeFY#t=133

Steps to Writing A Prediction Identify your independent and dependent variables. Know which one is which. IV = temperature DV = rate of crystal growth 2.Start your prediction by writing the word “If” If 3.Add your independent variable. If at all possible, make sure the variable is measurable. If the temperature 4. Describe how your independent variable will change. This usually means you will write “increases” or “decreases.” Place a comma in your sentence here. If the temperature increases, 5. Write the word “then” If the temperature increases, then 6. Write your dependent variable. Try to describe the variable in a way that is measureable. If the temperature increases, then the rate of crystal growth 7. Write the word “will”. If the temperature increases, then the rate of crystal growth will 8. Describe how you think your dependent variable will react to the independent variable. Usually, you will be using the word increase or decrease. Add a period because you are done! If the temperature increases, then the rate of crystal growth will increase.

Steps to Writing A Hypothesis from a Scientific Question: Step 1: Read the scientific question. Step 2: Identify the independent and dependent variables. Underline the words for the variables & write IV and DV above. Step 3: Write the hypothesis in an “if/then/because” format. Start with the word, “If.” Tell the reader how you’re going to manipulate or change the independent variable. Write a comma and the word, “then.” Predict how your independent variable affect your dependent variable. Write the word, “because.” Tell the reader why you made that prediction. (This part usually requires prior knowledge OR for the scientists to do some research first)

So after an experiment . . . . then what?? Community Analysis & Feedback

So after an experiment . . . . then what?? 1. Come to a Conclusion: Come to the simplest conclusion Analyze the data- this involves making/redoing data tables and graphs Always restate your hypothesis and say if your data supported it or not NEVER say “proves”- science doesn’t do that!

Share findings Publish papers – so others can repeat experiment your experiment and learn from your experiment Peer review – experts in field read and critique papers for good procedures, experiments, and conclusions Conferences and meetings to compare research and learn new knowledge

3. Ask new questions and contribute to existing findings – Theory building!

Scientific Theory- a group of hypotheses that provide an explanation of a phenomena that has been supported through research using the scientific method. Theories explain “How or Why” something happens in nature. Tested repeatedly and supported by evidence. ***A theory is NOT just an idea, thought, or belief***

Examples of theories: Newton’s theory of gravity, Einsteins’ theory of relativity, Darwin’s theory of natural selection

Law A hypothesis about a SPECIFIC topic that has been tested repeatedly and not been contradicted becomes a scientific law A law says “What” happens Summarizes a pattern in nature Examples: Law of motion, Law of Thermodynamics

SCIENTIFIC THEORIES (& Laws!) are… Based on a many related hypotheses Extensively tested Based on vast amounts of observations & data Accepted by science Sometime misunderstood by those unfamiliar with the area of science

Your turn… Make a Prediction AND a Hypothesis for the following scenario… You observe a Mentos being dropped into a can of Diet Coke and create an little spray of soda. You wonder what will happen if you put an entire package of Mentos into a 2-liter bottle of Diet Coke… Mentos & Diet Coke