introduction to science why science? it all starts with a …

Introduction to

Science

Why Science?

It all starts with a …

What is science?

A method (system) of organizing curiosities.

Why does iron rust?

Why do dogs bark?

How do penguins stay warm in the

cold?Why can’t we float on air?

True or False: Everything in science is a fact.

FALSE! Believe it or not, not everything that we will explore this year is proven to be 100% true.

Science is always changing! We’re even debating whether to

add in two more planets into our solar system or keep it to our familiar nine.

Fact vs. Inference vs. Opinion

Fact: something that can be proven true and is always found to be true. “I am 5 feet 7 inches tall.”

Inference: an idea based on facts that tries to explain facts. “It is going to be hot today because it is already

75 degrees outside!” Opinion: an expression of feelings or

attitude towards something. Miss Zitzmann is the coolest science teacher

ever!

What is Life Science?

Life Science: Study of living things.

How to think like a scientist…

No matter what a scientist may be curious about or what they are studying, they all use similar methods to investigate.

They all follow the scientific method. This helps scientists answer a question or solve a problem.

The Scientific Method

It can be used to study anything from a leaf to a dog to the entire Universe!!!!

Step One: State the Problem…

Did you ever wonder why something happens or where something comes from?

Just about everything starts with a question.

Usually, scientists come up with questions by looking at the world around them. "Hey look! What's that?"

Step Two: Make Observations

Observation: information (data) gathered by using your senses.

Senses: sight, smell, touch, hear, taste DO NOT EVER TASTE ANYTHING UNLESS

INSTRUCTED IN SCIENCE CLASS!!!! Measurement: an observation

expressed as a number with a unit. All measurements expressed in SI

units…(more later on these).

Step Three: Form a Hypothesis

Hypothesis- an educated guess. It is a possible explanation or

possible answer to the question you develop.

Usually in the form of: “If blah blah blah, then blah blah

blah.”

Step Four: Do the

Experiment

Test out your hypothesis and collect data.

Things to consider: Control group: used for comparison to see

if any change actually occurs during an experiment. The factors in this group are NOT manipulated or changed.

Experimental group(s): these groups experience manipulations/changes with their factors (called variable)

Why do we use experimental and control

groups? Because the variable differs between

the control group and experimental groups, scientists can be more certain that differences in the variable are causing any differences observed in the outcome of the experiment.

Was the one factor (variable) that you changed actually causing differences in the outcome of your experiment?

Step Five: Analyze the Results

Organize and analyze your data in order to come to a conclusion on whether or not your hypothesis was correct.

Step Six: Draw a conclusion

Were you correct? It is okay to be wrong!!! Some

scientists may go through their whole life and never come up with a hypothesis that actually worked out! Just think about how many attempts

have been made to cure cancer…unfortunately there are lots of failed hypotheses.

Measurement

History of Measurement

There are many different systems of measurement used throughout the world.

At one point, an inch was considered the size of one’s thumb; a yard from one’s neck to tip of one’s index finger; and a foot the length of one’s foot.

So why do we not use this system anymore? Consider the difference between the

following…

Sasquatch vs. Mini-Me

So how do we make it fair?

We use SI Units! SI Units: (International System of

Units). Used by most scientists in all countries.

The United States is actually the only country that uses feet, yards, and inches. The rest of the world uses SI Units.

Common SI Units

Length Meter (m)

Volume Cubic meter (cm3)

Mass Kilogram (kg)

Temperature Kelvin (K)

Length

Length: distance between two points.

Measured using a ruler, tape measure.

Different SI Units for Measurement

• We will work with the following measurements for length.• km=kilometer• hm=hectometer• dam=dekameter• m=meter• dm=decimeter• cm=centimeter• mm=millimeter

How do we convert between units?

SI units are based on multiples of 10…

km hm dam m dm cmmm

__ 10__ 10__10 __ 10 __ 10 __ 10

Or in another form..

1km= 1m X 10 X 10 X 10

1hm= 1m X 10 X 10

1dam=1m X 10

1m = 1m

1dm= 1m / 10

1cm= 1m /10 / 10

1mm= 1m / 10 /10 /10

Area

Area: measure of how much surface an object has.

To find area use the following formula: Area= Length X Width. Area = L X W Answers reported in square units or

units2 (ex:cm2)

Example Area Problem…

Find the area of the following piece of wood.

A = L X W =5cm X 3cm =15 cm2

5cm

3cm

Volume

Volume: The amount of space something takes up.

Measured using either a ruler or a graduated cylinder.

Volume = Length X Width X Height

V= L X W X H Answers are reported in

milliliters, liters, or units3 (ex: mL, L, or cm3).

Example Volume Problem

Find the volume of the fish tank.

V = L X W X H =

20 cm

24 cm

10 cm

How to read a graduated cylinder

Find the meniscus.

Read from the bottom of the meniscus at eye level!.

How to find the volume of oddly shaped

objects…Measure how much fluid the object displaces.

Step 1: Fill a graduated cylinder to an easy volume to work with (let’s say 100 mL).

Step 2: Place object in graduated cylinder. Step 3: Measure how much the water goes

up. (Let’s say the water went up to 150 mL). Step 4: Subtract your final volume from

your starting volume to get the volume of the object (150 mL – 100mL = 50mL!!)

Add rock

Start: 100mL End: 150mL

Volume of Rock=

50mL

Mass

Mass: amount of matter that makes up an object.

Measured using a triple beam balance. Answers are reported in grams.

Temperature

Temperature: Measure of how fast the molecules in a substance are moving (the faster the molecules are moving, the hotter the substance).

Answers reported using Kelvins (K) and Celcius (oC).

Measured using a thermometer.

Density

Density: measure of how packed together the molecules of a substance are.

To find the density of a substance use the formula: Density = mass/volume D = m / v

Example Density Problem

Types of Graphs

Circle, Line, and Bar Graphs

Circle/Pie Graphs

Compares proportions or percents.

Should only be used when all parts add up to one complete item.

Guidelines Include legend of slices Include data labels (%) on

slices

Percent of Foods in Daily Diet

30%55%

15%

FatsCarbohydratesProteins

Bar Graphs

Compares “Discrete” objects or items

Can be used over time if time intervals vary

Guidelines Add data labels Label all axes Title chart Avoid 3-D

Form I Student Height

010203040506070

Chuck Bob Sue

Student Name

Hei

gh

t (I

nch

es)

Line Graphs

Shows trends or changes over time.

Should only be used with continuous “X” variables.

Guidelines: Label all axes and title

graph Be sure time intervals

are appropriate distances apart on “X” axis!

Water Temperature Over Time

0

10

20

30

1 2 3 4 5 6 7 8 9

Time (Minutes)D

egre

es (

Cel

siu

s)