Introduction to Earth Science
Introduction
to
Earth
Science
Scientific Method
and the
Metric System
Scientific Method & the Metric System
The Nature of Science
• The goal of science is to understand the
world around us
• Special methods help to determine truths
about nature
Branches of Earth Science
The three main branches of science are:
•Life Science
•Earth Science
•Physical Science
Earth Science
•Earth science deals with the study of the Earth,
its history, changes, and its place in the Universe
•There are four branches
of earth science
Branches of Earth Science
• Geology- Earth’s origin, history, and
structure
• Meteorology- Earth’s atmosphere &
weather
• Oceanography- Earth’s oceans, including
their physical features, life forms, and
natural resources
• Astronomy- Planets, stars, and other
objects in space
The Scientific Method
• An orderly, systematic approach to
problem solving
• The way scientists, and
non-scientists,
look for answers
• There are seven
basic steps to the
scientific method
Step 1: Stating the problem
–Decide what you
want to know
–State the problem
in the form of a
question
Step 2: Gathering information on
the problem
–Research what’s
already known
–Collect
information
and facts
Step 3: Forming a hypothesis
- A hypothesis is a
proposed solution
to a scientific problem
– There are two main parts to a
hypothesis
1. An explanation- why it will happen
2. A prediction- what will happen
Step 4: Experimenting
– Perform one or more
experiments to test the
hypothesis
– When performing experiments:
1. Divide subjects into test groups
2. In each experiment you should have a control group,
that doesn’t get any of the variable, and several test
groups
3. Keep everything, except the amount of the variable,
the same between groups
Step 5: Recording and analyzing
data
–Observe and write
down important
information (data)
–Organize data using graphs,
tables, and charts
–Look for patterns or trends
Step 6: Stating the conclusion
–Look at data and
form conclusions
–Did the conclusions
support your hypothesis?
(why or why not?)
–Re-evaluate the hypothesis and
formulate new questions
Step 7: Repeating the work
– In order for a hypothesis to be
excepted it has to be able to
withstand repeated testing
– After many experiments, where a
hypothesis has continually been proven to
be correct, it may be accepted by the
scientific community and then considered
to be a theory
– A theory is the most logical explanation for
events that occur in nature
The Metric System
• A universal
measurement system
(also called the
International System)
• Being based on
multiples of ten
makes it easy to use
• Uses prefixes to
identify larger or
smaller units of
measure
Prefix
Symbol Multiple
kilo
K
1000
centi
c
.01
milli
m
.001
Metric Conversions - Length
x 1000
Km
÷ 1000
x 10
m
x 10
dm
÷ 10
x 10
cm
÷ 10
mm
÷10
Metric Conversions - Volume
x 1000
Kl
x 10
l
÷ 1000
x 10
dl
÷ 10
x 10
cl
÷ 10
ml
÷10
Metric Conversions - Mass
x 1000
Kg
x 10
g
÷ 1000
x 10
dg
÷ 10
x 10
cg
÷ 10
mg
÷10
Length
• A measure of linear distance
• Basic unit of length is the meter (m)
• Use a meter stick or metric ruler to make
measurements
•The entire meter stick
represents one meter
•Each number represents
a centimeter (there are
100 centimeters in a meter)
•Each little line is a millimeter
(there are 1000 millimeters
in a meter)
Area
• The amount of surface included within a set of
boundaries
• Determined by measuring the length and width
of an object, then multiplying
Length = 14 cm
Width = 7 cm
Area = 14 cm x 7 cm
= 98 cm2
(Area is always expressed
in square units)
Volume
• Volume is the space that an object occupies
• Represents the length, width, and height of an
object
• For solids, measurements are based on units
of length (ex. cm3) and can be calculated using
specific formulas
Calculating the volume
of a rectangle
Volume of a rectangle = length x width x height (l x w x h)
4 cm
3 cm
10 cm
Length = 10 cm
Width = 3 cm
Height = 4 cm
Volume = l x w x h
= 10 cm x 3 cm x 4 cm
= 120 cm3
Calculating the volume
of a cylinder
Volume of a cylinder =  x radius 2 x height ( x r2 x h)
 = 3.14
Diameter = 10 cm
Radius = ½ diameter
= ½ 10 cm
= 5 cm
20 cm
Height = 20 cm
Volume =  x r2 x h
= 3.14 x (5 cm)2 x 20 cm
= 3.14 x 25 cm2 x 20 cm
= 1570 cm3
Volume of a liquid
•A graduated cylinder is used to
accurately measure the volume of liquids
in milliliters
•Determine the volume in a graduated
cylinder by reading the bottom of the
meniscus at eye level
•Once the volume of a liquid is known,
it can be converted to a “solid volume” by
using the formula 1 ml = 1 cm3
Mass
•Mass is a measure of the amount of matter
•Mass is measured in grams using a balance
•The mass of an object remains the same,
no matter where in the universe it is
measured
Weight
Weight is a measure of the gravitational force exerted
on an object by a massive body
•Weight is measured in Newtons (N)
using a spring scale
•Weight varies from place to place
depending on the strength of the
gravitational force
Gravity
Gravity is the force of attraction between objects
The strength of the gravitational force between
objects depends on:
- the distance between the objects ( the
gravitational force between objects
decreases with distance)
-Mass ( the greater the mass
of an object, the greater it’s
gravitational force)
Density
•Density is the mass of a specific volume of
an object
•Density is calculated by dividing the mass
of an object by its volume
•Units for density are usually expressed in
grams per cubic centimeter (g/cm3 )
•Since the density of water is 1 g/cm3
anything with a density less than 1 g/cm3 will
float in water and anything greater will sink