Unit 1

The nature of science

Objectives (LT)

• Compare areas of study in Earth Science• Identify Earth’s systems• Explain relationships among Earth’s systems• Explain why technology is important to you

Section 1.1

• What does Earth Science encompass?– 5 areas of study• Astronomy• Meteorology• Geology• Oceanography• Environmental science

astronomy

• Study of objects beyond Earth’s atmosphere– Scientists called Astronomers– First viewed using only eye sight• Saw objects such as Sun, Moon and Stars

– Objects moved and were tracked over time– First calendars developed from these observations

– Technological breakthrough • Telescopes

– Saw greater detail– Piqued man’s curiosity– Eventually drove mankind to explore beyond Earth

Meteorology

• Study of forces and processes that cause atmosphere to change and produce weather– Atmosphere is 100 km thick! (60 miles)– Scientists called meteorologists• Attempt to predict (forecast) weather• See on TV every night• Important to know weather for business

– Farming, roofers, shipping at sea, etc.

• Weather affects and shapes climate

Geology• Study anatomy of earth:

– Crust—outer layer– Mantle—molten magma beneath the crust– Core—center of earth

• Study of material that makes up Earth• Study of processes that form and change these materials• Scientists called geologists• Study of history of planet and life forms

– Identify• Minerals• Rocks• Forces that change and alter these materials

Structure of solid Earth

Crust—outer layer of lighter rocks---10-60 km thickMantle—made of heavier rocky material—2900 km thick ---magma located here—molten materialOuter core—2000 km thick—made of liquid iron and sulfurInner core---2800 km diameter—solid iron and nickle

Oceanography

• Study of Earth’s oceans– Cover ¾ of Earth’s surface

• Scientists called Oceanographers– Study/observe• Creatures that inhabit seas• Physical and chemical processes that affect oceans• Track and map ocean currents• Map ocean floor and measure depth• Research affects of oceans on weather and climate

Environmental Science

• Study of interactions of organisms and their surroundings

• Scientists called environmentalists– Be careful—not all “environmentalists” are scientists!!

• Study how organisms affect their surroundings – Both positive and negative

• Topics studied– Natural resources

• Minerals, oil, natural gas, water, soil for farming

– Pollution– Impact, if any, of humans on atmosphere

Technology

• Application of scientific discoveries • Makes life easier and safer– Examples:• Freeze dried food• Calculator• Internet• Smoke detectors

Objectives (LT)

• Define scientific method• compare and contrast independent and dependent

variable• Define “good” experimental design• Know base measurements used in SI

– Convert one measurement into another in the same base unit

• Identify difference in mass and weight• Know and calculate derived measurements• Convert “normal” numbers into scientific notation

Section 1.2

• Methods of Scientists– Scientists are problem solvers– use something called Scientific Method• Observe problem• Hypothesize explanation

– Consists of if—then statement

• Design and conduct experiment• Conclude if hypothesis was correct or incorrect• Report results to scientific community for review

Observation

• Gather background information on problem– Research other experiments– Define the problem– Make sure the problem is real

Hypothesis

• Consists of an IF – THEN statement• This statement will define the experimental

design• If this variable is changed (independent) then

this result (dependent) will happen

Experiment

• Organized procedure– Observe and make measurements that test

hypothesis– 2 types of experiments• Qualitative

– Simply observe and describe using words what was observed

• Quantitative– Measurements taken using instruments

» Balance, ruler, thermometer, etc.

– Good experimental design consists of:

Good experimental design

• A good experiment tests only one thing at a time called a variable

• 2 types of variables– Independent• What is controlled by the experimenter

– Dependent• What changes because of the independent variable

• Control—identical setup to refer back to– Needed to measure change

Conclusion

• Analyze data from the experiment to determine if hypothesis was correct or incorrect.

• If hypothesis correct the experiment is repeated many times then submitted for peer review

• If hypothesis incorrect go back and change hypothesis

• All experimentation leads scientists to the truth!!!

Scientific method

• Easy to remember:– O----observation– H----hypothesis– E----experiment– C----conclusion

• Do you see it?? OHEC

Measurement

• All scientists use the same system of measurement: Metric system!! Called system international (SI)

• Length—meter (m)• Mass—kilogram (kg)

– Different than weight!! ( weight determined by gravity)– You have different weight on moon than earth!– You have same mass!! (you have same number of atoms in

both places)• Time—second• Temperature—kelvin scale—but we will use celcius (oC)

Derived measurements

• Area– Length x width = area

• m x m = m2

• Volume– Length x width x height = volume

• m x m x m = m3

– Liquid measurements usually in milliliter or liter• 1 ml = 1 cm3

• Density– Mass/volume

• g/ml or g/cm2 or kg/m3

Scientific notation

• Used to write very large or very small

numbers• Accomplish by moving decimal point• Example: 4,000,000 = 4 x 106

.000004 = 4 x 10-6

try some scientific notation problems

1. 100 = 1 x 102

2. 2,345,678 =2.345678 x 106

3. .01 =1 x 10-2

4. .2345678 = 2.345678 x 10-1

Objectives (LT)

• Explain why precise communication is crucial to science

• Compare and contrast scientific theories and laws

• Identify when it is appropriate to use a graph or a model

Section 1.3

• Communication in science– Must be truthful and ethical– Accomplished by peer review

• Peer review is when other scientists read your experiment and results then try to reproduce them

– You will report your results to me in lab reports• Lab reports will consist of

– Hypothesis—if then statement which defines the experiment– Observations (written words—qualitative)– Measurements (numbers with units—quantitative)– Graphs if necessary—picture form of data– Conclusions—was hypothesis correct or incorrect

Graphs

• Used to show relationships between data• Different types of graphs– Line graph

• 2 variables plotted– X-axis = independent variable– Y-axis = dependent variable

– circle graph (pie graph)• Used to show fixed quantity• Entire circle = total quantity• Slices = percentage of whole

– Bar graph• Vertical representation of quantitative data

Models

• Scientific model is an “idea picture”, system or mathematical expression that represents concept.

• You use models all the time when explaining a situation or experience to your friend when they were not present at the event. You use words such as: like, remember when, etc.

• Models change when new information discovered

Scientific theory vs. law

• Scientific theory is explanation based on many observations from many experiments over a long period of time.– May change if new information discovered

• Scientific law is a rule of nature that cannot be broken. It is really a theory that has NEVER BEEN WRONG—OVER HUNDREDS OF YEARS.

Review of chapter

• Complete ch.1 study guide in text pgs. 22-25• Complete study guide handout from instructor