WHAT IS SCIENCE?

How we know what we know

The Nature of Science

1. Science is a path to gaining knowledge about the natural world

2. Science does not rely on faith or opinions

3. Science is in the realm of facts and observations

4. Science does not make moral judgments5. Scientific ideas can change if we gather

more data or learn more

Scientific Method

1.A series of steps that help investigate a question

2.All things can be explained through natural processes

3.Based on data and observations

4.Free from religious/cultural interference

Question

Research

Hypothesis

Experiment

Data

Conclusion

Question1. Begin with a testable question then try to

answer the question with evidence and logic

a) Example: i. Why are there more earthquakes in California

than in North Carolina?ii. Why is the sky blue?

2. Some questions are impossible to testa) Example:

i. Is there life after death?ii. Do ghosts exist?

Research1. Someone has probably asked this

question before.2. Scientists keep good records, read a

lot, work together, and share information.

a)Books, magazines, Internet, experts

3.Determine what is already known.

Hypothesis

1.Testable prediction based on research

2.Must be something you can measure and documenta)Not supernatural things

3.You are usually proving only a tiny part of the problem

Experiment

1.Design a way to test your hypothesis

2.Have as few variables as possiblea)Independent Variablesb)Dependent Variablesc)All else should be

constant

Variables

1. Independent Variable: The factor that the experimenter will change or manipulate

a) Under the direct control of the experimenter

b) “manipulated variable”

2. Dependent Variable: The factor that changes based on the independent variable

a) May or may not be different among the trials

b) NOT under the control of the experimenter

c) “measured variable”

Variables

1.The effects of independent variable on dependent variable

2.Does the amount of sleep a student gets affect his/her grades?

3.The effects of sleep on grades.

Constant

1.Constant: Anything that is not a variable

a)Why is it important to keep everything else constant?

Control

1.The standard for comparison that will show the independent variable was the cause of the results

2.Control group vs. Experimental Group

a)Example: Drug trials placebos

Data1. Data: the information gathered

during the experimenta) Displayed in the form of graphs,

charts, or tablesb) May be quantitative or qualitativec) There must be enough data points to

prove your claimsd) Everything must be measured properlye) Notes and observations may also be

important

Conclusion1. Was your hypothesis supported?2. What experiments need to be done

in the future?3. Share data – Publish your results4. Different people may have different

conclusions from the same data

Scientific Community

1. Scientific discovery works best with collaboration

2. A hypothesis needs to be confirmed by many different scientists before it can become a theory

3. Scientists may publish their findings after several scientists review the paper – this is called “peer review”

Theory

1. If a hypothesis explains all the data and none of the data contradicts the hypothesis, the hypothesis becomes a theory

2. A theory is the simplest explanation that explains observable facts

a) Examples: Germ theory of Disease, Theory of Gravitation, Theory of Evolution, Atomic theory of matter, Quantum Theory

3. Theories can be constantly tested and revised

Scientific Models

1. Scientists often cannot directly touch or see what they are studying

2. Models are simpler representations of complex real world phenomena

3. Models are useful for testing hypotheses and making predictions about real world events

3 Types of Models

1. Physical Model: physical representation of subject being studied

a) Example: Globe or Map

2. Conceptual Model: ties together lots of ideas to create an explanation

a) Example: Giant Impact Hypothesis

3. Mathematical Model: complex equations that take many variables into account

a) Example: predicting the path of a hurricane

Earth Science

1.Main divisions of the earth2. Geosphere: solid earth Geology

Oceanography

1. Hydrosphere: water on earth Oceanography

Meteorology

1. Atmosphere: gases around earth Meteorology

Biology

1. Biosphere: living things on earth Biology

Environmental Science

1. Environmental Science: studies the effects people have on their environment and living things

Astronomy

1. Astronomy: study of outer space

Matter

1. Matter is anything that has mass and volume

a) Volume: the amount of space an object takes up

Atoms

1. The smallest unit of matter is the atom

Molecules

1. Atoms can be bonded together to form molecules

The delicate inner structure of a pentacene moleculehas been imaged with an atomic force microscope

Element

1. There are over 100 different kinds of atoms

a) Each type of atom has a different structure of protons, neutrons, and electrons

2. An element is a substance in which all the atoms have the same structure

States of Matter

1. Matter on Earth exists in one of three states:

a) Solid: atoms are moving very slowly (less energy)

Solid(Definite Shape; Definite Volume)

Liquid

a) Liquid: atoms are moving at intermediate speed (intermediate energy)

Liquid(Indefinite Shape; Definite Volume)

Gas

Gas: atoms are moving very rapidly (more energy)

Gas(Indefinite Shape; Indefinite Volume)

Energy

1.All matter has energya)E=MC2

Solid

Add Energy Add Energy

Liquid Gas

Continents

1.Mostly granitea)Less dense than ocean

basins2.Edges are often under water3.Very old

a)Billions of years old4.Subject to erosion and

mountain building

Ocean Basins

1.Mostly basaltic rocka)Denser than granite

2.Covered with water3.Young

a)Millions of years old4.Constantly expanding and

changing

Changing Earth

1. Earth’s surface is constantly changing over short and long periods of time

2. Constructive forces – formation of new landforms and seafloor

a) Volcanic activity or uplift of the crust

3. Destructive forces – modification of existing landforms

a) Erosion and weathering

Constructive Forces

Destructive Forces

Direction

1.North and South Poles: where the axis of rotation intersects with the planet

2.In space there is no up or down, so this system only works on Earth

3.Magnetic and Geographic Poles are different

North on the Earth

Latitude and Longitude1.Latitude

a)Equator: halfway between the poles0˚

b)North Pole: 90˚N; South Pole: 90˚ S

2.Longitudea)Prime Meridian: not natural 0˚b)International Date Line: 180˚c) Everything else is given as number

of degrees East or West 79˚ W

Latitude and Longitude

1.Parallels = Latitude a)All lines are parallel

2.Meridians = Longitudea)All lines intersect at the

Poles

Latitude and Longitude

1. LatitudeLaddera) Evenly spaced stepsb) Each step takes you higher or lower

2. LongitudeLonga) Longitude lines are longer than

most latitude linesb) Every longitude line is equally long

Latitude and Longitude