Easter Island What Happened? • What important lesson lesson can we learn? • Does it apply to “our island”?
Scientific Method • “The whole of science is nothing more than a refinement of everyday thinking” Albert Einstein
Theory Idea, principle, or model that is supported by a great deal of evidence Usually explains and ties together previously unrelated information Widely accepted Law Explains a phenomena that we observe in nature over and over in the same way with no KNOWN exceptions What we observe in nature Theory v. Law
Accuracy Finding a value that is agrees with the accepted or correct value Precision REPRODUCIBILITY How closely the same result will be achieved over and over again Accuracy v. Precision
pH Scale • Logarithmic Scale • pH of 7 means • 10-7 hydronium ions • pH < 7 Acid • pH = 7 Neutral • pH > 7 Basic
Using observations to reach a general conclusion If observations are true, then the conclusion is likely true. Using logic and rules to arrive at a specific conclusion If specific statements are true, then the conclusion must be true Inductive Deductive
Inductive Example • Example: Many pesticides lead to cancers and birth defects in animals and humans. Birds near a corn field have been giving birth to deformed birds. Conclusion: The deformities are being caused by pesticides.
Valid vs. invalid • Valid Deductive argument Helen is a girl. All girls have 2 X chromosomes. Conclusion: Helen has 2 X chromosomes. • Invalid Deductive arguments • Everardo loves doing homework. Everardo is a student in APES. • Conclusion: APES students love doing homework. If today is Monday, we have a test today. We have a test today. Conclusion: Today is Monday.
FRONTIER Preliminary results based on untested data, hypotheses, or models. CONTROVERSIAL, but newsworthy Consensus Data, theories, and laws that are WIDELY accepted by scientific experts Reliable, but not newsworthy Frontier v. Consensus Science
Validity of data • How do you accurately measure worldwide soil erosion? Or how many species have become extinct? • No one will EVER agree on these issues, which is why we develop models
Limitations • “Most environmental problems involve so many variables and such complex interactions that we often do not have enough information or sufficiently sophistocated mathematical models to aid in understanding them very well” • Miller
Systems(WAY Over Simplified) • Inputs – what goes in • Flows – how inputs travel: direction, rate • Stores – where stuff accumulates • Outputs – what comes out
Environmental Modeling • Models are computer examples based on past data used to predict future results. • Models must be continually updated as new data is incorporated • Most models are inherently inaccurate, WHY? SMOG CITY
Pros Cheaper Faster Allow us to predict environmental behavior Provide extensive data for study Can be refined over time Cons Inherently inaccurate Based on sometimes faulty inductive reasoning Impossible to capture all the variables Based on large numbers of assumptions Environmental Modeling
Some Types Models • Mathematical Models • Based on mathematical formulas • Stream flow modeling, air quality modeling • GIS models • Based on data tied to a specific location • Risk of lead poisoning based on location, income, and housing age • Statistical models • Based on probability of will happen based on what has happened • The overall probability of getting cancer is X, and based on your risk factors, your risk is Y
Positive Feedback loop • Also called a vicious cycle • A change in one direction causes a system to keep changing in that direction • i.e. Global warming, rewards
Population Growth • Large populations mean large numbers of babies. • Large numbers of babies mean a bigger population • Overall vicious cycle
Negative Feedback loop • A change in one direction causes the system to change in the opposite direction • i.e. homeostasis, heating systems
Carrying Capacity • As populations grow, resources become scarce. • These resource limitations cause population size to shrink.
Example 1 Population growth leads to family planning which leads to more birth control. Birth control leads to fewer pregnancies and less babies Positive or negative? Example 2 African countries have an AIDS epidemic, but do not have enough medicine or education to prevent new infections, leading to more infections. Positive or negative? Feedback Loops
Example 3 Water vapor forms and rises due to hot temperatures. The water vapor in the air traps humidity and increases the temperature creating more water vapor. Positive or negative? Example 2 The temperature rises in the room triggering the AC, the AC cycles on, lowers the temperature, and turns off. Positive or negative? Feedback Loops
Time Delays • The distance between a stimulus and the response to it. • Many environmental problems have large time delays which interrupt negative feedback loops • Smoking • Watershed pollution • Global warming
Synergy • Two or more processes combine to be bigger than the sum of the parts. • i.e. two people can each lift 40 lbs, but together they can lift 120 lbs. • i.e. the Thailand tsunami
MatterForms, Structure, and Quality • Matter is anything that has mass and takes up space. • Matter is found in two chemical forms: elements and compounds. • Various elements, compounds, or both can be found together in mixtures.
Atoms, Ions, and Molecules • Atoms: The smallest unit of matter that is unique to a particular element. • Ions: Electrically charged atoms or combinations of atoms. • Molecules: Combinations of two or more atoms of the same or different elements held together by chemical bonds.
What are Atoms? • The main building blocks of an atom are positively charged PROTONS, uncharged NEUTRONS, and negatively charged ELECTRONS • Each atom has an extremely small center, or nucleus, containing protons and neutrons.
Atomic Number and Mass Number. • Atomic number • The number of protons in the nucleus of each of its atoms. • Mass number • The total number of protons and neutrons in its nucleus.
Elements are organized through the periodic table by classifications of metals, nonmetals, and metalloids
Inorganic Compounds • All compounds not Organic (not living) • Ionic Compounds • Sodium chloride (NaCl) • Sodium bicarbonate (NaOH) • Covalent compounds • Hydrogen(H2) • Carbon dioxide (CO2) • Nitrogen dioxide (NO2) • Sulfur dioxide (SO2) • Ammonia (NH3)
Formation of Ionic Compounds • Transfer of electrons between the atoms of these elements result in drastic changes to the elements involved • Sodium and chlorine serves as a example • Sodium is a rather "soft" metal solid, with a silver-gray color • Chlorine is greenish colored gas • When a single electron is transferred between these elements, their atoms are transformed via a violent reaction into a totally different substance called, sodium chloride, commonly called table salt -- a white, crystalline, and brittle solid
Inorganic Compounds • The earth’s crust is composed of mostly inorganic minerals and rock • The crust is the source of all most nonrenewable resource we use: fossil fuels, metallic minerals, etc. Various combinations of only eight elements make up the bulk of most minerals.
Nonmetallic Elements. • Carbon (C), Oxygen (O), Nitrogen (N), Sulfur (S), Hydrogen (H), and Phosphorous (P) • Nonmetallic elements make up about 99% of the atoms of all living things
Covalent Bonds • The individual atoms are atoms of chlorine with only their valence electrons shown. • Note that each chlorine atom has only seven valence electrons, but really wants eight. • When each chlorine atom shares its unpaired electron, both atoms are tricked into thinking each has a full valence of eight electrons. • Notice that the individual atoms have full freedom from each other, but once the bond is formed, energy is released, and the new chlorine molecule (Cl2) behaves as a single particle.
A covalent bond is typically formed by two non-metals • Non-metals have similar electronegativities • Neither atom is "strong" enough to steal electrons from the other • Therefore, the atoms must share the electrons.
Organic Compounds (life) • Compounds containing carbon atoms combined with each other with atoms of one or more other elements such as hydrogen, oxygen, nitrogen, sulfur, etc. • Hydrocarbons • Compounds of carbon and hydrogen • Chlorofluorocarbons • Carbon, chlorine, and fluorine atoms • Simple carbohydrates • carbon, hydrogen, oxygen combinations
Organic Compounds Hydrocarbons Chlorofluorocarbons
Biological Organic Compounds Carbohydrates (Glucose) Protein (Cytochrome P450)
Biological Organic Compounds Lipid(Triglyceride) Nucleic Acid (DNA)
Environmental Surprises • AIDS, Ebola, Hantavirus • Global warming • Antibacterial resistance • Thalidomide (birth defects) • DDT (cancer) • CFCs ozone layer destruction) • Disasters (Bhopal, Chernobyl) • Zebra Mussel (invasive species)
Env. SurprisesCAUSES • Discontinuities – may be caused by an environmental threshold (dose response) • Synergystic relationships – multiple factors lead to a synergistic relationship causing unpredicted results. (deforestation and runoff)) • Chaotic Events – nature is unpredictable, we cannot control it or change it (hurricanes)
Solutions?? • No one really knows, but many people have ideas
Matter Quality • Matter quality • a measure of how useful a matter resource is, based in its availability and concentration. • High quality matter is organized, concentrated, and usually found near the earth’s crust. • Low quality matter is disorganized, dilute, and has little potential for use as a matter resource.
Quality Counts LOW QUALITY HIGH QUALITY