Science, Systems, Matter, and Energy

1. Science, Systems, Matter, and Energy G. Tyler Miller’s Living in the Environment 13th Edition Chapter 3

2. Key Concepts • Science as a process for understanding • Components and regulation of systems • Matter: forms, quality, and how it changes; laws of matter • Energy: forms, quality, and how it changes; laws of energy • Nuclear changes and radioactivity

3. Science, and Critical Thinking Ask a question Do experiments and collect data Interpret data Well-tested and accepted patterns In data become scientific laws Formulate hypothesis to explain data Do more Experiments to test hypothesis Revise hypothesis if necessary Well-tested and accepted hypotheses become scientific theories • Scientific data • Scientific hypotheses • Scientific (natural) laws • Scientific theories • Consensus science • Frontier science Fig. 3-2 p. 41

4. Models and Behavior of Systems • Inputs- matter, energy, information • Flows (throughputs) – of matter or energy • Stores (storage areas) – place where energy • or matter can accumulate for various lengths of time • (your body, water on earth) • Outputs-certain forms of matter or energy leave • the system and sink or absorbs into the environment • (air, water, soil)

5. System Regulation • Homeostasis • Positive Feedback • Negative Feedback • Time Delay – • corrective action can • be too late -smokers • Synergy Fig. 3-3 p. 46

6. Feedback Loops • Positive Feedback- ex: collecting interest in a bank account. • Negative feedback- ex: thermostat in a house, when the house reaches or exceeds the set temp, the air shuts off.

7. Threshold Level • Point when a fundamental shift occurs • Ex: your body becomes so overheated that you pass out. Your body has a threshold temperature and when it is reached, there is a change • Ex: Easter Island exceeded threshold of resource use. • Time delays can slow negative feedback and more rapidly approach threshold levels – population growth, unknown pollution, degradation of forests from air pollution.

8. Mt. Mitchell –Acid Rain Damage

9. Law of Conservation of Problems • The solution to one problem usually creates one or more new problems • Ex: chemical fertilizers –increases crop productivity, can become widespread, new problem of overstimulation of non-target plants and pollution to water supply • Do benefits outweigh potential harm? • Not enough data • Imperfect models • Different assumptions

10. Environmental Surprises • Result of • Shifts when threshold is met • Synergistic interaction • Unpredictable or natural events (weather, invasives) • Strategies to reduce: • Increase research • Better models • Prevent/reduce pollution, reduce population, benign products

11. Matter: Forms, Structure, and Quality • Elements -building block of matter • Compounds-two or more elements • Molecules-two or more atoms of same element • Mixtures-various elements, compounds or both

12. Atoms Subatomic Particles • Protons • Neutrons • Electrons Atomic Characteristics • Atomic number • Ions • Atomic mass • Isotopes

13. Examples of Atoms Fig. 3-4 p. 48

14. Chemical Bonds • Chemical formulas- # of atoms in compound • Ionic bonds- oppositely charged • Metal and nonmetal • Covalent bonds –valence • Electron sharing (less water soluble than ionic bonds) • Hydrogen bonds-H to • Electronegative, weakest bond, occurs in organic and inorganic

15. Organic Compounds • Organic vs. inorganic compounds • Hydrocarbons- C and H • Chlorinated hydrocarbons –C, H, and Cl • Chlorofluorocarbons- C and Fl • Simple carbohydrates- C, H, O • Complex carbohydrates- polymer- 2 or more simple sugars • Proteins- monomers of amino acids

16. Genetic Material • Genes • Nucleic acids • Gene mutations • Chromosomes Fig. 3-6 p. 50

17. The Four States of Matter • Solid • Liquid • Gas • Plasma Fig. 3-7 p. 50

18. Matter Quality and Material Efficiency • High-quality matter- near • Earth’s surface • Low-quality matter • Dilute, deep underground, ocean, atmosphere • Material efficiency(resource productivity) • Total amount of material needed to produce each • unit of goods or services. 2-6% of matter used • in developed countries provides useful goods. Fig. 3-8 p. 51

19. Energy: Forms • Kinetic energy • Potential energy • Heat Fig. 3-9 p. 52

20. Transfer of Heat Energy Convection Conduction Radiation Heat from a stove burner causes atoms or molecules in the pan’s bottom to vibrate faster. The vibrating atoms or molecules then collide with nearby atoms or molecules, causing them to vibrate faster. Eventually, molecules or atoms in the pan’s handle are vibrating so fast it becomes too hot to touch. Heating water in the bottom of a pan causes some of the water to vaporize into bubbles. Because they are lighter than the surrounding water, they rise. Water then sinks from the top to replace the rising bubbles.This up and down movement (convection) eventually heats all of the water. As the water boils, heat from the hot stove burner and pan radiate into the surrounding air, even though air conducts very little heat. Fig. 3-11 p. 553

21. Energy: Quality • High-quality energy • Low-quality energy Fig. 3-12 p. 53

22. Physical and Chemical Changes Fig. In text p. 54

23. The Law of Conservation of Matter • Matter is not consumed • Matter only changes form • There is no “away”

24. Matter and Pollution • Chemical nature of pollutants • Concentration • Persistence • Degradable (nonpersistent) pollutants • Biodegradable pollutants • Slowly degradable (persistent) pollutants • Nondegradable pollutants

25. Nuclear Changes Fig. 3-13 p. 56 • Natural radioactive decay –measured by half life • Radioisotope – ex: Uranium 235 and 238, different half-lives =different energy • Output or hazard • Gamma rays –high energy • Electromagnetic radiation • Alpha particles • Beta particles • Half life (See Table 3-2 p. 56) • Ionizing radiation –radiation from radioisotopes, harmful, often in normal • Activities, can be in large doses (Chernobyl or 3 mile island

26. Nuclear Reactions Fission Fusion Fig. 3-17 p. 58 Fig. 3-16 p. 57

27. Laws Governing Energy Changes First Law of Thermodynamics (Energy) • Energy is neither created nor destroyed • Energy only changes form • You can’t get something for nothing ENERGY IN = ENERGY OUT

28. Laws Governing Energy Changes Second Law of Thermodynamics • In every transformation, some energy is converted to heat • You cannot break even in terms of energy quality

29. Connections: Matter and Energy Laws and Environmental Problems • High-throughput (waste) economy • Matter-recycling economy • Low-throughputeconomy Fig. 3-20 p. 60; see Fig. 3-21 p. 61