Look at these two sets of animal tracks. List 3 OBSERVATIONS Make an INFERENCE

Now what do you think? Make 3 OBSERVATIONS Make an INFERENCE

Now what do you think? Make 3 OBSERVATIONS Make an INFERENCE

Source of graphic:

Science, Systems, Matter, and Energy G. Tyler Miller’s Living in the Environment 14 th Edition Chapter 3 G. Tyler Miller’s Living in the Environment 14 th Edition Chapter 3

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

Science Skepticism, Reproducibility and peer review Theory explanation supported by evidence that is likely true Natural law describes events of nature that reoccur in the same way over and over

Science, and Critical Thinking  Scientific data  Scientific (natural) laws  Scientific theories  Scientific hypotheses Ask a question Do experiments and collect data Formulate hypothesis to explain data Do more Experiments to test hypothesis Revise hypothesis if necessary Well-tested and accepted hypotheses become scientific theories Interpret data Well-tested and accepted patterns In data become scientific laws Fig. 3-2 p. 33

Variables Science seeks to isolate and study the effect of one variable. –In a chosen group one variable is changed –In the control group the chosen variable is not changed. –Multivariable analysis uses mathematical models to analyze interactions of many variables Not easy in environmental science

Types of Science Frontier Science –Scientific Results which have not been confirmed Consensus Science –Scientific Results which have been well tested and are widely accepted Junk Science –Results which have not been reviewed by peer scientists –A researcher describing their findings

Precision vs. Accuracy

Models and Behavior of Systems Mathematical models consist of a series of equations to describe the behavior of a system Useful with many variables, when time is long, or when a controlled experiment is not feasible. Answer if than question. Systems function in a predictable way

System Regulation Positive Feedback Loop –Causes system to do more of the same Clotting Generally can not be sustained in living things. Global Warming Population Growth Interest Negative Feedback Loop –Causes a system to “fight” an influence Thermostat Temperature in body

Feedback Systems Prolonged Delay –Effects of pollution on human health –Atmospheric effects of pollution Synergistic Interaction Environmental Threshold

Matter Atoms –Protons –Neutrons –Electrons Atomic Number Atomic Mass Isotopes

Ions Ionic Bonds –Metal Non-Metals Hydrogen Ions –H+ –Acids pH below 7 Hydroxide Ions –OH- –Bases pH above 7

Matter: Forms, Structure, and Quality  Elements  Compounds  Molecules  Ions  Atoms

Atoms Subatomic Particles  Protons  Neutrons  Electrons Atomic Characteristics  Atomic number  Ions  Atomic mass  Isotopes

Examples of Isotopes Fig. 3-5 p. 40

pH (percent hydrogen)  Measures acidity or alkalinity of water samples  Logarithmic Scale  Scale 0 – 14  Acids: 0 – 6.9  Neutral 7.0 (Water)  Alkaline (Basic) 7.1 – 14  Measures acidity or alkalinity of water samples  Logarithmic Scale  Scale 0 – 14  Acids: 0 – 6.9  Neutral 7.0 (Water)  Alkaline (Basic) 7.1 – 14

Chemical Bonds Chemical Formulas Ionic bonds Covalent bonds Hydrogen bonds

Organic Compounds  Organic vs. inorganic compounds  Hydrocarbons  Chlorinated hydrocarbons  Nucleic acids  Carbohydrates  Lipids  Proteins

Genetic Material  Nucleic acids  Genes  Genomes  Chromosomes Compare Fig. 3-7 p. 42

The Four States of Matter  Solid  Liquid  Gas  Plasma

Matter Quality and Material Efficiency Fig. 3-8 p. 43  High-quality matter  Highly Useful  High-quality matter  Highly Useful  Low-quality matter  Material efficiency (resource productivity)  Relate this to Pollution  Material efficiency (resource productivity)  Relate this to Pollution

Energy  Definition: Capacity to do “work” and transfer heat  Types:  Kinetic  Potential  Radiation: Energy & Wavelength  Definition: Capacity to do “work” and transfer heat  Types:  Kinetic  Potential  Radiation: Energy & Wavelength

Electromagnetic Spectrum Fig. 3-9 p. 44

Transfer of Heat Energy Fig p. 45 ConvectionConductionRadiation 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. As the water boils, heat from the hot stove burner and pan radiate into the surrounding air, even though air conducts very little heat. 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.

Energy: Quality Fig p. 46  High-quality energy  Low-quality energy

Changes in Matter  Physical- Changing State or properties without changing its chemical make-up  Chemical- changing the way atoms are bonded to one another  Physical- Changing State or properties without changing its chemical make-up  Chemical- changing the way atoms are bonded to one another

Chemical Changes or Reactions What law does this exemplify?

The Law of Conservation of Matter  Matter is not created or destroyed  Matter only changes form and Increases disorder (entropy)  Matter only changes form and Increases disorder (entropy)  There is no “away”  We live in a closed system for matter

Matter and Pollution  Chemical nature of pollutants  Concentration  Persistence  Degradable (nonpersistent) pollutants  Biodegradable pollutants  Slowly degradable (persistent) pollutants Metals  Slowly degradable (persistent) pollutants Metals  Nondegradable pollutants

Nuclear Changes  Natural radioactive decay  Radioactive isotopes (radioisotopes)  Gamma rays (electromagnetic)  Alpha particles (2 protons & 2 neutrons)  Beta particles (electrons)  Half life (10 halflives makes it safe)  Ionizing radiation

Fraction of original amount of plutonium-239 left 1 1/2 1/4 1/8 0 24,00048,00072,000 Time (years) 1st half-life 2nd half-life 3rd half-life

Nuclear Reactions Fission Fig p. 50 Fusion Fig p. 50

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

Connections: Matter and Energy Laws and Environmental Problems  High-throughput (waste) economy maximize the amount of matter and energy used  High-throughput (waste) economy maximize the amount of matter and energy used  Matter-recycling economy- reusing matter resources we have available  Matter-recycling economy- reusing matter resources we have available  Low-throughput economy- using less resources in energy and matter