Chapter 2Chapter 2

Science, Systems, Science, Systems, Matter, and EnergyMatter, and Energy

Chapter Overview QuestionsChapter Overview Questions

What is science, and what do scientists do?What is science, and what do scientists do? What are major components and behaviors What are major components and behaviors

of complex systems?of complex systems? What are the basic forms of matter, and what What are the basic forms of matter, and what

makes matter useful as a resource?makes matter useful as a resource? What types of changes can matter undergo What types of changes can matter undergo

and what scientific law governs matter?and what scientific law governs matter?

Chapter Overview Questions (cont’d)Chapter Overview Questions (cont’d)

What are the major forms of energy, and What are the major forms of energy, and what makes energy useful as a resource?what makes energy useful as a resource?

What are two scientific laws governing What are two scientific laws governing changes of energy from one form to another?changes of energy from one form to another?

How are the scientific laws governing How are the scientific laws governing changes of matter and energy from one form changes of matter and energy from one form to another related to resource use, to another related to resource use, environmental degradation and environmental degradation and sustainability?sustainability?

Updates OnlineUpdates Online

The latest references for topics covered in this section can be found at The latest references for topics covered in this section can be found at the book companion website. Log in to the book’s e-resources page at the book companion website. Log in to the book’s e-resources page at www.thomsonedu.com to access InfoTrac articles.www.thomsonedu.com to access InfoTrac articles.

InfoTrac: Underwater Microscope Finds Biological Treasures in InfoTrac: Underwater Microscope Finds Biological Treasures in Subtropical Ocean. Subtropical Ocean. Ascribe Higher Education News ServiceAscribe Higher Education News Service, June 26, , June 26, 2006.2006.

InfoTrac: In Bacterial Diversity, Amazon Is a 'Desert'; Desert Is an InfoTrac: In Bacterial Diversity, Amazon Is a 'Desert'; Desert Is an 'Amazon'. 'Amazon'. Ascribe Higher Education News ServiceAscribe Higher Education News Service, Jan 9, 2006., Jan 9, 2006.

InfoTrac: Making MGP wastes beneficial. Bob Paulson. InfoTrac: Making MGP wastes beneficial. Bob Paulson. Pollution Pollution EngineeringEngineering, June 2006 v38 i6 p20(5)., June 2006 v38 i6 p20(5).

NASA: Nitrogen CycleNASA: Nitrogen Cycle Environmental Literacy Council: Phosphorous CycleEnvironmental Literacy Council: Phosphorous Cycle National Sustainable Agriculture Information Service: Nutrient CyclesNational Sustainable Agriculture Information Service: Nutrient Cycles

Video: The Throw Away SocietyVideo: The Throw Away Society

This video clip is available in CNN Today This video clip is available in CNN Today Videos for Environmental Science, 2004, Videos for Environmental Science, 2004, Volume VII. Instructors, contact your local Volume VII. Instructors, contact your local sales representative to order this volume, sales representative to order this volume, while supplies last.while supplies last.

Core Case Study: Core Case Study: Environmental Lesson from Easter Environmental Lesson from Easter

IslandIsland Thriving societyThriving society

15,000 people by 1400.15,000 people by 1400. Used resources faster Used resources faster

than could be renewedthan could be renewed By 1600 only a few By 1600 only a few

trees remained.trees remained. Civilization collapsedCivilization collapsed

By 1722 only several By 1722 only several hundred people left.hundred people left.

Figure 2-1Figure 2-1

THE NATURE OF SCIENCETHE NATURE OF SCIENCE

What do scientists do?What do scientists do? Collect data.Collect data. Scientist Answer Scientist Answer

Questions & Solve Questions & Solve ProblemsProblems

Form hypotheses.Form hypotheses. Develop theories, Develop theories,

models and laws about models and laws about how nature works.how nature works.

Figure 2-2Figure 2-2

Scientific Theories and Laws: The Scientific Theories and Laws: The Most Important Results of ScienceMost Important Results of Science

Scientific TheoryScientific Theory Widely tested and Widely tested and

accepted hypothesis.accepted hypothesis. Has evidence that Has evidence that

supports it.supports it.

Scientific LawScientific Law What we find What we find

happening over and happening over and over again in nature.over again in nature.

Fact / Always TrueFact / Always True

Figure 2-3Figure 2-3

Important Features of Scientific ProcessImportant Features of Scientific Process

SkepticismSkepticism Scientists tend to be highly skepticle of new data Scientists tend to be highly skepticle of new data

until they can be verifieduntil they can be verified Peer ReviewPeer Review

Scientist working in the same field examine & Scientist working in the same field examine & criticize work of colleges either through Journals criticize work of colleges either through Journals or Conferences.or Conferences.

ReproducibilityReproducibility Experiments/Data should be reporducable by Experiments/Data should be reporducable by

other scientists.other scientists.

Testing HypothesesTesting Hypotheses

Scientists test hypotheses using controlled Scientists test hypotheses using controlled experiments and constructing mathematical experiments and constructing mathematical models.models. VariablesVariables or or factorsfactors influence natural processes influence natural processes Single-variable experiments involve a control and Single-variable experiments involve a control and

an experimental group.an experimental group. Most environmental phenomena are Most environmental phenomena are

multivariablemultivariable and are hard to control in an and are hard to control in an experiment.experiment.• Models are used to analyze interactions of variables.Models are used to analyze interactions of variables.

Scientific Reasoning and CreativityScientific Reasoning and Creativity

Inductive reasoningInductive reasoning Involves using specific observations and Involves using specific observations and

measurements to arrive at a general conclusion measurements to arrive at a general conclusion or hypothesis.or hypothesis.

Bottom-up reasoning going from specific to Bottom-up reasoning going from specific to general.general.

Deductive reasoningDeductive reasoning Uses logic to arrive at a specific conclusion.Uses logic to arrive at a specific conclusion. Top-down approach that goes from general to Top-down approach that goes from general to

specific.specific.

Controlled ExperimentsControlled Experiments

Controlled experiments limit the number of Controlled experiments limit the number of variables to testing primarily one variable.variables to testing primarily one variable.

Control group lacks variable (independent Control group lacks variable (independent variable) and experimental group has variable) and experimental group has variable.variable.

Q- Why are controlled experiments not Q- Why are controlled experiments not effective when analyzing environmental effective when analyzing environmental phenomena?phenomena?

Frontier Science, Sound Science, and Frontier Science, Sound Science, and Junk ScienceJunk Science

Frontier science has not been widely tested Frontier science has not been widely tested (starting point of peer-review).(starting point of peer-review).

Sound science consists of data, theories and Sound science consists of data, theories and laws that are widely accepted by experts.laws that are widely accepted by experts.

Junk science is presented as sound science Junk science is presented as sound science without going through the rigors of peer-without going through the rigors of peer-review.review.

Limitations of Environmental ScienceLimitations of Environmental Science

Inadequate data and scientific understanding Inadequate data and scientific understanding can limit and make some results can limit and make some results controversial.controversial. Scientists will rarely say 100%!Scientists will rarely say 100%!

Note- Realize that opportunists can take Note- Realize that opportunists can take advantage of morally correct scientists. advantage of morally correct scientists.

MODELS AND BEHAVIOR OF MODELS AND BEHAVIOR OF SYSTEMSSYSTEMS

Usefulness of modelsUsefulness of models Complex systems are predicted by developing a Complex systems are predicted by developing a

model of its inputs, throughputs (flows), and model of its inputs, throughputs (flows), and outputs of matter, energy and information.outputs of matter, energy and information.

Models are simplifications of “real-life”.Models are simplifications of “real-life”. Models can be used to predict Models can be used to predict if-thenif-then scenarios. scenarios.

States of MatterStates of Matter

The atoms, ions, and molecules that make up The atoms, ions, and molecules that make up matter are found in three physical states:matter are found in three physical states: solid, liquid, gaseous.solid, liquid, gaseous.

A fourth state, plasma, is a high energy A fourth state, plasma, is a high energy mixture of positively charged ions and mixture of positively charged ions and negatively charged electrons.negatively charged electrons. The sun and stars consist mostly of plasma.The sun and stars consist mostly of plasma. Scientists have made artificial plasma (used in Scientists have made artificial plasma (used in

TV screens, gas discharge lasers, florescent TV screens, gas discharge lasers, florescent light).light).

Types of PollutantsTypes of Pollutants

Factors that determine the severity of a Factors that determine the severity of a pollutant’s effects: pollutant’s effects: chemical naturechemical nature, , concentrationconcentration, and , and persistencepersistence..

Pollutants are classified based on their Pollutants are classified based on their persistence:persistence: Degradable pollutantsDegradable pollutants Biodegradable pollutantsBiodegradable pollutants Slowly degradable pollutantsSlowly degradable pollutants Nondegradable pollutantsNondegradable pollutants

Synergistic InteractionSynergistic Interaction

A synergisitc interaction occurs when tow or A synergisitc interaction occurs when tow or more processes interact so that the more processes interact so that the combined effect is greater than the sum of combined effect is greater than the sum of their individual effects when separate.their individual effects when separate.

Smokers- 10x the risk of lung cancerSmokers- 10x the risk of lung cancer Asbestos exposure- 5x the risk of lung Asbestos exposure- 5x the risk of lung

cancercancer Exposure to Both- 50xExposure to Both- 50x

Nuclear Changes: Radioactive DecayNuclear Changes: Radioactive Decay

Natural radioactive decay: unstable isotopes Natural radioactive decay: unstable isotopes spontaneously emit fast moving chunks of spontaneously emit fast moving chunks of matter (matter (alphaalpha oror beta particlesbeta particles), high-energy ), high-energy radiation (radiation (gamma raysgamma rays), or both at a fixed ), or both at a fixed rate.rate. Radiation is commonly used in energy production Radiation is commonly used in energy production

and medical applications.and medical applications. The rate of decay is expressed as a The rate of decay is expressed as a half-lifehalf-life (the (the

time needed for one-half of the nuclei to decay to time needed for one-half of the nuclei to decay to form a different isotope).form a different isotope).

Nuclear Changes: FissionNuclear Changes: Fission

Nuclear fission: Nuclear fission: nuclei of certain nuclei of certain isotopes with large isotopes with large mass numbers are mass numbers are split apart into split apart into lighter nuclei when lighter nuclei when struck by neutrons.struck by neutrons.

Figure 2-9Figure 2-9

Nuclear Changes: FusionNuclear Changes: Fusion

Nuclear fusion: two isotopes of light elements Nuclear fusion: two isotopes of light elements are forced together at extremely high are forced together at extremely high temperatures until they fuse to form a heavier temperatures until they fuse to form a heavier nucleus.nucleus.

Figure 2-10Figure 2-10

ENERGYENERGY

Energy is the ability to do work and transfer Energy is the ability to do work and transfer heat.heat. Kinetic energy – energy in motionKinetic energy – energy in motion

• heat, electromagnetic radiationheat, electromagnetic radiation Potential energy – stored for possible usePotential energy – stored for possible use

• batteries, glucose moleculesbatteries, glucose molecules

Electromagnetic SpectrumElectromagnetic Spectrum

Many different forms of electromagnetic Many different forms of electromagnetic radiation exist, each having a different radiation exist, each having a different wavelength and energy content.wavelength and energy content.

Figure 2-11Figure 2-11

Electromagnetic SpectrumElectromagnetic Spectrum

Organisms vary Organisms vary in their ability to in their ability to sense different sense different parts of the parts of the spectrum.spectrum.

Figure 2-12Figure 2-12

Fig. 2-13, p. 44

Low-temperature heat (100°C or less) for space heating

Moderate-temperature heat (100–1,000°C) for industrial processes, cooking, producing

steam, electricity, and hot water

Very high-temperature heat (greater than 2,500°C) for industrial processes and producing electricity to run electrical devices (lights, motors)

Mechanical motion to move vehicles and other things) High-temperature heat (1,000–2,500°C) for industrial processes and producing electricity

Dispersed geothermal energyLow-temperature heat (100°C or lower)

Normal sunlightModerate-velocity windHigh-velocity water flowConcentrated geothermal energyModerate-temperature heat

(100–1,000°C)Wood and crop wastes

High-temperature heat (1,000–2,500°C)Hydrogen gasNatural gasGasolineCoalFood

ElectricityVery high temperature heat (greater than 2,500°C)Nuclear fission (uranium)Nuclear fusion (deuterium)Concentrated sunlightHigh-velocity wind

Source of Energy RelativeEnergy Quality

(usefulness)

Energy Tasks (Diagram on pg 44)

ENERGY LAWS: TWO RULES WE ENERGY LAWS: TWO RULES WE CANNOT BREAKCANNOT BREAK

The first law of thermodynamics: we cannot create The first law of thermodynamics: we cannot create or destroy energy.or destroy energy. Environmentally- We cannot get something for nothing in Environmentally- We cannot get something for nothing in

terms of energy quantity..terms of energy quantity.. The second law of thermodynamics: energy quality The second law of thermodynamics: energy quality

always decreases.always decreases. When energy changes from one form to another, it is When energy changes from one form to another, it is

always degraded to a more dispersed form.always degraded to a more dispersed form. Energy efficiency is a measure of how much useful work Energy efficiency is a measure of how much useful work

is accomplished before it changes to its next form.is accomplished before it changes to its next form. When energy changes form one form to another- there is When energy changes form one form to another- there is

a decrease in energy quality- so less work can be a decrease in energy quality- so less work can be accomplished.accomplished.

Fig. 2-14, p. 45

Chemicalenergy(food)

Solarenergy

WasteHeat

WasteHeat

WasteHeat

WasteHeat

Mechanicalenergy

(moving,thinking,

living)

Chemical energy

(photosynthesis)

The Thermo Lesson- the best way to get The Thermo Lesson- the best way to get more energy is to stop wasting almost half more energy is to stop wasting almost half

of the energy we use!of the energy we use!

Methods of Reducing Energy Waste:Methods of Reducing Energy Waste: Driving gas efficient carsDriving gas efficient cars Living in well insulated housesLiving in well insulated houses Energy efficient lightsEnergy efficient lights Energy efficient heating & coolingEnergy efficient heating & cooling Energy efficient appliancesEnergy efficient appliances Running appliances from sun (renewable energy)Running appliances from sun (renewable energy)

SUSTAINABILITY AND MATTER SUSTAINABILITY AND MATTER AND ENERGY LAWSAND ENERGY LAWS

Unsustainable High-Throughput Economies: Unsustainable High-Throughput Economies: Working in Straight LinesWorking in Straight Lines Converts resources to goods in a manner that Converts resources to goods in a manner that

promotes waste and pollution.promotes waste and pollution.

Figure 2-15Figure 2-15

Fig. 2-15, p. 46

High-quality energy

Matter

Unsustainablehigh-waste

economy

SystemThroughputs

Inputs(from environment)

Outputs(into environment)

Low-quality energy (heat)

Waste and pollution

Sustainable Low-Throughput Sustainable Low-Throughput Economies: Learning from NatureEconomies: Learning from Nature

Matter-Recycling-and-Reuse Economies: Matter-Recycling-and-Reuse Economies: Working in CirclesWorking in Circles Mimics nature by recycling and reusing, thus Mimics nature by recycling and reusing, thus

reducing pollutants and waste.reducing pollutants and waste. It is not sustainable for growing populations.It is not sustainable for growing populations.

Fig. 2-16, p. 47

Recycleand

reuse

Low-quality Energy(heat)

Waste and

pollution

Pollutioncontrol

Sustainable low-waste economy

Waste and

pollution

Matter Feedback

Energy Feedback

Inputs (from environment)

Energyconservation

Matter

Energy

SystemThroughputs

Outputs(into environment)

Sustainable Low Throughput Economics- Sustainable Low Throughput Economics- Learning from Nature!Learning from Nature!

We can live more sustainably by reducing the We can live more sustainably by reducing the throughput of matter and energy in our throughput of matter and energy in our economies, not wasting matter and energy economies, not wasting matter and energy resources, recycling and reusing most of the resources, recycling and reusing most of the matter resources we use, and stabilizing the matter resources we use, and stabilizing the size of our population.size of our population.