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Chapter 2. Science, Systems, Matter, and Energy. Video: Easter Island. By what name did the early settlers refer to Easter Island? Which individuals are believed to be the first inhabitants of Easter Island? In 1722, which Dutch Admiral landed on Easter Island?

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Chapter 2

Chapter 2

Science, Systems, Matter, and Energy


Video easter island
Video: Easter Island

  • By what name did the early settlers refer to Easter Island?

  • Which individuals are believed to be the first inhabitants of Easter Island?

  • In 1722, which Dutch Admiral landed on Easter Island?

  • What is believed to be the cause of the fall of the civilization and population of Easter Island?

  • What is the name of the giant statues on Easter Island?

PLAY

VIDEO

  • From ABC News, Environmental Science in the Headlines, 2005 DVD.


Core case study environmental lesson from easter island
Core Case Study: Environmental Lesson from Easter Island

  • Thriving society

    • 15,000 people by 1400.

  • Used resources faster than could be renewed

    • By 1600 only a few trees remained.

  • Civilization collapsed

    • By 1722 only several hundred people left.

Figure 2-1


The nature of science
THE NATURE OF SCIENCE

  • What do scientists do?

    • Collect data.

    • Form hypotheses.

    • Develop theories, models and laws about how nature works.

Figure 2-2


Science systems matter and energy

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

Stepped Art

Fig. 2-3, p. 30


Scientific theories and laws the most important results of science
Scientific Theories and Laws: The Most Important Results of Science

  • Scientific Theory

    • Widely tested and accepted hypothesis.

  • Scientific Law

    • What we find happening over and over again in nature.

Figure 2-3


Testing hypotheses
Testing Hypotheses Science

  • Scientists test hypotheses using controlled experiments and constructing mathematical models.

    • Variables or factors

      • influence natural processes

    • Single-variable experiments involve a control and an experimental group.

    • Most environmental phenomena are multivariable and are hard to control in an experiment.

      • Models are used to analyze interactions of variables.


Scientific reasoning and creativity
Scientific Reasoning and Creativity Science

  • Inductive reasoning

    • Involves using specific observations and measurements to arrive at a general conclusion or hypothesis.

    • Bottom-up reasoning going from specific to general.

  • Deductive reasoning

    • Uses logic to arrive at a specific conclusion.

    • Top-down approach that goes from general to specific.


Frontier science sound science and junk science
Frontier Science, Sound Science, and Junk Science Science

  • Frontier science

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

  • Sound science

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

  • Junk science

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


Limitations of environmental science
Limitations of Environmental Science Science

  • Inadequate data and scientific understanding can limit and make some results controversial.

    • Scientific testing is based on disproving rather than proving a hypothesis.

      • Based on statistical probabilities.


Does the fact that science can never prove anything absolutely mean that it is not valid or useful
Does the fact that science can never prove anything absolutely mean that it is not valid or useful?

  • Yes

  • No


Models and behavior of systems
MODELS AND BEHAVIOR OF SYSTEMS absolutely mean that it is not valid or useful?

  • Usefulness of models

    • Complex systems are predicted by developing a model of its inputs, throughputs (flows), and outputs of matter, energy and information.

    • Models are simplifications of “real-life”.

    • Models can be used to predict if-then scenarios.


Feedback loops how systems respond to change
Feedback Loops: absolutely mean that it is not valid or useful?How Systems Respond to Change

  • Outputs of matter, energy, or information fed back into a system can cause the system to do more or less of what it was doing.

    • Positive feedback loop

      • causes a system to change further in the same direction

        • e.g. erosion

    • Negative (corrective) feedback loop

      • causes a system to change in the opposite direction

        • e.g. seeking shade from sun to reduce stress


Feedback loops
Feedback Loops: absolutely mean that it is not valid or useful?

  • Negative feedback can take so long that a system reaches a threshold and changes.

    • Prolonged delays may prevent a negative feedback loop from occurring.

  • Processes and feedbacks in a system can (synergistically) interact to amplify the results.

    • E.g. smoking exacerbates the effect of asbestos exposure on lung cancer.


Types and structure of matter
TYPES AND STRUCTURE OF MATTER absolutely mean that it is not valid or useful?

  • Elements and Compounds

    • Elements

      • represented on the periodic table

      • distinctive building blocks of matter

      • Can be found in atomic or molecular forms

    • Compounds

      • two or more different elements held together in fixed proportions by chemical bonds


Atoms
Atoms absolutely mean that it is not valid or useful?

Figure 2-4


Science systems matter and energy
Ions absolutely mean that it is not valid or useful?

  • Ion

    • atom or group of atoms with one or more net positive or negative electrical charges

    • Cations (+)

    • Anions (-)

    • Hydrogen ions (H+), Hydroxide ions (OH-)

    • Sodium ions (Na+), Chloride ions (Cl-)


Science systems matter and energy

Figure 2-5


Organic compounds carbon rules
Organic Compounds: Carbon Rules hydrogen ions in one liter of solution.

  • Organic compounds

    • Must contain carbon and hydrogen

    • May also contain oxygen, nitrogen, phosphorus, sulphur, chlorine

  • Most contain at least 2 carbon atoms

    • Methane (CH4) is the only exception

    • All other compounds are inorganic.


Organic compounds carbon rules1
Organic Compounds: Carbon Rules hydrogen ions in one liter of solution.

  • Hydrocarbons:

    • compounds of carbon and hydrogen atoms

      • e.g. methane (CH4)

  • Chlorinated hydrocarbons:

    • compounds of carbon, hydrogen, and chlorine atoms

      • e.g. DDT (C14H9Cl5)

  • Simple carbohydrates:

    • certain types of compounds of carbon, hydrogen, and oxygen

    • Usually in a 1:2:1 ratio

      • e.g. glucose (C6H12O6)


Cells the fundamental units of life
Cells: The Fundamental Units of Life hydrogen ions in one liter of solution.

  • Cells

    • basic structural and functional units of all forms of life.

    • Prokaryotic cells

      • bacteria

      • lack a distinct nucleus and membrane bound organelles

    • Eukaryotic cells

      • Fungi, plants and animals

      • distinct nucleus and organelles

Figure 2-6


Science systems matter and energy

(a) Prokaryotic Cell hydrogen ions in one liter of solution.

DNA(information storage, no nucleus)

Cell membrane

(transport of

raw materials and

finished products)

Protein construction

and energy conversion

occur without specialized

internal structures

Fig. 2-6a, p. 37


Science systems matter and energy

(b) Eukaryotic Cell hydrogen ions in one liter of solution.

Nucleus

(information

storage)

Energy conversion

Protein

construction

Cell membrane

(transport of raw

materials and

finished products)

Packaging

Fig. 2-6b, p. 37


Animation prokaryotic and eukaryotic cells
Animation: Prokaryotic and Eukaryotic Cells hydrogen ions in one liter of solution.


Macromolecules dna genes and chromosomes
Macromolecules, DNA, Genes and Chromosomes hydrogen ions in one liter of solution.

  • complex organic molecules (macromolecules) make up the basic molecular units found in living organisms

    • Complex carbohydrates

      • Ex. starch, glycogen, cellulose, chitin

    • Proteins

      • Ex. hemoglobin, pepsin

    • Nucleic acids

      • Ex. DNA, RNA

    • Lipids

      • Ex. fats, oils, waxes, pigments

Figure 2-7


Science systems matter and energy

A human body contains trillions hydrogen ions in one liter of solution.

of cells, each with an identical

set of genes.

There is a nucleus inside each

human cell (except red blood cells).

Each cell nucleus has an identical

set of chromosomes, which are

found in pairs.

A specific pair of chromosomes

contains one chromosome from

each parent.

Each chromosome contains a long

DNA molecule in the form of a coiled

double helix.

Genes are segments of DNA on

chromosomes that contain instructions

to make proteins—the building blocks

of life.

The genes in each cell are coded

by sequences of nucleotides in

their DNA molecules.

Stepped Art

Fig. 2-7, p. 38


States of matter
States of Matter hydrogen ions in one liter of solution.

  • Physical states

    • Solid

    • Liquid

    • Gaseous

    • Plasma

      • a high energy mixture of positively charged ions and negatively charged electrons

        • The sun and stars consist mostly of plasma.

        • Scientists have made artificial plasma (used in TV screens, gas discharge lasers, florescent light).


Matter quality
Matter Quality hydrogen ions in one liter of solution.

  • Matter can be classified as having high or low quality depending on how useful it is to us as a resource.

    • High quality matter

      • Concentrated

      • easily extracted

    • low quality matter

      • more widely dispersed

      • more difficult to extract

Figure 2-8


Science systems matter and energy

High Quality hydrogen ions in one liter of solution.

Low Quality

Solid

Gas

Solution of salt in water

Salt

Coal

Coal-fired power plant emissions

Gasoline

Automobile emissions

Aluminum can

Aluminum ore

Fig. 2-8, p. 39


Changes in matter
CHANGES IN MATTER hydrogen ions in one liter of solution.

  • Physical change

    • maintains original chemical composition.

  • Chemical change

    • involves a chemical reaction which changes the arrangement of the elements or compounds involved

      • Often oxidation or explosive

    • When a physical or chemical change occurs, no atoms are created or destroyed.

      • Law of conservation of matter.


Science systems matter and energy

Reactant(s) hydrogen ions in one liter of solution.

Product(s)

energy

carbon dioxide

carbon

+

oxygen

+

energy

+

O2

C

CO2

+

energy

+

+

black solid

colorless gas

colorless gas

p. 39


Types of pollutants
Types of Pollutants hydrogen ions in one liter of solution.

  • Factors that determine the severity of a pollutant’s effects: chemical nature, concentration, and persistence.

  • Pollutants are classified based on their persistence:

    • Degradable pollutants

    • Biodegradable pollutants

    • Slowly degradable pollutants

    • Nondegradable pollutants


Nuclear changes radioactive decay
Nuclear Changes: Radioactive Decay hydrogen ions in one liter of solution.

  • Natural radioactive decay:

    • unstable isotopes spontaneously emit:

      • fast moving chunks of matter (alphaorbeta particles)

      • high-energy radiation (gamma rays)

      • or both at a fixed rate

    • Radiation is commonly used in energy production and medical applications

    • The rate of decay is expressed as a half-life (the time needed for one-half of the nuclei to decay to form a different isotope)


Nuclear changes fission
Nuclear Changes: Fission hydrogen ions in one liter of solution.

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

Figure 2-9


Nuclear changes fusion
Nuclear Changes: Fusion hydrogen ions in one liter of solution.

  • Nuclear fusion:

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

Figure 2-10


Video nuclear energy
Video: Nuclear Energy hydrogen ions in one liter of solution.

  • What type of cancer is linked with exposure to radiation?

  • How many deaths resulted from the Three Mile Island accident in 1979?

  • What percentage of the total energy used in the US does nuclear energy represent? What percentage does nuclear energy represent in France?

  • How many nuclear reactors does China plan on building over the next two decades?

  • Discuss some ideas or ways to protect the public from further exposure to radiation from nuclear fallout.

PLAY

VIDEO

  • From ABC News, Environmental Science in the Headlines, 2005 DVD.


Energy
ENERGY hydrogen ions in one liter of solution.

  • Energy is the ability to do work and transfer heat.

    • Kinetic energy – energy in motion

      • heat, electromagnetic radiation

    • Potential energy – stored for possible use

      • batteries, glucose molecules


Science systems matter and energy

Sun hydrogen ions in one liter of solution.

Ionizing radiation

Nonionizing radiation

Near

infrared

waves

Far

infrared

waves

Near

ultra-

violet

waves

Far

ultra-

violet

waves

Cosmic

rays

Gamma

Rays

Visible

Waves

TV

waves

Radio

Waves

X rays

Micro-

waves

High energy, short

Wavelength

Wavelength in meters

(not to scale)

Low energy, long

Wavelength

Fig. 2-11, p. 43


Electromagnetic spectrum
Electromagnetic Spectrum hydrogen ions in one liter of solution.

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

Figure 2-12


Science systems matter and energy

Relative hydrogen ions in one liter of solution.

Energy Quality

(usefulness)

Source of Energy

Energy Tasks

Electricity

Very high temperature heat

(greater than 2,500°C)

Nuclear fission (uranium)

Nuclear fusion (deuterium)

Concentrated sunlight

High-velocity wind

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

High-temperature heat

(1,000–2,500°C)

Hydrogen gas

Natural gas

Gasoline

Coal

Food

Mechanical motion to move

vehicles and other things)

High-temperature heat

(1,000–2,500°C) for

industrial processes and

producing electricity

Normal sunlight

Moderate-velocity wind

High-velocity water flow

Concentrated geothermal energy

Moderate-temperature heat

(100–1,000°C)

Wood and crop wastes

Moderate-temperature heat

(100–1,000°C) for

industrial processes, cooking, producing

steam, electricity, and

hot water

Dispersed geothermal energy

Low-temperature heat

(100°C or lower)

Low-temperature heat

(100°C or less) for

space heating

Fig. 2-13, p. 44


Energy laws two rules we cannot break
ENERGY LAWS: TWO RULES WE CANNOT BREAK hydrogen ions in one liter of solution.

  • The first law of thermodynamics:

    • we cannot create or destroy energy

      • We can change energy from one form to another.

  • The second law of thermodynamics:

    • energy quality always decreases

      • When energy changes from one form to another, it is always degraded to a more dispersed form.

        • Energy is often lost in the form of heat

      • Energy efficiency is a measure of how much useful work is accomplished before it changes to its next form.


Science systems matter and energy

Mechanical hydrogen ions in one liter of solution.energy(moving,thinking,living)

Chemical

energy

(photosynthesis)

Chemical

energy

(food)

Solar

energy

Waste

Heat

Waste

Heat

Waste

Heat

Waste

Heat

Fig. 2-14, p. 45


Sustainability and matter and energy laws
SUSTAINABILITY AND MATTER AND ENERGY LAWS hydrogen ions in one liter of solution.

  • Unsustainable High-Throughput Economies: Working in Straight Lines

    • Converts resources to goods in a manner that promotes waste and pollution.

Figure 2-15


Sustainable low throughput economies learning from nature
Sustainable Low-Throughput Economies: Learning from Nature hydrogen ions in one liter of solution.

  • Matter-Recycling-and-Reuse Economies: Working in Circles

    • Mimics nature by recycling and reusing, thus reducing pollutants and waste.

    • It is not sustainable for growing populations.


Science systems matter and energy

Inputs hydrogen ions in one liter of solution.

(from environment)

System

Throughputs

Outputs

(into environment)

Energy

conservation

Low-quality

Energy

(heat)

Energy

Sustainable

low-waste

economy

Waste

and

pollution

Waste

and

pollution

Pollution

control

Matter

Recycle

and

reuse

Matter

Feedback

Energy Feedback

Fig. 2-16, p. 47