Chapter 2 Science, Systems, Matter, and Energy

Core Case Study: Environmental Lesson from Easter Island  Thriving society 15,000 people by ,000 people by  Used resources faster than could be renewed By 1600 only a few trees remained. By 1600 only a few trees remained.  Civilization collapsed By 1722 only several hundred people left. By 1722 only several hundred people left. Figure 2-1

KEY TERMS - ECONOMY  Gross National Product Measures economic growth in a country Measures economic growth in a country Market value in current dollars of all goods and services produced within and outside of a country by the country’s businesses during one year Market value in current dollars of all goods and services produced within and outside of a country by the country’s businesses during one year  Gross Domestic Product Market value in current dollars of all goods and services produced only within a country during one year Market value in current dollars of all goods and services produced only within a country during one year

KEY TERMS - ECONOMY  Economic Growth Increase in the capacity to provide goods and services for people’s use Increase in the capacity to provide goods and services for people’s use  Throughput of Matter and Energy Resources used to produce goods and services through an economy Resources used to produce goods and services through an economy High throughput means more consumption per person High throughput means more consumption per person

KEY TERMS - ECONOMY  More Developed Countries (MDC) Highly industrialized Highly industrialized Average per capita GNP above $4000 Average per capita GNP above $4000  Less Developed Countries (LDC) Low to moderate industrialization Low to moderate industrialization Average per capita GNP below $4000 Average per capita GNP below $4000 (Africa, Latin America, and parts of Asia) (Africa, Latin America, and parts of Asia)

WEALTH GAP  The gap between the per capita GNP of the rich, middle-income and poor has widened  More than 1 billion people survive on less than one dollar per day  Situation has worsened since 1980

Environmental Worldviews  How people think the world works  What they think their role in the world should be  What they see as right and wrong environmental behavior (environmental ethics)

Planetary Management Worldview  Increasingly common during the past 50 years.  We are the planet’s most important species  We are in charge of the rest of nature

Planetary Management Worldview  There is always more  All economic growth is good  Potential for economic growth is limitless  Our success depends on how well we manage earth’s system for our benefit

Earth-Wisdom Worldview  Nature exists for all of the earth’s species, not just for us  There is not always more  Not all forms of economic growth is beneficial to the environment  Our success depends on learning to cooperate with one another and with the earth

Working with the Earth  Earth Wisdom Learning as much as we can about how the earth sustains itself Learning as much as we can about how the earth sustains itself Adapt to ever-changing environmental conditions Adapt to ever-changing environmental conditions Integrating such lessons from nature into the ways we think and act Integrating such lessons from nature into the ways we think and act

Observations  Scientific data is collected by making observations and taking measurements  Observations involve the five senses, and help answer questions or problems  Qualitative of, relating to, or involving quality or kind of, relating to, or involving quality or kind  Quantitative of, relating to, or involving the measurement of quantity or amount of, relating to, or involving the measurement of quantity or amount

Qualitative  Red  Far from the earth  Microscopic  Burns quickly  Hot Quantitative  700 nm wavelength  300 million light years  Smaller than 1 um  Burns candle at 1 cm per minute  350 degrees C

Scientific Methods  There is no “one” scientific method However, there are careful, systematic ways of thinking that scientists use to gather data and formulate and test scientific hypotheses However, there are careful, systematic ways of thinking that scientists use to gather data and formulate and test scientific hypotheses  One way of applying a scientific method… Observation Observation Question Question Hypothesis Hypothesis Test the hypothsis Test the hypothsis Experiment Experiment Results Results Conclusion Conclusion New hypothesis…repeat New hypothesis…repeat

Scientific Reasoning and Creativity  Inductive reasoning Involves using specific observations and measurements to arrive at a general conclusion or hypothesis. Involves using specific observations and measurements to arrive at a general conclusion or hypothesis. Bottom-up reasoning going from specific to general. Bottom-up reasoning going from specific to general.  Deductive 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 specific. Top-down approach that goes from general to specific.

Frontier Science, Sound Science, and Junk 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 is presented as sound science without going through the rigors of peer- review.

TYPES AND STRUCTURE OF MATTER  Elements and Compounds Matter exists in chemical forms as elements and compounds. Matter exists in chemical forms as elements and compounds. Elements (represented on the periodic table) are the distinctive building blocks of matter.Elements (represented on the periodic table) are the distinctive building blocks of matter. Compounds: two or more different elements held together in fixed proportions by chemical bonds.Compounds: two or more different elements held together in fixed proportions by chemical bonds.

Ions  An ion is an atom or group of atoms with one or more net positive or negative electrical charges.  The number of positive or negative charges on an ion is shown as a superscript after the symbol for an atom or group of atoms Hydrogen ions (H + ), Hydroxide ions (OH - ) Hydrogen ions (H + ), Hydroxide ions (OH - ) Sodium ions (Na + ), Chloride ions (Cl - ) Sodium ions (Na + ), Chloride ions (Cl - )

 The pH (potential of Hydrogen) is the concentration of hydrogen ions in one liter of solution. Figure 2-5

Compounds and Chemical Formulas  Chemical formulas are shorthand ways to show the atoms and ions in a chemical compound. Combining Hydrogen ions (H + ) and Hydroxide ions (OH - ) makes the compound H 2 O (dihydrogen oxide, a.k.a. water). Combining Hydrogen ions (H + ) and Hydroxide ions (OH - ) makes the compound H 2 O (dihydrogen oxide, a.k.a. water). Combining Sodium ions (Na + ) and Chloride ions (Cl - ) makes the compound NaCl (sodium chloride a.k.a. salt). Combining Sodium ions (Na + ) and Chloride ions (Cl - ) makes the compound NaCl (sodium chloride a.k.a. salt).

Organic Compounds: Carbon Rules  Organic compounds contain carbon atoms combined with one another and with various other atoms such as H +, N +, or Cl -.  Contain at least two carbon atoms combined with each other and with atoms. Methane (CH 4 ) is the only exception. Methane (CH 4 ) is the only exception. All other compounds are inorganic. All other compounds are inorganic.

Organic Compounds: Carbon Rules  Hydrocarbons: compounds of carbon and hydrogen atoms (e.g. methane (CH 4 )).  Chlorinated hydrocarbons: compounds of carbon, hydrogen, and chlorine atoms (e.g. DDT (C 14 H 9 C l5 )).  Simple carbohydrates: certain types of compounds of carbon, hydrogen, and oxygen (e.g. glucose (C 6 H 12 O 6 )).

Cells: The Fundamental Units of Life  Cells are the basic structural and functional units of all forms of life. Prokaryotic cells (bacteria) lack a distinct nucleus. Prokaryotic cells (bacteria) lack a distinct nucleus. Eukaryotic cells (plants and animals) have a distinct nucleus. Eukaryotic cells (plants and animals) have a distinct nucleus. Figure 2-6

Macromolecules, DNA, Genes and Chromosomes  Large, complex organic molecules (macromolecules) make up the basic molecular units found in living organisms. Complex carbohydrates Complex carbohydrates Proteins Proteins Nucleic acids Nucleic acids Lipids Lipids Figure 2-7

States of Matter  The atoms, ions, and molecules that make up matter are found in three physical states: solid, liquid, gaseous. solid, liquid, gaseous.  A fourth state, plasma, is a high energy mixture of positively charged ions and 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 TV screens, gas discharge lasers, florescent light). Scientists have made artificial plasma (used in TV screens, gas discharge lasers, florescent light).

Matter Quality  Matter can be classified as having high or low quality depending on how useful it is to us as a resource. High quality matter is concentrated and easily extracted. High quality matter is concentrated and easily extracted. low quality matter is more widely dispersed and more difficult to extract. low quality matter is more widely dispersed and more difficult to extract. Figure 2-8

CHANGES IN MATTER  Matter can change from one physical form to another or change its chemical composition. When a physical or chemical change occurs, no atoms are created or destroyed. When a physical or chemical change occurs, no atoms are created or destroyed. Law of conservation of matter.Law of conservation of matter. Physical change maintains original chemical composition. Physical change maintains original chemical composition. Chemical change involves a chemical reaction which changes the arrangement of the elements or compounds involved. Chemical change involves a chemical reaction which changes the arrangement of the elements or compounds involved. Chemical equations are used to represent the reaction.Chemical equations are used to represent the reaction.

Nuclear Changes: Radioactive Decay  Natural radioactive decay: unstable isotopes spontaneously emit fast moving chunks of matter (alpha or beta particles), high-energy radiation (gamma rays), or both at a fixed rate. Radiation is commonly used in energy production and medical applications. 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). 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 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 fusion: two isotopes of light elements are forced together at extremely high temperatures until they fuse to form a heavier nucleus. Figure 2-10

ENERGY  Energy is the ability to do work and transfer heat. Kinetic energy – energy in motion Kinetic energy – energy in motion heat, electromagnetic radiationheat, electromagnetic radiation Potential energy – stored for possible use Potential energy – stored for possible use batteries, glucose moleculesbatteries, glucose molecules

Fig. 2-11, p. 43 Sun Nonionizing radiationIonizing radiation High energy, short Wavelength Wavelength in meters (not to scale) Low energy, long Wavelength Cosmic rays Gamma Rays X rays Far infrared waves Near ultra- violet waves Visible Waves Near infrared waves Far ultra- violet waves Micro- waves TV waves Radio Waves

Electromagnetic Spectrum  Organisms vary in their ability to sense different parts of the spectrum. Figure 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 energy Low-temperature heat (100°C or lower) Normal sunlight Moderate-velocity wind High-velocity water flow Concentrated geothermal energy Moderate-temperature heat (100–1,000°C) Wood and crop wastes High-temperature heat (1,000–2,500°C) Hydrogen gas Natural gas Gasoline Coal Food Electricity Very high temperature heat (greater than 2,500°C) Nuclear fission (uranium) Nuclear fusion (deuterium) Concentrated sunlight High-velocity wind Source of Energy Relative Energy Quality (usefulness) Energy Tasks

ENERGY LAWS: TWO RULES WE CANNOT BREAK  The first law of thermodynamics: we cannot create or destroy energy. We can change energy from one form to another. 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. When energy changes from one form to another, it is always degraded to a more dispersed form. Energy efficiency is a measure of how much useful work is accomplished before it changes to its next form. Energy efficiency is a measure of how much useful work is accomplished before it changes to its next form.