APES Unit 2: The Physical World

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APES Unit 2 The Physical World

• A little about the nature of science, chemistry,
  physics, soil science, atmospheric science, plate
  tectonics, the rock cycle and water

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Chapter 3

• Physical Science Review

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The Nature of Science

• Science is a pursuit of knowledge about how the
  world works
• Scientific data is collected by making
  observations and taking measurements
• Observations involve the five senses, and help
  answer questions or problems
• Data can be qualitative (red, far away, hot)
• Can be quantitative (700 nm wavelength, 300 light
  years, 120 degrees Celsius)

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Scientific Law

• A Scientific Law
• A description of what we find happening in nature
  over and over again in a certain way
• Can often be stated in one sentence or one
  equation
• Examples
• Law of Conservation of Matter
• Law of Conservation of Energy
• Law of Entropy
• Law of Gravity (F Gm1m2/d2, Newton)
• 2nd Law of Motion (F ma, Newton)
• Law of Segregation (Mendel)
• Law of Independent Assortment (Mendel)

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Scientific Theory

• Scientific Theory
• More complex set of statements than a scientific
  law
• Describes how and/or why a scientific phenomenon
  occurs
• A hypothesis that has been supported by multiple
  scientists experiments in multiple locations
• Consensus of scientists agree
• Can never be proven true, can only be proven
  false
• Examples
• Atomic Theory
• Germ Theory of Disease
• Theory of Evolution (Darwin)
• Quantum Theory (Heisenberg, et al)
• Theory of General Relativity (Einstein)
• Theory of Special Relativity (Einstein)

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Scientific Law Scientific Theory

• A theory never becomes a law
• A law never becomes a theory
• They serve two different purposes
• They are equally supported and valued by the
  consensus of the scientific community

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Reasoning

• Inductive Reasoning
• Uses specific observations and facts to arrive at
  a general conclusion
• A dog breathes oxygen, a dog is an animal,
  therefore all animals breathe oxygen.
• Deductive Reasoning
• Uses logic to arrive at a specific conclusion
  based on a generalization
• All birds have feathers, eagles are birds,
  therefore all eagles have feathers.

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Models

• A model is used to describe or represent an
  observed or predicted behavior
• Feedback Loops
• Positive Loop Runaway cycles
• where a change in a certain direction
• causes further change in the same
• direction (compound interest,
• exponential population growth,
• greenhouse effect)
• Negative Loop a change in a certain
• direction leads to a lessening of the change
• (thermostat, predator-prey cycles)

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Positive Feedback Loop

• CO2 emission levels rise
• Surface temperatures rise
• Polar ice melts, forms liquid water
• Solar rays hit the ice and water
• Ice reflects rays, water absorbs them
• As ice decreases, more radiation is absorbed
• More absorbed radiation leads to warmer
  temperatures
• Warmer temperatures lead to more ice melting,
  which leads to warmer temperatures and more
  melting ice
• Once the feedback starts, even with constant CO2
  levels, the cycle will continue

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Synergy

• The whole is greater than the sum of the
  individual parts
• Two chemicals combine and interact, and have a
  greater effect than the added individual effects
  (e.g., alcohol and valium)
• Pollutants often interact in a synergistic way,
  as do pesticides

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Time Delay

• Effects arent seen immediately (CFC release
  leading to ozone depletion, DDT use leading to
  thinning eggshells)
• Some events have an immediate impact as well as a
  time delay effect (e.g., the oil spill in the
  Gulf of Mexico)

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Basic Chemistry Review

• Matter
• Atoms
• Nucleus
• Protons Neutrons
• Electrons
• Atomic number
• Atomic mass
• Ions
• Elements
• Isotopes
• Chemical reactions

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Inorganic Molecules

• All molecules not classified as organic
• Some important environmental inorganic molecules
• hydrogen (H2)
• oxygen (O2)
• water (H2O)
• nitrogen (N2)
• carbon dioxide (CO2)
• nitrogen dioxide (NO2)
• sulfur dioxide (SO2)
• ammonia (NH3)

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Organic Molecules

• Molecules containing carbon atoms combined with
  each other with atoms of one or more other
  elements such as hydrogen, oxygen, nitrogen,
  sulfur, etc.
• Carbon has 4 valence electrons it is versatile,
  able to combine with other elements in long and
  complex molecules
• Hydrocarbons have carbon and hydrogen only (the
  most simple is methane, CH4)
• Chlorofluorocarbons have carbon, fluorine
  chlorine atoms
• CO and CO2 are not organic

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Macromolecules

• Very large organic molecules
• Carbohydrates
• cellulose
• Lipids
• fat
• Proteins
• enzymes
• Nucleic Acids
• DNA and RNA

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Matter Quality

• Low quality
• hard to extract
• dispersed
• coal plant emissions
• High quality
• easy to extract
• concentrated
• lump o coal

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Law of Conservation of Matter

• The Earth is a closed system for matter
• In any closed system, the amount of matter stays
  the same
• There is no away, everything must go somewhere
• All the stuff that was ever on the earth is
  still here (a few exceptions include meteors
  hitting the earth and space probes launched from
  earth)

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Energy

• The ability to do work and transfer heat
• Kinetic, potential, gravitational, electrical,
  thermal, mechanical, electromagnetic, nuclear
• High quality energy includes electricity, nuclear
  fission and fusion, etc. that can be used for
  industrial purposes and to run electrical devices
  and motors
• We are always interested in energy transformations

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Nuclear Reactions

• Change the identity of the elements involved
• The atomic number changes
• Nuclear fission (nuclear reactors)
• Nuclear fusion (the sun stars, 3-4 times the
  energy as fission)

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Laws of Thermodynamics

• 1st Law (Conservation of Energy)
• The Earth is an open system for energy
• Energy is neither created nor destroyed, it
  changes form

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Laws of Thermodynamics

• 2nd Law (Entropy)
• Systems move towards disorder
• In any energy transformation, some of the energy
  usually ends up as heat ( e.g., energy lost in
  power line transmission)

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Chapter 4, 6 16 (4.2, 4.6, 6.1, 6.2,16.1-16.4)

• Earth Science Review

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Earth Structure

• Inner core
• Outer core
• Mantle
• Lithosphere
• Upper mantle
• Crust (fossil fuels, minerals,
• nonrenewables are found here)

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Earth Structure

• Biosphere - where all life is located
• Hydrosphere - where all water is located
• Atmosphere - compared to the size of the Earth
  (104 km), the atmosphere is a thin shell (120 km)
  
• Troposphere (ground to 7 miles, weather, smog)
• Stratosphere (7-30 miles, protective ozone)
• Mesosphere (30-50 miles)
• Thermosphere (50 miles and beyond, includes
  ionosphere)

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Soil

• Soil is a complex mixture of minerals, nutrients,
  eroded rock, air, water, decaying organic matter,
  and humus (decayed organic matter)
• Soil provides the food for all plants (and thus
  for all humans), and when healthy, will often
  include many microorganisms and fungi
• Healthy soil is often rich in nutrients
• Leaching is the loss of water-soluble nutrients
  from the soil due to rain and irrigation

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Soil Horizons

• O horizon (organic matter, litter layer)
• A horizon (topsoil)
• E horizon (location of leached minerals from
  upper layers)
• B horizon (subsoil, silt and sand)
• C horizon
• Bedrock (deep, underlying non-soil materials)

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Weather Climate

• Weather occurs in the troposphere and includes
  temperature, precipitation, barometric pressure
  and wind speed and direction
• Climate is the general pattern of weather over a
  period of at least 30 years
• The two most important factors in climate are
  temperature and precipitation

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Ocean Currents
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Ocean Currents and Winds

• Influence climate by redistributing solar energy
  (heat) from one place to another
• Winds can impact aquatic as well as terrestrial
  life
• Wind blowing along steep western coasts on some
  continents pushes water away from land
• This outgoing surface water is replaced by an
  upwelling of cold nutrient-rich bottom water
• These nutrients support many diverse life forms

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Weather

• Weather patterns can vary on a large scale
  without being a change in climate
• El Nino-Southern Oscillation (ENSO) is a periodic
  fluctuation (every 3-8 years) in the Pacific and
  Indian Oceans surface waters temperature
• A change in the direction of winds warms coastal
  surface waters, suppresses upwellings and alters
  much of the Earths weather
• Causes warmer temperatures and drought in the
  western Pacific and rain in the east
• La Nina is the reverse of this effect, when the
  Pacific and Indian Ocean surface waters cool
• Causes wetter and cooler winters in the Pacific

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Earth Processes

• Continental Drift
• The movement of large plates of rock on the
  earths surface
• The motion of tectonic plates accounts for most
  of the earthquakes, mountain formations,
  earths volcanic activity

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Earth Processes

• Vulcanism
• Process of bringing material from the deep
  interior of a planet and spilling it forth on the
  surface
• Generally caused by subduction
• When two sections of the earth's crust collide,
  one slab of crust is forced back down into the
  deeper earth regions

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Earth Processes

• Weathering erosion affects all types of rock
• The rock cycle
• metamorphic rock gt melting and cooling gt igneous
  rock gt erosion and weathering gt sedimentary rock
  gt heat and pressure gt metamorphic rock

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Chapter 15

• Water

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Water

• Unique qualities that impact the environment
• High specific heat
• Takes a lot of energy exchange to cause a change
  in temperature, changes temperature slowly (water
  1.0cal/g Celsius, aluminum 0.22cal/g Celsius)
• Keeps coastal areas moderate in temperature
• The North Atlantic Current provides warm water
  for Europe and North America

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Water

• Expands as it freezes
• Ice floats, life continues in the winter in
  northern lakes
• Universal solvent (ppm, ppb, ppt)
• Dissolves and transports nutrients (upwelling is
  the movement of cool nutrient-rich water from the
  bottom to the surface)
• Filters UV light
• Sticky (adhesive and cohesive)

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Water Issues Availability
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Water Use

• Approximately 1 of the water on the planet is
  available for use by humans.
• A lot of water is necessary for agriculture,
  industry, energy production and transportation.
• Personal and home use accounts for the smallest
  percentage, but it is still important to
  conserve.

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Home Water Use

• Some experts estimate that 50 of the landscaping
  water goes to waste due to over-watering and
  runoff
• Leaky faucets that drip at the rate of one drip
  per second can waste more than 3,000 gallons of
  water each year

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Water Waste

• Why water is wasted
• The responsibility for water resource management
  of a single watershed is often divided among
  many state and local governments
• Irrigation systems lose water to runoff,
  evaporation and seepage
• Removing vegetation causes flooding and erosion
• Water prices are artificially low

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Water Issues Availability

• The most economically and environmentally sound
  choice for conserving water is to increase the
  efficiency of the way we use water.
• Desalination is sometimes suggested, but it is
  very expensive and inefficient.
• The Jubail Desalination
• Plant in Saudi Arabia is
• the largest in the world
• and produces 800
• million gallons of fresh
• water per day

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Water Sustainability

• Sustainable use of water involves
• Participatory decision making
• Preservation of ecological integrity of water
  supply systems
• Integrated governance of water pollution
• Education about water issues
• Implementation of water conservation systems in
  business, industry, agriculture and personal use
  (rainwater harvesting, gray water use)

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Water Issues Who Gets It?

• Farmers
• Fishers
• Energy
• Hydroelectric Nuclear
• Businesses
• Native peoples
• City dwellers
• Non-human species
• Natural ecosystems