| |
The Role of Standards in Public School Education
Looking over the proposed "standards" the question immediately arises--who will use them, and for what purpose? If these standards are meant to help teachers define a curriculum, they are far too brief and too general to be of much use.
Take the very first item: "By the end of K-3, students use objects to demonstrate that energy is needed to get physical things to happen." What does it mean? What are "physical things"? How would an 8-year old know what "energy" means? What is "use objects"?
A useful set of standards should be more explicit. I have tried to draft one, on subjects covered on the provided list. This may of course be a completely different approach, requiring a complete rethinking of the concept of standards. However, if the Maryland Dept. of Education is interested in following it up, I would gladly help in the process.
Some Guiding Principles
- Different levels of science education:
- In grades K-3 the child discovers the world and should be introduced to phenomena and objects involving science. This continues throughout the school year, as the phenomena and objects get more complex.
- In grades 4-5 the children are introduced in a qualitative way to the explanations of processes and phenomena. This again continues in later years, on a higher level.
- In grades 6-8 students begin to understand the way science allows processes in nature to be measured and predicted.
- In grades 9-12 students begin to apply some of their knowledge and derive results by calculation. Students in these grades also acquire a synoptic view of the role of science and technology in society, helping them in choosing life careers.
- The science taught should be as concrete and relevant as possible. While it is hard to provide extensive hands-on experience, examples and illustrations should be drawn as much as possible from everyday life. What students learn in school should help them understand the technology they use and phenomena they observe. (e.g.: electricity and plumbing in the home, car engines, airplane flight, eclipses, seasons, calories in food).
- Avoid as much as possible memorization of "book knowledge", facts the student only believes because book and teacher tell him so. Even if the student cannot verify first hand what is being taught, details or at least glimpses should be given of the process by which assertions were substantiated. Students should realize that the laws and concepts of science are the result of observations which admit no other interpretation.
- In teaching science, the framework into which various laws and observations fit is just as important as the material itself. Only if the framework exists can students arrange the information in their minds in meaningful patterns.
- Including the stories of discoveries and theories, and of the people involved, helps create a framework for the scientific material and places it in the proper perspective. It also helps present science as a human endeavor, part of society rather than an arcane speciality.
Outline of Goals
No more than a very rough draft!
THESE LISTS ONLY COVER PHYSICS, EARTH SCIENCES AND ASTRONOMY.
Mechanics
By the end of K-3, students will know
- Matter can be solid, liquid or gas, with examples. Heat melts solids, evaporates liquids. Students should be familiar with this process in water.
- Water flows from high to low places, and objects fall or move to lower positions if free to do so.
- Some objects are light, some heavy; learn to use scales
also to measure distances.
- Sugar and salt dissolve in water, may be recovered by evaporation.
Water dissolves in air (humidity), wet objects dry.
By end of 4-5 students will know
- The way water flows in pipes, from tanks and reservoirs through plumbing in home. The way pumps work (water pistol). Air pressure
and siphoning of water.
- That "energy" is what turns machines, warms our homes, lifts loads.
Energy is contained in electricity, substances that burn (wood, gasoline, coal)
food, light. Heat itself is also a form of energy.
- Energy can change forms: sunlight gives energy to green plants,
solar cells, solar water heater, electric heater etc.
- Simple machines--levers, block and tackle, jacks, capstan.
By overcoming a small resistance over a long distance, we can overcome big resistance for a short distance. Law of levers.
By end of 6-8 students will know
- Concept of velocity, adding velocities in the same direction
- Concept of density--calculate it from weighing and measuring volume.
- Center of gravity (intuitive), how scales work.
- Pressure in water--Pascal's law, Archimedes law. Buoyancy--ships, balloons.
- How steam engine, gas engine, turbine work. Power stations and the way we get electric power.
(Also familiarity with the analogy between the flow of electricity in wires and that of water in pipes).
- Concepts of kinetic and potential energy (roller coaster, bicycle, pendulum).
By end of 9-12 students will know
- Acceleration due to gravity, motion of falling objects, thrown objects. Concept of vector.
- Newton's laws, mass and weight
- Conservation of momentum: recoil of guns, operation of rockets.
- Motion in a circle, centrifugal/centripetal forces.
- Gravitation, orbital motion in a circle
- Qualitative understanding of Kepler's laws.
- Laws of friction, with applications.
- Basic notions of airplane flight--Bernoulli's principle, action of wing, streamlining, propeller, controls, lift, stall etc.; history of aviation.
Heat
By the end of K-3, students will know
- The Sun warms the Earth, makes life possible.
- Temperature and how it is measured.
Temperature scales--Farenheit, Centigrade, examples.
Thermometer, temperature of freezing, boiling, of body.
Melting, boiling of pure substances have well defined
temperatures, with examples.
- Casting of metal, making of bricks and pottery.
By end of 4-5, students will know
- Heat can be produced by chemical change,
for instance, in fire which combines the fuel with oxygen.
- Heat in the home: heat conduction and insulation.
Warm clothing, cost of heat, losses.
- Expansion and contraction: how thermometer and
thermostat work, gaps between rails and in bridges.
By end of 6-8, students will know
- Concept of heat (as distinct from temperature),
calories. Calculate temperature of mixing of water.
- Specific heat, heat needed for melting and evaporation.
Cooling by evaporation.
- Caloric values of foods and what they mean,
also of fuels.
- Loss of heat by radiation. Greenhouses, solar heaters.
How the atmosphere gets rid of its heat and
relation to weather.
By end of 9-12, students will know
- The gas laws, with calculations.
Conceptual relation to kinetic theory of gases.
- Cooling by expansion--principle of refrigerator,
air conditioner, also heat pump.
- Heat and energy: qualitative understanding
of 2nd law of thermodynamics.
Electricity and Magnetism
By the end of K-3, students will know
- How a flashlight works. Switches, batteries,
need for complete circuit.
- Electricity flows in metal wires, like water in pipes.
It also comes by power lines from power stations
- Iron magnets, their poles, attraction and
repulsion, the compass and why it points north.
By end of 4-5, students will know
- Understand house wiring. Dangers of shock and fire,
use of fuses and circuit breakers. Use of electricity in a car.
- Circuits, switches, grounding. Electric lightbulbs.
- Conductors and insulators.
- Static electricity, lightning
By end of 6-8, students will know
- Further analogy between flow of electricity in wires and
flow of water in pipes: voltage is like pressure,
current like volume of flow. Ohm's law.
- Electric power: Watts, kilowatt-hours, electric bills.
- Electrons. How TV picture tubes and computer monitors work.
By end of 9-12, students will know (mostly qualitatively):
- Further calculations with Ohm's Law.
- How electric currents produce magnetic forces.
Story of Oersted, Ampere.
- How magnetic fields can produce electric currents.
- Alternating currents.
Faraday and his invention, the transformer.
Use of transformers in the power grid.
Formula for the voltage produced.
- Plasma and fluorescent lights, ballast coils.
- Telephones.
- Relation between electromagnetism and light: radio waves.
- Electronics--vacuum tubes, transistors, amplification
of signals, production of sound and music.
- Computers and their applications--calculators, memories, word processors etc.
- Electrons and atoms: electric structure of matter.
Light and Sound
By the end of K-3, students will know
- Recognize sources of light: flame, hot wire in lightbulb (also: TV, neon light)
- Sources of sound: voice, impact, vibrating air (whistle, flute, trumpet)
vibrating string (guitar, piano) vibrating surface (drum, loudspeaker) Sound is a vibration (in a general sense).
- Reflection of light and sound: mirrors, echo.
By end of 4-5, students will know
- Some details about structure of the eye and the ear.
- About waves in water: wavelength, speed.
- About the speed of sound: lightning and thunder.
More about what sound is.
- Colors from prism (or grating). Rainbow.
- Straw in a glass of water seems broken.
By end of 6-8, students will know (mostly qualitatively)
- About resonance: in xylophone, tuning forks, quartz watches.
Wavelength of sound in a string is
determined by its fixed points (guitar, violin).
- Doppler effect
- Energy carried by waves
- Spectrum of substances (and why flames are yellow).
- 3-color theory of light: difference in color as sensed by eye
and as observed by a spectroscope
By end of 9-12, students will know
- Refraction of light, with calculations. Refractive index
and its relation to the slowing-down of light
inside a transparent substance. Lens, focusing, slide projector,
camera, telescope, microscope etc.
- Intensity of light: grease-spot photometer.
- Photography. How to use a camera.
- Radio waves (with electricity). Antennas, radar, microwave ovens.
- Other "kinds of light": infra-red, ultra-violet, x-rays, microwaves.
- More on spectra: Mercury and sodium lamps. Use of neon lamps.
- Photoelectric effect. Question whether light is a wave or particles.
- Lasers and their uses
Space
By the end of K-3, students will know
- About the Sun, moon, stars, planets, comets. Shapes of the moon, reason for eclipses.
- Know the Earth is a big sphere, you can travel around it.
(Also, climates in different regions of the Earth.)
- About spaceflight, astronauts, rockets and their stages.
By end of 4-5, students will know
- How to identify the big and little dipper, Cassiopeia, Orion.
- That the Earth rotates around its axis, causing the sky to seem to rotate.
Stars, Sun and Moon may rise and set, only Pole star is fixed;
how one uses it to find north (also about south pole of sky).
- Latitude, longitude and maps. Story of Columbus
(he thought globe was smaller, hence India was near).
- Summer days are long, winter days short; equinox and solstice.
- Names of planets and what makes each special.
- The solar system is flat, and therefore the planets, Sun
and Moon are all seen along (or near) the same
line across the sky, called the ecliptic.
- Stars are distant suns.
- Gravity keeps the Earth from escaping the Sun,
and the Moon from escaping the Earth.
Rockets with enough speed can escape Earth.
By end of 6-8, students will know
- What is seen through a telescope, story of Copernicus, Galileo, Kepler.
- Seasons of the year& their causes, climates on Earth (in more detail).
- About the Milky Way and its relation to our galaxy. Other galaxies.
- The Moon and its craters. Also, tides.
- Story of artificial satellites, Sputnik and Apollo.
By end of 9-12, students will know
- Velocity of light, light years. Also, dimensions of the solar system.
- Kepler's laws and Newton's gravity. How the distance
of a satellite from the Earth, or a planet from the Sun,
determines its orbital period. Examples.
- The Sun, its energy source, sunspots, sunspots and their
cycle, other features
- The ecliptic, view of planets in the sky. Retrograde motion
- Evolution of stars and of the universe, big bang.
- Principle of rockets. Space missions--weightlessness, escape
velocity orbital velocity.
Geology
By the end of K-3, students will know
- Local stones and mineral, soils--how their sand, silt, clay and humus
settle out in water. Also how bricks and concrete are made.
- About the erosion of soil and its prevention, also erosion of Maryland beaches.
- About the Potomac and its floods, also floods elsewhere in the US, and flood control by dams.
- About springs and wells, "water table" below which the ground
is saturated, and its connection with wet basements.
By end of 4-5, students will know
- About the geology of the US: Appalachians and Rocky Mtns, Grand Canyon.
- Volcanos in the US (Hawaii, St. Helens) and elsewhere. Lava, basalts.
- Mineral resources: coal (and how it is mined--pit and strip mining), iron, copper, gold (gold rush),
silver, zinc, also (briefly) aluminum and what all these are used for.
Oil, gas and shale, resources in the US and the world.
- Mohs' hardness scale of minerals.
- Earthquakes, including San Francisco, Charleston S.C. Mercalli scale (and about Richter's), Tsunamis.
By end of 6-8, students will know
- About glaciers, erosion by ice, and evidence of ice ages.
The finger lakes of NY State, fjords of Norway and in
Alaska's panhandle. Icecaps today in Greenland and Antarctica.
- Sedimentary vs. igneous rocks: limestone, its uses (incl. marble), corals
and fossils in limestone. Also caves and sinkholes.
Formation of coal (relation to peat) and of oil. Shale, granite.
- Ancient fossils: dinosaurs, extinct species. Signs of the great age of Earth.
By the end of 9-12, students will know
- About radioactive dating and evidence for the age of the Earth.
- About plate tectonics and evidence from it from sea bottom magnetism.
"Floating continents", ocean trenches and the
adjoining ranges of volcanically active mountains.
The mountainous "backbone" of the Americas.
- Evidence from earthquakes for molten core, and role of
radioactivity in generating that heat. Seismometers.
- Emergence and evolution of life on Earth. Extinctions and meteor
impact, on the moon and on Earth: Meteor Crater, Ariz;
Manicougan, Quebec.
- Evidence for ancient humans.
- Distribution of mineral resources in the world.
Weather and Climate
By the end of K-3, students will know
- To read temperatures, rain gauge, understand windvane.
- What clouds are, fog. Beginning of the water cycle, and Sun's role.
- Further poleward, colder; equatorward, hotter and sometimes wetter.
By end of 4-5, students will know
- More about the water cycle, and be aware that motions in the
atmosphere are driven by the Sun's heat, which is
gradually lost back to space.
- Winds and Beaufort's scale. Tornadoes, hurricanes, thunderstorms.
- Climates of the US: compare Maryland to Arizona, California, Maine, Florida, Alaska, Hawaii.
By end of 6-8, students will know
- Importance of water in the atmosphere: humidity (relative, absolute).
Formation of rain and dew, seeding of clouds.
- Buoyancy of hot air, convection and thunderheads. In a
thunderstorm, air gets rid of water, warms up and rises.
"Thermals" and how birds and sailplanes use them.
- Climates of the Earth: Gulf stream, monsoons, el Nino. Variations of
rainfall in the US and world, and types of
agriculture that suit them.
By end of 9-12, students will know
- About barometric pressure and the swirling of the
atmosphere, hurricanes. Reading weather maps, fronts.
- Layers of the atmosphere, the drop in temperature and pressure
with height and their relation to the gas laws.
- Composition of air, pollutants, "greenhouse effect" and ozone.
- How mountains affect climate, how they can create and shield rain.
- Modern meteorology: weather satellite, weather station networks,
about computer simulations.
Modern Physics and Nuclear Power
Very difficult to accomodate, unless the physics curriculum is started early. All
in high school. Many assertions can be given only sketchy justifications.
- Atoms and molecules. Avogadro's number. Atoms contain electrons.
Electrolysis and ions in solutions (these come under chemistry).
- Edison effect. How Millikan showed evidence for electron (qualitative)
- Photoelectric effect: light kicks electrons out of matter.
- Ionized gases conduct electricity. Fluorescent lights, plasmas. Geiger counters.
- Radioactivity: alpha, beta, gamma rays. Origin of helium on Earth.
- Structure of matter: atoms have nuclei, contain protons and electrons.
- "Quantum mechanics" requires atoms and molecules to have specific
energy levels, explains light emission in narrow spectral "lines."
Mercury, sodium lamps, lasers.
- Nuclear forces bind nuclei together, electric repulsion opposes them.
Hence very heavy nuclei may fall apart.
- Nuclear fission, role of neutrons (slow and fast). Its history, use for
nuclear power. Uranium 235, plutonium. Fission products and the problem of their disposal.
- Atomic weapons and nuclear fallout. The test ban treaty.
- The creation of nuclei--hydrogen and helium in the big bang,
others "cooked" in stars by nuclear fusion and in supernovas.
Iron as the most stable element. About attempts to harness the
energy of controlled nuclear fusion.
|
|