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Copyright Houghton Mifflin Company. All rights reserved.1| *Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *This CoursePhysics, Geology, Meteorology, and AstronomyAttempts to describe the physical world in which we liveMeasurements movement, temperature, weather conditions, time, etc.Constant use of measurements many examples in book.Can everything be measured w/ certainty??As smaller and smaller objects were measured it became apparent that the act of measuring distorted the object.Section 1.1Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Scientific LawScientific Law after a series of experiments a concise statement (words/math) about a relationship/regularity of natureExample Law of Conservation of Mass (no gain or loss during chemical reaction)The law simply states the finding, but does not explain the behavior.Section 1.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *HypothesesHypothesis tentative explanation(s) of the relationship/regularity in natureExample: Matter consists of small particles (atoms) that simply rearrange themselvesA good hypothesis must suggest new experiments that serve to test its validity.The hypothesis is supported if it correctly predicts the experimental results Section 1.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *TheoryTheory tested explanation for a broad segment of basic natural phenomenaExample: Atomic Theory This theory has withstood testing for 200+ years and continues to correctly predict atomic behavior.Section 1.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Standard Units and Systems of UnitsExpressed in magnitude and unitsFundamental Physical Quantities length, mass, time, and electric chargeStandard Unit fixed and reproducible value to take accurate measurementsSection 1.4Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Standard Units and Systems of Units continuedTwo major systems of unitsBritish (English) system only used widely in the United States (miles, inches, pounds, seconds, etc.)International System of Units (Metric system) used throughout most of the world (kilometers, meters, grams, etc.)The U.S. officially adopted the metric system in 1893, but continues to use the British system.Section 1.4Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Metric SystemUses acronym mks system from standard units of length, mass, and time meter, kilogram, secondIt is a decimal (base-10) system this is much better than the British systemAdministered by -- Bureau International des Poids et Mesures (BIPM) in ParisInternational System of Units (SI)Contains seven base unitsSection 1.5Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Modern Metric System (SI)The base units are a choice of seven well-defined units which by convention are regarded as dimensionally independent: meter, m (length)kilogram, kg (mass)second, s (time)ampere, A (electrical current)kelvin, K (temperature)mole, mol (amount of a substance)candela, cd (luminous intensity) Section 1.5Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Base-10 ConvenientEasy expression and conversionMetric examples vs. British examples1 kilometer = 1000 meters1 mile = 5280 feet1 meter = 100 centimeters1 yard = 3 feet or 36 inches1 liter = 1000 milliliters1 quart = 32 ounces or 2 pints1 gallon = 128 ouncesSection 1.5Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Unit CombinationsWhen a combination of units becomes complex and frequently used it is given a name. Examples:newton (N) = kg x m/s2joule (J) = kg x m2/s2 watt (W) = kg x m2/s3 Section 1.6Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Significant FiguresSignificant figures (SF) a method of expressing measured numbers properlyA mathematical operation, such as multiplication, division, addition, or subtraction cannot give you more significant figures than you start with.For example, 6.8 has two SF and 1.67 has three SF.Section 1.7Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *When we use hand calculators we may end up with results like: 6.8/1.67 = 4.0718563Are all these numbers significant?Section 1.7Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Rounding off Numbers ExamplesRound off 0.0997 to two SF0.0997 0.10What about this? 5.0 x 356 = 1780Round off 1780 to 2 SF 1780 1800Section 1.7Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Powers-of-10 Notation (Scientific Notation)Many numbers are very large or very small it is more convenient to express them in powers-of-10 notation1,000,000 = 10x10x10x10x10x10 = 106Section 1.7Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Scientific Notation10000 = 10 x 10 x 10 x 10 = 1041000 = 10 x 10 x 10 = 103100 = 10 x 10 = 10210 = 101 1 = 100Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Scientific Notation0.1 = 1/10 = 1/101 = 10-10.01 = 1/100 = 1/102 = 10-20.001 = 1/1000 = 1/103 = 10-30.0001 = 1/10000 = 1/104 = 10-4Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Scientific NotationThe distance to the sun can be expressed many ways:93,000,000 miles93 x 106 miles9.3 x 107 miles0.93 x 108 milesAll four are correct, but 9.3 x 107 miles is the preferred format.Section 1.7Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Cartesian CoordinatesA two-dimensional system is one in which two lines are drawn perpendicular with an origin assigned at the point of intersection.Horizontal line = x-axisVertical line = y-axisThe system we commonly use is the Cartesian coordinate system, named after the French philosopher/mathematician Ren Descartes (1596-1550).Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Cartesian Coordinates Two Dimensionalx number gives the distance from the y-axis.y number gives the distance from the x-axis.Many cities are laid out in a Cartesian pattern with streets running N-S & E-W.Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *LatitudeLatitude - the angular measurement in degrees north and south of the equatorThe latitude angle is measured from the center of the earth relative to the equator.Lines of equal latitude are circles drawn on the surface and parallel to the equator.Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *LongitudeLongitude is the angular measurement, in degrees, east or west of the reference meridian, the Prime Meridian (0o) at Greenwich, England.A large optical telescope was located there.Maximum value of 180o E or WCopyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *TimeTime - the continuous forward flowing of eventsThe continuous measurement of time requires the periodic movement of some object as a reference.The second has been adopted as the international unit of time.Vibration of the cesium-133 atom now provides the reference of a second 9,192,631,770 cycles per secondCopyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *DaysApparent Solar Day the elapsed time between two successive crossings of the same meridian (line of longitude) by the sun (361o)Sidereal Day the elapsed time between two successive crossings of the same meridian by a star other than the sun (360o)Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Diagrams of Sun's Position (Degrees Latitude) at Four Different Times of the YearCopyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Two Different YearsTropical Year the time interval from one vernal equinox to the next vernal equinox 365.2422 mean solar daysThe elapsed time between 1 northward crossing of the sun above the equator to the next northward crossing.Sidereal year the time interval for earth to make one complete revolution around the Sun with respect to any particular star other than the sun 365.2536 mean solar days20 minutes longer than the tropical yearCopyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Gregorian CalendarThe Julian calendar was fairly accurate and was used for over 1500 years.In 1582 Pope Gregory XIII realized that the Julian calendar was slightly inaccurate.The Vernal Equinox was not falling on March 21.A discrepancy was found. To correct this the Pope decreed that 10 days would be skipped.365.2422 not 365.25 = discrepancyEvery 400 years 3 leap years would be skipped.This is the calendar we use today.Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *The Solar SystemThe solar system - complex system of moving masses held together by gravitational forcesSun is center Sun is the dominant massRevolving around the sun -- 8 planets, over 70 moons, 1000s of other objects (asteroids, comets, meteoroids, etc.) Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Johannes Kepler (1571-1630)German mathematician and astronomerKeplers 1st Law Law of Elliptical Paths All planets move in elliptical paths around the sun with the sun as one focus of the ellipseAn ellipse is a figure that is symmetric about two unequal axesCopyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Keplers Second LawLaw of Equal areas An imaginary line (radial vector) joining a planet to the sun sweeps out equal areas in equal periods of timeCopyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Keplers Third LawHarmonic Law the square of the sidereal period of a planet is proportional to the cube of its semimajor axisT2 = k R3 T = period (time of one revolution)R = length of semimajor axisk = constant (same for all planets) = 1y2/AU3 Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Copyright Houghton Mifflin Company. All rights reserved.16 | *Our Solar SystemSun 99.87% of the mass of solar systemOf the remaining 0.13%, Jupiter is > 50%Planets with orbits smaller than earth are classified as inferiorPlanets with orbits larger than earth are classified as superiorSection 16.1Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Copyright Houghton Mifflin Company. All rights reserved.16 | *AlbedoAlbedo the fraction of the incident sunlight reflected by an objectEarths albedo is 33%Moons albedo is 7% (from Earth the moon is the 2nd brightest object in the night sky)Venus albedo is 76% (3rd brightest is sky)Since the Moon is so close to Earth it is brighter than VenusSection 16.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Copyright Houghton Mifflin Company. All rights reserved.16 | *Stellar ParallaxThe observation of parallax is indisputable proof that the Earth revolves around the Sun.In addition, the measurement of the parallax angle is the best method we have of determining the distance to nearby starsSection 16.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Copyright Houghton Mifflin Company. All rights reserved.16 | *Terrestrial PlanetsThe terrestrial planets include: Mercury, Venus, Earth, MarsDue to physical/chemical characteristics they resemble EarthAll four terrestrial planets are Relatively small in size and composed of rocky material and metalsRelatively close together and close to SunHave no ringsOnly Earth and Mars have moonsOnly Earth has surface water and oxygenSection 16.3Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Copyright Houghton Mifflin Company. All rights reserved.16 | *The Jovian Planets Jupiter, Saturn, Uranus, Neptune Much larger than the terrestrial planetsComposed mainly of hydrogen and heliumThe four Jovian planets have a very low average density (approximately 1.2 g/cm3)All four are thought to have a rocky core composed of iron and silicatesThick layers of frozen methane, ammonia, and water are found above the coreSection 16.4Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Copyright Houghton Mifflin Company. All rights reserved.16 | *Terrestrial versus Jovianrelatively small in mass and sizecomposed of rocky material and metals (having a core mostly of iron and nickel)relatively dense (~5 g/cm3) solid surfaces weak magnetic fieldsno ring systemsrelatively large in mass and sizecomposed mainly of hydrogen and helium (rocky core with layers of ice above it)low density (~1.2 g/cm3) no real surfaces;strong magnetic fieldsmany moons and ring systemsCopyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Copyright Houghton Mifflin Company. All rights reserved.16 | *Origin of the Solar SystemAny theory that purports to explain the origin and development of the solar system must account for its present formAccording to our best measurements, our solar system has been in its present state for about 4.5 billion yearsA valid theory for solar system formation must be able to explain a number of major properties of our solar systemSection 16.5Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Copyright Houghton Mifflin Company. All rights reserved.16 | *The Formation of the Solar System Condensation TheorySection 16.5Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Copyright Houghton Mifflin Company. All rights reserved.17 | *The MoonSecond brightest object in the skymoon unknown origin of the wordMany primitive and modern societies base their religious ceremonies on the cycles of the moon (e.g., new and full moons).Our month is based on moons cycle.Human ovarian cycle is also synchronized to the 29.5 day lunar cycle.Section 17.1Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Copyright Houghton Mifflin Company. All rights reserved.17 | *Characteristics of the MoonNearly spherical, with a diameter of 3476 km (2160 mi) approx. the earths diameterMass of the moon = 1/81 of the earthAverage density of 3.3 g/cm3 (earth is 5.5)Surface gravity of the moon is only one-sixth of Earths.Therefore ones weight on the moon would only be one-sixth of that on Earth.Average reflectance (albedo) = only 7% (only 7% of the light received from the sun is reflected)Section 17.1Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Copyright Houghton Mifflin Company. All rights reserved.17 | *Inside the MoonCopyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Copyright Houghton Mifflin Company. All rights reserved.17 | *Origin of the Moon??Must take into account these facts:Lunar rocks are similar to the earths mantle.Oxygen isotope ratios indicate that the earth and the moon were formed at a similar distance from the sun.There is no water in lunar rocks.There is a deficiency of volatile elements (which were driven off by heat).Relative to earth, moon has less iron.3.3 g/cm3 = moon; 5.5 g/cm3 = earthThe oldest rocks on earth and moon are similar.Section 17.1Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.17 | *Origin of the MoonMost widely accepted theory is the great impact theory.A planet-sized object (size of Mars) struck the earth with a glancing blow 4.4 billion years ago, resulting in the ejection of matter into orbit to form the moon.Section 17.1Copyright Houghton Mifflin Company. All rights reserved.Relative Motions of the Moon and EarthSection 17.2Copyright Houghton Mifflin Company. All rights reserved.17 | *New Phase or New MoonOccurs when earth, sun, and moon are all in the same plane, with the moon positioned between the Sun and EarthAt this position, the dark side of the moon is fully toward the Earth (dark of the moon).Section 17.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.17 | *Positions of the Sun, Moon, and Earth During a Total Solar EclipseSection 17.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.17 | *A Lunar EclipseSection 17.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Copyright Houghton Mifflin Company. All rights reserved.17 | *Tidal Bulges The two tidal bulges result in two high tides and two low tides dailySection 17.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.17 | *Spring and Neap TidesSection 17.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.17 | *Asteroids or Minor PlanetsSection 17.5Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *The SunStar - a self-luminous sphere of hot gases, energized by nuclear reactions and held together by the force of gravity.The Sun is the nearest star to Earth.The Sun is enormous in size relative to the size of Earth.The Suns diameter is approximately 4 times the distance between the Earth and the Moon.Section 18.1Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Structure and Composition of the SunThe Sun can divided into four concentric layers:Core - the innermost part of the Sun where nuclear fusion occursPhotosphere - the surface that we seeChromosphere the layer of very hot gases above the photosphere, also known as the Suns lower atmosphereCorona - the Suns outer atmosphereSection 18.1Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Radial Cross Section of the SunThe boundary between any two layers is not sharply defined.Section 18.1Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Interior of the SunThe Suns interior is so hot that individual atoms cannot exist.Continuous high-speed collisions result in the separation of nuclei and electrons.A fourth phase of matter, called a plasma, is created where nuclei and electrons exist as a high-temperature gas. The temperature at the central core of the Sun is 15,000,000 K and the density is 150 g/cm3.The innermost 25% of the Sun, the core, is where H is consumed to form He.Section 18.1Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Proton-Proton ChainIn the net reaction of the PP Chain, four protons form a He nucleus, two positrons, two neutrinos, and two gamma rays.The amount of energy released by the conversion of mass conforms with Einsteins equation, E = mc2 .Section 18.1Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *The Celestial SphereCelestial sphere the huge imaginary sphere of the sky on which all the stars seem to appearDuring any given night, the great dome of stars appear to progressively move westward, from an observers vantage point on Earth.North celestial pole (NCP) the point in the Northern Hemisphere that the stars seem to rotate aroundPolaris or the North StarSouth celestial pole (SCP) the point in the Southern Hemisphere that the stars seem to rotate aroundSection 18.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Celestial SphereBecause of the 23.5o tilt of the Earths rotational axis, the ecliptic & celestial equator are inclined to one another, these two planes intersect at only two points.Section 18.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Celestial Prime MeridianCelestial prime meridian the half-circle created by the intersection of the NCP, the vernal equinox, and the SCPThe celestial prime meridian is therefore a reference line or starting line used to measure celestial longitude.Section 18.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Celestial Longitude & LatitudeThe measure of celestial longitude is called the right ascension (RA) of the star or galaxy.The RA is the position of the star/galaxy to the east of the celestial prime meridian.Measured in hours, minutes, and seconds with the full circle having a total of 24 hoursThe declination (DEC) of a star or galaxy is an angular measurement (in degrees, minutes, and seconds) north or south of the celestial equator.Section 18.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Celestial DistanceThe distance to most celestial bodies is measured in astronomical units (AU), light-years, or parsecs.Astronomical unit (AU) the mean distance between the Earth and the Sun (1.5 x 108 km)Light-year (ly) the distance light travels through a vacuum in one year (9.5 x 1012 km)Parsec (pc) distance to a star when the star exhibits a parallax of 1 second of arc (3.26 ly = 3.09 x 1013 km)Section 18.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Celestial MagnitudeThe Greek astronomer and mathematician Hipparchus was a dedicated observer of the stars.He compiled the first star catalog by measuring the location and assigning apparent brightness magnitudes to more than 800 stars.Apparent magnitude the brightness of any celestial object as observed from EarthFirst magnitude stars were the brightest and sixth magnitude stars were barely visible to the unaided eye.Section 18.3Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Apparent MagnitudeThe apparent magnitude scale in use today is a modified version of Hipparchus scale.Instruments are used to accurately measure and quantify the apparent magnitudes.The modern scale is constructed such that a difference of 5 magnitudes represents a difference of 100 in apparent brightness.Therefore a first-magnitude star appears 100 times brighter than a sixth-magnitude star.Section 18.3Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Apparent Magnitude of other Celestial BodiesThe brightest celestial body is the Sun. The Sun has an apparent magnitude of 27.The full moon is the second brightest celestial body.The full moon has an apparent magnitude of 13.Venus is the brightest planet.Venus has an apparent magnitude of 4.Sirius is the brightest star. (8.7 ly in distance)Sirius has an apparent magnitude of 1.Section 18.3Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Absolute MagnitudeObviously, a stars distance from Earth tremendously affects its apparent brightness.Absolute magnitude the brightness a star would have if it were placed 10 pc (32.6 ly) from EarthOur Sun, for example, has an absolute magnitude of +5.If we know the distance to a star and its apparent magnitude, the absolute magnitude can be calculated.Section 18.3Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *The H-R (Hertzsprung-Russell) DiagramThe H-R Diagram results from plotting the stars absolute magnitudes versus the temperatures of their photospheres.Most stars become brighter as they get hotter.These stars plot as a narrow diagonal band in the diagram. The hottest (and generally brightest) stars are blue. The coolest (and generally least bright) stars are red.Section 18.3Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Hertzsprung-Russell DiagramNote that some stars do not fall along the main sequence.Section 18.3Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Stellar Evolution on the H-R DiagramSection 18.4Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Evolution of a low-mass starProtostar, main-sequence star, red giant, planetary nebula, and white dwarfSection 18.4Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *High-Mass vs. Low-Mass StarsHigh-mass stars and low-mass stars form initially in similar manners.High-mass stars are hotter and brighter than low-mass stars.High-mass star move onto the main sequence at higher points.High-mass stars do not stay on the main sequence as long as low-mass stars, due to their higher rate of thermonuclear fusion.Section 18.5Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Evolution of a High-Mass StarWhen high-mass stars moves off the main sequence they become red supergiants and eventually explode as Type II supernovae. Much of the material is scattered into space leaving behind a neutron star or black hole.Section 18.5Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *GalaxiesGalaxy a very large aggregate of stars, gas, and dust held together by their mutual gravitational attractionGalaxies are considered to be fundamental components of the universe.Section 18.6Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *The Milky Way GalaxyFace-on and edge-on Views of our GalaxySection 18.6Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Hubble & Spectrum ShiftsHubble examined the spectral shifts of different galaxies.During his investigations he noted that some shifts were blue and some red.The blue shift indicates that the galaxy is moving toward us.The red shift indicates that the galaxy is moving away from us.Section 18.7Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Expanding UniverseHubble noticed that far-away galaxies all exhibited red shifts.He also noted that the farther away the galaxy, the larger the red shift.As a result, Hubble concluded that the universe must be expanding.Section 18.7Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Hubbles LawThe greater the distance, the greater the recessional velocity (calculated from the observed red shift)Section 18.7Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Hubbles LawHubbles Law the recessional speed of a distant galaxy is directly proportional to its distance from the Milky Way galaxy v = Hdv = recessional velocity of the galaxyd = distance away from usH = the Hubble constant H has not been precisely established yet but lies somewhere between 50 and 80 km/s per million parsecs, depending on what galaxies are being observed and what experimental techniques are used.Section 18.7Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Consequences of Hubbles LawWhat does it mean if all the other galaxies are all receding from away from us?We must be at the center of the universe No!Almost all astronomers agree that we live in an ever expanding universe.Therefore, every galaxy is receding from every other galaxy.An observer, from anywhere in the universe would witness the same phenomena receding galaxies.Section 18.7Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *Rising Bread Analogy of the Expanding UniverseThe raisins represent galaxies and the dough represents space. As the loaf of bread rises, every raisin recedes from every other raisin.The greater the initial distance from a given raisin, the faster and farther the other raisins moveSection 18.7Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.18 | *The Big Bang Broad AcceptanceExperimental evidence supports the Big Bang in three major areas:Cosmological redshift galaxies today have a redshift in their spectrum linesCosmic microwave background microwave radiation that fills all space and is thought to represent the redshifted glow from Big BangThere is a H to He mass ratio of 3 to 1 in the stars and interstellar material, as predicted by the Big Bang model.Section 18.7Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.19 | *Composition of the AtmosphereThe air of our atmosphere is composed of a mixture of gases and holds varying amounts of suspended liquid droplets and solid particlesOnly two gases, nitrogen and oxygen, make up close to 99%, by volume, of air near the EarthBoth of these dominant gases are diatomic - N2 & O2Argon (Ar, 0.9%) and carbon dioxide (CO2, 0.03%) are the other major constituents of airVery small quantities of many other gases are found in the atmosphereSection 19.1Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.19 | *TemperatureMajor recognizable divisions within the atmosphere can be distinguished based on vertical temperature variationsVertically, Earths atmosphere is divided into four temperature regionsTroposphere ground to about 16 km (10 mi)Stratosphere 16 km to about 50 km (10 30 mi)Mesosphere 50 km to about 80 km (30 50 mi)Thermosphere 80 km to outer spaceSection 19.1Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.19 | *Vertical Structure of the AtmosphereMajor divisions of the atmosphere based on temperature variationsCopyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.19 | *Insolation DistributionInsolation is affected by a number of different processes as it arrives and transects the Earths atmosphereNote that only about 50% of the total insolation actually reaches the Earths surfaceSection 19.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.19 | *AlbedoAlbedo the amount of light a body reflectsOf the insolation received by Earth, about 33% is returned to space via reflection and scatteringTherefore the Earth has an albedo of 33%The moon only has an albedo of 7% due to its dark surface and lack of atmosphereAs viewed from space the Earth is much brighter and more impressive than the moonSection 19.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.19 | *The Greenhouse EffectSection 19.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.19 | *Latent Heat of CondensationA great deal of evaporation occurs globally due to the insolation that reaches the surfaceTherefore, enormous quantities of latent heat is transferred into the atmosphere as this energy is released during the condensation of the gaseous water into clouds, fog, rain, dew, etc.Section 19.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.19 | *Fundamental Atmospheric MeasurementsTemperatureAir temperature measurements should not be taken when the thermometer is exposed to direct sunlightPressureHumidityWind Speed and DirectionPrecipitationSection 19.3Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.19 | *Air Motion in the AtmosphereWind the horizontal movement of air along the Earths surfaceAir Currents vertical movement of air, broken down into updrafts and downdraftsAtmospheric gases within the atmosphere are subject to two primary forcesGravityPressure differences due to temperature variationsSection 19.4Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.19 | *IsobarsWind direction will always be at right angles to the isobar and in the direction of the lower pressureSection 19.4Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.19 | *Earths General Circulation PatternAlthough many local variations occur within the cells, the prevailing winds of this semi-permanent circulation structure are important in influencing general weather movement around the globe Section 19.4Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.20 | *CondensationWater droplets do not form randomly, but form around microscopic foreign particles called hygroscopic nuclei present in the airHygroscopic nuclei may consist of dust, smoke, soot, salt, or other small airborne particlesSince droplets form around these hygroscopic nuclei, condensation provides a mechanism for cleansing the atmosphereIf the proper type/size of airborne particles are not present, condensation may not occur or will be retardedSection 20.1Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.20 | *The Bergeron ProcessThe mixing of ice crystals and supercooled water vapor lead to the production of large ice crystals These large ice crystals will then melt into large droplets of water in the lower portion of the cloud, coalesce, and fall as precipitationSection 20.1Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.20 | *Air MassesThe general weather conditions at any given place depend largely on vast air masses that move across the countryAir mass a large body of air that takes on physical characteristics that distinguish it from the surrounding airThe main physical characteristics the distinguish an air mass are temperature and moisture contentSection 20.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.20 | *Air-Mass Source RegionsAir masses that affect North AmericaSection 20.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.20 | *Cold and Warm FrontsCold fronts generally form a sharp, steep boundary where the lighter warm air is displaced upward. As a result, cold fronts are accompanied by more violent and sudden changes in weather.Warm fronts form a more gradual boundary because it is more difficult for the lighter warm air to displace the denser cold air.Section 20.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.20 | *TornadoesTornado the most violent of stormsAlthough tornadoes may not be as large as other storms, its concentrated energy results in great destructive potentialTornadoes are most common in the U.S. and AustraliaMost tornadoes in the U.S. occur between the Rockies and AppalachiansApril, May, and June are the peak times for tornadoes in the U.S.Section 20.3Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.20 | *Tropical StormsTropical storm a massive weather disturbance that forms over tropical oceanic regionsTropical storms are classified as hurricanes once their wind speed exceeds 119 km/h (74 mi/h)Hurricane diameters range from 480 to 960 km and their wind speeds range from 118 to 320 km/hSection 20.3Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.20 | *Temperature InversionNormally the lapse rate near the Earths surface decreases uniformly with altitudeA temperature inversion exists when near the surface the temperature locally increases with increasing altitudeSection 20.4Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.20 | *Air Pollutants and Their Major SourcesNote that transportation is the largest contributor to air pollutionThe particulates emitted from industrial processes include a number of harmful metals, including Pb and AsStationary sources refer mainly to power generation plantsSection 20.4Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.21 | *MineralsMineral a naturally occurring, inorganic, crystalline (solid) substance consisting of one or more chemical elements in fairly specific proportions with a distinctive set of physical propertiesMinerals are around us everywhere some are quite valuable (diamond, sapphires, emeralds) other minerals are very common (calcite, quartz.)Mineralogy the study of mineralsSection 21.1Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.21 | *Relative Abundance by Mass of Elements in the Earths CrustOnly two elements, O & Si, account for 74% of the elements (by mass) in the Earths crust.Section 21.1Section 21.1Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.21 | *Identification of MineralsMineral classification is based on both physical and chemical properties.This is advantageous because there are some minerals that have the same chemical formula but different molecular structures.For example the two minerals graphite and diamond are both made of pure C but they are dramatically different minerals.Pure diamond is very hard, clear, and crystalline.Pure graphite is soft and black (dry lubricant and pencil lead.)Section 21.1Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.21 | *Physical Properties - SummaryCrystal formHardnessCleavageFractureColorStreakLusterSpecific gravityCopyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.21 | *Igneous RocksIgneous rock a type of rock formed from a molten material that has cooled and solidifiedMagma molten rock material that originates deep within the EarthRocks that solidify from a magma, beneath the Earths surface, are called intrusive igneous rocks.Lava molten rock material that reaches the Earths surface due to a volcanic eruptionRocks that solidify from lava, at the surface, are called extrusive igneous rocks.Section 21.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.21 | *Sedimentary RocksSedimentary rock rocks that form at or very near the surface of the Earth due to compaction and cementation of sedimentsThe sediments that comprise sedimentary rocks come from three general sources:Rock fragments due to the erosion of preexisting (older) rocksMinerals chemically precipitated from solutionPlants or animal remains (fossils)Section 21.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.21 | *Metamorphic RocksMetamorphic rock forms by the alteration of a preexisting rock due to the effects of pressure, high temperature, and/or a chemical changeMetamorphism generally occurs well below the surface of the Earth but at shallower depths and temperatures than would cause the rock to melt.Section 21.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.21 | *UniformitarianismBeginning with the Scottish physician/scientist James Hutton, scientists started to realize that ancient rocks were formed the same way as modern rocks.Since they were formed the same way, they can be interpreted similarly.Uniformitarianism geologic processes occurring today operated similarly in the past and can therefore be used to explain past geologic eventsThe present is the key to the pastSection 21.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.21 | *The Rock CycleSection 21.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.21 | *Plate TectonicsThe prediction of individual volcanic eruptions is generally not possible.However we are aware of specific trends where volcanic eruptions typically do occur.Most active volcanoes are located along linear zones, particularly along the margins of the Pacific Ocean.The so-called ring of fireThe theory of plate tectonics can explain why volcanoes occur where they do.Section 21.3Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.21 | *Plate TectonicsAccording to the Theory of Plate Tectonics the solid outermost shell of the Earth is called the lithosphere.The lithosphere is separated into several large and small fragments, called plates.The rigid lithosphere rests or floats on a semimolten layer called the asthenosphere.We will study plate tectonics in greater detail in the next chapter. According to plate tectonics the lithospheric plates slowly move over the semimolten asthenosphere.Section 21.3Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.21 | *Plate BoundariesThe lithospheric plates interact with each other in three basic ways:Convergent boundary two plates move towards each otherDivergent boundary two plates move away from each otherTransform boundary two plates slide past each otherThe vast majority of the volcanoes on Earth occur at convergent boundaries.Section 21.3Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.21 | *Magma ViscosityMagma viscosity, in turn, is dependent on two factors: 1.temperature and 2.silica contentThe higher the temperature the lower the viscosity. (flows easier)In general magmas that originate deep within the Earth have higher temperatures.The higher the silica content the higher the viscosity. (more difficult to flow)In general magmas that originate at shallow depths have a higher silica content.Section 21.4Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.22 | *Continental DriftFormulation of the TheoryAs one looks at a current world map, it is apparent that the coastlines of eastern South America and western Africa fit together fairly well.Is this a coincidence or were these two and the other continents once attached?Over the past several hundred years scientists have speculated as to the meaning of this observation. Have the continents drifted?Section 22.1Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.22 | *Seafloor SpreadingIn 1960, the American geologist Harry Hess suggested a viable mechanism that could explain continental drift.At the time the mid-ocean ridge system and the deep sea trenches had been mapped in fair detail throughout the worlds oceans.The mid-ocean ridge system was known to stretch throughout the world.The trenches were known to be very deep and very long and narrow.Section 22.1Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.22 | *Plate TectonicsWe now visualize ocean basins to be in a constant cycle with new crust being created at the mid-ocean ridges and old crust descending along the ocean trenches.We also know that the lithosphere is composed of a series of solid segments called plates.These plates are constantly moving and interacting with other plates.The theory of plate tectonics encompasses all these processes.The lithosphere is divided into approximately 20 plates.Section 22.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.22 | *Section 22.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.22 | *Causes of EarthquakesEarthquakes are most likely to occur along plate boundaries.Stresses are exerted on the rock formations in adjacent plates, as movement occurs.Since rock possess elastic properties, energy is stored until the stresses can overcome the friction between the two plates.At the moment of energy release, the rocks along the fault suddenly move, the energy is released, and an earthquake occurs.Section 22.3Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.22 | *Anatomy of an EarthquakeSection 22.3Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.22 | *SeismographDuring a quake, the spool vibrates and the light beam is relatively still.Section 22.3Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.22 | *Seismic Wave Travel Through the Earths InteriorS waves do not travel through the liquid outer core.P waves are refracted at density boundaries.Section 22.3Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.22 | *Fault Terminology IllustratedSection 22.4Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.24 | *FossilsFossil any remnant or indication of past life that is preserved in rockPaleontology - the study of fossils.The study of fossils is of great interest to both geologists and biologists.Paleontologists combine present-day biologic information with ancient fossil and rock data to make an interpretation of past events and environments.Section 24.1Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.24 | *Principle of SuperpositionPrinciple of superposition in a sequence of undisturbed sedimentary rocks, lavas, or ash the oldest layer is on the bottom with each ascending layer progressively youngerIn other words, the bottom layer was deposited first and is therefore the oldest layer; the top layer was deposited last and is therefore the youngest layer.If the layers have been disturbed (faulted or folded) this must be taken into account.Section 24.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.24 | *Principle of Cross-Cutting RelationshipsPrinciple of cross-cutting relationships an igneous rock is younger than the rock layers that it has intrudedThis principle also applies to faults and folds, where the fault or fold is younger than any rocks that are affected.Section 24.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.24 | *Index FossilsIndex fossils fossils that are wide-spread in distribution, easily identified, and limited to a particular time segment of the Earths historyThese fossils can be of major assistance during the process of correlation.Once a particular index fossil has been thoroughly established, geologists immediately know the age of any rocks containing this index fossil anywhere in the world.Section 24.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.24 | *Relative Geologic Time ScaleEons are divided into eras.There are three eras contained within the Phanerozoic Eon:Paleozoic Era the oldest and age of ancient lifeMesozoic Era the age of reptilesCenozoic Era the youngest and age of mammalsSection 24.2Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.24 | *Geologic Time ScaleTime is given in millions of years before present, along with major geologic and biologic eventsSection 24.5Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Copyright Houghton Mifflin Company. All rights reserved.Copyright Houghton Mifflin Company. All rights reserved.1| *Copyright Houghton Mifflin Company. All rights reserved.

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