Solutions Manual
Earth Portrait of a Planet 5th Edition
by Stephen Marshak All Chapters Covered
, CHAPTER 1m
Cosmology and the Birth of Earth
m m m m m
LearningmObjectives
1. StudentsmshouldmbemawaremofmthemBigmBangmtheorymandmthemmajormevidenc
emsupportingmit.mDistantmgalaxiesmaremuniformlymred-
shiftedmrathermthanmblue-
m shifted;mthismimpliesmthatmtheymaremallmmovingmawaymfrommus.mThemfarthest
m galaxiesmaremthosemthatmaremmostmstronglymred-
shifted,mmeaningmthatmtheymaremrecedingmthemfastest.mExtrapolationmofmvelo
citiesmandmtrajectoriesmintomthempastmsuggestsmthatmallmmatterminmthemUniver
semwasmcontainedminmamsinglempoint,mapproximatelym13.7mbillionmyearsmago.
m Atmthatmtime,mthemUniversemexplosivelymcamemintomexistence.
2. Stars,mincludingmourmSun,maremnuclearmfusionmreactors.mFormmostmofmtheirmlifem
historiesm(onmthemordermofmbillionsmofmyears),mhydrogenmatomsmaremfusedmtoget
hermtomformmhelium.mLatermstagesminmstellarmevolutionmincludemfusionmofmheliu
mmatomsmandmother,mheaviermelements;multimately,mironmismthemheaviestmelem
entmthatmcanmbemproducedmthroughmfusionmreactionsmwithinmstars.
3. Aftermtheirmcyclesmofmfusionmaremcomplete,mlargemstarsmviolentlymexplodem(for
mingmsupernovae),mproducingmelementsmheaviermthanmironmandmleavingmbehin
dmamresiduemofmdiffusemnebulae,mwhichmmaymbemrecycledmtomformmamnewmstarm
atmsomempointminmthemfuture.
4. OurmSolarmSystemmismapproximatelym4.57mGam(billionmyearsmold).mAllmeightmpla
netsmrevolvemaroundmthemSunminmcoplanar,mellipticalmorbits.mAllmplanetsmorbitm
inmthe
, samemdirectionm(counterclockwisemasmviewedmfrommabovemEarth’smNorthmPole
).mThesemfactsmimplymsimultaneousmplanetarymformationmfrommamswirlingmnebu
lamsurroundingmthemSunm(themsimilaritiesminmorbitsmwouldmthenmbemamnaturalmre
sultmofmconservationmofmangularmmomentum).mThemplanetsmaccretedmfrommthis
m nebulamthroughmgravitationalmattractionmandmhaphazardmcollisions.mPluto,mlon
g
consideredmthem“ninthmplanet,”mhasmseenmitsmstatusmdemoted;mastronomersmno
w
recognizemeightmmajormplanets.
5. Themterrestrialmplanetsm(Mercury,mVenus,mEarth,mandmMars)maremrelativelymsma
ll,mdense,mandmrockymworlds.mThemgiantmplanetsmarempredominantlymcomposed
mofmthemlightmgasesmhydrogenmandmheliumm(JupitermandmSaturn)mormicesm(Uranu
smandmNeptune);mtheymaremmuchmlargermandmmuchmlessmdensemthanmthemterre
strialmplanets.
6. OurmMoonmismchemicallymsimilarmtomthemEarth’smmantle.mThemMoonmismthoug
htmtomhavemoriginatedmfrommdebrismaccumulatedmwhenmamprotoplanetmcollid
edmwithmEarthmapproximatelym4.3mGa.
SummarymfrommthemText
ThemgeocentricmmodelmplacedmEarthmatmthemcentermofmthemUniverse,mwithmthempl
anetsmandmSunmorbitingmaroundmthemEarthmwithinmamcelestialmspheremspeckledmwithms
tars.mThemheliocentricmmodel,mwhichmgainedmacceptancemduringmthemRenaissance,mp
lacedmthemSunmatmthemcenter.
EratosthenesmwasmablemtommeasuremthemsizemofmEarthminmancientmtimes,mbutmitm
wasmnotmuntilmfairlymrecentlymthatmastronomersmaccuratelymdeterminedmthemdistances
tomthemSun,mplanets,mandmstars.mDistancesminmthemUniversemaremsomlargemthatmtheym
m
mustmbemmeasuredminmlight-years.
ThemEarthmismonemofmeightmplanetsmorbitingmthemSun,mandmthismSolarmSystemmlies
m onmthemoutermedgemofmamslowlymrevolvingmgalaxy,mthemMilkymWay,mwhichmismcompose
dmofmaboutm300mbillionmstars.mThemUniversemcontainsmatmleastmhundredsmofmbillionsmof
galaxies.
m
Themredmshiftmofmlightmfrommdistantmgalaxies,mammanifestationmofmthemDopplermeff
, ect,mindicatesmthatmallmdistantmgalaxiesmaremmovingmawaymfrommEarth.mThismobservatio
nmleads
Earth Portrait of a Planet 5th Edition
by Stephen Marshak All Chapters Covered
, CHAPTER 1m
Cosmology and the Birth of Earth
m m m m m
LearningmObjectives
1. StudentsmshouldmbemawaremofmthemBigmBangmtheorymandmthemmajormevidenc
emsupportingmit.mDistantmgalaxiesmaremuniformlymred-
shiftedmrathermthanmblue-
m shifted;mthismimpliesmthatmtheymaremallmmovingmawaymfrommus.mThemfarthest
m galaxiesmaremthosemthatmaremmostmstronglymred-
shifted,mmeaningmthatmtheymaremrecedingmthemfastest.mExtrapolationmofmvelo
citiesmandmtrajectoriesmintomthempastmsuggestsmthatmallmmatterminmthemUniver
semwasmcontainedminmamsinglempoint,mapproximatelym13.7mbillionmyearsmago.
m Atmthatmtime,mthemUniversemexplosivelymcamemintomexistence.
2. Stars,mincludingmourmSun,maremnuclearmfusionmreactors.mFormmostmofmtheirmlifem
historiesm(onmthemordermofmbillionsmofmyears),mhydrogenmatomsmaremfusedmtoget
hermtomformmhelium.mLatermstagesminmstellarmevolutionmincludemfusionmofmheliu
mmatomsmandmother,mheaviermelements;multimately,mironmismthemheaviestmelem
entmthatmcanmbemproducedmthroughmfusionmreactionsmwithinmstars.
3. Aftermtheirmcyclesmofmfusionmaremcomplete,mlargemstarsmviolentlymexplodem(for
mingmsupernovae),mproducingmelementsmheaviermthanmironmandmleavingmbehin
dmamresiduemofmdiffusemnebulae,mwhichmmaymbemrecycledmtomformmamnewmstarm
atmsomempointminmthemfuture.
4. OurmSolarmSystemmismapproximatelym4.57mGam(billionmyearsmold).mAllmeightmpla
netsmrevolvemaroundmthemSunminmcoplanar,mellipticalmorbits.mAllmplanetsmorbitm
inmthe
, samemdirectionm(counterclockwisemasmviewedmfrommabovemEarth’smNorthmPole
).mThesemfactsmimplymsimultaneousmplanetarymformationmfrommamswirlingmnebu
lamsurroundingmthemSunm(themsimilaritiesminmorbitsmwouldmthenmbemamnaturalmre
sultmofmconservationmofmangularmmomentum).mThemplanetsmaccretedmfrommthis
m nebulamthroughmgravitationalmattractionmandmhaphazardmcollisions.mPluto,mlon
g
consideredmthem“ninthmplanet,”mhasmseenmitsmstatusmdemoted;mastronomersmno
w
recognizemeightmmajormplanets.
5. Themterrestrialmplanetsm(Mercury,mVenus,mEarth,mandmMars)maremrelativelymsma
ll,mdense,mandmrockymworlds.mThemgiantmplanetsmarempredominantlymcomposed
mofmthemlightmgasesmhydrogenmandmheliumm(JupitermandmSaturn)mormicesm(Uranu
smandmNeptune);mtheymaremmuchmlargermandmmuchmlessmdensemthanmthemterre
strialmplanets.
6. OurmMoonmismchemicallymsimilarmtomthemEarth’smmantle.mThemMoonmismthoug
htmtomhavemoriginatedmfrommdebrismaccumulatedmwhenmamprotoplanetmcollid
edmwithmEarthmapproximatelym4.3mGa.
SummarymfrommthemText
ThemgeocentricmmodelmplacedmEarthmatmthemcentermofmthemUniverse,mwithmthempl
anetsmandmSunmorbitingmaroundmthemEarthmwithinmamcelestialmspheremspeckledmwithms
tars.mThemheliocentricmmodel,mwhichmgainedmacceptancemduringmthemRenaissance,mp
lacedmthemSunmatmthemcenter.
EratosthenesmwasmablemtommeasuremthemsizemofmEarthminmancientmtimes,mbutmitm
wasmnotmuntilmfairlymrecentlymthatmastronomersmaccuratelymdeterminedmthemdistances
tomthemSun,mplanets,mandmstars.mDistancesminmthemUniversemaremsomlargemthatmtheym
m
mustmbemmeasuredminmlight-years.
ThemEarthmismonemofmeightmplanetsmorbitingmthemSun,mandmthismSolarmSystemmlies
m onmthemoutermedgemofmamslowlymrevolvingmgalaxy,mthemMilkymWay,mwhichmismcompose
dmofmaboutm300mbillionmstars.mThemUniversemcontainsmatmleastmhundredsmofmbillionsmof
galaxies.
m
Themredmshiftmofmlightmfrommdistantmgalaxies,mammanifestationmofmthemDopplermeff
, ect,mindicatesmthatmallmdistantmgalaxiesmaremmovingmawaymfrommEarth.mThismobservatio
nmleads
