The Universal Context of Life (Chap 3 – Bennett & Shostak)Overview of Chapter 3Overview of Chapter 3Food for thought...1st Law of Thermodynamics2nd Law of ThermodynamicsPhases and Phase DiagramPlanck’s Radiation CurvesWien’s LawStefan-Boltzmann LawDoppler ShiftThe Birth of Stars Like Our SunThe Structure of Stars Like Our SunHow Bright is It?How Hot Is It?Classes for SpectraH-R DiagramDeath of Stars like SunGalaxiesThe Big BangThe Big Bang Summary TimescaleThe Evidence So FarCosmic BackgroundWhat CMB means?Putting it into contextThe CMB remainder...Question for ThoughtQuestion for ThoughtQuestion for ThoughtQuestion for ThoughtQuestion for ThoughtQuestion for ThoughtQuestion for ThoughtQuestion for ThoughtQuestion for ThoughtQuestion for ThoughtQuestion for ThoughtQuestion for ThoughtQuestions to ConsiderObservations to be ExplainedObservations to be ExplainedAbundance of the Chemical ElementsLog Plot of AbundanceAnother Log ViewA Linear View of AbundanceAnother Linear ViewPlanetary SummaryOther Planet ObservationsSome ConclusionsNebular Condensation PhysicsNebular Condensation ChemistryNebular Condensation (protoplanet) ModelA Pictorial ViewPictorial View ContinuedHST Pictorial Evidence?HST Pictorial Evidence?More Pictorial EvidenceNebular Condensation SummaryThe Universal Context of Life (Chap 3 – Bennett & Shostak)1 February 2007 - Lecture 46 February 2007 – Lecture 5HNRS 228 - AstrobiologyProf. GellerOverview of Chapter 3The Universe and Life (3.1)Age, Size, Elements, LawsThe Structure, Scale, and History of the Universe (3.2)Planets, Solar System, Galaxy, Local Group, Supercluster, UniverseBig Bang Theory of creation of universe⌧Evidence for expansion, age and compositionThe Nature of the Worlds (3.3)The solar system and its formation (remember 227)Overview of Chapter 3A Universe of Matter and Energy (3.4)Atoms, Energy, Electromagnetic Radiation, SpectroscopyChanging Ideas about the Formation of the Solar System (3.5)Nebular Condensation ModelFood for thought...“The grand aim of all science is to cover the greatest number of empirical facts by logical deduction from the smallest number of hypotheses or axioms.”–Albert Einstein, 1950The Following Slides are from HONORS 2271st Law of ThermodynamicsIn an isolated system, the total amount of energy, including heat energy, is conserved.ENERGY IS CONSERVED2nd Law of ThermodynamicsTwo key componentsheat flows from a warmer body to a cooler bodyentropy increases remains constant or increases in timePhases and Phase DiagramPlanck’s Radiation CurvesA way to depict frequency (inverse of wavelength) versus intensityFrequencyIntensityWien’s LawPeak wavelength is inversely proportional to the temperature of the blackbodyIntensityFrequencyCooler BodyHotter BodyPeak WavelengthStefan-Boltzmann LawEnergy radiated by blackbody is proportional to the temperature to the 4th power•E = σ T4Energy vs. Temperature01000020000300004000050000600000246810121416TemperatureEnergyDoppler ShiftA change in measured frequency caused by the motion of the observer or the sourceclassical example of pitch of train coming towards you and moving awaywrt light it is either red-shifted (away) or blue-shifted (towards)The Birth of Stars Like Our SunGas cloud Fragmentation ProtostarKelvin-HelmholzContraction Hayashi Track Ignition Adjustment to Main SequenceThe Structure of Stars Like Our SunCoreRadiative ZoneConvective ZonePhotosphereChromosphereCoronaHow Bright is It?Apparent Magnitude (from Earth)Absolute MagnitudeHow Hot Is It?Remember Wien’s LawClasses for SpectraO,B,A,F,G,K,MThere are also subclasses 0…9H-R DiagramDeath of Stars like Sun Hydrogen Core Depletion  Hydrogen Shell Burning ("Red Giant Branch")  Helium Flash  Helium Core Burning/Hydrogen Shell Burning ("Helium MS" "Horizontal Branch")  Helium Core Depletion  Helium Shell Burning  Asymptotic Giant Branch  Planetary Nebula  White DwarfGalaxies Elliptical Galaxies S0 (lenticular) Galaxies Spiral Galaxies Barred-Spiral Galaxies Irregular GalaxiesThe Big BangThe Big BangSummary TimescaleEra Epochs Main Event Time after bangThe Vacuum Era Planck EpochInflationary EpochQuantumfluctuationInflation<10-43 sec.<10-10 sec.The Radiation Era Electroweak EpochStrong EpochDecouplingFormation ofleptons, bosons,hydrogen, heliumand deuterium10-10 sec.10-4 sec.1 sec. - 1 monthThe Matter Era Galaxy EpochStellar EpochGalaxy formationStellar birth1-2 billion years2-15 billion yearsThe DegenerateDark EraDead Star EpochBlack Hole EpochDeath of starsBlack holesengulf?20-100 billion yrs.100 billion - ????The Evidence So FarEvidence for a “Big Bang”expansion of the universe⌧Distant galaxies receding from us• everywhere the sameremnants of the energy from the “Big Bang”⌧a very hot body that has cooled• 2.7 K cosmic background radiationthe primordial abundance of chemical elementsCosmic BackgroundHow hot would the cosmic background radiation beclose to 3 K⌧first noticed by Penziasand Wilson⌧confirmed by COBE satellite• Mather and Smoot won 2006 Nobel Prize for thisWhat CMB means?Remember Wien’s LawRemember DopplerCOBE resultsPutting it into contextTaking the perspective of the universe with you at the centerThe CMB remainder...Using COBE DIRBE data for examining the fine differencesfine structure of the universe⌧led to the galaxies and their locationQuestion for ThoughtWhat is a light year and how is it defined?The light year is a unit of distance. It is defined as the distance traveled by light in a year, about 6 trillion miles or 10 trillion kilometers.Question for ThoughtWhy are astronomical distances not measured with standard reference units of distance such as kilometers or miles? Because astronomical distances are so large (1 ly = 9.5 x 1012km).Question for ThoughtWhich stars have the longest life span?The lowest mass stars have the longest life span. Red dwarfs can live 100 billion years. Stars like our Sun live about 10 billion years.Question for ThoughtWhat is the Hertzsprung-Russell diagram? What is its significance and how can it be used? Basically a plot of temperature vs. luminosity. You can determine the approximate age of a star cluster with an H-R Diagram. You can follow the life cycle of a star with an H-R Diagram.Question for