AST 105 1st Edition Final Exam Study Guide Important Summary for Final Exam Quiz 9 The local group is the name of the cluster that our galaxy the Milky Way belongs to Hubble s law of expansion is the mathematical expression for the recessional velocity of galaxies as a function of distance We know that the universe is expanding because light from the most distant galaxies is redshifted Quasars Blazars and Radio Galaxies are all basically the same but viewed at different angles Quiz 10 Based upon the rate of expansion using the Hubble constant the age of the universe is about 14 billion years old The beginning of the universe and the theory of the evolution of the universe goes by the name the Big Bang Theory During the 1980 s Alan Groth introduced a modification to explain the horizon problem He called this modification inflation Again we know that the universe is expanding because light from distant objects is red shifted Quiz 11 The strong force is responsible for binding together quarks to form protons and neutrons also binds protons and neutrons to form nuclei An isolated neutron decays into a proton electron and neutrino If there is significant matter in the universe the outward expansion will eventually halt reverse direction and the universe will end up as big crunch The electromagnetic force and the weak force become the same force at higher temperatures or higher energies This force is called the electroweak Important People Tully and Fisher Tully and Fisher relation broader line brighter galaxy in terms of 21 cm hydroflip line These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Tully Fisher Law Hubble Hubble s law Hubble s constant Universe is expanding cosmological red shift Baade and Minkowski Photographed Cyngas A in 1951 Einstein General relativity Original formula for cosmology Penzias and Wilson Detected CMBR 1st real evidence in support of Big Bang Alan Guth Proposed inflation solved horizon problem Max Planck Energy of a photon Freynman Diagram for quantum electro dynamics Steven Weinberg Recognized W boson behaves like a photon in the 1970 s Recognized that could reproduce neutron decay w altered Freynman Diagram Larry Krauss Particle physicist Quintessence new theory that is an alternative theory to vacuum energy gets rid of fine tuning Topic Summaries for Exam 3 Age of Universe About 14 billion years old Based upon the rate of expansion using Hubble s constant the age of the universe is about 14 billion years old The universe began as a very small dense region of compressed energy Outward expansion here is known as the Big Bang Universe is expanding because light from distant objects is red shifted Time distance velocity Age distance traveled velocity o separation distance recessional velocity H0 72 km sec per MpC Alan Guth Introduced inflation During the 1980 s specifically 1981 Alan Guth introduced a modification to explain the horizon problem He called this modification inflation Universe expanded rapidly during this inflation period perhaps greater than the speed of light See inflation Big Bang Theory The beginning of the universe and the theory of the evolution of the universe goes by the Big Bang Theory Outward explosion of the universe Scientific theory that predicts what the universe was like early in time All the matter in our observable universe came into being at a single moment in time as an extremely hot dense mixture of subatomic particles and radiation The Big Bang the name given to the event thought to mark the birth of the universe Big Crunch Name given to the event that would presumably end the universe if gravity ever reverses the universal expansion and the universe someday begins to collapse A re collapsing universe w all the matter collapsed together If there is significant matter in the universe the outward expansion will eventually halt reverse direction and the universe will end up as a Big Crunch Contraction of the universe implies the Big Crunch If the expansion velocity is to small the universe will collapse and end in a big crunch Blazars Quasars Blazars and radio galaxies are all basically the same but viewed at different angles High luminosities more signal Where located relative to spin axis helps determine whether Quasar Blazar or radio galaxy o If 00 Blazar Clusters Mutually attracted due to their gravity Due to general relativity they cause space to blur distort light We can use clusters as magnifying glasses into the past Due to long range gravity planets orbit each other in groups Collection of galaxies bound together by gravity Smaller collections of galaxies are called groups The Local Group is the name of the cluster that our galaxy the Milky Way belongs to Superclusters Clusters combined with each other Gravitational attraction much stronger The largest known structures of the universe consisting of many clusters of galaxies and individual galaxies Cosmic Microwave Background Radiation CMBR Remnant radiation from the Big Bang We detect CMBR using radio telescoped sensitive to microwaves which are short wavelength radio waves Perfectly isotropic intensity is the same in all directions 1965 Penzias and Wilson detected CMBR 1 st evidence is support of Big Bang o 1 mm signal wavelength detected Cosmological Constant name given to term in Einstein s equations of General Relativity if it is not zero then it represents a repulsive force or a type of energy sometimes called dark or quintessence that might cause the expansion of the universe to accelerate with time Today data tells us that the universe has acceleration to the expansion To account for this we must add the cosmological constant back into the equation Represents the energy of space Cosmological Red Shift The red shift we see from distant galaxies caused by the fact that expansion of the universe stretches all the photons w in it to longer redder wavelengths We know that the universe is expanding because light from the most distant galaxies is red shifted The further out the more red shift Shift to the right red shift moving away Via Hubble Used Doppler formula red shift recessional velocities Space time is expanding hence wavelengths increase Produce red shift expansion of space time itself produces the cosmo red shift Cosmology Study of the overall structure and evolution of the universe Origin evolution current structure and fate Einstein s GR is framework for