PHY 102 1st Edition Outline of Last Lecture I Review a Hubble Constant b Big Bang c Radiation d Matter condenses II Specific Laws a Weir s Law b Stefan Boitzmann Law III Expansion and Olber s Paradox IV Echo of the Big Bang Outline of Current Lecture I Big Bang Review II The First Epoch a Temperature not time b Predictions III Standard Model s Cosmic Zoo a Quarks b Radiation IV The Second Epoch 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 V The Third Epoch VI The Fourth Epoch VII The Fifth Epoch VIII Proton Proton Reaction IX The Sixth Epoch X The Seventh Epoch XI Summary Current Lecture I Big Bang Review a Evidence for the Big Bang i Hubble s law v HR shows that galaxies at greater distances move faster ii 2 7k scosmic background radiation iii Look back time shows evolution iv Theoretical models of the universe are consistent with observations b The expansion age of the universe is 1 H which gives 13 8 billion years c Farther out you go the further back in time you go II The First Epoch 1014K T infinity a Considerations i Time is not as important as temperature because temperature determines makeup of the universe 1 Astronomers do not understand the beginning of the universe 2 Temperatures at the beginning were near infinity ii Predictions do appear to match observations b Ignoring details for a moment radiation quickly condenses into quarks leptons and bosons c Quarks become hadrons with the number of matter particles slightly outnumbering the anti particles due to CP charge conjugation parity violation i Quarks are the smallest particle of matter if one can even say that d The universe is expanding and the material in the universe is simply being carried along by the expansion III Standard Model s Cosmic Zoo a Quarks are the building blocks of hadrons baryons mesons i We have never looked inside of a proton to see the quarks but from indirect observation we know they exist b Quarks have various intrinsic properties including electric and color charge mass and spin c They are never directly observed or found in isolation today due to their high threshold temperatures d Each quark and lepton has its own antiparticle e Gauge bosons are force carriers f Geiger Counter i We are being showered with radiant particles as they approach the speed of light ii We might have very highly energized objects hitting the atmosphere and showering the earth with highly charged particles IV The Second Epoch 1012K T 1014K a As space expands and temperature drops a few nanoseconds after BB quarks and anti quarks begin to separate and experience the strong nuclear force mediated by the gluons force carriers due to symmetry breaking i Einstein went to President and said to have discovered the atomic bomb based on e mc2 ii By 1947 a nuclear bomb was used b Radiant Energy flows from the antiquarks to the quarks i The forces that attract quarks is so strong that the only way to separate them is to be put under extremely high radiation pressure and extremely high temperature can t be done on earth c Quarks combine to form hadrons V Epoch 3 1010K T 1012K a The universe is now 1 10 000 seconds old b A small contamination of protons and neutrons due to their earlier formation from quarks c Radiant energy produces quarks quarks produce protons and neurons VI Epoch 4 109K T 1010 K a One second has passed since the Big Bang b The universe is composed mostly of electrons positrons 3 types of neutrinos photons and a small amount of protons and neutrons i There are roughly the same number of protons as there are electrons ii Electrons pull into the nuclei and allow a burst of radiation to scatter through the universe decoupling c Electrons actually form a fog which scatters light d Overall density of the universe has dropped and neutrinos decouple from matter e At the end of this period anti matter has pretty much disappeared due to CP violation matter now dominates VII Epoch 5 108K T 109K a 3 minutes after Big Bang b Photons and neutrinos still dominate c Protons and neutrons start to interact with each other d Nuclear particles 87 protons 13 neutrons e Universe cooks protons and neutrons producing alpha particles the nuclei of He in the proton proton reaction f At the end the main mass of the universe is 74 H nuclei and 26 He nuclei by mass 90 H and 10 He by number VIII Proton Proton Reactions a What powers the hydrogen bombs basically bring small suns to the surface of the earth b Process i Hydrogens floating around ii When they get close enough they exchange gluons iii Create positrons and neutrinos iv Mass is conserved by converting hydrogen to helium and the rest of the mass is antimatter neutrinos and positrons c During WWII Germans were using water and pulled out the deuteron from the water in order to attempt a nuclear bomb IX Epoch 6 15 000 K T 108K a About 5 hours after the big bang b H and He nuclei and electrons are immersed in a sea of photons c 1 6 billion photons for every nucleon a ratio that remains fixed even today d Universe still dominated by neutrinos and radiation e Electromagnetic radiation trapped due to scattering processes with charged particles X Epoch 7 3 000 K T 15 000 K a 25 000 years after big bang b Matter begins to dominate c Temperature drops XI Summary I a The cause of the Big Bang is unknown to scientists b It began with pure radiant energy c One could not have stood outside and watched the Big Bang as space was part of the Big Bang as well d As the universe expanded and cooled matter formed according to Einstein s equation E mc2 e Among the first particles to form were electrons and quarks quarks later formed the nucleons e g protons neutrons in equal amounts both matter and antimatter f It is not well understood why matter dominates today one possible answer is the CP violation g As the universe continued to expand and cool radiation became decouple d from matter and that is the origin from cosmic background radiation h The cosmic radiation is seen as highly red shifted today due to the expansion of the universe and has a black body temperature of 2 725 K observed i The early protons and neutrons fused to form He nucleus via the proton proton reaction and limited amounts j The universe becomes 90 H and 10 He by number k Stars and galaxies form and we see the universe we do today