The Emergence of Science: The Standard Model of Cosmology Ubi - PowerPoint PPT Presentation

The Emergence of Science: The Standard Model of Cosmology Ubi Wichoski Laurentian University Ubi Wichoski By Anonymous - Camille Flammarion, L'Atmosphère: Météorologie Populaire (Paris, 1888), pp. 163., Public Domain, https://commons.wikimedia.org/w/index.php?curid=318054

Outlook • Philosophy and Cosmology • Early studies and discoveries • The scientific method and instrumentation • Cosmology as Science • Standard Model of Cosmology • The Standard Model of Particle Physics • Summary of the thermal history of the Universe • Precision era of Cosmology • What we know that we don’t know • What we don’t know that we don’t know • Conclusions 2 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Philosophy and Cosmology • The Universe has been a subject of study for millennia • What are the questions that have been asked? • Ultimately, what do we want to know? • What the means and methods that we have been employing? • What is progress? • Where do we stand now? • How did we get here? 3 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Early studies and discoveries • Aristotle and the Greeks: The Universe • Astronomers: Eudoxus, Callippus à Spheres à Aristotle à Physical model of the Universe • Aristotle epistemology: based on the study of things that exist or happen in the world à the knowledge of the universal is achieved by induction from the knowledge of the particular, and the use of deduction • Unaided observation of the sky • 5 planets known: Mercury, Venus, Mars, Jupiter and Saturn • Moon • Sun • Star shell Ptolemy, Hipparchus à Epicycles à explains the retrograde motion of the planets 4 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Early studies and discoveries • Aristotle and the Greeks: The Universe • Epicycles à very convoluted model • Spherical Earth • Antikythera à complexity only matched by devices in the 14 th century J. Ferguson (1710-1776), based on diagrams by G. Cassini (1625-1712) Antikythera: used to predict astronomical positions Universe: Geocentric, eternal and finite distinction between here and beyond 5 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Early studies and discoveries • Aristotle and the Greeks: Matter • Democritus à Atomism Aristotle's elements Possible Element Hot/Cold Wet/Dry Mo1on associa1on • What is matter made of? Earth Cold Dry Down Solid • What is the Universe made of? Water Cold Wet Down Liquid Air Hot Wet Up Gas • Content difference between here and beyond Fire Hot Dry Up Plasma (divine Circular Aether — Dark energy?? substance) (in heavens) Example of a syllogism • Syllogism: Type of proof In words In terms All men are mortal. M a P All Greeks are men. S a M All Greeks are mortal. S a P Dark ages à Earth is flat again 6 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Early studies and discoveries • Copernicus and Galileo: The Universe • Universe: Heliocentric, rebirth of science • Experimentation à Knowledge through measurements • Instrumentation à Telescope • Unaided observations à not accurate data Heliocentric Universe: easier to explain the retrograde motion of the planets 7 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Early studies and discoveries • Newton and Maxwell: The Universe • Universe: Heliocentric, infinite, absolute time • Experimentation à Knowledge through measurements • Instrumentation à Better instruments, better knowledge of the solar system • More and more accurate data • New theories Newton: Theory of Gravitation Pillars of Classical Physics Maxwell: Electromagnetic theory 8 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Early studies and discoveries • Newton and Maxwell: Matter Newton: Theory of Gravitation And beyond… Maxwell: Electromagnetic theory What are atoms made of? Democritus à Newton/Maxwell à Thomson à Rutherford à Bohr…. … Quantum Mechanics, ParUcle Physics… * NegaUve electrons orbiUng posiUve nuclei * NegaUve electrons orbiUng nuclei made of protons and neutrons * Protons and neutrons are made of quarks 9 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Early studies and discoveries • Newton and Maxwell: Matter Newton: Theory of Gravitation And beyond… Maxwell: Electromagnetic theory What are atoms made of? Democritus à Newton/Maxwell à Thomson à Rutherford à Bohr…. … Quantum Mechanics, ParUcle Physics… * NegaUve electrons orbiUng posiUve nuclei * NegaUve electrons orbiUng nuclei made of protons and neutrons * Protons and neutrons are made of quarks 10 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Early studies and discoveries ScienUfic Method • Observations • Controlled experiments Scientific theories do not represent • Measurement • Uncertainty the absolute truths • Scientific theories are provisional • explanations consistent with the available evidence DATA This also applies to the Scientific • Method itself PREDICTIONS PATTERNS Scientific theories HYPOTHESIS 11 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Cosmology as Science Reaching beyond the solar system: W. Herschel • Milky Way à a separate “Island Universe” • Observation of thousands of “Island Universes” à distant galaxies, nebulae, supernova remnants (1783) Nebula: Island universes Later (1850) à Spiral structure of nearby galaxies • Confirmed by Hubble (1924) as extragalactic objects • 12 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Standard Model of Cosmology Observa1onal basis § Expansion of the Universe § Cosmic Microwave Background (CMB) § Primordial Nucleosynthesis § Large Scale Structure § AcceleraUon 13 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Standard Model of Cosmology t R(t 3 ) Hubble 1920: linear relaUonship R(t 2 ) between velocity that the galaxies recede from us and their distance R(t 1 ) 14 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Standard Model of Cosmology WMAP PLANCK 2009 15 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Standard Model of Cosmology CMB monopole à T = 2.725 K NASA / WMAP Science Team Preferred Referential CMB dipole à T = 3.353 mK Blue = 2.721 K and Red = 2.729 K 16 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Standard Model of Cosmology Primordial Nucleosynthesis … 17 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Standard Model of Cosmology Structure formation ESA – C. Carreau NASA, ESA, G. Illingworth, D. Magee, and P. Oesch (University of California, Santa Cruz), R. Bouwens (Leiden University), and the HUDF09 Team 18 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Standard Model of Cosmology Accelerating expansion NASA/STSci/Ann Feild MD DE RD 0 ~ 6000 yr R(t) ~now 19 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Standard Model of Cosmology Theore1cal basis § Cosmological Principle § General RelaUvity § Geometry of the spaceUme § Perfect Fluid descripUon of ma\er § Standard Model of ParUcle Physics 20 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Standard Model of Cosmology Cosmological Principle Observations To a good approximation on Large Scale Structure (LSS) large scales the Universe is data shows no structure on homogeneous and isotropic scales greater than 100 Mpc There are no privileged CMB is homogeneous and positions or directions isotropic better to 1 part in 10,000 21 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Standard Model of Cosmology Geometry of the spatial sections 22 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology

Standard Model of Cosmology General Relativity The presence of ma\er (energy) makes the spaceUme curved Le] hand side: “ Geometry ” Right hand side: “ Physics ” 1 G R g R 8 G T g ≡ − = π + Λ µ ν µ ν µ ν µ ν µ ν 2 23 UW - Oct. 2, 2019 Lecture Series: Philosophy and Cosmology