Where is the Universe?
Cosmological Cosmological QuestionsQuestions TemporalTemporal SpatialSpatial CompositionalCompositional TeleologicalTeleological
Behind physics is the more ancient and honorable traditionBehind physics is the more ancient and honorable traditionof attempts to understand where the world came from, whereof attempts to understand where the world came from, whereit is going, and why.it is going, and why.
P. J. E. PeeblesP. J. E. Peebles
Early ConceptionsEarly Conceptions BabylonianBabylonian EgyptianEgyptian HebraicHebraic Pre-SocraticPre-Socratic AristotelianAristotelian
Geocentric/AristotelianGeocentric/Aristotelian
Principle of Principle of PlenitudePlenitude
QuintessenceQuintessence
MedievalMedieval Dante’sDante’s
‘Moral’‘Moral’CosmologCosmologyy
GeocentriGeocentricc
TheologyTheology basedbased
Copernican CosmosCopernican Cosmos
Matter & SpaceMatter & Space
So, the Universe is……So, the Universe is……
Created?Created?
Changing?Changing?
M a y b M a y b ee . . . . . . . . . .
DEFINITELY DEFINITELY NOT!NOT!
Geometry 0Geometry 0
Uniform: homogeneous & isotropicUniform: homogeneous & isotropic Congruence geometryCongruence geometry
Euclidean (Euclid)Euclidean (Euclid) Spherical (Riemann)Spherical (Riemann) Hyperbolic (Gauss, Lobachevski, Bolyai)Hyperbolic (Gauss, Lobachevski, Bolyai)
Geometry 1Geometry 1 EuclideanEuclidean
1 parallel1 parallel
Triangle: 180Triangle: 180oo
C = C = ππ D D
Geometry 2Geometry 2 SphericalSpherical
0 parallels0 parallels
Triangle: >180Triangle: >180oo
C < C < ππ D D
Geometry 3Geometry 3 HyperbolicHyperbolic
∞ ∞ parallelsparallels
Triangle: <180Triangle: <180oo
C > C > ππ D D
Geometry Affects AppearanceGeometry Affects Appearance EuclideanEuclidean
SphericalSpherical
HyperbolicHyperbolic
EinsteinEinstein Special RelativitySpecial Relativity
Space-TimeSpace-Time General RelativityGeneral Relativity
Mass curves Mass curves SpacetimeSpacetime
Solutions of Einstein’s Solutions of Einstein’s Field EquationsField Equations Evolving universeEvolving universe
Cosmological Cosmological constantconstant
Evolving UniversesEvolving Universes
How much can we see?How much can we see?
Hubble’s LawHubble’s Law
V = HV = H0 0 DD
Everything recedes from everything!Everything recedes from everything!
Abundance of Light IsotopesAbundance of Light Isotopes
CCosmic osmic MMicrowaveicrowaveBBackground ackground RRadiationadiation
Tiny (significant) FluctuationsTiny (significant) Fluctuations
Hot Big Bang ModelHot Big Bang Model
ProblemsProblems Horizon Horizon
problemproblem
Flatness Flatness problemproblem
‘‘Goldilocks’ Goldilocks’ problemproblem
More?More?
InflationInflation
Ω = 1Ω = 1
Dark Matter: The EvidenceDark Matter: The Evidence ‘‘Peculiar’ motion of Peculiar’ motion of
stars (Oort)stars (Oort) Coma cluster Coma cluster
(Zwicky)(Zwicky)ClusterSimClusterSim
Galaxy rotationGalaxy rotation GalRotGalRot
Galaxy clustersGalaxy clusters SuperclustersSuperclusters
NGC3198
Dark Matter: What is it?Dark Matter: What is it?
Dark Matter Not Dark Matter
BaryonicBaryonic MACHOsMACHOs
PlanetsPlanetsBrown dwarfsBrown dwarfsRed dwarfsRed dwarfsBlack holesBlack holes
Hot gasHot gas
Non-BaryonicNon-Baryonic HDMHDM
NeutrinosNeutrinos CDMCDM
WIMPsWIMPsAxionsAxionsPhotinosPhotinosQuark nuggetsQuark nuggets
WhatWhat’s the Matter?’s the Matter?
Accidents HappenAccidents Happen
Find the SupernovaFind the Supernova
How It’s DoneHow It’s Done
SupernovaeSupernovae
SNAPSNAP
CMBCMB Penzias/WilsonPenzias/Wilson
COBECOBE
BoomerangBoomerang
WMAPWMAP
Dark EnergyDark Energy Cosmological Cosmological
constant (constant (ΛΛ) or ) or vacuum energyvacuum energy constantconstant
QuintessenceQuintessence DynamicDynamic EvolvingEvolving Spatially Spatially
dependentdependent
k-essencek-essence ““tracker” fieldstracker” fields predicted by predicted by
some particle some particle physics theoriesphysics theories
WhatWhat’s the Universe?’s the Universe?
Putting It All TogetherPutting It All Together
Recipe for Our UniverseRecipe for Our Universe
History of UniverseHistory of Universe
Cubs return to Cubs return to World SeriesWorld Series
Whither the Universe?Whither the Universe?2 BY2 BY6 BY6 BY14 14 BYBY24 24 BYBY33 33 BYBY44 44 BYBY65 65 BYBY75 75 BYBY