The Evolution of the UniverseThe Evolution of the Universe**

John D. BarrowJohn D. Barrow

Are You Are You ExpandinExpandin

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There is no centreThere is no centre and and

there is no edgethere is no edge

A Recipe for LifeA Recipe for Life

helium + helium helium + helium berylliumberyllium

helium + beryllium helium + beryllium carboncarbon

carbon + helium carbon + helium oxygenoxygen

Why is the Universe so Why is the Universe so

Big ?Big ?hydrogen hydrogen helium helium carboncarbon10 billion years of 10 billion years of alchemyalchemy10 billion years of 10 billion years of expansionexpansion10 billion light years of 10 billion light years of spacespace

The Universe The Universe is is

Almost EmptyAlmost Empty

The Universe contains The Universe contains onlyonly

1 Atom per cubic metre1 Atom per cubic metre1 Earth per (10 l–yr)1 Earth per (10 l–yr)33

1 Star per (1000 l–yr)1 Star per (1000 l–yr)33 1 Galaxy per (101 Galaxy per (1077 l–yr) l–yr)33

1 ‘universe’ per (101 ‘universe’ per (101010 l–yr) l–yr)33

Our Our UniverseUniverse

IsIsCoolCool

T 1/size

The Sky is Dark The Sky is Dark at Nightat Night

Life-supporting Space is….Life-supporting Space is….

Almost emptyAlmost emptyBig and OldBig and Old

Dark and ColdDark and Cold

Habitable UniversesHabitable UniversesNeedNeed

Close to critical expansionClose to critical expansionIsotropic expansionIsotropic expansion

Graininess level of aboutGraininess level of about 1 part in 10 1 part in 1055

The Inflationary UniverseThe Inflationary Universe

Very early 10-35 sec

Planck Mission Microwave Sky MapPlanck Mission Microwave Sky Map

The Spectrum of Temperature FluctuationsThe Spectrum of Temperature Fluctuations

Changing the visible matter density

Wayne Hu

Changing the dark matter density

Wayne Hu

A Cosmological CornucopiaA Cosmological Cornucopia

Gravitational-Wave ‘Twist’ Signature Gravitational-Wave ‘Twist’ Signature in the radiation polarisationin the radiation polarisation

BICEP 2, 2014

Planck Dust Map

The Universe is DustyThe Universe is Dusty

Chaotic InflationChaotic Inflation

Eternal InflationEternal Inflation

Will the Universe Will the Universe Expand Expand ForeverForever

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The Violent End of the Solar SystemThe Violent End of the Solar System

Dark energy () and deviation from critical expansion (k)Wayne Hu

Dark Energy Dominates the UniverseDark Energy Dominates the Universe