INTO The DARK:INTO The DARK:the FAR FUTUREthe FAR FUTUREof OUR universe of OUR universe

INTO The DARK:INTO The DARK:the FAR FUTUREthe FAR FUTUREof OUR universe of OUR universe

Fred C. Adams

University of MichiganFred C. Adams

University of Michigan

The Copernican Time PrincipleThe Copernican Time Principle

The current cosmological The current cosmological epoch epoch has no special has no special significance.significance.

Interesting physics processes will Interesting physics processes will continue to take place in the future,continue to take place in the future,despite decreasingly energy levelsdespite decreasingly energy levels

Yet Another Principle:Yet Another Principle:

The cosmological future The cosmological future informsinformsour understanding of our understanding of astrophysics astrophysics in the present day universe. in the present day universe.

Cosmological DecadeCosmological Decade

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t =10η years

Cosmic TimelineCosmic Timeline

Five Ages of the UniverseFive Ages of the UniverseFive Ages of the UniverseFive Ages of the Universe

Primordial Era n < 6 Stelliferous Era n = 6 - 14 Degenerate Era n = 14 - 40 Black Hole Era n = 40 - 100 Dark Era n > 100

Primordial Era n < 6 Stelliferous Era n = 6 - 14 Degenerate Era n = 14 - 40 Black Hole Era n = 40 - 100 Dark Era n > 100

The Inflationary Universe

Time in seconds

(Guth)

Matter > Antimatter Matter > Antimatter

Dark matter abundance freezes before universe is 1 second old

The synthesis of light elements beginsThe synthesis of light elements begins when the universe is one second oldwhen the universe is one second old

and ends three minutes later…and ends three minutes later…

Helium

Deuterium

Lithium

(Schramm)

The Primordial EraThe Primordial EraThe Primordial EraThe Primordial Era

The Big Bang Inflation Matter > Antimatter Quarks --- protons & neutrons Nuclear synthesis of the light elements Cosmic Microwave Background Universe continues to expand

The Big Bang Inflation Matter > Antimatter Quarks --- protons & neutrons Nuclear synthesis of the light elements Cosmic Microwave Background Universe continues to expand

WMAP: Cosmic Background Radiation

WMAP: Cosmic Background Radiation

The VIRGO consortium

Large Scale Structure of the Universe

The Present Epoch

Cosmological ParametersCosmological Parameters

IslandUniverse

14 Gyr

54 Gyr

92 Gyr

Dark matter halos approacha well-defined asymptotic formwith unambiguous total mass, outer radius, density profile

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ρ ≈ρ0

ξ (1+ ξ )3

Andromeda: Our sister galaxyAndromeda: Our sister galaxy

Collision with AndromedaCollision with Andromeda

AB

C

Earth swallowed by the SunEarth swallowed by the Sun

(probably…)

Red Dwarf saves the EarthRed Dwarf saves the Earth

sun

red dwarf

earth

moon

Red dwarf captures the Earth

Sun exits with one red dwarf as a binary companion

Earth exits with the other red dwarf

Sun and Earth encounter binary pair of red dwarfs

9000 year interaction

Solar System ScatteringSolar System Scattering

Many Parameters +Chaotic Behavior

Many Simulations Monte Carlo Scheme

Cross Sections vs Stellar MassCross Sections vs Stellar MassCross Sections vs Stellar MassCross Sections vs Stellar Mass

2.0 M1.0 M

0.5 M0.25 M

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σej

=C0

aPAU

⎛

⎝ ⎜

⎞

⎠ ⎟M∗

Msun

⎛

⎝ ⎜

⎞

⎠ ⎟

−1/ 2

where

C0 =1350 ±160 (AU)2

Galilean Satellites:

Ganymede Callisto Io Europa

Icy worlds are easy to make

Some current data suggest that life on Earth might have originated deep underground,independent ofsunlight, so that life could arise onfrozen planets across the Galaxy.

Galaxy continues to make new stars.Time scales are lengthened by: - Recycling- Infall onto disk- Reduced SF rate

Star formation continues until the galaxy runs out of gas (at n = 14)

Long term Evolution of Red Dwarfs

Long term Evolution of Red Dwarfs

Log

[L]

Temperature

Life Span of Red DwarfsLife Span of Red Dwarfs

Lif

etim

e (T

rill

ion

yr)

Mass (Msun)

Late time light curve for Milky Way

(Adams, Graves, & Laughlin 2004)

The Stelliferous EraThe Stelliferous EraThe Stelliferous EraThe Stelliferous Era Stars dominate energy production Lowest mass stars increasingly important Star formation and stellar evolution end

near cosmological decade n = 14 Future tells us why stars become red giants,Future tells us why stars become red giants, why dark matter halos have their forms, how why dark matter halos have their forms, how

to define the mass of a galaxy, new results to define the mass of a galaxy, new results on orbit instabilities, dynamical scattering…on orbit instabilities, dynamical scattering…

Stars dominate energy production Lowest mass stars increasingly important Star formation and stellar evolution end

near cosmological decade n = 14 Future tells us why stars become red giants,Future tells us why stars become red giants, why dark matter halos have their forms, how why dark matter halos have their forms, how

to define the mass of a galaxy, new results to define the mass of a galaxy, new results on orbit instabilities, dynamical scattering…on orbit instabilities, dynamical scattering…

Nuclear physics Nuclear physics determinesdetermineshow stellar evolution how stellar evolution takestakesplace, and sets the place, and sets the cosmic cosmic abundance of the abundance of the elements, elements, as well as the as well as the inventory of inventory of the Degenerate the Degenerate Era… Era…

Inventory of Degenerate EraInventory of Degenerate Era Brown dwarfs (from brown dwarfs) White dwarfs (from most stars, M=0.08-8) Neutron stars (from massive stars M > 8) Stellar Black Holes (from largest stars)

Brown dwarfs (from brown dwarfs) White dwarfs (from most stars, M=0.08-8) Neutron stars (from massive stars M > 8) Stellar Black Holes (from largest stars)

BD WD

Brown Dwarf CollisionsBrown Dwarf Collisions

J. Barnes

White Dwarfs of Degenerate Era Accrete Dark Matter Particles

White Dwarfs of Degenerate Era Accrete Dark Matter Particles

Power = quadrillions of watts

Dynamical Relaxation of the GalaxyDynamical Relaxation of the Galaxy

Stellar scattering changes the structure of the galaxy over time

Spiral disk becomes extended and diffuse

Most stars are lost, but a few fall to center

Stellar scattering changes the structure of the galaxy over time

Spiral disk becomes extended and diffuse

Most stars are lost, but a few fall to center

Time scale = 20 cosmological decadesTime scale = 20 cosmological decades

Proton DecayProton Decay Many possible channels Lifetime is recklessly uncertain Experiments show that n > 33 Theory implies that n < 45

Changes the universe more dramatically than any other process in our future history

Many possible channels Lifetime is recklessly uncertain Experiments show that n > 33 Theory implies that n < 45

Changes the universe more dramatically than any other process in our future history

Proton decay channelProton decay channel

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u

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u

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d

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e⊕

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π 0

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u

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u

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XP

Fate of Degenerate Objects

Temperature Temperature

P

ower

P

ower

The Degenerate EraThe Degenerate EraThe Degenerate EraThe Degenerate Era

Inventory includes Brown Dwarfs, White Dwarfs, Neutron Stars, and Black Holes Star formation through brown dwarf collisions White dwarfs capture dark matter particles Galaxy relaxes dynamically Black holes accrete stars, gas, and grow

Era ends when Protons decay at cosmological decade n = 40

Inventory includes Brown Dwarfs, White Dwarfs, Neutron Stars, and Black Holes Star formation through brown dwarf collisions White dwarfs capture dark matter particles Galaxy relaxes dynamically Black holes accrete stars, gas, and grow

Era ends when Protons decay at cosmological decade n = 40

Every galaxy has a

supermassive black hole anchoring its center

Mbh = millions to billions of Suns

Every galaxy produces about one million stellar mass black holes

Hawking Radiation

BlackBlack holehole

Virtual particles

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λ ≈GM ≈ Rs

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TH =1/(8πGM)

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τ =1065 yr M /Mo[ ]3

The Black Hole EraThe Black Hole EraThe Black Hole EraThe Black Hole Era

Black holes are brightest stellar objects Generation of energy via Hawking radiation Every galaxy contributes one supermassive

and about one million stellar black holes Black hole lifetime is mass dependent:

Black holes are brightest stellar objects Generation of energy via Hawking radiation Every galaxy contributes one supermassive

and about one million stellar black holes Black hole lifetime is mass dependent:

One solar mass: n=65Million solar mass: n=83Galactic mass: n=98Horizon mass: n=131

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tT ∝Mbh3

The Dark EraThe Dark EraThe Dark EraThe Dark Era

No stellar objects of any kind Inventory of elementary particles:

electrons, positrons, neutrinos, & photons Positronium formation and decay Low level annihilation

No stellar objects of any kind Inventory of elementary particles:

electrons, positrons, neutrinos, & photons Positronium formation and decay Low level annihilation

The Cosmos could experience a Future Phase Transition

As the phase transition completes, the laws of physics could change, and the universe gets a new start

As our own universeAs our own universeexperiences its time-experiences its time-line, other parts of line, other parts of the global space-timethe global space-time(other universes) can (other universes) can live through their ownlive through their ownlifetimes, as part of lifetimes, as part of a cosmic archipelagoa cosmic archipelagosometimes called thesometimes called theMULTIVERSE.MULTIVERSE.

SummarySummarySummarySummary Our current understanding of the laws of

physics and astrophysics allow us to construct a working picture of the future.

Studying physical processes of the future provides insight into current astrophysical problems, e.g., the reason for red giants, structure of dark matter halos, dynamical scattering problems, defining the masses of galaxies, etc.

Our current understanding of the laws of physics and astrophysics allow us to construct a working picture of the future.

Studying physical processes of the future provides insight into current astrophysical problems, e.g., the reason for red giants, structure of dark matter halos, dynamical scattering problems, defining the masses of galaxies, etc.

DisclaimerDisclaimerDisclaimerDisclaimer

As one journeys deeper into future time, projections necessarily become more uncertain (this talk stops at n = 100).

As we learn more about the fundamental laws of physics, or if the laws change with cosmological time, corrections (both large and small) to this timeline must be made.

As one journeys deeper into future time, projections necessarily become more uncertain (this talk stops at n = 100).

As we learn more about the fundamental laws of physics, or if the laws change with cosmological time, corrections (both large and small) to this timeline must be made.