The Five Ages of the Universe
Encyclopedia
The Five Ages Of The Universe is a popular science
book
written by Professor Fred Adams
and Gregory Laughlin first published in 1999.
Era, the Stelliferous Era, the Degenerate Era, the Black Hole
Era and the Dark Era.
In addition to explaining current cosmological theory, the authors speculate on what kinds of life might exist in future eras of the universe. The speculation is based on a scaling hypothesis, due to Freeman Dyson
, the idea being that all other things being equal the rate of metabolism -- and therefore rate of consciousness -- of an organism should be in direct proportion to the temperature at which that organism thrives. The authors envision life forms completely different from the biochemical ones of Earth, for example based on networked black holes.
.
, the subsequent inflation
, and Big Bang nucleosynthesis
are thought to have taken place. Toward the end of this age, the recombination of electrons with nuclei made the universe transparent for the first time. The authors discuss the horizon and flatness problems.
is discussed.
and continue with a nominal energy output. As this era continues, the authors hypothesize that protons will begin to decay
(violating the conservation of baryon
number given by the Standard Model
). If proton decay takes place, the sole survivors will be black holes.
. By the end of this era, only extremely low-energy photons, electrons, positrons, and neutrinos will remain.
atoms. These structures are unstable, however, and their constituent particles must eventually annihilate. Other low-level annihilation events will also take place, albeit very slowly.
Popular science
Popular science, sometimes called literature of science, is interpretation of science intended for a general audience. While science journalism focuses on recent scientific developments, popular science is broad-ranging, often written by scientists as well as journalists, and is presented in many...
book
Book
A book is a set or collection of written, printed, illustrated, or blank sheets, made of hot lava, paper, parchment, or other materials, usually fastened together to hinge at one side. A single sheet within a book is called a leaf or leaflet, and each side of a leaf is called a page...
written by Professor Fred Adams
Fred Adams
Fred C. Adams is an American astrophysicist who has made contributions to the study of physical cosmology.- Biography:Fred Adams is professor of physics at the University of Michigan, where his main field of research is astrophysics theory focusing on star formation, background radiation fields,...
and Gregory Laughlin first published in 1999.
Book contents
The book The Five Ages of the Universe discusses the history, present state, and probable future of the universe, according to cosmologists' current understanding. The book divides the timeline of the universe into five eras: the PrimordialPrimordial
Primordial may refer to:* Primordial sea . See abiogenesis* Primordial nuclide, nuclides, a few radioactive, that formed before the Earth existed and are stable enough to still occur on Earth...
Era, the Stelliferous Era, the Degenerate Era, the Black Hole
Black hole
A black hole is a region of spacetime from which nothing, not even light, can escape. The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole. Around a black hole there is a mathematically defined surface called an event horizon that...
Era and the Dark Era.
In addition to explaining current cosmological theory, the authors speculate on what kinds of life might exist in future eras of the universe. The speculation is based on a scaling hypothesis, due to Freeman Dyson
Freeman Dyson
Freeman John Dyson FRS is a British-born American theoretical physicist and mathematician, famous for his work in quantum field theory, solid-state physics, astronomy and nuclear engineering. Dyson is a member of the Board of Sponsors of the Bulletin of the Atomic Scientists...
, the idea being that all other things being equal the rate of metabolism -- and therefore rate of consciousness -- of an organism should be in direct proportion to the temperature at which that organism thrives. The authors envision life forms completely different from the biochemical ones of Earth, for example based on networked black holes.
Ages
The time scales treated in the book are sufficiently vast that the authors find it convenient to use scientific notation. They refer to the "nth cosmological decade," meaning 10n years after the big bang. In what follows, n refers to the cosmological decadeCosmological decade
A cosmological decade is a division of the lifetime of the cosmos. The divisions are logarithmic in size, on base 10. Each successive cosmological decade represents a ten-fold increase in the total age of the universe....
.
Primordial Era
The Primordial Era is defined as "-50 < n < 5". In this era, the Big BangBig Bang
The Big Bang theory is the prevailing cosmological model that explains the early development of the Universe. According to the Big Bang theory, the Universe was once in an extremely hot and dense state which expanded rapidly. This rapid expansion caused the young Universe to cool and resulted in...
, the subsequent inflation
Cosmic inflation
In physical cosmology, cosmic inflation, cosmological inflation or just inflation is the theorized extremely rapid exponential expansion of the early universe by a factor of at least 1078 in volume, driven by a negative-pressure vacuum energy density. The inflationary epoch comprises the first part...
, and Big Bang nucleosynthesis
Big Bang nucleosynthesis
In physical cosmology, Big Bang nucleosynthesis refers to the production of nuclei other than those of H-1 during the early phases of the universe...
are thought to have taken place. Toward the end of this age, the recombination of electrons with nuclei made the universe transparent for the first time. The authors discuss the horizon and flatness problems.
Stelliferous Era
The Stelliferous Era is defined as "6 < n < 14". This is the current era, in which matter is arranged in the form of stars, galaxies, and galaxy clusters, and most energy is produced in stars. Massive stars use up their fuel very rapidly, in as little as a few million years. Eventually, the only stars will be miserly red dwarf stars. By the end of this era, bright stars as we know them will be gone, their nuclear fuel exhausted, and only white dwarfs, brown dwarfs, and black holes will remain. In this section, Olbers' paradoxOlbers' paradox
In astrophysics and physical cosmology, Olbers' paradox is the argument that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe. It is one of the pieces of evidence for a non-static universe such as the current Big Bang model. The argument is also...
is discussed.
Degenerate Era
The Degenerate Era is defined as "15 < n < 39".This is the era of brown dwarfs, white dwarfs, and black holes. White dwarfs will assimilate dark matterDark matter
In astronomy and cosmology, dark matter is matter that neither emits nor scatters light or other electromagnetic radiation, and so cannot be directly detected via optical or radio astronomy...
and continue with a nominal energy output. As this era continues, the authors hypothesize that protons will begin to decay
Proton decay
In particle physics, proton decay is a hypothetical form of radioactive decay in which the proton decays into lighter subatomic particles, such as a neutral pion and a positron...
(violating the conservation of baryon
Baryon
A baryon is a composite particle made up of three quarks . Baryons and mesons belong to the hadron family, which are the quark-based particles...
number given by the Standard Model
Standard Model
The Standard Model of particle physics is a theory concerning the electromagnetic, weak, and strong nuclear interactions, which mediate the dynamics of the known subatomic particles. Developed throughout the mid to late 20th century, the current formulation was finalized in the mid 1970s upon...
). If proton decay takes place, the sole survivors will be black holes.
Black Hole Era
The Black Hole Era is defined as "40 < n < 100". In this era, according to the book, organized matter will remain only in the form of black holes. Black holes themselves slowly "evaporate" away the matter contained in them, by the quantum mechanical process of Hawking radiationHawking radiation
Hawking radiation is a thermal radiation with a black body spectrum predicted to be emitted by black holes due to quantum effects. It is named after the physicist Stephen Hawking, who provided a theoretical argument for its existence in 1974, and sometimes also after the physicist Jacob Bekenstein...
. By the end of this era, only extremely low-energy photons, electrons, positrons, and neutrinos will remain.
Dark Era
The Dark Era is defined as "n > 101". By this era, with only very diffuse matter remaining, activity in the universe will have tailed off dramatically, with very low energy levels and very large time scales. Electrons and positrons drifting through space will encounter one another and occasionally form positroniumPositronium
Positronium is a system consisting of an electron and its anti-particle, a positron, bound together into an "exotic atom". Being unstable, the two particles annihilate each other to produce two gamma ray photons after an average lifetime of 125 ps or three gamma ray photons after 142 ns in...
atoms. These structures are unstable, however, and their constituent particles must eventually annihilate. Other low-level annihilation events will also take place, albeit very slowly.