The Five Ages of the Universe: Inside the Physics of Eternity

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Simon and Schuster, Jun 19, 2000 - Science - 251 pages
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THE FIVE AGES OF THE UNIVERSE is a riveting biography of the universe which describes for the first time five distinct eras that Adams and Laughlin themselves defined as a result of their own research. From the first gasp of inflation that caused the Big Bang, through the birth of stars, to the fading of all light, THE FIVE AGES OF THE UNIVERSE describes the death of our own sun, tremendous fiery supernovae explosions, dramatic collisions of galaxies, proton decay, the evaporation of black holes and the possibility of communications when there are no planets or stars or even black holes left. This is a voyage to a land of red giants, white dwarfs, brown dwarfs, great walls larger than galaxies and WIMPs. With daring uncharacteristic of most scientists, the authors have applied themselves to the question of what precise kind of biology could possibly exist when, say, carbon atoms no longer exist. What, ultimately, is a lifeform? Their insight into the fundamental physics that allows life is both fascinating and provocative. Readers will find all the strange colour of science fiction with none of the fiction in this awesome scientific epic.

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User Review  - Miro - LibraryThing

An interesting paragraph from the book; ".... the fact emerges that our universe does indeed have the proper special features to allow for our existence. Given the laws of physics, as they are ... Read full review

The five ages of the universe: inside the physics of eternity

User Review  - Not Available - Book Verdict

In order to tell the story of the universe from its origin to its ultimate demise, the authors (both well-known astrophysicists) have divided all of time into five eras. The first, the Primordial Era ... Read full review



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About the author (2000)


A guide to the big picture, fundamental physical law, windows of space and time, the great war, and extremely big numbers.

January 1, 7,000,000,000 A.D., Ann Arbor:

The New Year rings in little cause for celebration. Nobody is present even to mark its passing. Earth''s surface is a torrid unrecognizable wasteland. The Sun has swelled to enormous size, so large that its seething red disk nearly fills the daytime sky. The planet Mercury and then Venus have already been obliterated, and now the tenuous outer reaches of the solar atmosphere are threatening to overtake the receding orbit of Earth.

Earth''s life-producing oceans have long since evaporated, first into a crushing, sterilizing blanket of water vapor, and then into space entirely. Only a barren rocky surface is left behind. One can still trace the faint remains of ancient shorelines, ocean basins, and the low eroded remnants of the continents. By noon, the temperature reaches nearly 3000 degrees Fahrenheit, and the rocky surface begins to melt. Already, the equator is partly ringed by a broad glowing patchwork of lava, which cools to form a thin gray crust as the distended Sun eases beneath the horizon each night.

A patch of the surface which once cradled the forested moraines of southeastern Michigan has seen a great deal of change over the intervening billions of years. What was once the North American continent has long since been torn apart by the geologic rift which opened from Ontario to Louisiana and separated the old stable continental platform to produce a new expanse of sea floor. The sedimented, glaciated remains of Ann Arbor were covered by lava which arrived from nearby rift volcanos by coursing through old river channels. Later, the hardened lava and the underlying sedimentary rock were thrust up into a mountain chain as a raft of islands the size of New Zealand collided with the nearby shoreline.

Now, the face of an ancient cliff is weakened by the Sun''s intense heat. A slab of rock cleaves off, causing a landslide and exposing a perfectly preserved fossil of an oak leaf. This trace of a distant verdant world slowly melts away in the unyielding heat. Soon the entire Earth will be glowing a sullen, molten red.

This scenario of destruction is not the lurid opening sequence from a grade B movie, but rather a more or less realistic description of the fate of our planet as the Sun ends its life as a conventional star and expands to become a red giant. The catastrophic melting of Earth''s surface is just one out of a myriad of events that are waiting to occur as the universe and its contents grow older.

Right now, the universe is still in its adolescence with an age of ten to fifteen billion years. As a result, not enough time has elapsed for many of the more interesting astronomical possibilities to have played themselves out. As the distant future unfolds, however, the universe will gradually change its character and will support an ever changing variety of astonishing astrophysical processes. This book tells the biography of the universe, from beginning to end. It is the story of the familiar stars of the night sky slowly giving way to bizarre frozen stars, evaporating black holes, and atoms the size of galaxies. It is a scientific glimpse at the face of eternity.


Our biography of the universe, and the study of astrophysics in general, plays out on four important size scales: planets, stars, galaxies, and the universe as a whole. Each of these scales provides a different type of window to view the properties and evolution of nature. On each of these size scales, astrophysical objects go through life cycles, beginning with a formation event analogous to birth and often ending with a specific and deathlike closure. The end can come swiftly and violently; for example, a massive star ends its life in a spectacular supernova explosion. Alternatively, death can come tortuously slowly, as with the dim red dwarf stars, which draw out their lives by slowly fading away as white dwarfs, the cooling embers of once robust and active stars.

On the largest size scale, we can view the universe as a single evolving entity and study its life cycle. Within this province of cosmology, a great deal of scientific progress has been accomplished in the past few decades. The universe has been expanding since its conception during a violent explosion -- the big bang itself. The big bang theory describes the subsequent evolution of the universe over the last ten to fifteen billion years and has been stunningly successful in explaining the nature of our universe as it expands and cools.

The key question is whether the universe will continue to expand forever or halt its expansion and recollapse at some future time. Current astronomical data strongly suggest that the fate of our universe lies in continued expansion, and most of our story follows this scenario. However, we also briefly lay out the consequences of the other possibility, the case of the universe recollapsing in a violent and fiery death.

Beneath the grand sweep of cosmology, at a finer grain of detail, are the galaxies, such as our Milky Way. These galaxies are large and somewhat loosely knit collections of stars, gas, and other types of matter. Galaxies are not distributed randomly throughout the universe, but rather they are woven into a tapestry by gravity. Some aggregates of galaxies have enough mass to be bound together by gravitational forces, and these galaxy clusters can be considered as independent astrophysical objects in their own right. In addition to belonging to clusters, galaxies are loosely organized into even larger structures that resemble filaments, sheets, and walls. The patterns formed by galaxies on this size scale are collectively known as the large-scale structure of the universe.

Galaxies contain a large fraction of the ordinary mass in the universe and are well separated from each other, even within their clusters. This separation is so large that galaxies were once known as "island universes." Galaxies also play the extremely important role of marking the positions of space-time. As the universe expands, the galaxies act as beacons in the void that allow us to observe the expansion.

It is difficult to comprehend the vast emptiness of our universe. A typical galaxy fills only about one-millionth of the volume of space that contains the galaxy, and the galaxies themselves are extremely tenuous. If you were to fly a spaceship to a random point in the universe, the chances of landing within a galaxy are about one in a million at the present time. These odds are already not very good, and in the future they will only get worse, because the universe is expanding but the galaxies are not. Decoupled from the overall expansion of the universe, the galaxies exist in relative isolation. They are the homes of most stars in the universe, and hence most planets. As a result, many of the interesting physical processes in the universe, from stellar evolution to the evolution of life, take place within galaxies.

Just as they do not thickly populate space, the galaxies themselves are mostly empty. Very little of the galactic volume is actually filled by the stars, although galaxies contain billions of them. If you were to drive a spaceship to a random point in our galaxy, the chances of landing within a star are extremely small, about one part in one billion trillion (one part in 1022). This emptiness of galaxies tells us much about how they have evolved and how they will endure in the future. Direct collisions between the stars in a galaxy are exceedingly rare. Consequently, it takes a very long time, much longer than the current age of the universe, for stellar collisions and other encounters to affect the structure of a galaxy. As we shall see, these collisions become increasingly important as the universe grows older.

The space between the stars is not entirely empty. Our Milky Way is permeated with gas of varying densities and temperatures. The average density is only about one particle (one proton) per cubic centimeter and the temperature ranges from a cool 10 degrees kelvin to a seething million degrees. At low temperatures, about 1 percent of the material lives in solid form, in tiny rocky dust particles. This gas and dust that fill in the space between stars are collectively known as the interstellar medium.

The stars themselves give us the next smaller size scale of importance. Ordinary stars, objects like our Sun which support themselves through nuclear fusion in their interiors, are now the cornerstone of astrophysics. The stars make up the galaxies and generate most of the visible light seen in the universe. Moreover, stars have shaped the current inventory of the universe. Massive stars have forged almost all of the heavier elements that spice up the cosmos, including the carbon and oxygen required for life. Most of what makes up the ordinary matter of everyday experience -- books, cars, groceries -- originally came from the stars.

But these nuclear power plants cannot last forever. The fusion reactions that generate energy in stellar interiors must eventually come to an end as the nuclear fuel is exhausted. Stars with masses much larger than our Sun burn themselves out within a relatively brief span of a few million years, a lifetime one thousand times shorter than the present age of the universe. At the other end of the range, stars with masses much less than that of our Sun can last for trillions of years, about one thousand times the current age of the universe.

When stars end the nuclear burning portion of their lives, they do not disappear altogether.

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