September 21, 2017

Review: The Five Ages of the Universe by Fred Adams and Greg Laughlin.

A cosmological classic!

A cosmological classic!


   This week, we’re going to look at a classic book on cosmology that is both fascinating and frightening. About 10 years ago, I read the Five Ages of the Universe by Fred Adams and Greg Laughlin.  This book built upon information gathered in the swiftly growing field of cosmology, a science that has just come into its own from one largely of late night philosophy to one of hard science with real observational data. Five Ages does nothing short of trace the history of the universe from its first moments to its logical end, or lack thereof. The discovery that we appear to live in an open universe that will indeed expand ad infinitum holds some very bizarre and disconcerting conclusions, all of which the authors explore in vivid detail using the most up-to-date data available. It’s strange to think that we may occupy a tiny sliver of space and time where life can occur, and a vast, infinite stretch of nothing may be in store. However, the authors are careful to make every attempt to abandon their own human bias towards the current era, and instead look at subsequent epochs on their own terms.     


When dealing with a topic as expansive as the history and fate of the universe, one has to become accustomed to discussing extremely large numbers. Creationists aside, we live in a universe that is about 13.7 billion years old, give or take about 100 million years. But that is peanuts compared to the gargantuan timescales discussed in this book. Instead, the authors resort to what are termed cosmological decades, (henceforth called CDs) exponential scales where each decade is ten times longer than the last. Thus we are said to exist at the very beginning of the 10th decade, or 1010, which began 3.7 billion years ago and will last until decade 11 over 96 billion years from now. And trust me, the time scales just get larger from there…

The first era covered is termed the primordial epoch, from the moment time and space began until CD 6. During this time of rapid inflation matter coalesced via nucleosythesis, the cosmic microwave background separated out the cooling universe, and the first stars began to shine.

The next era explored is our own, termed the stelliferous era. This is the time we see today and are most familiar with. Stars shine via fusion, galaxies collide, and the processes that power life that is possible to contemplate the wonder of it all and write books (and blogs about books!) is possible. During this period, which is expected to last up until about CD 15, stars will pass through their life cycle until the universe is littered with white dwarfs, pulsars, and black holes. Miserly red dwarf stars, with an expected fusion producing life span of up to about 10 trillion years are expected to be the last stars to go. Then the universe gets really weird…

From CD 15-40 we enter what is known as the degenerate era, a time when white dwarfs turn black, protons decay, and dark matter annihilates the galactic halo. Perhaps an occasional brown dwarf pair will merge in this far-off time and an old school star will shine briefly in the void. But by CD 40, the start of the black hole era, only the stellar remnants of black holes will remain. Even these are anticipated to decay via the process of Hawking radiation with even one million solar mass monsters dissipating after around CD 83. Axions are also predicted to decay into photons at about this time.


Of course, what happens during the final dark era of about CD100 on is highly speculative. Will time itself cease to exist? Will quantum fluctuations randomly spout new universes? Will a sort of cosmological phase transition reconstruct our present universe? Keep in mind, long before this time, the edge of the observable universe will have expanded to a mindboggling point, as if it’s not brain blowing big enough now. In fact, the distance between whatever passes for individual particles in the far off dark era will be larger than the observable universe today!

Read The Five Ages of the Universe to gain a cosmic perspective on the consequences of just what living in an infinite universe might mean. Each chapter also opens with an engaging “you are there” narrative to help gain a perspective on these alien realms through the forces propelling the universe through its transitions. Perhaps I would first read Stephen Hawkings’ landmark A Brief History of Time to provide some background, and then follow up Ages with Douglas Adams Hitch-hikers Guide to the Galaxy as a way to cheer oneself up as to the inevitability of it all!           


You are here… (credit: NASA/WMAP).

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LIGO, Livingston. (All Photos by Author).
LIGO, Livingston. (All Photos by Author).

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