Publications Topics:

Books

ASP Conference Series

Monograph Publications

IAU Publications

Books of Note

Purchase through the AstroShop

Journals

Publications of the ASP (PASP)

Magazines

Mercury Magazine

Archive

Guidelines for Authors

Order Mercury Issues

Mercury Advertising Rates

Newletters

The Universe in the Classroom

ASP E-mail Newsletters

Special Features

Astronomy Beat

Contact Us

Mercury, September/October 2003 Table of Contents

Image courtesy of John Whatmough (www.extrasolar.net/artist.html).

by Volker Bromm

The formation of the first stars and quasars brought an end to the universe’s Dark Ages.

Modern cosmology is one of humanity’s grandest endeavors. It attempts nothing less than to reconstruct the entire history of the universe. Ultimately, we seek answers to the fundamental questions of the ages: Where do we come from? What are our cosmic origins? Which processes shaped the cosmos, and eventually led to the emergence of stars, planets, life, and intelligent beings?

Over the past few decades we have come to understand that the universe started out from simple initial conditions. The state of the universe moments after the Big Bang can be described by a small set of equations that would literally fit on a sheet of paper. But the present-day universe is highly structured and exceedingly complex; all of our libraries and supercomputers combined could not produce a complete description. How and when did the universe undergo the transition from simplicity to complexity? Recent theoretical results have shown that this watershed is marked by the emergence of the first stars and quasars some 100-200 million years after the Big Bang.

The formation of the first luminous objects spelled an end to the cosmic Dark Ages. This remote epoch, still shrouded in mystery, began roughly 500,000 years after the Big Bang, when cosmic expansion redshifted the photons of the cosmic microwave background (CMB) out of the visible waveband and into the infrared. From the perspective of a human observer, the universe descended into a state of complete darkness.