In the early part of the twentieth century, the universe, as put together with over two centuries' worth of theories and hard-won astronomical observations, simply came undone. Until the mid-1920s, the cosmos was conceived of as serene, static, and mostly empty. Stars wandered through space randomly, planets revolved unperturbed around the Sun, and disk-like whorls, thought to be nearby stars in the making, were known only as "spiral nebulae." Today we know the spiral nebulae as galaxies--immense and remote systems of billions of stars--and the ordered and serene universe has been replaced by one that appears dynamic, fluctuating, and infinitely more voluminous.
A new dominant model of the universe has emerged. In its simplest form, the most widely accepted model describes an expanding universe filled with countless galaxies rushing away from an explosive, seminal event called the big bang. Mainstream astronomers believe the big bang clarifies the picture of universal genesis by predicting what otherwise would be unpredictable and explaining what otherwise would be unexplainable.
And yet, there is a growing alliance of "renegades"--physicists and astronomers who feel the big bang model not only fails to describe what is observed, but fails altogether as a cosmology.
Three cosmological pillars
Astronomers today cite three "pillars" shoring up the big bang cosmology. The first, the expanding universe, was hefted into place in the early part of this century, when American astronomer Edwin Hubble, using Mount Wilson Observatory's 100-inch reflecting telescope, discovered that the more distant a galaxy was from the Earth, the faster it was receding. The universe appeared to be blowing up like a balloon, expanding. The implications were astonishing: For the entire universe to be expanding, a propulsive force of unimaginable magnitude--an explosion of some sort--must have set matter on its outward-flowing course.
The expanding universe is probably the best known of the big bang pillars. There are two others--equally formidable, say supporters; equally flawed, rejoin the critics.
The second of the three pillars is the measured total abundance of light elements in the universe, "light elements" being hydrogen, deuterium (an isotope of hydrogen), helium, and lithium. Measuring the cosmic abundance is analogous to ascertaining the ingredients of an immense cake after it has been baked.
Like a cake, the matter composing the universe today retains a substantial imprint of its initial cosmic "batter." These primeval elements are commonly sampled by
...
