Many writers have long glorified the drama of human life in the universe and its accompanying cooperation, competition, enslavement, genocide, and wars in the name of conflicting human-generated creeds. Much less concern has been given to the platform on which the drama is staged. Let us consider some characteristics of the stage.
Earth is the third of eight planets in near-circular orbit around the sun. It rotates on its axis once a day and revolves around the sun once a year. The sun and planets, along with smaller asteroids, constitute the solar system.
The sun is described as a typical star. However, the range of kinds of stars is very wide, from red giants as large as Earth’s orbit in our solar system (sun plus planets) to white dwarfs where a cubic inch of material weighs tons (atoms stripped of their electrons).
Now, recognize that 1 billion = 1,000,000,000, a thousand times a million. A trillion is a million times a million: one followed by twelve zeros. Astronomers estimate that the Milky Way galaxy contains a trillion stars, and in turn the universe contains one trillion galaxies. Thus, the universe contains a trillion times a trillion stars: one followed by twenty-four zeroes.
With distances so vast, it is convenient to express a distance by the time it takes light to traverse it. The speed of light is phenomenal 186,282 miles per second. At 240,000 miles distance, it takes light from the moon but 1.3 seconds to reach us. At ninety-three million miles, it takes light from the sun 8.3 minutes to arrive at Earth. From the nearest star, light requires 4.3 light-years to reach us. The distance light travels in a year is designated a light-year, and it is 5.9 trillion miles.
The distance across the arms of our spiral Milky Way galaxy is about one hundred thousand light-years. There are about forty galaxies in our stellar neighborhood. The distance to the nearest galaxy, the Andromeda galaxy, is 2.5 million light-years. It is hurtling toward the Milky Way at seventy-five miles per second (one hundred times the rate of a speeding bullet). The two galaxies are scheduled to collide in 2.5 billion years. The dimension of the entire universe is fifteen billion light-years.
In recent years, despite their relatively small sizes and vast distances from Earth, astronomers have been successful in identifying several hundred planets orbiting hundreds of stars in the Milky Way galaxy. Planet formation about stars appears commonplace.
The universe was born in the “Big Bang” about fourteen billion years ago. The solar system is younger, born 4.6 billion years ago. It is estimated that the sun will last another five billion years, at which time it will swell, become a red giant, and envelop Earth.
Though often conflated in the single term evolution, life on Earth consists of two parts: abiogenesis, the appearance of living from inanimate matter, and evolution. Abiogenesis occurred sometime at the end of the first billion years of Earth’s history, about 3.6 billion years ago. We may never learn the mode of abiogenesis, because the aggressiveness of existing life would have wiped out any previously formed materials. Evolution to the current kinds of life evolved from earlier forms during the subsequent 3.6 billion years.
There are now millions of species extant and even more that have become extinct, including over one thousand species of dinosaurs that became extinct sixty-five million years ago, after existing on Earth for 175 million years. The span of 3.6 billion years is ample to account for the diversity of life. Modern humans (Homo sapiens) evolved but two hundred thousand years ago, or in about 1/18,000 (0.006 percent) of the time that Earth has existed.
Thus, the scale of the universe is enormous in mass of material, distances, and time. Is it reasonable that a universe of a trillion times a trillion stars (one followed by twenty-four zeros), spanning fifteen billion light-years, has evolved beginning fourteen billion years ago just so that very late-arriving humans can tussle with interpretations of good and evil on Earth? As stated by the Nobel Prize–winning physicist Richard Feynman, “The stage is too big for the drama.”
Bruce Martin is professor emeritus of chemistry at the University of Virginia. He is a contributor to Skeptical Inquirer magazine.