Pale Blue Dot - Carl Sagan [14]
Today we have firm evidence for at least three planets orbiting an extremely dense star, the pulsar designated B1257+12, about which I’ll say more later. And we’ve found, for more than half the stars with masses like the Sun’s, that early in their careers they’re surrounded by great disks of gas and dust out of which planets seem to form. Other planetary systems now look to be a cosmic commonplace, maybe even worlds something like the Earth. We should be able, in the next few decades, to inventory at least the larger planets, if they exist, of hundreds of nearby stars.
Well, if our position in space doesn’t reveal our special role, our position in time does: We’ve been in the Universe since The Beginning (give or take a few days). We’ve been given special responsibilities by the Creator. It once seemed very reasonable to think of the Universe as beginning just a little before our collective memory is obscured by the passage of time and the illiteracy of our ancestors. Generally speaking, that’s hundreds or thousands of years ago. Religions that purport to describe the origin of the Universe often specify—implicitly or explicitly—a date of origin of roughly such vintage, a birthday for the world.
If you add up all the “begats” in Genesis, for example, you get an age for the Earth: 6,000 years old, plus or minus a little. The universe is said to be exactly as old as the Earth. This is still the standard of Jewish, Christian, and Moslem fundamentalists and is clearly reflected in the Jewish calendar.
But so young a Universe raises an awkward question: How is it that there are astronomical objects more than 6,000 light-years away? It takes light a year to travel a light-year, 10,000 years to travel 10,000 light-years, and so on. When we look at the center of the Milky Way Galaxy, the light we see left its source 30,000 years ago. The nearest spiral galaxy like our own, M31 in the constellation Andromeda, is 2 million light-years away, so we are seeing it as it was when the light from it set out on its long journey to Earth—2 million years ago. And when we observe distant quasars 5 billion light-years away, we are seeing them as they were 5 billion years ago, before the Earth was formed. (They are, almost certainly, very different today.)
If, despite this, we were to accept the literal truth of such religious books, how could we reconcile the data? The only plausible conclusion, I think, is that God recently made all the photons of light arriving on the Earth in such a coherent format as to mislead generations of astronomers into the misapprehension that there are such things as galaxies and quasars, and intentionally driving them to the spurious conclusion that the Universe is vast and old. This is such a malevolent theology I still have difficulty believing that anyone, no matter how devoted to the divine inspiration of any religious book, could seriously entertain it.
Beyond this, the radioactive dating of rocks, the abundance of impact craters on many worlds, the evolution of the stars, and the expansion of the Universe each provides compelling and independent evidence that our Universe is many billions of years old—despite the confident assertions of revered theologians that a world so old directly contradicts the word of God, and that at any rate information on the antiquity of the world is inaccessible except to faith.* These lines of evidence, as well, would have to be manufactured by a deceptive and malicious deity—unless the world is much older than the literalists in the Judeo-Christian-Islamic religion suppose. Of course, no such problem arises for those many religious people who treat the Bible and the Qur’an as historical and moral guides and great literature, but who recognize that the perspective of these scriptures on the natural world reflects the rudimentary science of the time in which they were written.
Ages rolled by before the