Many scientists are fond of explaining the stunning fine-tuning of universe by theorizing that there are countless other universes that must not be fine-tuned – meaning humanity is simply the inevitable result of a numbers game.
But denigrating Earth’s place in the cosmos isn’t that simple, according to Howard A. Smith, an astronomy lecturer at Harvard and senior astrophysicist in the Harvard-Smithsonian Center for Astrophysics.
He writes in The Washington Post that Earth and its intelligent inhabitants “seem to be cosmically special, perhaps even unique — at least as far as we are likely to know for eons”:
The strengths of the four forces that operate in the universe — gravity, electromagnetism, and the strong and weak nuclear interactions (the latter two dominate only at the level of atoms) — for example, have values critically suited for life, and were they even a few percent different, we would not be here. The most extreme example is the big bang creation: Even an infinitesimal change to its explosive expansion value would preclude life.
He notes that even atheist philosopher Thomas Nagel of New York University has argued that this perfect balance indicates “that intelligent beings must somehow be the directed goal” of what many scientists write off as impersonal chance.
And don’t write off how complicated it is to produce intelligence:
Paleontologist Peter Ward and astronomer Donald Brownlee summarize the many constraints in their book “Rare Earth: Why Complex Life is Uncommon in the Universe” and show why it takes vastly more than liquid water and a pleasant environment to give birth even to simple (much less complex) life. At a minimum, it takes an environment stable for billions of years of evolution, plus all the right ingredients.
The “exotic diversity of exoplanets” also shows how rare our corner of the universe is:
Many have highly elliptical orbits around unstable stars, making evolution over billions of years difficult if not impossible; other systems contain giant planets that may have drifted inward, disrupting orbits; and there are many other unanticipated properties. These unexpected discoveries are helping scientists unravel Earth’s complex history.
Smith chides his colleagues who reject what is plain before them:
Yes, we all have beliefs — but beliefs are not proof. … All the observations so far, however, are consistent with the idea that humanity is not mediocre at all and that we won’t know otherwise for a long time. It seems we might even serve some cosmic role.