Our Vexing Planet: Still Privileged After All These Years
I love Denyse O'Leary's current series for ENV, "Science Fictions," documenting the failures of scientific materialism. Denyse is a shrewd journalist. Funny, too. Her friends and email correspondents know her as the Dorothy Parker of the intelligent design movement. To these encomiums add that she has good timing.
Miss O'Leary's story this week, "Behold, Countless Earths Sail the Galaxies ... That Is, if You Would Only Believe," is eerily illustrated by a wave of adulation in the popular media over a paper in PNAS, "Prevalence of Earth-size planets orbiting Sun-like stars." "Milky Way Teeming With Billions Of Earth-Size Planets," the AP's Seth Borenstein exults. The problem is that the significance of the news shrivels as you read more about it.
Astronomers using NASA data have calculated for the first time that in our galaxy alone, there are at least 8.8 billion stars with Earth-size planets in the habitable temperature zone.
As for what it says about the odds that there is life somewhere out there, it means "just in our Milky Way galaxy alone, that's 8.8 billion throws of the biological dice," said study co-author Geoff Marcy, a longtime planet hunter from the University of California at Berkeley.
That sounds impressive, like a coup for upholders of the Copernican Principle that holds, as Denyse summarizes, "Earth cannot be special by definition." But wait. If Earth isn't special, which carries with it the apparent corollary that we aren't special, then after all that biological dice-rolling:
The findings...raise a blaring question, Marcy said: If we aren't alone, why is "there a deafening silence in our Milky Way galaxy from advanced civilizations?"
Good question. The study is supposed to be a major step forward because of its unprecedented accuracy:
For the first time, scientists calculated -- not estimated -- what percent of stars that are just like our sun have planets similar to Earth: 22 percent, with a margin of error of plus or minus 8 percentage points.
Oh! You see, they calculated. They didn't just estimate.
Because there are probably hundreds of planets missed for every one found, the study did intricate extrapolations to come up with the 22 percent figure -- a calculation that outside scientists say is fair.
Oh. They calculated in the sense of "extrapolating" to "come up" with a figure. In other words, they estimated. The figure of "8.8 billion stars with Earth-size planets in the habitable temperature zone" comes down a bit too when you talk about actual planets that have been observed instead of being merely conjectured and "calculated."
Scientists at a Kepler science conference Monday said they have found 833 new candidate planets with the space telescope, bringing the total of planets they've spotted to 3,538, but most aren't candidates for life.
Kepler has identified only 10 planets that are about Earth's size circling sun-like stars and are in the habitable zone, including one called Kepler 69-c.
Ah hah. So from the initial, trumpets-blaring figure of 8.8 billion we're down more realistically to 10. Not 10 billion, just 10. Meanwhile the silence from space continues absolutely unabated.
That's the way it tends to go with stories like this, the blaring headline and the inevitable letdown. Well, materialists are in kind of a bind, aren't they. Per the Copernican Principle a/k/a the Principle of Mediocrity, planets like ours teeming with intelligent life should be legion. Yet if they're out there, they are not making themselves known.
If there really are lots of possible Earth-like worlds, yet no life among the stars capable of signaling to us or anyone else, that might preserve the principle of our planet's mediocrity but it would highlight the uniqueness of our earthly biosphere. And that hardly solves the problem that the mediocrity principle was intended to address: that of our own, not so much our planet's, apparent uniqueness.
Of that vexing dilemma, the only realistic resolution favorable to materialism would be offered by the hope, still elusive after years of listening, of a signal from space.
Image: Kepler-69c; NASA Ames/JPL-Caltech. NB: Artist's rendition! This planet is probably a lot more like Venus than it is like Earth. Nice place to visit? Not so much.