The Odds of Oddities
Our own Stephen J remarks: “I have to admit I’m always a little wary of arguments from improbability”
My comment: everyone should be. Most such arguments depend on a faulty idea of probability.
In cases where, like tossing a coin, there are a known and finite number of possible outcomes (heads or tails), and the factors leading to the outcome are known but too chaotic to measure (the initial impulse imparted by the thumb, the Brownian motions of the air), there can be many cases inspected, so that a sense of the likelihood of a given outcome can be assessed: having a coin toss land a hundred times in a row is unusual enough that if you came across one hundred coins all laying heads-up in a line, the conclusion that an intelligent designer placed rather than flipped the coins into position is reasonable.
In a case where we have one data point (for example, human life exists on Earth), and there are an unknown number of outcomes (we could have been fish-men or dinosaur-men rather than hairless ape-men), and the factors leading to those outcomes are unknown AND too chaotic to measure, and there are NO other cases to inspect, no statement about likelihood is sound.
Far, far too often, people merely count the number of current outcomes (how many planets have moons, for example) assume all outcomes are controlled by equal factors occurring in equal numbers, and then made unsound statements about likelihood (that life can arise only on small planets with large moons, like Earth; and since the other nine planets in the solar system have tiny moons compared to their mass, or none, the conclusion blindly leaped-to is that Earth is an unlikely case, hence evidence of ‘fine-tuning.’)
Well, to the contrary, if the laws governing planetary formation were known (we have no first hand observations as yet to study) we might know whether or not rocky, inner worlds with large moons are commonplace.
We might discover, once we make contact with the Sevagram, that the case of Mercury and Venus and Mars with small moons or none is so odd that Galactic sightseers will come from all over the Milky Way to marvel at them, puzzled at these unusual moonless orphan worlds, and astonished to find three in one star system.
Of course, all these sightseers will be mile-long wormlike organisms born in the depth of gas giants larger than Jupiter and hotter than Venus, where all known forms of life are born under conditions extremely favorable to abiogenesis. The high pressures and lead-melting temperatures needed for known biological reactions being entirely absent from Earth, our world will be the only known case of life evolving on a small and deathly cold planet with no noticeable atmosphere. The use of liquid water as a fluid medium in the place of the normal semisolid methane gasses with astonish the scientists from these immense, boiling worlds.
They will have been carefully monitoring the frequencies of gravity waves and neutron vibrations that all the other races use to send messages across the void, wondering why Earthmen have never broadcast any. Their scientists speculate that no intelligent race would use radio waves, due to the massive interference both involved in atmospheric conditions of small planets and large, and due to stellar radio output. And so no one involved in the extraterrestrial search for earthly life bothers monitoring radio frequencies for signs of intelligent patterns.