We can’t just assume countless lands out there

Dartmouth College Physicist and Astronomer Marcelo Gleiser recently wrote that the Copernican principle has been misused to imply that the Earth is somehow insignificant. This, he says, is a philosophical attitude, unrelated to science. We don’t know where the Earth is in relation to other planets because we don’t yet have telescopes that can get a lot of detail about planets outside of our solar system.

Gleiser, author of The island of knowledge (2014), also discussed the Principle of mediocrity (because Earth is nothing special, there must be countless intelligent civilizations out there).

According to Britannica, “Widely believed by astronomers since the work of Nicolaus Copernicus, this principle states that the properties and evolution of the solar system are not unusual in any way. Therefore, the processes on Earth that led to life, and ultimately to thinking beings, could have occurred throughout the cosmos. “

Gleiser finds the logic of the principle of mediocrity similarly want:

If we limit the Copernican Principle to a statement that Earth is not a special planet in terms of its location in the universe, then all is well. The problems start when we extrapolate to statements about the ubiquity of life in the universe, following the mistaken notion that if Earth is not special, neither is life. This is a massive non-sequitur. It becomes exponentially absurd when elevated to the so-called principle of mediocrity: since there is life on Earth and Earth is not a special place, life should be abundant on similar planets. to Earth around the universe, including intelligent life. In other words, the principle states that life is so abundant there that it is a poor property of the universe. This kind of thinking is not only bad science but also bad philosophy, and it has serious repercussions on our current project of civilization. If our planet and the abundant life it contains are so insignificant to the point of being mediocre, why respect either?

MARCELO GLEISER, “THE MEDIOCRITY OF THE PRINCIPLE OF MEDIOCRITY (FOR LIFE IN THE UNIVERSE)” TO THINK BIG

He concedes that the Principle may be quite valid under controlled circumstances: if most of the balls in a box are red, you are more likely to draw a red one at random. Where stars are otherwise similar, the Principle can be useful in making probability decisions in astronomy.

But the probability of life on other planets presents us with a very different situation: the Principle assumes, in the absence of any evidence, that the Earth is typical in terms of properties and life forms, not just its position. And this is what he considers an unwarranted assumption.

Read the rest on Mind matters, published by the Bradley Center for Natural and Artificial Intelligence at the Discovery Institute.