I find the definition of intelligent life, specially as given by astronomers, amusing. Looking for a second carbon-based lifeform, in a planet identical to Earth, beeping out on the radio spectrum, in the same time frame as us? How cute.
Meanwhile, we miss a bigger definition of life right under our noses. Unfortunately reductionism is ingrained in science.
Certainly one that doesn't put lifeforms in a lifeless universe like actors in a stage.
Astronomers should be the first to propose that, since they know how the carbon molecules in them can be traced back to a nebula, just like mitochondria can be traced back to a life form from Earth's early days. The parallel is obvious to me.
The Gaya hypothesis, for instance, gives a saner view of how the biota and biome are the same thing, and still, gets dismissed as New Age stuff. And that's talking just about Earth, mind you. Expand the theory to the entire Universe and you will be ridiculed by Dawkins himself, even though this "hunch" is persistent.
Many past thinkers had a gut feeling about this, with less data than we have today. Read about "Anatta" (Buddha's concept of "not self"). Or read about "Tao" (Lao Zi's concept that has surprisingly parallel to what we now call "Big Bang" and how nature works out of pure probability). This is all surprisingly insightful knowledge, made out of pure intuition.
But because post-illuminism abolished holism, we end up looking for analogous of humans with radio antennas, Dyson spheres, among other increasingly ridiculous things, and that gets called science. Meanwhile, ideas like Universal Darwinism are ignored.
Meanwhile, we miss a bigger definition of life right under our noses. Unfortunately reductionism is ingrained in science.