Privileged Planet (Chapter 3 of 12) the search for purpose in the universe
This starts off with a statement that the Copernicus Principle (an outgrowth of???) and maintains the belief that habitable planets and complex life are abundant throughout our galaxy and universe and this is simply not true.
The mediocrity principle is the notion in the philosophy of science that there is nothing very unusual about the evolution of our solar system, the Earth, any one nation, or humans. The mediocrity, as the Copernican principle, states that life on Earth depends on just a few basic molecules, the elements that make up these molecules are (to a greater or lesser extent) common to all stars, and the laws of science we know apply to the entire universe (and there is no reason to assume that they do not). Given sufficient time, it seems reasonable to expect that life would originate somewhere, and has probably originated elsewhere in the cosmos. This idea is bolstered by Edwin Hubble's discovery that the universe is substantially larger than humans first thought. The Hubble Deep Field is a long exposure of thousands of galaxies, making it one of the best pictorial representations of the principle of mediocrity.
In short, Copernican mediocrity is a series of astronomical findings that the Earth is a relatively ordinary planet orbiting a relatively ordinary star in a relatively ordinary galaxy which is one of countless others in a giant universe, possibly within an infinite multiverse.
SETI (Search for ET) is a pointless endeavor to find the aliens simply because of the time constraints, in the 10’s of thousands of years … wake me when the call comes in, hehehe. As much as we like to think of the future, all we can do is look to the past for our answers, go figure. Astrobiologists have discovered 100 planets in our immediate neighborhood (a measly few thousand light years). How about within 50 billion light years I wonder.
Are habitable planets rare or common in the universe … is unanswerable today because we are just technological midgets and have a few things to learn yet (like civility hehehe). Someone in there said there were one hundred trillion billion stars in the observable universe (???) … but that could also be just a drop in the bucket. All I do know is that the universe is infinite at least as far as humans are concerned because we cannot comprehend 46 billion light years … and besides an end would require something that would have to be irrational??? Like God?
Conditions for life in the universe factors required are numerous agreed, but the requirements go down if one is not interested in growing humans … but we do think a lot of ourselves don’t we.