“The Fermi paradox is the conflict between an expectation of a high ex-ante probability of intelligent life elsewhere in the universe and the apparently lifeless universe we in fact observe.”
We can estimate the chances of being alone in the universe with the Drake equation. Here it is: N = R * fp * ne * fl * fi * fc * L, where fi is the fraction of life-bearing planets on which intelligent life emerges, fl = The fraction of suitable planets on which life actually appear, and fc is the fraction of civilizations that develop a technology that releases detectable signs of their existence into space.
Let’s examine fi-fc transition. The word “civilization” exists only on Eartha and by applying that notion to aliens we assume that they would behave like humans, that they would have a wheel, New York, wars, and so forth. But would you consider any intelligent life a civilization? The scope of intelligence must be much broader.
Can you think of a chance that a bunch of carbon atoms would after a billion years discover radio waves and invent a way to transport them?
Yet we wonder why we don’t get any radio signals, don’t see any spaceships from Star Wars in vast space or any signs of colonization. We are the ones who created that stuff.
Also, the reason we don’t notice anybody may be that there are many other ways to perceive the world around us that we are not ware of, and they may just function in other “dimensions”. We forgot that we don’t know what we don’t know.
Estimates in “Dissolving the Fermi paradox” were built upon “historical estimates”, “best estimates” and “the authors’ best judgment of the scientific uncertainties for each parameter”. There are no pessimistic/ optimistic numbers for the fractions because we don’t have a single solitary piece of data. The fact that we exist makes the likelihood of human-like life existing elsewhere in the universe miserable. So when it comes to ETI, we can’t let ourselves think about it by analogy. We won’t find life as we imagine it.