Here is a possible solution of the Fermi Paradox.

If we could look outside the planetarium enclosing our Solar System, we would see the pitch darkness of a universe grown unimaginably old. Quintillions of years after the Big Bang; even the longest living stars have died; entire galaxies have evaporated and the gaps between them have increased a trillionfold. Life, however, still exists, though not life as we know it. Civilization is coterminous with the universe, living off energy released by feeding stellar corpses into the central black holes of galaxies.

Once there has been organic life. It arose in nearly every solar system of the young universe and rapidly (within a few billion years or so) flowered into civilization. The young universe positively teemed with civilizations, so that no inhabited world was more than a few lightyears distant from its nearest neighbours. They quickly integrated into galaxy-spanning wholes which eventually learned to communicate over intergalactic distances, giving rise to a universal culture. But with the aging of the universe, organic life gave way to machine-life, and the first generation of living machines was succeeded by other generations -- each one developed to cope with a new aera of the ever-changing environment. Now, after a quintillion years, even the number of these successive generations is no longer known. And as for organic life, it is all but forgotten. Some scientists actually deny that there ever was such a thing as organic life and propose that a fully formed machine civilization emerged from the Big Bang. The chances of such a thing happening are almost infinitely small, but one might posit an infinity of Big Bangs, just one of which spewed out a fully operational "seed". Anyway, there are no actual records left from the mythical age of organic life, so how life and civilization (which are almost synonymous) arose in the early universe is everybody's guess.

But the question could be investigated. The Department of Deep History decided to do an experiment. Some of its vast stores of energy were used to create enough hydrogen and other long-vanished chemical elements to shape a primordial solar system with exactly the mass and angular momentum which most theories of organic life predicted to be necessary. This primordial solar sytem -- our Solar System -- was encased into a spherical planetarium studded on the inside with projectors creating an electromagnetic an corpuscular backdrop which was programmed to faithfully mimic what the experimentors imagined the Extremely Early Universe to have looked like. This having been done, the experiment was allowed to develop naturally for a few billion years.

To the experimenters, living with very slow thought-processes in an extremely cold environment, a few billion years are almost nothing. A passing thought takes a century, the coffee break takes a few million years. The one lightmonth diametre planetarium, to them, would be no larger than a microscope slide to us. But to them, it's mean temperature of around three Kelvin would be something like the heat of a nuclear explosion to us. Because what they are trying to do is to recreate, in a very small volume, the conditions pertaining in the universe almost immediately after the Big Bang -- akin to what we are doing with our accelerators.

And of course there are no other civilizations "out there" for us to communicate with...