When we attempt to think about domains about which we lack much in the way of substantive knowledge it's rarely a good idea to use analogies and wild extrapolations. The universe is not like "a computer simulation" any more than it is like "a giant steam engine." Every age seems doomed to interpret the world in terms of whatever the dominant whizzy technology happens to be, and every age therefore fails to avoid misleading similes. Moving on to the idea that "we are not alone" it is necessary to define the word "alone." The universe - even the small portion we can presently observe - is vast. To all intents and purposes we are, and necessarily always will be, completely alone. At the risk of violating my own precept, imagine someone on a small island in the middle of the Pacific ocean. Yes, there are billions of human beings elsewhere on the planet, but as this lonely human has no means of leaving the island, nor any means of communicating with anyone, and as the island is far from any shipping lane or flightpath, our representative person is to all intents and purposes totally alone. The fact that other humans exist elsewhere is irrelevant because they can never be contacted in any way. This is a reasonable analogy for our situation, except that when it comes to the universe, we have to factor in time as well. Suppose that some extremely rare technological civilization came into being in a galaxy 10 million lightyears away. They exist in their technological state for around 1,000 Earth-years before accidentally exterminating themselves. In 2024 we detect a few faint signals they emitted ten million years ago. Does this mean we aren't alone? Of course not. By way of analogy, let's imagine our desert island dweller one day finds a message in a bottle washed up on their beach. The message is from someone who lived in the 19th century and thus died long ago. Does this mean our island dweller is no longer alone? Of course not.
Finally, we really do need to realize that technological civilizations are probably vanishingly rare, for reasons I've elaborated on in a Medium article several months ago. Sci-fi stories are amusing but a very poor guide to reality. It's a shame so many have been so influenced by them.
