Does the Fermi Paradox keep you up at night? Have you ever wondered if humanity is the only technologically advanced species in the observable universe? Are the FAZA actually going to invade!?!?! I know, really scary questions. 🙂
To give it some serious thought: given the universe’s 13.7 billion year age, the number of galaxies in it, the number of known and estimated planets in the habitable zone of stars in our Milky Way Galaxy, the speed at which single cell and multi-cellular life started on Earth, how soon intelligent and tool-using organisms developed on Earth, and given how long technological human civilization has been around (and assuming we don’t destroy ourselves, there’s the potential humanity will become interplanetary and interstellar), scientists like Enrico Fermi have wondered, where is everyone?
Let’s learn more from one of my favorite YouTube Channels, PBS Spacetime.
Good questions, but Fermi didn’t consider the time factor. Here’s one way to look at it: The estimated lifespan of the universe is 100 trillion years (100,000 billion years). At 14 billion years, we’re just over 1/100,000th of the way through the universe’s lifespan. Yet we know for certain life and sentient life evolved at least once – that happened pretty fast! Let’s also suppose 1 million sentient species evolve over the universe’s lifespan – sounds like a lot, right? That would come out to one sentient specie every 100 million years (keep in mind the dinosaurs died out just 65 million years ago). It’s entirely possible that life is so rare, and sentient life rarer still, that sentient life never coexists in time and for 99% of the time, there is no life or sentient life anywhere in the universe. The universe just doesn’t operate on our tiny time scale.