We’ve been asking ourselves if we’re alone in the universe for a long time, but the general lack of data about the rest of the universe means that the question has so far been impossible to answer. Generally, people are either optimistic that aliens exist, or pessimistic about the idea. Since 1961, we’ve been relying on the Drake Equation, developed by astronomer Frank Drake, to figure out the chances of alien civilizations existing. Generally, the equation says it’s unlikely, but we honestly didn’t know much about the universe then.
Fast forward to, well, the present, and we’re finding other planets all over the place. We used to think that very few stars had planets, and that even fewer could possible support liquid water (which we’ve assumed is required for life). Turns out that the percentage of stars with planets is probably a lot closer to 100%, and maybe as many as a quarter of those planets are the right distance for liquid water. We also know so much more about life, even on this planet, that it seems possible life could develop in very different ways.
Which brings us to this: while we don’t know if there are other technological civilizations out there right now, there’s basically no chance that we were the first such civilization to arise. Adam Frank and his colleague Woodruff Sullivan have been doing some updated math, and they’ve discovered some interesting numbers to share. If there is less than one habitable planet out of 10 billion, then yeah, we might be the first. But, even if there is only one habitable planet per 10 billion planets, then there has been about a trillion civilizations during the life of the universe.
Those are absurdly big numbers, but they boil down to one simple point: even if we’re alone right now, we’re not the first to feel that way.Alien Civilizations Had to Exist