Before we get into the many possibilities and theories about the universe as a whole and what resides within it, let's try to understand what the Fermi paradox actually is. The Fermi paradox, named after the founder of the theory, Enrico Ferm, a physicist, is a simple yet complex bundle of ideas and questions asking if we really are alone. First off, there are an estimate of over 200 billion stars in our galaxy, and on top of that, at least 100 billion planets in just the Milky Way alone — whether any of them are habitable or uninhabitable, we’ll get to that soon. As for the number of galaxies within the observable known universe itself, there are an estimated 100 billion to 200 hundred billion, and possibly more, galaxies each containing of their own billions of stars and planets. Now you know how tiny we are compared to the universe. We’re smaller than a grain of salt. Scary, isn’t it?
The Milky Way Galaxy
So, now you would think that since there are so many stars, planets, and even suns in our galaxy that could support some type of life elsewhere beyond our little blue globe, whether it be microbial and/or bacterial existing life or an actual legitimate and advanced civilization like ours, the universe must be flourishing and thriving with life. And it just might be. After all, the universe is over 13 billion years old, and with Earth being a little over 4.5 billion years old, we couldn’t just be the only ones who just happened to evolve and harbor life on our tiny blue planet; there must be many many planets already containing life, possibly in the hundreds, thousands, or millions. Yes, there could be millions of planets that could harbor some form of intelligent life besides our own. Many even getting a head start of a some million or billion years ahead of us in advancement, but… where are they? Whenever we look up into the sky, why don’t we see hundreds of ships flying over us? Or whenever we visited the moon, why weren’t there several others who were willing to do a meet and greet with us? Maybe the universe actually is teeming with ships, with everyone visiting and contacting one another but they don’t always make their presence known, or maybe we’re not advanced yet and so we don’t know how to give and receive messages. For all we know, we could have hundreds and thousands of missed calls, or ignored messages from our neighbors in space. How rude of us! Maybe when we did visit the moon, there were many flying all around us, and possibly, the moon itself could be inhabited, but why weren’t we informed of such? Well, the government doesn’t always tell us everything, now do they? But hopefully one day there will be a full disclosure and the public won’t be kept in the dark anymore.
Planets Within a Galaxy
As for the number of planets that could be habitable, there are several estimates and opinions since we do not know the exact number. According to some major scientists there are well over 30-60 billion planets within our own galaxy that show similarities with the Earth that orbit the zones of sun-like stars. Some are even thought to have two or more suns. So that begs the same question all over again: where is everyone? There are many theories and evidences that show us that others may have visited us and have done so for a very long time and for various different reasons. Just like us, they would also be curious to study the universe and planets around them and finding us would be like finding gold or treasure of some sort. It’s not every day you find some major discovery so it is very likely that many others have discovered us, talked to some of us, or have kept themselves hidden and observe us from a certain distance. As for us visiting them? There’s two things you can theorize. One, we simply do not have the technology to go out far into our galaxy and definitely not venture out into other galaxies so that would make galactic traveling for us a bit difficult. So, in other words, we will not discover the many habitable planets, or visit them for a couple hundred more years or longer. They’re just too far away and we can’t risk it. Time is very different when you’re in space. You could travel some hundred light years and it may feel like a short time has passed but when you go back to Earth, everyone you ever knew would either be very old, or dead. This is not science fiction, it is science fact. Two, maybe we do have some form of hidden technology and we are able to use it to travel within the limits of our galaxy however, it has not been revealed to us yet and may not be for the next few hundred years or so.
Galactic Travel Wormhole
Some people also suggest space travel through wormholes, which are thought to be portals that could lead us to many worlds in a short period of time — and by some, are said to be time machines. However, that’s also a risky thought due to many of the dangerous possibilities of diving into one since we know so little about them. As of now, all we can do is improve and advance further and hopefully one day we will explore the universe without worrying about time in space and we might even find many (uninhabited) habitable worlds for humanity to thrive on.