Most of you have heard the argument by physicist Enrico Fermi, who posited that if there are so many stars in the galaxy, and with all the probability that a lot of them have developed intelligent life, that even with the slow speeds of interstellar travel the whole galaxy could be completely traversed in a few million years.
So, the question of the Fermi Paradox is, where are they?
That tiny little speck that the arrow points to is our little sun. While our sun is pretty much essential to us, it might not be that interesting to a space-faring civilization. Look at the map, all the action seems to be in the center there. We are in the middle of nowhere, with the closest stars being Alpha Centauri A and B (4.3 light years) and Proxima Centauri (4.22 light years).
Even though Proxima Centauri looks pretty close at only 4.22 light years, with our current technology it could take about 81,000 years to get there (assuming we could go about 56,000 km/hr with about 80 kg of propellant). If something like the EM drive becomes possible, we could knock that time down to about 13,000 years. There is another promising theory for propulsion using nuclear pulse, and this could knock the time down to 36 years. That would be a lot more feasible for us, but for now we aren’t even sure it is possible.
If you look at these limitations, and start thinking about where you would want to go, Earth just wouldn’t be on your alien bucket list.
The other thing is, we just discovered radio waves in the 1890’s. So we’ve only been able to detect radio waves for a few hundred years. We might discover new ways to communicate, like something using quantum entanglement, that would allow us to communicate at large distances faster than the speed of light. There is likely some technology that will obviate the use of radio waves, and if so then a developing civilization might only use radio waves for a few hundred years. If aliens developed radio waves a few thousand years ago, and then started talking with their quantum iPhones to each other, well we would have missed that window where we could have picked up and interpreted their radio signal.
There are many other theories about why we haven’t heard from anyone, like there is a super intelligent race that wipes out any advanced civilizations before they become a threat, to the idea that we are so unique in the universe that we are the first and only intelligent beings that exist. If that last statement is true, then I feel like we should be doing everything we can to explore and colonize space, rather than fighting each other over resources here on Earth.
If you think about it, compared to the resources we have here on Earth, the resources available to us in the galaxy, especially if we are the only intelligent life forms that exist, are essentially unlimited. We should be spreading out and giving every person their own planet, rather than fighting each other over what we have here.