The Fermi Paradox

Introduction

Using data from NASA's Kepler space telescope, an analysis was conducted to find out how many stars have atleast one planet within their habitable zone. The results were unexpectedly optimistic: According to NASA's data, 22% of sun-like stars have earth-sized planets within their habitable zone. With 40 billion sun-like stars in our galaxy, that leaves us with 8.8 billion earth-sized planets in their stars habitable zone in just the Milky Way.

To clarify, this is not an estimate for our entire universe. This is not an estimate for Laniakea, our galaxy supercluster. This is not an estimate for our local group but just our galaxy. Based on what we now know, it would be insane to wholeheartedly believe and assume we are alone in the universe.

Then again, why don't we see anyone? To be able to determine what we are looking for and what our best chance at trying to find it would be, we first have to understand how future civilizations would most likely evolve.

Technological evolution

From as long as we can think, our state of technological progress has formed our way of living. We lived in caves when we didn't know how to build, we lived in tents when we figured that out and we lived in small houselike structures when we found out how to heat them. With the industrial revolution taking place in the second half of the 19th century, rural agrarian societies were transformed into cities with large factories, replacing small productions.

As the amount of energy available to us increases, so does our infrastructure, adapting to the newest state of the art. It is expectable for other species to behave likewise, which is why the Kardashev Scale is the preferred measurement when trying to find out what more advanced species probably look like and what they would most likely build. After all, we can't search for fast food stores and soccer stadiums on distant planets, so we have to find out what kind of megastructures they are likely to build for us to be able to look out for those.

Therefore, let's find out what we are looking for!

Additional Resources

1.
UniverseToday has published an article discussing the data from NASA's Kepler space telescope in a more thorough manner, if you want to find out more about the data analyzed.