In a galaxy far far away… alien life forms exist. However, if these aliens are truly existent in the universe, how come we have not been in contact with them?

It is theorized that there are millions, possibly billions, of habitable planets throughout the universe. Unfortunately, even if this is true, the human race will never be able to discover planets outside of our Local Group due to the ever expanding universe caused by the ubiquity of dark matter. This being said, our Local Group containing various galaxies is still believed to inhabit millions of life-sustaining planets.

Earth is roughly 4.5 billion years old, making it a relatively new planet when considering the Milky Way is approximately 13.2 billion years old and the Local Group with other galaxies preceded it. With all of this time in a suitable environment, isn’t it only logical that there were millions of chances for life to develop and create an advanced society? With these hypothetical planets having billions of years of societal development on the human race, shouldn’t they have achieved accelerated space travel, ominous galaxy satellites, and other unknown futuristic technological advances? If aliens did exist, they’d have the resources to reach out to other intelligible life forms. Which begs the question: where are they?

This phenomenon is known as the Fermi Paradox, named after the Italian physicist Enrico Fermi. He argued that since there is no plausible evidence suggesting that aliens exist, they simply do not. This incoherent logic is one that scientists use to dismiss many scientific enigmas. Perhaps the most controversial one being the question of does God exist. The utter lack of evidence allows for people to easily conclude if something either does or does not exist. Ironically, the most ludicrous part of this predicament is that no one can prove each other wrong on neither side! Thankfully, several modern physicists have taken the effort to define the different types of civilizations, where the human race lies in it, and possible ideas as to why we have not had any alien encounters.

The differentiation of life forms’ advancements is currently measured on the Kardashev Scale. The lowest level, Type 1, is able to utilize all of their planet’s natural resources and efficiently use its energy. A Type 2 civilization would be able to fully harness the energy from its home star. While this seems unreasonable, conceptually it is doable with contraptions such as the Dyson Sphere (a hypothetical structure that completely encloses around a star to encapture all or most of its energy). Lastly, a Type 3 society is one that would be able to control the energy within its entire galaxy. This type of civilization is the one most commonly displayed in science fiction movies, who travel throughout the galaxy to siphon resources from all of the sustainable planets, while the victim’s inhabitants die as collateral damage. This omnipotent society would seem god-like to us, and virtually become the rulers of the Local Group.

On the Kardashev Scale, Earth is currently 0.73 and is expected to reach Type 1 within the next couple hundred years. This fact of Earth coming short of 1 on the scale blatantly shows how young this planet is in our universe.

Earth’s youth is one of the biggest concerns when looking at the current reasoning as to why other life forms have not been found. The main theory is the ideology of filters. A filter in this sense would be an obstacle that a habitable planet cannot pass in order to develop life. This has led us to believe that it is truly harder than we perceive for life to begin and develop into complex organisms, and Earth has miraculously made it through these formidable filters. On the other hand, our train of thought may be heading in the complete opposite direction.

The worst case scenario when considering filters, is the concept that there are several filters, with there being a final filter that no planet has ever passed. This implies that life on Earth could possibly be eliminated by this final obstacle. Perhaps there have been several civilized planets equivalent to Earth’s human race. However, these civilizations may have never been able to reach out to us, for their technology was not advanced enough before they reached that final filter. The most astonishing thought of all is the possibility that this has recurred millions of times, with every time ending in annihilation.

However, maybe the easiest answer is that there are no other life forms and the human race is stranded on a mired planet with no other inhabitants in the entire universe; that we are purely alone in this majestic space of nothingness.

Perhaps that is the scariest thought of them all.