Fermi Paradox: Where is Everyone?

Aayushi Vaish
3 min readNov 22, 2021


Are we the only living beings in the entire Universe? This is a bizarre question itself.

The observable universe is about 90 billion light-years in diameter consisting of 1000 billion galaxies with billions of stars in them. Recently we have learned that planets are very common. There are probably trillions and trillions of planets in this Universe which means there should be lots of opportunities for life to exist and develop right. But where is it?

Fermi Paradox questions the existence of any intelligent extraterrestrial life. So, Where are the Aliens? Since the whole Universe is so big and even with small assumptions, there are still millions of planets that can harbor life as we know it. But we haven't found any evidence of it yet!


Are there any great filters that are acting as barriers? The great filter can be divided into two sections. The one which we have crossed already, which means we are one of the first intelligent civilizations. These can be like the protein-synthesis process for a multicellular being that can be a very complex process that only happens very rarely and need some precise conditions to occur. So, Congratulations! We are the first intelligent civilizations and most likely to expand throughout this galaxy in about a million years which is pretty good news for us.

On the contrary, the worst-case scenario could be in the form of the great filter which lies ahead of us. For example- Any event that can wipe out the whole civilization. So it is high time that we should start taking climate change quite seriously, moreover the use of Nuclear weapons should be reduced. The most horrifying filter can be an asteroid from the outer galaxy hitting our planet. If this is the case we just have to venture to the Stars and become the first type-3 civilization to keep the delicate flame of life existing and to spread it until the universe breathes its final breath and vanishes into oblivion.


The classification of civilization is defined by Kardashev Scale. The Kardashev scale is a method of measuring a civilization’s level of technological advancement based on the amount of energy it is able to use. There are three categories-

The types of civilization harnessing energies respectively.

Type one: This civilization would be able to access the whole energy available on its planet. In case you’re wondering we’re currently around 0.73 on the scale and we should reach type 1 sometime in the next couple of hundred years.

Type two: This civilization is capable of harnessing all of the energy of its home star. This would require some serious science fiction but it is doable in principle concepts like the Dyson Sphere a giant, the complex surrounding the Sun would be conceivable.

Type three: This is a civilization that basically controls its whole galaxy and its energy an alien race that this advanced would probably be godlike to us but why should we be able to see such an alien civilization.

But why should we be able to see such an alien civilization in the first place?

If we were to build generation spaceships that could sustain a population for around 1,000 years we could colonize the whole galaxy in 2 million years, sounds like a long time but remember the Milky Way is huge so if it takes a couple of million years to colonize the entire galaxy and there are possibly millions if not billions of planets that sustain life in the Milky Way and these other life-forms have had considerably more time than we’ve had then where are all the aliens?

The universe is too beautiful not to be experienced by someone!



Aayushi Vaish

An Explorer of the Infinite Multiverse . MS - Physics , Northeastern University.