If we think for a moment about the size of our universe and how many Earth like planets orbiting a star much like our Sun, it doesn’t take long to begin to wonder, where is everybody else? This is called the Fermi Paradox. Some estimate that there should be about 10 quadrillion (10 million billion) intelligent species in the universe, so why do we not have any evidence of even just one other intelligent species. While there are various possible explanations for this paradox, one especially interesting one is called the Great Filter theory. This theory suggests that before an intelligent species can reach the point of interstellar colonization (Type III Civilization), it must accomplish a difficult evolutionary leap that almost all species fail to achieve. So, what does this theory suggest about our species? The first of three possible options is that we’re the rare species that managed to already make the almost impossible evolutionary leap.
This would mean that we are already on our way to achieve interstellar colonization, and that it is simply a matter of time before we do so.
The second possibility is that no civilization has reached the Great Filter yet, and that we may have the necessary resources to achieve Type III Civilization.
One objection to this option is, if the universe has been along for such a long time before our civilization developed, how could we be the first to achieve Type III Civilization? One explanation is that the universe is only now capable to sustain life long enough for it to develop. This is backed by our observance of gamma-ray bursts in distant galaxies, which would prevent life from developing.
The third and final option for where we stand in the Great Filter theory is that we lie before it.
This means that it is only a matter of time before we hit the metaphorical brick wall that stopped all other instances of intelligent life from achieving interstellar colonization.
Sources: The Fermi Paradox
Featured picture: Interstellar sunrise illustration