The Great Filter
Have We All Become Really Lucky, Or Are We All Doomed?
J. Pan
With the universe’s existence spanning 13.7 billion years and humanity taking less than 0.0001 percent of that to go from pre-civilisation to space exploration, with the millions of possibly inhabitable stars in the Milky Way galaxy, alien life – or more specifically, the lack thereof, has astonished scientists for decades. Described as the Fermi paradox, despite many attempts to connect with other planets, it seems that life is way scarcer than it should be in the universe. Not only have we not found life, but life has not found us – if there existed sufficiently advanced life that developed to the point of interstellar travel, they would have massive incentives to contact us.
Clearly, there must be something that hinders the creation of civilisations other than ours. The Great Filter Theory formalises this – there must be a “stage” that is so rare that it filters through basically every possible star and planet in the universe to make it impossible for life, thus making us the only ones to survive.
The Great Filter argument describes nine primary stages:
- The right star system (including organics and potentially habitable planets)
- Reproductive molecules (e.g. RNA)
- Simple (prokaryotic) single-cell life
- Complex (eukaryotic) single-cell life
- Sexual reproduction
- Multi-cell life
- Tool-using animals with intelligence
- A civilisation advancing toward the potential for a colonisation explosion (where we are now)
- Colonisation explosion
Currently we are at Stage 8 – a functioning civilisation and in the next 1000 years, SpaceX and NASA have placed precedents for the potential of interstellar travel. The Great Filter states that at one stage, the vast majority of potential civilisations were “filtered” out from possible interstellar exploration. Two distinct possibilities are presented through the theory:
On one hand – the Great Filter could be from stages 1 to 8 which we’ve already passed through. In these cases we are lucky – we’ve passed through the Filter already, and there’s no definite risk of extinction in the future.
However, on the other hand, if we find another civilisation at the same stage of development as us – we may be doomed. The existence of another civilisation in stage 8 implies that we have not yet passed the Great Filter and it is in stage 9 – thus, we are doomed to extinction prior to colonisation explosion, and both we and the other civilisation are doomed. The question of alien life continues to astonish both academics and the average person alike, and the Great Filter might be the theory to explain it. Is the Great Filter just an outlandish theory? Have we already passed the Filter, or are we doomed to extinction in the near future?