I have come across this idea once or twice and wanted to put up a post about it.
The basic idea tries to explain one of the infinite solutions to the Fermi Paradox ( Which states that when you do the math, and based on all the stars and planets out there, coupled with the age of the universe, there should be an abundance of intelligent life in the universe. But despite playing the numbers game and as far as everyone else, myself included, knows there are no other intelligent life forms out there, hints the paradox.) The Great Filter (GF)Theory is a theory that may help to explain why this is the case.
The theory states that along the way life has many hurdles to overcome. The first is obviously coming into being, that is the largest hurdle, and nothing short of some kind of a statistical miracle all by its lonesome. But once that takes place then the race is on. The article goes on to state that single celled organisms ruled the earth for over 3 billion years, yes with a ”B.” Then for whatever reason the single celled organisms evolved into multi-celled creatures, then from there it was just a matter of time before we came along. Along with this theory there are a variety of other theories sprinkled in. One states that as I alluded to above that life, we/humans, are just the lucky pinnacle of a line of highly, insane, astronomical, series of events, in other words we are very extremely lucky to be here. The other line of thought is that more or less life will find a way. I am more inclined to believe the latter, as it seems to make more sense in terms of what we observe in the universe. If life were not an extreme statistical anomaly then I think we would have made contact by now or at least found something saying that we are not alone. But there is also a quote I remember from Stephen Hawking in his book A brief History of Time, it was something like, “the odds of the peak of our civilization and the peak of another civilization coinciding is infinitesimally small, so basically it would almost never happen. Although if the universe it infinite then it is bound to happen sooner or later, but then you have to think about the odds that it would happen to us. So we are back to another cyclical argument.
The interesting thing here is that some scientist think we may have already passed the GF by evolving from single celled to multi- celled creatures, stating that this feat was quite miraculous. They believe that getting past this point is truly amazing and that potentially most life in the universe may never make it past the single celled phase. Others are not so sure that this is or was the GF. Some scientist claim that we have yet to make it to the GF and are not sure if we will survive long enough to make it there, whatever it may be.
I would like to think that maybe there are two GFs. One that produces multi-celled organisms and another where the intelligent civilization figures out a way to have sustainable clean energy. I honestly believe that for an emerging intelligent civilization (ie. humans) this is the biggest problem to overcome. If we continue to grow as a species not only in size but also our energy consumption something will have to be done or we could very easily destroy ourselves either though pollution or the potential consumption of the majority of all natural resources. Recently I posted about World Overshoot Day, so this scenario is not as farfetched as it sounds.
Overall the theory is very interesting and does raise some valuable questions. Maybe a few more points are needed to make the theory viable, like, when a civilization reaches a certain threshold maybe another filter approaches. For us we have surpassed the single celled/milti-celled filter, out of pure luck, now we are looking at the energy crisis filter. In my mind there is no other threat that could potentially destroy us as a species, except nuclear war, but let’s hope that never happens.
Another post I put up not too long ago had to do with the measurement of intelligent life in the universe, known as the Kardashev Scale. This scale basically says how advanced a civilization is based on their energy consumption. For the record we do not even classify as a category I civilization, that is a little depressing to say the least. If we want to eventually explore/colonize the universe we will have to be able to surpass the energy filter. If we do not we are in for a long slow agonizing death on the Earth probably along with most other living things on the planet. Bummer…
The really crazy thing to think about is what filter lies beyond the energy filter. Once we have solved the energy crisis what will the next problem to face and or limit humanity be? I think that could possibly be our inability to travel in deep space. Right now this problem is multifaceted as we do not know what will power a vehicle long enough to travel in deep space, along with how our flesh and bone bodies could survive such a trip. These are just a few I am sure there are a ton of other things, but if we could figure out the energy part then that opens up a whole new set of possibilities.
Check out the article if you get a chance pretty interesting read.