Ask Lemmy

I think there are many great filters, but I think one of those filters is fighting over limited resources and wars. Perhaps limited to humans/earth, but I doubt it. Nukes, dropping rocks from orbit, and theoretical (but possible) weapons like black hole bombs are all going to tempt irrational beings to take someone's stuff.

We have to be extremely careful that we don't accidentally trigger a weapon that is going to kill or dramatically cripple our civilization before we become a truly interstellar species. There is so much to learn out there, while so many people are currently focused on the wrong things such as minor conflicts or what children aren't allowed to learn.

I'm sure simply continuing to live will show me more about possible great filters than most teachers could unfortunately.

Resources often get squandered on trivial vanity and novelty products instead of being channeled into advancing science and medicine. Imagine if we had a cosmic ledger tracking every resource used to develop simple items, like a pencil. It would show countless fires burned and animals consumed just to fuel the human ingenuity required for lumber, materials, and mining. Now, think about how many more resources are required for rockets, heat shields, and life support systems. Extend that to space stations, energy capture, and escaping Earth’s gravity.The resources on a planet are abundant, and nothing is ever truly destroyed. However, we’ve often allocated too much to building flat-screen TVs, leaving little for constructing even a modest space station in orbit, let alone an interstellar spaceship. It's as if the planet offers a finite amount of resources, challenging its inhabitants to focus on space travel. Only a species wise enough to stay on track can unlock the universe's resources. Otherwise, we risk ending up like Australian pines, choking ourselves out in our isolated star systems, having wasted our potential.

Imagine it like interstellar travelling having a single path to achieve it while the path to self destruction is limitless.

It's a society (or the whole humanity) becoming big enough to survive even when ignorant murderers are the elite and the majority of it, and civilized people - a smaller part and almost a property, similar to animals in a zoo.

When such a point is reached, the former will make the transition, and the latter will diminish over time. Then it just has no future.

A bit like with Ottoman empire and Qajar Iran, only on the scale of the whole humanity there won't be someone else to buy weapons and technologies from to keep going. Then some of the previously passable filters will kick in. Like hunger or resource scarcity.

I don't think there is a single universal Great filter, and living and then potentially sentient beings with various traits will face various obstacles.

First, life needs suitable materials for polymers and a lot of energy. Most places don't have both.

Next, basic blocks of life that would be self-replicating and adaptive should be randomly generated, which is extremely unlikely and literally took over a billion years on Earth, a planet with generally great conditions for such process.

Then, those blocks should be able to get together to form complex structures - ideally, many separate ones, so that one event wouldn't destroy the entire effort. Earth had it easy, with billions of super simple life forms.

Next, assuming life survived up to this point in a potentially unfriendly and ever-changing environment, bombarded by UV light and exposed to myriad of sources of damage, it should not destroy itself or environment too badly to never recover. Earth had periods when life generated too much carbon dioxide or too much oxygen (yes, that too was a thing), and those were critical points at which our story could very much end.

Then, life has to evolutionize and get into complex forms, either by forming multicellular organisms or by making a cell a powerhouse of everything.

Then, life has to get sentient, and some kind of response system should be available and get highly complex.

Then, most of the sentient creatures just won't be tribal, and civilization requires society and a common effort.

Then, many more won't be expansionist, and will die out in some small region.

Many also won't be competitive, which would slow down evolution.

For those species who are competitive, they shouldn't destroy each other while they're at it, and this is currently one of the risks of our own.

And after all that, they should develop space travel and either get as developed and decisive and resource-rich as to send a generational ship to some random planet named Earth populated by genocidal monkeys, or to somehow hyperdrive here. They can very much decide it's not worth it, and they may be so far away we couldn't see signs of their civilization.

Pushing Ice by Alastair Reynolds is one of my favorite scifi books and it deals with this question in an interesting way. It proposes that Time is the great filter. Life exists in this galaxy, but intelligent life is so fleeting when considering galactic distances that the probability of one sentient lifeform finding another during their "peaks" is vanishingly small. Extinction, societal collapse, evolution to a higher form, whatever you want to imagine, it all gets in the way of the fantasy of meeting a thinking being from another planet.

The way the news has been going I wouldn't be surprised if plastic is a candidate. After a little less than a century of rapid development in petrol-plastics we're starting to figure out the long term effects. But the next 1000 generations may be dealing with the fallout.

sentience. I think it usually immediately leads to suicide