Well, I’m not sure you’ve considered the time-frames involved in that concern. We have a whole lot of time before the sun goes out on us. It took Earth about 2 billion years to develop multicellular life. It then took another 2.5 b before we got vertebrates. That was the hard part though and it’s done, I don’t think there’s any undoing it. There aren’t many things that could wipe out all forms of vertebrates on earth, so I’m confident that would be as far back as the planet could reasonably be set back by any disaster.
Just 60 million years ago, mammals were not at all a dominant form of life, yet that’s all it took for early rodent-like mammals to evolve into human beings (as well as all the other mammals we know today). So based on that timeline, if all human life on the planet were wiped out tomorrow, I’d estimate (pessimistically) it would take less than another 200 million years before another species gained a similar level of intelligence and began a new era of civilization (and perhaps as little as 10 m years, as some species are already quite intelligent). In fact, if the next species screws up, and gets themselves killed, I expect earth will get another go at it in another 10–200 million years, over and over again.
On the other side of the equation, the sun will expand into a red giant and consume the earth in about 5 billion years. That gives us a whole lot of tries to get it right.
I have, but I’m also concerned that humanity got “lucky” so far and that this won’t happen again. There are theories positing that there are several blocking “gates” to civilization, and humanity passed an exceptional number of them already.
It’s reasonable to assert that’s a misleading, human centric perspective; but I’d also point out that the Fermi Paradox supports it. Either:
The conditions that gave birth to our civilization are not exceptional, and spread intelligent life is hiding from us (unlikely at this point, I think)
They are exceptional, and we just happened to have passed many unlikely hurdles so far (hence it is critical we don’t trip up at the end here).
They are not that exceptional (eg more intelligent vertebrates will rise, and would rise on other planets), but there is some gate we are not aware of yet (which I have heard called the Great Filter).
Another suspicious coincidence I’d point out is that we are, seemingly, the only advanced civilization from Earth so far. If we died out soon, other vertebrates that rise would find evidence of us by this point, wouldn’t they? Hence odds are we wouldnt be the first and we would have found precursors if ‘vertebrates rising and then killing themselves off’ was a likely scenario.
TL;DR: I suspect vertebrates -> our tech level is a difficult jump.
Well that’s all true, we don’t actually know what the real filters are, are we already past them, or are they still ahead of us? Certainly people have speculated about this for a long time, and I won’t pretend to have any more real answers than anyone else. But honestly, I’d have a hard time believing that the really rare event, that the great filter lays somewhere between the development of the brain and the development of the kind of intelligence humans have. It just seems like a relatively small jump (relative to all the other hurdles) between many of the smarter animals on earth and human beings. For example, many species use tools a whole lot actually. Only a few other species actually make tools or alter them to a large degree, but you know, give it 10 million years and see if that changes. Likewise, many species have languages, some species even give themselves names, so they can intentionally address other individuals in their social group.
If you don’t mind a bit of total speculation on my part, in my opinion, the explanation to the Fermi paradox is actually pretty simple, there really is no paradox. Intelligent life is probably relatively common in the universe, the reason we don’t see aliens all over the place is that intelligent life thrives too well for that. Once a species is capable of traveling other stars, it’s just a matter of time before they settle most of their galaxy, like within a million years (which is very quick on evolutionary scales). We’re just the first intelligent life in this galaxy, we can assume this because if there were others, they’d already have colonies right here on earth, because it’s a great planet.
Humanity survived though. Even with ‘humans’ dying out, I’d like some form of life to expand and go on.
My biggest fear is Earth ‘fizzling’ and never expanding before the Sun eats it, and the odds of that happening are pretty high.
Well, I’m not sure you’ve considered the time-frames involved in that concern. We have a whole lot of time before the sun goes out on us. It took Earth about 2 billion years to develop multicellular life. It then took another 2.5 b before we got vertebrates. That was the hard part though and it’s done, I don’t think there’s any undoing it. There aren’t many things that could wipe out all forms of vertebrates on earth, so I’m confident that would be as far back as the planet could reasonably be set back by any disaster.
Just 60 million years ago, mammals were not at all a dominant form of life, yet that’s all it took for early rodent-like mammals to evolve into human beings (as well as all the other mammals we know today). So based on that timeline, if all human life on the planet were wiped out tomorrow, I’d estimate (pessimistically) it would take less than another 200 million years before another species gained a similar level of intelligence and began a new era of civilization (and perhaps as little as 10 m years, as some species are already quite intelligent). In fact, if the next species screws up, and gets themselves killed, I expect earth will get another go at it in another 10–200 million years, over and over again.
On the other side of the equation, the sun will expand into a red giant and consume the earth in about 5 billion years. That gives us a whole lot of tries to get it right.
I have, but I’m also concerned that humanity got “lucky” so far and that this won’t happen again. There are theories positing that there are several blocking “gates” to civilization, and humanity passed an exceptional number of them already.
It’s reasonable to assert that’s a misleading, human centric perspective; but I’d also point out that the Fermi Paradox supports it. Either:
The conditions that gave birth to our civilization are not exceptional, and spread intelligent life is hiding from us (unlikely at this point, I think)
They are exceptional, and we just happened to have passed many unlikely hurdles so far (hence it is critical we don’t trip up at the end here).
They are not that exceptional (eg more intelligent vertebrates will rise, and would rise on other planets), but there is some gate we are not aware of yet (which I have heard called the Great Filter).
Another suspicious coincidence I’d point out is that we are, seemingly, the only advanced civilization from Earth so far. If we died out soon, other vertebrates that rise would find evidence of us by this point, wouldn’t they? Hence odds are we wouldnt be the first and we would have found precursors if ‘vertebrates rising and then killing themselves off’ was a likely scenario.
TL;DR: I suspect vertebrates -> our tech level is a difficult jump.
Well that’s all true, we don’t actually know what the real filters are, are we already past them, or are they still ahead of us? Certainly people have speculated about this for a long time, and I won’t pretend to have any more real answers than anyone else. But honestly, I’d have a hard time believing that the really rare event, that the great filter lays somewhere between the development of the brain and the development of the kind of intelligence humans have. It just seems like a relatively small jump (relative to all the other hurdles) between many of the smarter animals on earth and human beings. For example, many species use tools a whole lot actually. Only a few other species actually make tools or alter them to a large degree, but you know, give it 10 million years and see if that changes. Likewise, many species have languages, some species even give themselves names, so they can intentionally address other individuals in their social group.
If you don’t mind a bit of total speculation on my part, in my opinion, the explanation to the Fermi paradox is actually pretty simple, there really is no paradox. Intelligent life is probably relatively common in the universe, the reason we don’t see aliens all over the place is that intelligent life thrives too well for that. Once a species is capable of traveling other stars, it’s just a matter of time before they settle most of their galaxy, like within a million years (which is very quick on evolutionary scales). We’re just the first intelligent life in this galaxy, we can assume this because if there were others, they’d already have colonies right here on earth, because it’s a great planet.