Do you think any aliens exist in the universe?

[Harry Bosch]

I hope not. The problem is the Fermi Paradox--why don't we see them? The time it takes to colonize the galaxy is very short compared to the time life has been around, why didn't somebody beat us? And even if they leave habitable worlds alone why do we not at least see their works?

This basically says there must be something phenomenally unlikely about a race reaching starfaring status. Have we been phenomenally lucky and passed that barrier, or does it lie in the future--and note there's very little future between now and starfaring.

Agreed. I believe that life is very common in the universe. But intelligence ..... Not so sure. It took the earth 4.5 Billion years to generate intelligent life.

 

[bilby]

I hope not. The problem is the Fermi Paradox--why don't we see them? The time it takes to colonize the galaxy is very short compared to the time life has been around, why didn't somebody beat us? And even if they leave habitable worlds alone why do we not at least see their works?

This basically says there must be something phenomenally unlikely about a race reaching starfaring status. Have we been phenomenally lucky and passed that barrier, or does it lie in the future--and note there's very little future between now and starfaring.

Agreed. I believe that life is very common in the universe. But intelligence ..... Not so sure. It took the earth 4.5 Billion years to generate intelligent life.

Did I miss a memo?

I thought we were still waiting on that…

 

[Playball40]

In a spatially infinite universe it follows that if one planet in a billion or a trillion or whatever is inhabited, then there are an infinite number of inhabited planets. However, if life and especially intelligent live is exceedingly rare, these life forms may be so vastly separated in space and time that there will be almost zero chance of them coming into contact with one another.

This ^

 

[steve_bank]

You have to define alien. Do you mean humanoids or algae? An Earth like ecosystem?

There is no way to now. Scince tells us the evolution of the ecosystem including O2 was a very complex causal sequence. The moon as I understand it gives us a stable rotation.

Throught all of the unverse to date Eath may be the only place. Or it may be common and not extraordinary.

 

[Loren Pechtel]

I hope not. The problem is the Fermi Paradox--why don't we see them? The time it takes to colonize the galaxy is very short compared to the time life has been around, why didn't somebody beat us? And even if they leave habitable worlds alone why do we not at least see their works?

This basically says there must be something phenomenally unlikely about a race reaching starfaring status. Have we been phenomenally lucky and passed that barrier, or does it lie in the future--and note there's very little future between now and starfaring.

Agreed. I believe that life is very common in the universe. But intelligence ..... Not so sure. It took the earth 4.5 Billion years to generate intelligent life.

Which means you either consider the jump to multicellular life the barrier or the jump to intelligence.

 

[excreationist]

You have to define alien. Do you mean humanoids or algae? An Earth like ecosystem?

I think the first video is talking about alien civilizations but any form of life at all would imply that there could be intelligent life somewhere....

 

[bilby]

You have to define alien. Do you mean humanoids or algae? An Earth like ecosystem?

There is no way to now. Scince tells us the evolution of the ecosystem including O2 was a very complex causal sequence. The moon as I understand it gives us a stable rotation.

Throught all of the unverse to date Eath may be the only place. Or it may be common and not extraordinary.

O₂ isn’t required for life; Life on Earth developed in a strongly reducing atmosphere wherein O₂ was highly toxic to every living thing.

Then some organisms developed a photosynthetic pathway that generated a shitload of O₂, along with the ability to tolerate it without dying. This caused a mass extinction on a scale that makes the demise of the dinosaurs look like a minor blip.

All subsequent life on Earth has had to be able to survive this hugely difficult oxidising environment, and much of it is now dependent on that O₂ to survive; But O₂ is very much something life thrives despite, not because of.

 

[Jokodo]

I hope not. The problem is the Fermi Paradox--why don't we see them? The time it takes to colonize the galaxy is very short compared to the time life has been around, why didn't somebody beat us? And even if they leave habitable worlds alone why do we not at least see their works?

This basically says there must be something phenomenally unlikely about a race reaching starfaring status. Have we been phenomenally lucky and passed that barrier, or does it lie in the future--and note there's very little future between now and starfaring.

You're equivocating between starfaring and colonising the galaxy. It may very well be that we're only a few hundred years away from being hypothetically able to send a manned ship to a distant star and have it arrive with living humans on board - and yet that we won't ever colonise the galaxy, simply because it isn't worth it.

From the perspective of securing the survival of the species in case of e.g. a supernova very close to the sun, there is arguably some benefit in finding a couple or so New Earths as an insurance policy. Anything beyond that is objectively futile.

And it's not like "someone is going to do it on their own account" cuts through this argument. A rich trader of the 16th century may have been able to equip a few ships and send a few colonists across an ocean, but no Elon Musk of the 26th century is going to pay a colonising troop across the vastness of interstellar space - of we are going to be able to do it, it's always going to be a civilization wide effort.

 

[Bomb#20]

Which means you either consider the jump to multicellular life the barrier or the jump to intelligence.

Multicellular life is no barrier -- here it happened independently at least four times (animals, fungi, plants, kelp). But the jump from bacteria to eukaryotes might be a barrier.

 

[Bomb#20]

You can talk about seeding the galaxy with automated probes, but as that’s both expensive and utterly futile,...

And self-replicating probes ain’t free, because if they were, I would have a dozen of them.

Those sentences really don't go together...

 

[Jokodo]

The solution to the Fermi Paradox is understanding exponential growth.

At a given speed, the volume of space that can be reached in time t growth in proportion to the cube of t. The population that needs to be hosted, or the resources that need extracting, however, grow exponentially with a given growth rate.

The thing is that the exponential growth catches up with the cubic growth real fast. So if you believe continued growth is a requisite for a healthy civilisation, colonising space won't help, the rot of stagnation and hell of extreme scarcity is going to catch up with us in no time, on astronomical scales. If, on the other hand, you believe we can wean ourselves off the necessity of having ever more people consume ever more resources and still maintain a thriving civilisation, space colonisation becomes unnecessary - we can do that right here on earth.

You'd think we all gained a bit of an understanding of exponential growth after two and a half years of the pandemic, but the speed with which this happens is still counterintuitive. For example, with a growth rate of just 1%/ year and an expansion speed of c, the c tipping point where demand for more space grows faster than the supply of new star systems is reached in a mere 301 years (because (302/301)^3<1.01), and in 31 years for a more realistic speed of 0.1c. From that point on, its only a matter of a few more centuries at most before we've used up whatever buffer we managed to make while we still expanded faster than our needs before the rot of stagnation catches up with us. That is, unless we manage to achieve stagnation without the rot.

 

[Jokodo]

Actually brain knot. The time it takes to the tipping point is constant for a given growth rate, so still 301 years at 0.1c. The difference is that we'll only have explored a sphere of radius 30ly, and much less of a buffer to fill up.

 

[bilby]

You can talk about seeding the galaxy with automated probes, but as that’s both expensive and utterly futile,...

And self-replicating probes ain’t free, because if they were, I would have a dozen of them.

Those sentences really don't go together...

Are you sure? I see no contradictions.

 

[bilby]

The solution to the Fermi Paradox is understanding exponential growth.

At a given speed, the volume of space that can be reached in time t growth in proportion to the cube of t. The population that needs to be hosted, or the resources that need extracting, however, grow exponentially with a given growth rate.

The thing is that the exponential growth catches up with the cubic growth real fast. So if you believe continued growth is a requisite for a healthy civilisation, colonising space won't help, the rot of stagnation and hell of extreme scarcity is going to catch up with us in no time, on astronomical scales. If, on the other hand, you believe we can wean ourselves off the necessity of having ever more people consume ever more resources and still maintain a thriving civilisation, space colonisation becomes unnecessary - we can do that right here on earth.

You'd think we all gained a bit of an understanding of exponential growth after two and a half years of the pandemic, but the speed with which this happens is still counterintuitive. For example, with a growth rate of just 1%/ year and an expansion speed of c, the c tipping point where demand for more space grows faster than the supply of new star systems is reached in a mere 301 years (because (302/301)^3<1.01), and in 31 years for a more realistic speed of 0.1c. From that point on, its only a matter of a few more centuries at most before we've used up whatever buffer we managed to make while we still expanded faster than our needs before the rot of stagnation catches up with us. That is, unless we manage to achieve stagnation without the rot.

Population growth and economic growth need not be related; And human population growth is a twentieth century thing, which we already grew out of (pun intended) without having to colonise other planets.

Exponential population growth isn’t a thing anymore, and any alien species that doesn’t decide to dispense with it is likely to have a lot of problems at home that make expansion into space very difficult - and they can probably also work out that it’s utterly futile, using the same simple maths you just did.

Economic growth is constrained only by the continued availability of larger numbers, and doesn’t necessarily imply increasing use of space or resources; You can achieve economic growth with fixed population and resources, by turning your resources into things that are more valuable than they were previously.

 

[Elixir]

However rare “alien” civilizations might be, have been or will be, contacts between them are orders of magnitude more rare.

 

[Jokodo]

The solution to the Fermi Paradox is understanding exponential growth.

At a given speed, the volume of space that can be reached in time t growth in proportion to the cube of t. The population that needs to be hosted, or the resources that need extracting, however, grow exponentially with a given growth rate.

The thing is that the exponential growth catches up with the cubic growth real fast. So if you believe continued growth is a requisite for a healthy civilisation, colonising space won't help, the rot of stagnation and hell of extreme scarcity is going to catch up with us in no time, on astronomical scales. If, on the other hand, you believe we can wean ourselves off the necessity of having ever more people consume ever more resources and still maintain a thriving civilisation, space colonisation becomes unnecessary - we can do that right here on earth.

You'd think we all gained a bit of an understanding of exponential growth after two and a half years of the pandemic, but the speed with which this happens is still counterintuitive. For example, with a growth rate of just 1%/ year and an expansion speed of c, the c tipping point where demand for more space grows faster than the supply of new star systems is reached in a mere 301 years (because (302/301)^3<1.01), and in 31 years for a more realistic speed of 0.1c. From that point on, its only a matter of a few more centuries at most before we've used up whatever buffer we managed to make while we still expanded faster than our needs before the rot of stagnation catches up with us. That is, unless we manage to achieve stagnation without the rot.

Population growth and economic growth need not be related; And human population growth is a twentieth century thing, which we already grew out of (pun intended) without having to colonise other planets.

Exponential population growth isn’t a thing anymore, and any alien species that doesn’t decide to dispense with it is likely to have a lot of problems at home that make expansion into space very difficult - and they can probably also work out that it’s utterly futile, using the same simple maths you just did.

Economic growth is constrained only by the continued availability of larger numbers, and doesn’t necessarily imply increasing use of space or resources; You can achieve economic growth with fixed population and resources, by turning your resources into things that are more valuable than they were previously.

I agree with everything you just said.

However, the most frequent argument I see for why we need space colonisation, or why we should expect aliens to engage in it, is exactly that: that there is no continued growth (tm) without it, and without that, there will be rot and decay.

I merely intent to show, with math, that if that's so, space colonisation won't save us either. And if it isn't so, which you and I are in agreement, it's unnecessary.

 

[Loren Pechtel]

I hope not. The problem is the Fermi Paradox--why don't we see them? The time it takes to colonize the galaxy is very short compared to the time life has been around, why didn't somebody beat us? And even if they leave habitable worlds alone why do we not at least see their works?

This basically says there must be something phenomenally unlikely about a race reaching starfaring status. Have we been phenomenally lucky and passed that barrier, or does it lie in the future--and note there's very little future between now and starfaring.

You're equivocating between starfaring and colonising the galaxy. It may very well be that we're only a few hundred years away from being hypothetically able to send a manned ship to a distant star and have it arrive with living humans on board - and yet that we won't ever colonise the galaxy, simply because it isn't worth it.

Those that favor reproduction eventually outbreed those that don't. Expansion will happen. If we can colonize one star we can colonize the galaxy.

And it's not like "someone is going to do it on their own account" cuts through this argument. A rich trader of the 16th century may have been able to equip a few ships and send a few colonists across an ocean, but no Elon Musk of the 26th century is going to pay a colonising troop across the vastness of interstellar space - of we are going to be able to do it, it's always going to be a civilization wide effort.

Or dissent groups that want to set up their own society. It will eventually drop to the point that it need not be a government effort.

 

[Loren Pechtel]

The solution to the Fermi Paradox is understanding exponential growth.

At a given speed, the volume of space that can be reached in time t growth in proportion to the cube of t. The population that needs to be hosted, or the resources that need extracting, however, grow exponentially with a given growth rate.

The thing is that the exponential growth catches up with the cubic growth real fast. So if you believe continued growth is a requisite for a healthy civilisation, colonising space won't help, the rot of stagnation and hell of extreme scarcity is going to catch up with us in no time, on astronomical scales. If, on the other hand, you believe we can wean ourselves off the necessity of having ever more people consume ever more resources and still maintain a thriving civilisation, space colonisation becomes unnecessary - we can do that right here on earth.

I don't believe growth is essential. I believe growth will happen if it's practical.

 

[Jokodo]

I hope not. The problem is the Fermi Paradox--why don't we see them? The time it takes to colonize the galaxy is very short compared to the time life has been around, why didn't somebody beat us? And even if they leave habitable worlds alone why do we not at least see their works?

This basically says there must be something phenomenally unlikely about a race reaching starfaring status. Have we been phenomenally lucky and passed that barrier, or does it lie in the future--and note there's very little future between now and starfaring.

You're equivocating between starfaring and colonising the galaxy. It may very well be that we're only a few hundred years away from being hypothetically able to send a manned ship to a distant star and have it arrive with living humans on board - and yet that we won't ever colonise the galaxy, simply because it isn't worth it.

Those that favor reproduction eventually outbreed those that don't. Expansion will happen. If we can colonize one star we can colonize the galaxy.

And it's not like "someone is going to do it on their own account" cuts through this argument. A rich trader of the 16th century may have been able to equip a few ships and send a few colonists across an ocean, but no Elon Musk of the 26th century is going to pay a colonising troop across the vastness of interstellar space - of we are going to be able to do it, it's always going to be a civilization wide effort.

Or dissent groups that want to set up their own society. It will eventually drop to the point that it need not be a government effort.

Will it? Can you elucidate the science that shows this? Or is this just wishful thinking?

 

[Jokodo]

The solution to the Fermi Paradox is understanding exponential growth.

At a given speed, the volume of space that can be reached in time t growth in proportion to the cube of t. The population that needs to be hosted, or the resources that need extracting, however, grow exponentially with a given growth rate.

The thing is that the exponential growth catches up with the cubic growth real fast. So if you believe continued growth is a requisite for a healthy civilisation, colonising space won't help, the rot of stagnation and hell of extreme scarcity is going to catch up with us in no time, on astronomical scales. If, on the other hand, you believe we can wean ourselves off the necessity of having ever more people consume ever more resources and still maintain a thriving civilisation, space colonisation becomes unnecessary - we can do that right here on earth.

I don't believe growth is essential. I believe growth will happen if it's practical.

Growth isn't practical when it requires bridging the interstellar void. It may be possible, to a point, but not in any meaningful sense practical.