Banned
I don’t know if I have said this before, but a few years ago, there was talk about neutrino communications. These would require large facilities, but would eliminate the need for com-sats, depressing the need of space launch. That alone may be an answer to Fermi. If power sources shrink and you could have instantaneous comm, the need for occupied craft would lessen.
So there may be all kinds of Voyager probes out there. All small. All silent.
Established Member
If power sources shrink and you could have instantaneous comm
"large facilities" does not mean "shrink", and neutrinos are not tachyons.
SHARKS (crossed out) MONGEESE (sic) WITH FRICKIN' LASER BEAMS ATTACHED TO THEIR HEADS
Order of Kilopi
Neutrino production is harder and less energy efficient that EM. Neutrino detection, harder than EM detection. But both travel at C.Originally Posted by publiusr
Now if you have a need to communicate inside a solid body, I might see a need, perhaps. But it'd be a niche technology.
"I'm planning to live forever. So far, that's working perfectly." Steven Wright
Established Member
The Great Filter (the factor that has prevented the Galaxy from being colonised) may be that galaxies are less tameable-by-technology than theorists have imagined.
Can hi tech produce systems with long-term (geological time) stability comparable to the stability of natural systems, and different enough from natural systems to be detectable at interstellar distances?
If the answer happens to be no…
The galaxy may contain abundant life and multiple long-lived cultures of highly intelligent beings, but none that produce Dyson Swarms, Type 3 Civilisations etc…
The cultures that survive are not ambitious colonisers and transformers of galaxy, they are cultures that respect natural systems.
They do change their environment, as does every living thing, but the changes they make are subtle, and are not at all easy for our astronomers to detect.
I’m not saying that this must be the answer to the Fermi paradox. I’m just saying that it is a possible answer, and one which to me seems at least as likely as others I’ve seen.
Last edited by Colin Robinson; 2021-Mar-25 at 11:07 PM.
Established Member
Further on the idea of eco-system instability as a possible Great Filter — a factor preventing galaxy colonisation...
Looking back through this lengthy thread, very little has been said about the problem of waste, i.e. forms of matter and energy that living things produce but don't have an immediate use for.
All living things seem to produce wastes. That is why the list of functional attributes of life, expressed in the acronym MRS GREN (Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion and Nutrition) includes "excretion", i.e. methods of expelling unwanted by-products.
Modern technology produces new forms of waste (pollution), which we struggle to control.
Global warming is a problem because waste CO2 and other gaseous wastes (greenhouse gases) are building up in the atmosphere.
Yes, there are new technologies which don't produce the same amounts of harmful waste.
But will we ever create industries which produce no waste at all?
Or would that be a contradiction in terms, like a living thing that didn't need to excrete anything?
Can we escape the problem of waste by expanding into space?
Maybe we can't. For our space technology has already given rise to new forms of pollution, e.g. orbiting debris (space junk).
Other forms of waste have built up inside the ISS. After a few years in orbit, it is "smelly, noisy, messy, and awash in shed skin cells and crumbs", according to this news report.
It's easy to talk about taking Mercury to bits, and using its minerals to build a Dyson swarm. But how much waste material (debris) would be produced by doing that?
It's easy to talk about modular space habitats, where you put in a new module whenever an existing one wears out. But that creates another form of waste, namely the decommissioned modules...
The natural web of life is an extremely complex system in which the wastes of one organism regularly become useful inputs for another. Which has made it possible for Earth's biosphere to keep going over geological time.
The Biosphere 2 experiment tried to accomplish a similar balance artificially, but couldn't.
No, I'm not saying our species is doomed. I am saying that we need to take the problem of waste (in all its forms) much more seriously.
And that this point applies not only to us, but also to technological species on other worlds. Those that survive in the long term may do so by working within the eco-system they evolved in and taking great care not to overload it with miscellaneous garbage.
Maybe they haven't built swarms of artificial space habitats because they figured out it wouldn't work.
Last edited by Colin Robinson; 2021-Mar-26 at 09:08 AM.
Order of Kilopi
I’m not sure if I brought it up in this thread but I sometimes discuss various issues that would come up if an advanced civilization is to survive thousands of years, millions, or more. I usually don’t see much interest, so it rarely goes very far.
One issue is the requirement for efficient recycling. Our civilization will need to significantly improve recycling to last centuries (and that’s assuming population largely stabilizes) but in the true long run recycling needs to reach virtually 100% and losses must be eliminated, or civilization will eventually run out of resources. One example of thr problem has been brought up publicly under the name “peak phosphorus.” There are widely varying estimates on how long economically available sources will remain, from a few decades to centuries, but it is finite. There are methods to reduce losses like better crop management and recycling, as with sewage processing. On this issue alone, we can expect parts of our civilization to be organized very differently centuries from now. In the long run, Earth cities could look much more like we imagine space habitats, so it is easy to recycle and retain resources.
But eventually essentially everything needs recycling. Today, recycling is very limited and mining is very inefficient. Robert A. Freitas Jr. has looked into how biology mines and recycles. Humans typically rely on heavily enriched, uncommon ores for mining materials, but plants have little choice where they are to build themselves and find materials. As it turns out, biological systems are extremely efficient at separating and concentrating elements. Freitas has considered what could be possible using nanomachines working about as efficiently as biological models. The energy input would go down radically so impractical and uneconomic processes today could become highly competitive. For instance, he expects mine tailings and landfills will become major mining sites in the future.
This could allow for very effective recycling. What we consider waste today either would no longer be produced or would be recycled.
I believe something like what he is discussing will need to be developed for long term survival.
The way the ecosystem developed, waste from one organism is used and often vital to another. I expect a mature technosystem would be much the same because it is necessary for it to be made that way.But will we ever create industries which produce no waste at all?
Or would that be a contradiction in terms, like a living thing that didn't need to excrete anything?
The long term issue I’ve considered with a large number of habitats, like a Dyson swarm, is lost volatiles. If your air escapes to space it is unrecoverable. By building huge numbers of habitats you’ve probably used up much of the material and volatiles available in system. If you don’t build habitats specifically to retain volatiles with virtually no loss, eventually you’ll have to close them down unless there is a very large economic supply. Maybe if something like star lifting can be developed, that can last for billions of years, but I’m not convinced such speculative technology will ever be practical.Maybe they haven't built swarms of artificial space habitats because they figured out it wouldn't work.
Last edited by Van Rijn; 2021-Mar-26 at 01:28 PM.
"The problem with quotes on the Internet is that it is hard to verify their authenticity." — Abraham Lincoln
I say there is an invisible elf in my backyard. How do you prove that I am wrong?
The Leif Ericson Cruiser
Order of Kilopi
One civilization's waste is another civilization's resources.
As far as volatiles lost into vacuum, I can't see any way to prevent or recover that, but perhaps a post-human mind could. If not, those resources will eventually get gone.
Suns and planets are not permanent, either, so there we are.
"I'm planning to live forever. So far, that's working perfectly." Steven Wright
Established Member
In relation to this thread, it seems like a crucial point.
Considering the age of the Galaxy (13.5 billion years), it could be that advanced civilisations have repeatedly emerged, but none is alive just now, unless we count ourselves as one. Some survived for thousands of years, some millions, but none for much more. That's why we don't see their space craft cruising about today. We may eventually stumble over their ruins, but will we recognise them as such?
A more optimistic possibility (if you like the idea that we're not alone), is that some civilisations have survived to this day, but not by building Dyson swarms or practising interstellar colonisation. And maybe there were other civilisations that did (or tried to do) either or both of these things, but their works didn't last...
What sort of imagined space habitats do you have in mind?One issue is the requirement for efficient recycling. Our civilization will need to significantly improve recycling to last centuries (and that’s assuming population largely stabilizes) but in the true long run recycling needs to reach virtually 100% and losses must be eliminated, or civilization will eventually run out of resources. One example of thr problem has been brought up publicly under the name “peak phosphorus.” There are widely varying estimates on how long economically available sources will remain, from a few decades to centuries, but it is finite. There are methods to reduce losses like better crop management and recycling, as with sewage processing. On this issue alone, we can expect parts of our civilization to be organized very differently centuries from now. In the long run, Earth cities could look much more like we imagine space habitats, so it is easy to recycle and retain resources.
Yes, that makes a lot of sense.But eventually essentially everything needs recycling. Today, recycling is very limited and mining is very inefficient. Robert A. Freitas Jr. has looked into how biology mines and recycles. Humans typically rely on heavily enriched, uncommon ores for mining materials, but plants have little choice where they are to build themselves and find materials. As it turns out, biological systems are extremely efficient at separating and concentrating elements. Freitas has considered what could be possible using nanomachines working about as efficiently as biological models. The energy input would go down radically so impractical and uneconomic processes today could become highly competitive. For instance, he expects mine tailings and landfills will become major mining sites in the future.
This could allow for very effective recycling. What we consider waste today either would no longer be produced or would be recycled.
I believe something like what he is discussing will need to be developed for long term survival.
The way the ecosystem developed, waste from one organism is used and often vital to another. I expect a mature technosystem would be much the same because it is necessary for it to be made that way.
Question... Would the sort of mature technosystem you're talking about be easier or more difficult to detect at interstellar distances, compared to a less mature technosystem?
For instance, it's been suggested that ET astronomers could have figured out that Earth has a technological civilisation by detecting waste CFCs (chlorofluorocarbons) in Earth's atmosphere, since CFCs are unlikely to be produced naturally. But CFC levels have declined globally due to the Montreal Protocol on protection of the ozone layer. Which will logically makes us less detectable...
Very relevant point.The long term issue I’ve considered with a large number of habitats, like a Dyson swarm, is lost volatiles. If your air escapes to space it is unrecoverable. By building huge numbers of habitats you’ve probably used up much of the material and volatiles available in system. If you don’t build habitats specifically to retain volatiles with virtually no loss, eventually you’ll have to close them down unless there is a very large economic supply. Maybe if something like star lifting can be developed, that can last for billions of years, but I’m not convinced such speculative technology will ever be practical.
Maybe every civilisation that made Dyson swarms eventually wrecked its own planetary system, by leaking its volatiles into space. And this happened in a short time compared to the natural life expectancy of their planetary systems... Today all that's left of their engineering is a bunch of rocky planetoids in unstable orbits, now and then crashing into each other and making craters, or flinging each other into their host star...
Last edited by Colin Robinson; 2021-Mar-27 at 01:37 AM.
Order of Kilopi
Perhaps a mature civilization (however you define it) would reach the position of regulating their reproduction so they don't grow out of control. That might require the more advanced portions of their society riding herd on their more ambitious and expansive populations... which of course will lead to conflict and power struggles. No reproducing organism wants to curb their own spread, but they do so in nature to maintain a balanced niche and not devour their way to extinction.
Our bodies fight cancerous cell replication by repairing our own DNA and immune systems. A stable society might also manage their growth, though it would be a tremendous challenge under the best of circumstances.
"I'm planning to live forever. So far, that's working perfectly." Steven Wright
Established Member
No reproducing organism wants to curb their own spread, but they do so in nature to maintain a balanced niche and not devour their way to extinction.
Isn't it other factors that control an organism's spread in nature? Either exhaustion of food resources or predation?
SHARKS (crossed out) MONGEESE (sic) WITH FRICKIN' LASER BEAMS ATTACHED TO THEIR HEADS
Order of Kilopi
Most organisms do not consume all food in reach. If they eat until starvation and dieback, their population booms and busts repeatedly until it becomes too unstable and resource-poor to survive, like a virus that kills its host before it can replicate.
Predators do often act as a natural check on population. It's one mechanism that can contribute to the metastability of a balanced niche.
An advanced technological civilization would presumably not face a natural predator. A sentient population could, however, easily outgrow their environments and die back. Reduced to barbarism on a livable world, certain death in space... Rinse, repeat, only now their planet's non-renewable resources have been used up so they start from a weaker position to rise again.
"I'm planning to live forever. So far, that's working perfectly." Steven Wright
Order of Kilopi
Actually many do.
That happens,If they eat until starvation and dieback, their population booms and busts repeatedly
Predators boom and bust tooPredators do often act as a natural check on population. It's one mechanism that can contribute to the metastability of a balanced niche.
Just like us!An advanced technological civilization would presumably not face a natural predator. A sentient population could, however, easily outgrow their environments and die back. Reduced to barbarism on a livable world, certain death in space... Rinse, repeat, only now their planet's non-renewable resources have been used up so they start from a weaker position to rise again.
sicut vis videre esto
When we realize that patterns don't exist in the universe, they are a template that we hold to the universe to make sense of it, it all makes a lot more sense.
Originally Posted by Ken G
Order of Kilopi
Many is not most. Words have meanings!
"I'm planning to live forever. So far, that's working perfectly." Steven Wright
Order of Kilopi
Sorry, I might be wrong about this, but when you say:
Doesn't that mean "the majority do not" so it means "many do not" rather than "most do consume all food in reach, but there are some that don't"?Most organisms do not consume all food in reach.
In that case, "many do" would be saying, "you are saying that few do, but in fact many do." I interpreted your statement as "few organisms consume all food in reach." Isn't that the normal way to interpret that?
As above, so below
Order of Kilopi
In relation to the Fermi paradox, which I do not see as a paradox given the distances to stars, we have to look at our kind of society that can emit, accidentally or deliberately, EM radiation such as radio or flashing lights, or nuclear explosions. We do those things. We have to include the possibility that the very intelligence that makes that possible, includes self destructive tendencies too. We may well go back to the stone age and stop radiating, or we may deliberately curb our emissions. Maybe. Or our planet system may suffer a final extinction event. The paradox has an implied assumption that once intelligent life evolves, it’s a one way growth scenario. But on Earth we have had civilisations rise and fall many times. Maybe Malthus was right, we do expand until resources are gone, then we collapse and such collapse does not maintain the advances previously made.
One maybe hopeful idea is that we develop artificial reproducing machines without the negative emotional baggage that limits us to tribal conflict. But if given control would such AI want growth or sustainability? Growth either runs out of food or runs into a competing growing system, with conflict.
So if we ever get a signal, it may well be from what we call AI, and it is sanguine naivety to assume that is good for us.
sicut vis videre esto
When we realize that patterns don't exist in the universe, they are a template that we hold to the universe to make sense of it, it all makes a lot more sense.
Originally Posted by Ken G
Order of Kilopi
But I may be confused. Maybe by saying "words have meanings," you were meaning to point out that what you said "most do not" could also mean "many do" so that in fact there was no disagreement between you, even though the reply started with "But." My brain is starting to hurt.
As above, so below
Order of Kilopi
I took most to mean the majority and , without quoting evidence, I assume most actually do eat everything they can, limited only by the reproduction rates of eater and food. Of course in complex food chains there are other factors. If humans and human like aliens are the main subject here, well, we are over consuming, is there any doubt? We are told we must change diets because we cannot sustain the meat and fish, but population collapse may come first.But I may be confused. Maybe by saying "words have meanings," you were meaning to point out that what you said "most do not" could also mean "many do" so that in fact there was no disagreement between you, even though the reply started with "But." My brain is starting to hurt.
sicut vis videre esto
When we realize that patterns don't exist in the universe, they are a template that we hold to the universe to make sense of it, it all makes a lot more sense.
Originally Posted by Ken G
Order of Kilopi
It is actually quite an interesting question, and to be honest, I don't know the answer. Surely the exhaustion of food resources and predation plays a part. And on the other hand, it is wildly unlikely that things like insects have the wisdom to realize that they should conserve resources. So the other possibility I guess is that somehow a genetic pattern that doesn't consume all the resources tends to be selected for. I'm sure there are scientists who actually study this and have knowledge of what the mechanism is.
As above, so below
Order of Kilopi
James Lovelock with his Gaia hypothesis used exactly those arguments. If you have a planet with just grass and goats, the goat population will grow and crash cyclically. As you add species interacting, you get stability, the more species the more stable, although in some places you get the goat grass situation. He argued the net result was self correcting homeostasis. But then mankind starts managing and surviving, upsetting the balance like no other species. But now he is very pessimistic about the biosphere because of mankind. If he is right, we can expect other planets to go the same way and have brief spells of high tech lives, with long spells of stone ages.
sicut vis videre esto
When we realize that patterns don't exist in the universe, they are a template that we hold to the universe to make sense of it, it all makes a lot more sense.
Originally Posted by Ken G
Order of Kilopi
I can't answer for others how they interpret what I said. I can only try to clarify my own statements.But I may be confused. Maybe by saying "words have meanings," you were meaning to point out that what you said "most do not" could also mean "many do" so that in fact there was no disagreement between you, even though the reply started with "But." My brain is starting to hurt.
Most species do not boom-and-bust population wise because of starvation, to the best of my knowledge. Those that do, seem to be a minority.
"I'm planning to live forever. So far, that's working perfectly." Steven Wright
Order of Kilopi
Seems like a species that constantly veers wildly between plenty and starvation, would be dynamically unstable. If that's true, then a balanced ratio of food to population would certainly be a survival characteristic. Predation, disease, etc might contribute to that.
"I'm planning to live forever. So far, that's working perfectly." Steven Wright
Order of Kilopi
No , just a natural oscillator, it is the wealth of other species that dampen the oscillations. Some oscillations annual, others may take centuries. It is people who mess it up when they think they can optimise better. It works for a while then things go wrong. We have yet to achieve anything like a stable world system that could last thousands of years. Except when we weren't around!
sicut vis videre esto
When we realize that patterns don't exist in the universe, they are a template that we hold to the universe to make sense of it, it all makes a lot more sense.
Originally Posted by Ken G
Order of Kilopi
Well, I certainly can't argue on the basis of current consumer society. Whether we humans can actually make something sustainable long term is an open question.
As for the rest, all species live in a wealth of other species; there's no exceptions that I know of. So the interactions between them are part of evolution and adaptation, including the dampening effects.
"I'm planning to live forever. So far, that's working perfectly." Steven Wright
Order of Kilopi
Well, locusts,
So, in terms of evidence of alien civilisations, what is your conclusion?
sicut vis videre esto
When we realize that patterns don't exist in the universe, they are a template that we hold to the universe to make sense of it, it all makes a lot more sense.
Originally Posted by Ken G
Order of Kilopi
I don't think it's really a question of clarification, but rather that I don't understand what you mean by "many is not most"? It seemed like a fairly typical exchange, with some examples:
Case 1
A: Most people live in cities. (true)
B: But many do not. (also true).
A (presumably): Yes, that's true.
Case 2
A: Most people don't know the location of KIC 8462852. (very true)
B: But many do. (very dubious, probably about 5 people do...)
A: No, I don't think that many people do. Maybe five people in the world do...
Case 3
A: Most people live in cities. (true)
B: But many don't. (also true)
A: Most and many are different! (What?)
As above, so below
Order of Kilopi
So the question is, how exactly do you get a balanced ratio of food to population?
As above, so below
Order of Kilopi
Well when you do, the food, say grass, is eaten by several competing species with several predators. If one eater gets too numerous the relevant predators increase in number. But some, like locusts, have occasional swarms and eat everything, before collapsing. So it is always dynamic with trends due to climate change.
sicut vis videre esto
When we realize that patterns don't exist in the universe, they are a template that we hold to the universe to make sense of it, it all makes a lot more sense.
Originally Posted by Ken G
Order of Kilopi
Yes, that sounds reasonable to me. In effect, we are always seeing veering, but it is not so wild.
As above, so below
Order of Kilopi
Yes, there is always oscillation in exact numbers. Some species do veer more wildly than others, but eating-to-starvation's not so common, so the outliers stick out to our awareness.
"I'm planning to live forever. So far, that's working perfectly." Steven Wright
Order of Kilopi
If as one poster here once speculated, perhaps useful levels of fusion power under conditions less than a star never becomes practical at any achievable tech level. Hard physical limits might make it a dead-end path. This drastically cuts into not only interstellar travel but also where you can establish a viable habitat.
Or perhaps there's competition for choice "real estate". If multiple civilizations exist (of one species or many) then they're too busy defending their own stars to expend effort on starting new settlements. (I know, I know, there's always more space to move out into. But why travel longer to establish a virgin colony in a wild system when there's perfectly useful established infrastructure to plunder? There might be universal needs a space habitat has that we have not yet foreseen; requiring a large or rare technical or ecological capacity, making colonization expensive enough to be worth fighting over, especially if you intend to preserve your target for your own use.) Complex conflict might at least slow down the spread of life.
Alternatively, perhaps small closed ecosystems are simply too unstable to make long range colonization efforts worth while.* You'd need a whole world to replenish your habitat from. A permanent link to the home planet or a terraformed one, would definitely hobble the rapid expansion of one's progeny throughout space.
* I hate this idea with a passion, of course. But I have to acknowledge it as at least a realistic possibility. Perhaps humans in space will need an umbilical cord to the old mudball for centuries, until we establish enough variety of ecologies and methods of survival offworld that stations can support each other entirely.
"I'm planning to live forever. So far, that's working perfectly." Steven Wright
Posting Permissions
Reply With Quote