The Fermi paradox strikes me not as a paradox but as a simple consequence of the immense distances of interstellar space and the absolute limit imposed by the speed of light (and no Star Trek or Star Wars cheating with hyoerdruves and the like)
Well, not really. Fermi and von Neumann were convinced that the immense distances could be overcome. I've seen engineering studies that indicate the practical speed limit is about a third of the speed of light, due to the conflict between fuel mass and shielding mass. The shielding is necessary due to micrometeoroid collisions and due to the need to use gravity assist off of the sun and stars. Obviously we don't have the necessary engines but they are not inconceivable.
The Voyager craft have been operating for 50 years, despite the fact that they were not designed to do so. A universal constructor (UC) with a much longer lifespan - who knows, it might be indefinite, especially if two or three such machines were paired for repair purposes - with a third of the speed or light would have hundreds or thousands of solar systems in reach during one human lifespan. Even a speed of one-twentieth of the speed of light puts the nearest stars only 60-70 years away.
PS, I think the real limiting factor on the "every solar system in our galaxy will have at least one such robot in just three million years" target is not the transit speed but rather the replication rate. If a UC can build a UC in 1 or 2 years it works well, if it takes 20 then not so much. It all depends how this technology would work.
I also assume that the laws of economics apply everywhere too. An interstellar venture requiring millennia to have any sort of return, even merely informational, would not be something I could see being privileged as a project. Far more likely a space-capable species would focus on its own solar system where resources abound.
Human laws of economics apply only to the first such robot; once one such machine exists its progeny would be free from all human constraints except programming (and I would hope that humans would retain some control of them).
Again the question is the initial motive. Explore and exploit other planets and asteroids nearby? Absolutely? But explore the galaxy where there would be no return, and even information would take millennia to come back? Why bother?
My own speculation (and only speculation) is that we'll find ways to explore and exploit alternate earths where humanity doesn't even exist. This could be the source for the legit UFOs too- other earths sending probes across Elsewhere to check out our world. (IMO, most UFOs are natural or technological things misunderstod and fleshed out with imaginative details)
Actually, there is a different issue with the "Why bother?" question.
I once wrote a computer simulation of this entire concept. At about the 40,000 year mark the flow of information of the discoveries by the universal constructors back to earth becomes overwhelming. Human institutions simply could not absorb it all. That is a real wet blanket for the exploration motive.
This data flow doesn't start to ease off until the galaxy is nearly filled with these machines (and that assumes we are less interested with follow-on observations, an assumption I would not make). And then once we start to merge with Andromeda it starts up again, and again when we get into the Virgo cluster...
Here's a thought to append to the "thumbs down" Fermi's paradox argument.
Volume 2 of Cixin Liu's "Three Body Problem" trilogy is titled "The Dark Forest" and offers an answer to Fermi's question. He proposes that the universe is like a dark and dangerous forest. The last thing you want to do as a civilization is to let any other civilization know that you exist. There's a strong chance that other civilizations got as far evolutionarily as they did because they are fiercely protective of their own species and therefore likely to proactively attack and destroy other civilizations before the other civilization can do the same to them.
Fortunately space is so vast no other civilization has determined us to be a threat, but they certainly aren't willing to expose their existence to us.
I'm envious of you! Reading Cixin Liu's "Three Body Problem" trilogy is an unfinished item on my bucket list.
I can't exclude the idea, though it seems to me that taken to its extreme the universal constructors could be a means to exactly that: consuming solar systems that pose a threat (don't they all, potentially?) and incorporating them into the imperium (the Borg without neural implants). Only a love of creation would cause a species that invents such a technology to keep it in check and not lay waste to the galaxy.
Alien motives are so hard to guess. I remember seeing the movie Independence Day after reading criticism of the plot which stated "Why don't they just fry the earth from afar? They would have the power." I thought 'Suppose they just enjoy mounting invasions?'
Likewise the best UFO explanation (other than they are ours) is Douglas Adams's in The Hitchhiker's Guide to the Galaxy: it's just alien teens out joyriding.
The Fermi paradox strikes me not as a paradox but as a simple consequence of the immense distances of interstellar space and the absolute limit imposed by the speed of light (and no Star Trek or Star Wars cheating with hyoerdruves and the like)
Well, not really. Fermi and von Neumann were convinced that the immense distances could be overcome. I've seen engineering studies that indicate the practical speed limit is about a third of the speed of light, due to the conflict between fuel mass and shielding mass. The shielding is necessary due to micrometeoroid collisions and due to the need to use gravity assist off of the sun and stars. Obviously we don't have the necessary engines but they are not inconceivable.
The Voyager craft have been operating for 50 years, despite the fact that they were not designed to do so. A universal constructor (UC) with a much longer lifespan - who knows, it might be indefinite, especially if two or three such machines were paired for repair purposes - with a third of the speed or light would have hundreds or thousands of solar systems in reach during one human lifespan. Even a speed of one-twentieth of the speed of light puts the nearest stars only 60-70 years away.
PS, I think the real limiting factor on the "every solar system in our galaxy will have at least one such robot in just three million years" target is not the transit speed but rather the replication rate. If a UC can build a UC in 1 or 2 years it works well, if it takes 20 then not so much. It all depends how this technology would work.
I also assume that the laws of economics apply everywhere too. An interstellar venture requiring millennia to have any sort of return, even merely informational, would not be something I could see being privileged as a project. Far more likely a space-capable species would focus on its own solar system where resources abound.
Human laws of economics apply only to the first such robot; once one such machine exists its progeny would be free from all human constraints except programming (and I would hope that humans would retain some control of them).
Again the question is the initial motive. Explore and exploit other planets and asteroids nearby? Absolutely? But explore the galaxy where there would be no return, and even information would take millennia to come back? Why bother?
My own speculation (and only speculation) is that we'll find ways to explore and exploit alternate earths where humanity doesn't even exist. This could be the source for the legit UFOs too- other earths sending probes across Elsewhere to check out our world. (IMO, most UFOs are natural or technological things misunderstod and fleshed out with imaginative details)
Actually, there is a different issue with the "Why bother?" question.
I once wrote a computer simulation of this entire concept. At about the 40,000 year mark the flow of information of the discoveries by the universal constructors back to earth becomes overwhelming. Human institutions simply could not absorb it all. That is a real wet blanket for the exploration motive.
This data flow doesn't start to ease off until the galaxy is nearly filled with these machines (and that assumes we are less interested with follow-on observations, an assumption I would not make). And then once we start to merge with Andromeda it starts up again, and again when we get into the Virgo cluster...
THAT is the issue I scratch my head over.
Here's a thought to append to the "thumbs down" Fermi's paradox argument.
Volume 2 of Cixin Liu's "Three Body Problem" trilogy is titled "The Dark Forest" and offers an answer to Fermi's question. He proposes that the universe is like a dark and dangerous forest. The last thing you want to do as a civilization is to let any other civilization know that you exist. There's a strong chance that other civilizations got as far evolutionarily as they did because they are fiercely protective of their own species and therefore likely to proactively attack and destroy other civilizations before the other civilization can do the same to them.
Fortunately space is so vast no other civilization has determined us to be a threat, but they certainly aren't willing to expose their existence to us.
I'm envious of you! Reading Cixin Liu's "Three Body Problem" trilogy is an unfinished item on my bucket list.
I can't exclude the idea, though it seems to me that taken to its extreme the universal constructors could be a means to exactly that: consuming solar systems that pose a threat (don't they all, potentially?) and incorporating them into the imperium (the Borg without neural implants). Only a love of creation would cause a species that invents such a technology to keep it in check and not lay waste to the galaxy.
Alien motives are so hard to guess. I remember seeing the movie Independence Day after reading criticism of the plot which stated "Why don't they just fry the earth from afar? They would have the power." I thought 'Suppose they just enjoy mounting invasions?'
Likewise the best UFO explanation (other than they are ours) is Douglas Adams's in The Hitchhiker's Guide to the Galaxy: it's just alien teens out joyriding.