It is not at all clear to me that most of the atoms in a planet could be harnessed for technological structures, or that doing so would be energy efficient. Most of the mass of an earthlike planet is iron, oxygen, silicon and magnesium, and while useful things can be made out of these elements, I would strongly worry that other elements that are needed also in those useful things will run out long before the planet has been disassembled. By historical precedent, I would think that an AI civilization on Earth will ultimately be able to use only a tiny fraction of the material in the planet, similarly to how only a very small fraction of a percent of the carbon in the planet is being used by the biosphere, in spite of biological evolution having optimized organisms for billions of years towards using all resources available for life.
The scenario of a swarm of intelligent drones eating up a galaxy and blotting out its stars I think can empirically be dismissed as very unlikely, because it would be visible over intergalactic distances. Unless we are the only civilization in the observable universe in the present epoch, we would see galaxies with dark spots or very strangely altered spectra somewhere. So this isn’t happening anywhere.
There are probably some historical analogs for the scenario of a complete takeover, but they are very far in the past, and have had more complex outcomes than intelligent grey goo scenarios normally portray. One instance I can think of is the Great Oxygenation Event. I imagine an observer back then might have envisioned that the end result of the evolution of cyanobacteria doing oxygenic photosynthesis would be the oceans and lakes and rivers all being filled with green slime, with a toxic oxygen atmosphere killing off all other life. While indeed this prognosis would have been true to a first order approximation—green plants do dominate life on Earth today—the reality of what happened is infinitely more complex than this crude picture suggests. And even anaerobic organisms survive to this day in some niches.
The other historical precedent that comes to mind would be the evolution of organisms that use DNA to encode genetic information using the specific genetic code that is now universal to all life, in whatever pre-DNA world existed at the beginning of life. These seem to have indeed completely erased all other kinds of life (claims of a shadow biosphere of more primitive organisms are all dubious to my knowledge), but also have not resulted in a less complex world.
It is not at all clear to me that most of the atoms in a planet could be harnessed for technological structures, or that doing so would be energy efficient. Most of the mass of an earthlike planet is iron, oxygen, silicon and magnesium, and while useful things can be made out of these elements, I would strongly worry that other elements that are needed also in those useful things will run out long before the planet has been disassembled. By historical precedent, I would think that an AI civilization on Earth will ultimately be able to use only a tiny fraction of the material in the planet, similarly to how only a very small fraction of a percent of the carbon in the planet is being used by the biosphere, in spite of biological evolution having optimized organisms for billions of years towards using all resources available for life.
The scenario of a swarm of intelligent drones eating up a galaxy and blotting out its stars I think can empirically be dismissed as very unlikely, because it would be visible over intergalactic distances. Unless we are the only civilization in the observable universe in the present epoch, we would see galaxies with dark spots or very strangely altered spectra somewhere. So this isn’t happening anywhere.
There are probably some historical analogs for the scenario of a complete takeover, but they are very far in the past, and have had more complex outcomes than intelligent grey goo scenarios normally portray. One instance I can think of is the Great Oxygenation Event. I imagine an observer back then might have envisioned that the end result of the evolution of cyanobacteria doing oxygenic photosynthesis would be the oceans and lakes and rivers all being filled with green slime, with a toxic oxygen atmosphere killing off all other life. While indeed this prognosis would have been true to a first order approximation—green plants do dominate life on Earth today—the reality of what happened is infinitely more complex than this crude picture suggests. And even anaerobic organisms survive to this day in some niches.
The other historical precedent that comes to mind would be the evolution of organisms that use DNA to encode genetic information using the specific genetic code that is now universal to all life, in whatever pre-DNA world existed at the beginning of life. These seem to have indeed completely erased all other kinds of life (claims of a shadow biosphere of more primitive organisms are all dubious to my knowledge), but also have not resulted in a less complex world.