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Do other galaxies matter here? A civilization would need to be incredibly powerful to be detectable from another galaxy.

by pavlov 1y ago

ben_w 1y ago
At the moment, rapid and massive expansion seems likely with tech only just on the horizon. Enough AI and robotics for an autonomous factory may be a mirage (such mirages have (metaphorically) happened before), but it seems like it's on the horizon. Even with relatively mundane growth assumptions, that can go from "species inventing writing" to "Dyson sphere completed, is now sending out seeds to every accessible galaxy" on significantly less than the timescale of light crossing a spiral galaxy's disk.
- kingkawn 1y ago
  Cmon the number of hypothetical extrapolations based on no data in these statements is beyond superstition to something like delusion
  - ben_w 1y ago
    If I put citations into everything I write, I'd be a Wikipedia article, and people would still criticise the conclusions without reading any of them. But contrawise, I do have data, they're broadly categorised as "history", "biology", and "all the stuff cited by Stuart Armstrong that time".
  - javier2 1y ago
    I think its the fact that if we really wanted to, we could probably make it happen already today. On a scale of a couple hundred million years, its possible we could reach most of our own galaxy, which is a small slice of time in the life span of the Milky Way. So the question remains, why hasn't this already happened, or has it?
pfdietz 1y ago
Galactic colonization, carried to saturation, would detectably modify the appearance of a galaxy. So called "type 3 civilizations" would convert a significant fraction of starlight to lower grade heat, which would be radiated. Searches have been conducted for this signature, with the result that no more than 1 in 100,000 galaxies has such a civilization, and with the result being consistent with none.
- pavlov 1y ago
  This is interesting speculation, but it adds one more completely unknown variable to the Drake equation. What’s the probability that a radio-capable civilization becomes a galactic type 3 one? Looking at the only example we have, it appears very unlikely. It seems much more probable that we’ll destroy ourselves within the next centuries.
- runarberg 1y ago
  I am not an astrophysicist but I have a hunch any speculations of galactic colonization fails to entertain just how big space actually is. I feel like there is ample reason to suspect the probability of galactic (or even interstellar) colonization is exactly 0, and no civilization in the history of the entire universe will ever colonize an entire galaxy (and probably not even more than a handful of solar systems outside their home world; if any).
  - pfdietz 1y ago
    Your argument shows a lack of understanding of exponential growth. Any given colony has to create only slightly more than 1 additional colony in order to drive exponential growth. There doesn't have to be any coordinated action by a central authority for it to happen. For it not to happen (if it is physically feasible), in contrast, every species has to refrain from doing it at all points in their history, almost without exception. And those that do the colonization will seed additional colonies with a mindset that led to colonization; such mindsets will be selected for for further expansion.
    - runarberg 1y ago
HarHarVeryFunny 1y ago
I guess it depends what question are we trying to ask. It may well be that there is no other intelligent life close enough to us, or coexisting with us in time, that we will ever be aware of it, but yet the universe may still be teeming with intelligent life. In either case it's a statistical question of how common is life, and intelligent life, but of course there's the human interest in potential contact with another intelligent life form.

Do other galaxies matter here? A civilization would need to be incredibly powerful to be detectable from another galaxy.

by pavlov 1y ago

Do other galaxies matter here? A civilization would need to be incredibly powerful to be detectable from another galaxy.

ben_w 1y ago

At the moment, rapid and massive expansion seems likely with tech only just on the horizon. Enough AI and robotics for an autonomous factory may be a mirage (such mirages have (metaphorically) happened before), but it seems like it's on the horizon. Even with relatively mundane growth assumptions, that can go from "species inventing writing" to "Dyson sphere completed, is now sending out seeds to every accessible galaxy" on significantly less than the timescale of light crossing a spiral galaxy's disk.

kingkawn 1y ago
Cmon the number of hypothetical extrapolations based on no data in these statements is beyond superstition to something like delusion
- ben_w 1y ago
  If I put citations into everything I write, I'd be a Wikipedia article, and people would still criticise the conclusions without reading any of them. But contrawise, I do have data, they're broadly categorised as "history", "biology", and "all the stuff cited by Stuart Armstrong that time".
- javier2 1y ago
  I think its the fact that if we really wanted to, we could probably make it happen already today. On a scale of a couple hundred million years, its possible we could reach most of our own galaxy, which is a small slice of time in the life span of the Milky Way. So the question remains, why hasn't this already happened, or has it?

pfdietz 1y ago

Galactic colonization, carried to saturation, would detectably modify the appearance of a galaxy. So called "type 3 civilizations" would convert a significant fraction of starlight to lower grade heat, which would be radiated. Searches have been conducted for this signature, with the result that no more than 1 in 100,000 galaxies has such a civilization, and with the result being consistent with none.

pavlov 1y ago
This is interesting speculation, but it adds one more completely unknown variable to the Drake equation. What’s the probability that a radio-capable civilization becomes a galactic type 3 one? Looking at the only example we have, it appears very unlikely. It seems much more probable that we’ll destroy ourselves within the next centuries.
runarberg 1y ago
I am not an astrophysicist but I have a hunch any speculations of galactic colonization fails to entertain just how big space actually is. I feel like there is ample reason to suspect the probability of galactic (or even interstellar) colonization is exactly 0, and no civilization in the history of the entire universe will ever colonize an entire galaxy (and probably not even more than a handful of solar systems outside their home world; if any).
- pfdietz 1y ago
  Your argument shows a lack of understanding of exponential growth. Any given colony has to create only slightly more than 1 additional colony in order to drive exponential growth. There doesn't have to be any coordinated action by a central authority for it to happen. For it not to happen (if it is physically feasible), in contrast, every species has to refrain from doing it at all points in their history, almost without exception. And those that do the colonization will seed additional colonies with a mindset that led to colonization; such mindsets will be selected for for further expansion.
  - runarberg 1y ago

HarHarVeryFunny 1y ago

I guess it depends what question are we trying to ask. It may well be that there is no other intelligent life close enough to us, or coexisting with us in time, that we will ever be aware of it, but yet the universe may still be teeming with intelligent life. In either case it's a statistical question of how common is life, and intelligent life, but of course there's the human interest in potential contact with another intelligent life form.