4 ms·

We have observed exactly one sentient species, (ours) and it is sending probes already. There are 200 sextillion stars. For the opposite position (they shouldn

by ericb 3y ago

We have observed exactly one sentient species, (ours) and it is sending probes already. There are 200 sextillion stars. For the opposite position (they shouldn't be here) to make sense, there has to be either no other civilizations, or our probe-sending habits are so rare that no other civilizations do it, or we are the first. Any of those other stances seem vastly more improbable, as they assume that our sample-of-one society just happens to be ludicrously different than all others.

actionfromafar 3y ago
Since we have only a sample of one, I can never make my mind up on about what is probable or improbable. But I do believe it is technically possible in principle to construct and build von Neuman probes. Once they work inside a solar system, then work on making them withstand, say, a few million years in orbit and see if they still work, once they survive a few million years "inactive" (or constantly repairing themselves or whatever it takes), send them off to the stars. But it would take a patience and scale of industry we humans literally can only vaguely dream of.
- ericb 3y ago
  > withstand, say, a few million years in orbit > ...scale of industry They don't have to do that. The probe just has to make more "child probes" before it dies. You don't need a huge industry if they are self-replicating. You need only one working probe to start, the rest handles itself.
  - actionfromafar 3y ago
    The "only" there does a lot of work. :-) And it has to survive for millions of years until it reaches a new solar system without something to "feed" on. In many ways it seems easier to make a Neuman probe which can survive within a solar system than something which can travel to another.
    - gremlinsinc 3y ago
      it's only 75k to our nearest neighbor, and that's with current craft speeds, there's theoretical ideas for craft that's faster using solar sails and much smaller lower mass that might do it in a century.
- Teever 3y ago
  https://youtu.be/zQTfuI-9jIo?si=vYYxLP_yQfgsYEA9 https://youtu.be/zQTfuI-9jIo?si=vYYxLP_yQfgsYEA9 This is a fascinating talk that goes into the details of such an endeavor.
x86x87 3y ago
Space is huge. The odds of being "close enough" to another sentient species are very low.
- ericb 3y ago
  Exponential math is huge too.
georgeecollins 3y ago
I think the reason why it seems improbable is that we conceptualize interstellar travel with a mental model of travel and exploration based on our human history of exploration and travel on Earth. So we think-- if there were a civilization a thousand light years away of course they would come visit and study us. What if the time it takes to travel between stars is longer than most civilizations exist? What if we aren't that interesting to alien species or aren't worth the time and energy to discover? We've never sent a functioning probe to any other star and probably won't in my lifetime. And life may not be at the nearest star, it may be thousands of light years away. We may never have the resources available to do it.
- ericb 3y ago
  > What if the time it takes to travel between stars is longer than most civilizations exist? The probe doesn't require its parent civilization to continue existing to keep working. It self-replicates. You don't have to "pick" where self-replicating probes go. Each can self-replicate, and you can get nigh-infinite probes for "free." A von Neuman probe finds its own resources.
  - georgeecollins 3y ago
    We have never built anything complicated enough to self - replicate or self -repair that could last a hundred years. We have never built a biosphere that can exist in a self contained manner for a hundred years. I am not saying we won't but you are assuming we will figure out how to makes something that will maintain its message integrity for a hundred thousand years and then we will have the energy or the ability to shrink it enough to be able to send it off to some life supporting star. We have only had complicated writing for a few thousand years. People have wondered if a technical civilization existed on earth a hundred million years ago would there be any thing around now as evidence. If it takes a million years of travel in the freezing, radioactive vacuum of space to reach another life form, you don't know that humans will be around long enough as a civilization to figure out how to actually build the thing that you are describing. I hope so, but I don't think its been proven to be possible yet.

by ericb 3y ago

actionfromafar 3y ago

Since we have only a sample of one, I can never make my mind up on about what is probable or improbable. But I do believe it is technically possible in principle to construct and build von Neuman probes. Once they work inside a solar system, then work on making them withstand, say, a few million years in orbit and see if they still work, once they survive a few million years "inactive" (or constantly repairing themselves or whatever it takes), send them off to the stars. But it would take a patience and scale of industry we humans literally can only vaguely dream of.

ericb 3y ago
> withstand, say, a few million years in orbit > ...scale of industry They don't have to do that. The probe just has to make more "child probes" before it dies. You don't need a huge industry if they are self-replicating. You need only one working probe to start, the rest handles itself.
- actionfromafar 3y ago
  The "only" there does a lot of work. :-) And it has to survive for millions of years until it reaches a new solar system without something to "feed" on. In many ways it seems easier to make a Neuman probe which can survive within a solar system than something which can travel to another.
  - gremlinsinc 3y ago
    it's only 75k to our nearest neighbor, and that's with current craft speeds, there's theoretical ideas for craft that's faster using solar sails and much smaller lower mass that might do it in a century.
Teever 3y ago
https://youtu.be/zQTfuI-9jIo?si=vYYxLP_yQfgsYEA9 https://youtu.be/zQTfuI-9jIo?si=vYYxLP_yQfgsYEA9 This is a fascinating talk that goes into the details of such an endeavor.

x86x87 3y ago

Space is huge. The odds of being "close enough" to another sentient species are very low.

ericb 3y ago
Exponential math is huge too.

georgeecollins 3y ago

I think the reason why it seems improbable is that we conceptualize interstellar travel with a mental model of travel and exploration based on our human history of exploration and travel on Earth. So we think-- if there were a civilization a thousand light years away of course they would come visit and study us. What if the time it takes to travel between stars is longer than most civilizations exist? What if we aren't that interesting to alien species or aren't worth the time and energy to discover? We've never sent a functioning probe to any other star and probably won't in my lifetime. And life may not be at the nearest star, it may be thousands of light years away. We may never have the resources available to do it.

ericb 3y ago
> What if the time it takes to travel between stars is longer than most civilizations exist? The probe doesn't require its parent civilization to continue existing to keep working. It self-replicates. You don't have to "pick" where self-replicating probes go. Each can self-replicate, and you can get nigh-infinite probes for "free." A von Neuman probe finds its own resources.
- georgeecollins 3y ago
  We have never built anything complicated enough to self - replicate or self -repair that could last a hundred years. We have never built a biosphere that can exist in a self contained manner for a hundred years. I am not saying we won't but you are assuming we will figure out how to makes something that will maintain its message integrity for a hundred thousand years and then we will have the energy or the ability to shrink it enough to be able to send it off to some life supporting star. We have only had complicated writing for a few thousand years. People have wondered if a technical civilization existed on earth a hundred million years ago would there be any thing around now as evidence. If it takes a million years of travel in the freezing, radioactive vacuum of space to reach another life form, you don't know that humans will be around long enough as a civilization to figure out how to actually build the thing that you are describing. I hope so, but I don't think its been proven to be possible yet.