7 ms·

"...chances of life are 1000 times higher in the distant future than now." I still don't see this as a solution to the Fermi paradox, considering the billions

by Meegul 10y ago

"...chances of life are 1000 times higher in the distant future than now." I still don't see this as a solution to the Fermi paradox, considering the billions (more?) of planets in our galaxy.

jtolmar 10y ago
Simple solution - relativity holds up. Our light cone is much smaller than the galaxy. The universe could be teaming with intelligent life but not so full that you'd expect any to overlap the period where we're both using radio waves to communicate.
- btilly 10y ago
  The Milky Way is about 100k light years across. If colonization proceeded at 1% of the speed of light, it would take 10 million years to colonize the galaxy. That is roughly 0.2% of the time that the Earth has existed. And a bit under 2% of the time since the Cambrian that we've had complex life forms. Speed of light is a barrier for intergalactic colonization. It is not a barrier for an advanced civilization trying to colonize a galaxy. Even a relatively large galaxy such as our own.
  - sampo 10y ago
    > Speed of light is a barrier for intergalactic colonization. The distance to Andromeda is about 20x times the diameter of Milky Way. But of course this is massively longer that hopping from a solar system to the next.
    - btilly 10y ago
      Right. There are no intermediate stopping points between the two. And Andromeda is in our local cluster and so close on the scale of the universe. Point of interest, we'll meet Andromeda in about 3 billion years or so. Point of additional interest. Due to the expansion of the universe, it is impossible even in theory to travel to most of the galaxies that we can see. Point of amazement. Our telescopes can pick out more galaxies in the universe than individual stars!
- TheOtherHobbes 10y ago
  Once you get to civs that last >10^6 years, the galaxy becomes a trivial size. The galaxy - and the speed of light limit - are also trivial distractions to any low-energy civs that evolved to run at a much slower metabolic rate, or adapted themselves to same. With Fermi, the smart money is on the galaxy being full of life - but it's either avoiding Earth completely, or it's here already and doesn't want to be seen. Besides - the goals and technology of >10^6 civs are literally unimaginable from a human perspective. We assume that exploration and travel are major interests. They may not be. There may be other pastimes we're completely unfamiliar with - ones which make getting into metal spaceships and banging atoms together to make them move through spacetime in a linear way seem about as interesting as sleeping in tree branches are to us.
  - adrianratnapala 10y ago
    The thing is that all told, humans pick more fruit than other primates, and have more visible effects on forests than other primates. It's not unreasonable to think something similar applies to space-capable supercivilisations.
agentgt 10y ago
There was a discussion thread a while back about this on HN [1]. The first argument is a fairly weak argument/theory but about the same strength as most of the other common arguments/theories. To me the strongest argument that there is a paradox is the idea of probes that can replicate. That it would be fairly easy with some sort of advance but not FTL technology to easily deal with the size and expansion of the universe (of course I could be full of it on this as I haven't looked into this idea in some time). Basically why haven't we run into a probe yet? [1]: https://news.ycombinator.com/item?id=9916085 https://news.ycombinator.com/item?id=9916085
- p_zakharov 10y ago
  Issuing von Neumann probes like this seems like a flashing neon advertisement of your presence in space: not necessarily the best strategic choice. On the other hand it's possible that such a species of probe already exists but is more or less of the Fred Saberhagen Berserker variety and desires to operate stealthily. Perhaps the crews of these vessels like to sing Das Lied vom außerirdischen U-Boot Mann. (As you might have already guessed I have views on astrobiology vastly different from those of the late Carl Sagan.)
- Teever 10y ago
  My personal belief is that we haven't run into them yet because they are quietly observing us from the asteroid belt. It's only been a few years since we have been able to even begin to survey the solar system and that would mean that a bracewell probe could have been burrowed in an asteroid for millenia observing the development of the human race. Perhaps it choses to not make contact with us because we have not yet crossed a threshold that it is programmed to observe before making contact/annihilating us.
  - WildUtah 10y ago
    There used to be thousands of UFO sightings every year. Now with the arrival of smartphones and ubiquitous cameras, there are almost none. Which indicates that the UFOs are an intelligent civilization that is adapting to observe us in secret. Whenever we develop means of tracking them, they hide better.
p_zakharov 10y ago
The Fermi paradox really isn't an issue though to begin with. The following is an excerpt from the excellent Contact with Alien Civilizations: Our Hopes and Fears About Encountering Extraterrestrials: "The vast majority of search space remains unexplored. Search space does not just mean the three-dimensional volume of the Galaxy. As the Jet Propulsion Laboratory’s Michael Klein explained, it is a multidimensional space that includes source location, signal frequency, power level, time of arrival, signal modulation, and polarizations.[9]" And this assumes that electromagnetic transmissions are what we need to look for. Anyhow the Fermi paradox is like seeing just one straw in an enormous haystack, observing that it is not a needle, and then quitting.
- mrec 10y ago
  The Fermi paradox isn't "why aren't we seeing alien civilizations at the specific stars/times/wavelengths/etc we happen to look at". It's "why haven't alien civilizations colonized the entire galaxy by now, using conceptually simple things like von Neumann probes which even our none-too-sophisticated primate brains can come up with?"
  - p_zakharov 10y ago
    I suppose there are now different formulations of the Fermi paradox but if I remember Fermi's original words they were about the apparent radio silence (possibly minus the Wow! signal). Anyhow, the assumption here is that doing so is desirable. I deal with the desirability of doing so (openly) elsewhere in the thread. It's not clear that doing this is the best idea.
    - deleted 10y ago
      [deleted]
    - mrec 10y ago
      Again, though, it doesn't need to be the best idea, it just needs ONE civilization somewhere in the galaxy to have done it ONCE. We can't be the only species with a tendency to derp on occasion.
jessriedel 10y ago
The OP argument isn't about the Fermi paradox. To see this, first note that those words don't appear in it. Second, consider the possibility that abiogenesis is just stupendously rare. This solves the Fermi paradox (regardless of whether you think this solution engenders problem of its own, such as why life seemed to develop so soon after Earth initially formed), but the anthropic issue raised by the OP argument would persist.
- delecti 10y ago
  > Second, consider the possibility that abiogenesis is just stupendously rare I think a better way to phrase this is that abiogenesis is stupendously picky, but also incredibly eager. My understanding is that current life developed about as quickly as it possibly could have, at least on a geological scale. It's possible that worlds we're finding that look "ideal for life" from the perspective of what we can detect from this distance may be missing something vital that Earth had.
  - jessriedel 10y ago
    > My understanding is that current life developed about as quickly as it possibly could have, at least on a geological scale. This is commonly quoted, but actually not at all implied by the data, at least as long as you allow for the very real possibility that the road from inert matter to conscious observers required multiple improbable steps. For counter-intuitive probabilistic reasons, you can't infer the "improbableness" of a step from the amount of time it took to occur when several such steps occur. http://mason.gmu.edu/~rhanson/greatfilter.html http://mason.gmu.edu/~rhanson/greatfilter.html
    - delecti 10y ago
      I actually mean solely abiogenesis. From the perspective of the Drake Equation [0], I think it's likely that ne [1] is quite low, and fl [2] is quite high. I don't think we can speculate on fi [3], given a sample size of 1. Though as we seem to be somewhat of an anomaly across several great extinction events, a low estimate there seems fair as a starting point. The great filter theory implies that the last two terms are also low, but again, my point was mainly focused on going from no life to basic life. Essentially I think that while there are improbably steps between inert matter and consciousness, abiogenesis itself does not seem to be one of them, though the suitability for abiogenesis likely is. [0] https://en.wikipedia.org/wiki/Drake_equation#Equation https://en.wikipedia.org/wiki/Drake_equation#Equation [1] the average number of planets that can potentially support life per star that has planets [2] the fraction of planets that could support life that actually develop life at some point [3] the fraction of planets with life that actually go on to develop intelligent life (civilizations)
Aelinsaar 10y ago
I prefer the "Lots of life, utterly separated by time and space, running into some version of the 'Great Filter'." Space is just too damned big, and the timescales involved in two way communication are too nasty. Maybe the solution is that any sufficiently advanced species either blows up, or stays focused entirely on what it can realistically communicate with 2-way (so incredibly close by, cosmically speaking).

by Meegul 10y ago

"...chances of life are 1000 times higher in the distant future than now." I still don't see this as a solution to the Fermi paradox, considering the billions (more?) of planets in our galaxy.

jtolmar 10y ago

Simple solution - relativity holds up. Our light cone is much smaller than the galaxy. The universe could be teaming with intelligent life but not so full that you'd expect any to overlap the period where we're both using radio waves to communicate.

btilly 10y ago
The Milky Way is about 100k light years across. If colonization proceeded at 1% of the speed of light, it would take 10 million years to colonize the galaxy. That is roughly 0.2% of the time that the Earth has existed. And a bit under 2% of the time since the Cambrian that we've had complex life forms. Speed of light is a barrier for intergalactic colonization. It is not a barrier for an advanced civilization trying to colonize a galaxy. Even a relatively large galaxy such as our own.
- sampo 10y ago
  > Speed of light is a barrier for intergalactic colonization. The distance to Andromeda is about 20x times the diameter of Milky Way. But of course this is massively longer that hopping from a solar system to the next.
  - btilly 10y ago
    Right. There are no intermediate stopping points between the two. And Andromeda is in our local cluster and so close on the scale of the universe. Point of interest, we'll meet Andromeda in about 3 billion years or so. Point of additional interest. Due to the expansion of the universe, it is impossible even in theory to travel to most of the galaxies that we can see. Point of amazement. Our telescopes can pick out more galaxies in the universe than individual stars!
TheOtherHobbes 10y ago
Once you get to civs that last >10^6 years, the galaxy becomes a trivial size. The galaxy - and the speed of light limit - are also trivial distractions to any low-energy civs that evolved to run at a much slower metabolic rate, or adapted themselves to same. With Fermi, the smart money is on the galaxy being full of life - but it's either avoiding Earth completely, or it's here already and doesn't want to be seen. Besides - the goals and technology of >10^6 civs are literally unimaginable from a human perspective. We assume that exploration and travel are major interests. They may not be. There may be other pastimes we're completely unfamiliar with - ones which make getting into metal spaceships and banging atoms together to make them move through spacetime in a linear way seem about as interesting as sleeping in tree branches are to us.
- adrianratnapala 10y ago
  The thing is that all told, humans pick more fruit than other primates, and have more visible effects on forests than other primates. It's not unreasonable to think something similar applies to space-capable supercivilisations.

agentgt 10y ago

There was a discussion thread a while back about this on HN [1]. The first argument is a fairly weak argument/theory but about the same strength as most of the other common arguments/theories. To me the strongest argument that there is a paradox is the idea of probes that can replicate. That it would be fairly easy with some sort of advance but not FTL technology to easily deal with the size and expansion of the universe (of course I could be full of it on this as I haven't looked into this idea in some time). Basically why haven't we run into a probe yet? [1]: https://news.ycombinator.com/item?id=9916085 https://news.ycombinator.com/item?id=9916085

p_zakharov 10y ago
Issuing von Neumann probes like this seems like a flashing neon advertisement of your presence in space: not necessarily the best strategic choice. On the other hand it's possible that such a species of probe already exists but is more or less of the Fred Saberhagen Berserker variety and desires to operate stealthily. Perhaps the crews of these vessels like to sing Das Lied vom außerirdischen U-Boot Mann. (As you might have already guessed I have views on astrobiology vastly different from those of the late Carl Sagan.)
Teever 10y ago
My personal belief is that we haven't run into them yet because they are quietly observing us from the asteroid belt. It's only been a few years since we have been able to even begin to survey the solar system and that would mean that a bracewell probe could have been burrowed in an asteroid for millenia observing the development of the human race. Perhaps it choses to not make contact with us because we have not yet crossed a threshold that it is programmed to observe before making contact/annihilating us.
- WildUtah 10y ago
  There used to be thousands of UFO sightings every year. Now with the arrival of smartphones and ubiquitous cameras, there are almost none. Which indicates that the UFOs are an intelligent civilization that is adapting to observe us in secret. Whenever we develop means of tracking them, they hide better.

p_zakharov 10y ago

The Fermi paradox really isn't an issue though to begin with. The following is an excerpt from the excellent Contact with Alien Civilizations: Our Hopes and Fears About Encountering Extraterrestrials: "The vast majority of search space remains unexplored. Search space does not just mean the three-dimensional volume of the Galaxy. As the Jet Propulsion Laboratory’s Michael Klein explained, it is a multidimensional space that includes source location, signal frequency, power level, time of arrival, signal modulation, and polarizations.[9]" And this assumes that electromagnetic transmissions are what we need to look for. Anyhow the Fermi paradox is like seeing just one straw in an enormous haystack, observing that it is not a needle, and then quitting.

mrec 10y ago
The Fermi paradox isn't "why aren't we seeing alien civilizations at the specific stars/times/wavelengths/etc we happen to look at". It's "why haven't alien civilizations colonized the entire galaxy by now, using conceptually simple things like von Neumann probes which even our none-too-sophisticated primate brains can come up with?"
- p_zakharov 10y ago
  I suppose there are now different formulations of the Fermi paradox but if I remember Fermi's original words they were about the apparent radio silence (possibly minus the Wow! signal). Anyhow, the assumption here is that doing so is desirable. I deal with the desirability of doing so (openly) elsewhere in the thread. It's not clear that doing this is the best idea.
  - deleted 10y ago
    [deleted]
  - mrec 10y ago
    Again, though, it doesn't need to be the best idea, it just needs ONE civilization somewhere in the galaxy to have done it ONCE. We can't be the only species with a tendency to derp on occasion.

jessriedel 10y ago

The OP argument isn't about the Fermi paradox. To see this, first note that those words don't appear in it. Second, consider the possibility that abiogenesis is just stupendously rare. This solves the Fermi paradox (regardless of whether you think this solution engenders problem of its own, such as why life seemed to develop so soon after Earth initially formed), but the anthropic issue raised by the OP argument would persist.

delecti 10y ago
> Second, consider the possibility that abiogenesis is just stupendously rare I think a better way to phrase this is that abiogenesis is stupendously picky, but also incredibly eager. My understanding is that current life developed about as quickly as it possibly could have, at least on a geological scale. It's possible that worlds we're finding that look "ideal for life" from the perspective of what we can detect from this distance may be missing something vital that Earth had.
- jessriedel 10y ago
  > My understanding is that current life developed about as quickly as it possibly could have, at least on a geological scale. This is commonly quoted, but actually not at all implied by the data, at least as long as you allow for the very real possibility that the road from inert matter to conscious observers required multiple improbable steps. For counter-intuitive probabilistic reasons, you can't infer the "improbableness" of a step from the amount of time it took to occur when several such steps occur. http://mason.gmu.edu/~rhanson/greatfilter.html http://mason.gmu.edu/~rhanson/greatfilter.html
  - delecti 10y ago
    I actually mean solely abiogenesis. From the perspective of the Drake Equation [0], I think it's likely that ne [1] is quite low, and fl [2] is quite high. I don't think we can speculate on fi [3], given a sample size of 1. Though as we seem to be somewhat of an anomaly across several great extinction events, a low estimate there seems fair as a starting point. The great filter theory implies that the last two terms are also low, but again, my point was mainly focused on going from no life to basic life. Essentially I think that while there are improbably steps between inert matter and consciousness, abiogenesis itself does not seem to be one of them, though the suitability for abiogenesis likely is. [0] https://en.wikipedia.org/wiki/Drake_equation#Equation https://en.wikipedia.org/wiki/Drake_equation#Equation [1] the average number of planets that can potentially support life per star that has planets [2] the fraction of planets that could support life that actually develop life at some point [3] the fraction of planets with life that actually go on to develop intelligent life (civilizations)

Aelinsaar 10y ago

I prefer the "Lots of life, utterly separated by time and space, running into some version of the 'Great Filter'." Space is just too damned big, and the timescales involved in two way communication are too nasty. Maybe the solution is that any sufficiently advanced species either blows up, or stays focused entirely on what it can realistically communicate with 2-way (so incredibly close by, cosmically speaking).