3 ms·

The problem is that if you exclude the scenarios that obviously didn't happen you are still left with no likely scenarios given the present consensus understand

The problem is that if you exclude the scenarios that obviously didn't happen you are still left with no likely scenarios given the present consensus understanding of biology and physics. The timescale for megascale engineering to occur throughout our galaxy as the result of the launch of one megascale engineering minded self replicating probe is small (1 million years) in comparison to the age of the galaxy (13 billion years). It is unlikely that we are sitting here while someone else is in the process of doing it; that's not the scenario to focus on. All it takes, remember, is one small group in one sufficiently advanced culture to start this going. Some (post)human group will clearly do it at some point if we as a species continue. Why hasn't someone already done it, where "it" is visibly engineer the totality of the future light cone? The problem is less one of why don't we see Dyson spheres and other similar type II projects within a few hundred light years of our position, and more one of why do we see no obviously altered galaxies among the hundreds of thousands cataloged to date. At this scale the zoo hypothesis looks stretched, and the simulation argument begins to look more plausible.

thesteamboat 12y ago
Your comment sparked an interesting question in my mind: If some entity is trying to colonize in every direction at near the speed of light what is the expected gap time between the light of the actions reaching us and them reaching and colonizing us? A partial answer to the Fermi paradox by appeal to the anthropic principle: there is a very small fraction of time between being able to observe an alien species and being consumed by it.
Udo 12y ago
Good points, but I'd like to offer some counter arguments to the megascale engineering idea, hopefully without sounding too pedantic. The need for megascale projects is not as obvious as it's sometimes made out to be. There might well be reasonable limits beyond which the maximizing of habitat space and energy consumption tapers off in utility. Even if our civilization continues on its present course, it's not certain that we will get to the point where we (or some of us) feel the need to change the face of the galaxy. If you go one step down from the galactic stage, the detectability of solar system-scale megatech is also open to debate, especially as you move beyond a couple hundred light years from here. You're right of course when you say all it takes is one civilization (or even one member of a sufficiently advanced society) to undertake projects that are liable to make all kinds of strange phenomena appear in our night sky. But the number if beings capable of doing so on a whim, multiplied by the chance they'd be interested in such things, might be very very small without breaking any of our current expectations about biology and physics. Finally, I'd like to address the simulation argument. There are two extreme ends of the simulation scenario spectrum. At the one extreme, we're talking about an artificial reality made especially for us, humans. This would be the popular "Matrix"-style simulation. No scientific argument I've heard so far makes it a convincing model for the reality we live in, except as a possible explanation for the Fermi paradox. At the other end of the spectrum, we have a full simulated universe. It's hard to argue for or against that notion, simply because either way it fits with our observable reality. The catch is of course that it's a neutral proposition with no impact on us at all. This variant does not offer any explanation for the Fermi paradox. As I see it, the simulation argument as pertinent to the Fermi problem offers two options, neither of which are intellectually appealing: one is a borderline-untenable just-so make-believe world where all rules are an illusion and anything can happen, and the other one is virtually undistinguishable from our "normal" world, up to and including an absence of any obvious explanation for the Fermi paradox.

thesteamboat 12y ago

Your comment sparked an interesting question in my mind: If some entity is trying to colonize in every direction at near the speed of light what is the expected gap time between the light of the actions reaching us and them reaching and colonizing us? A partial answer to the Fermi paradox by appeal to the anthropic principle: there is a very small fraction of time between being able to observe an alien species and being consumed by it.

Udo 12y ago

Good points, but I'd like to offer some counter arguments to the megascale engineering idea, hopefully without sounding too pedantic. The need for megascale projects is not as obvious as it's sometimes made out to be. There might well be reasonable limits beyond which the maximizing of habitat space and energy consumption tapers off in utility. Even if our civilization continues on its present course, it's not certain that we will get to the point where we (or some of us) feel the need to change the face of the galaxy. If you go one step down from the galactic stage, the detectability of solar system-scale megatech is also open to debate, especially as you move beyond a couple hundred light years from here. You're right of course when you say all it takes is one civilization (or even one member of a sufficiently advanced society) to undertake projects that are liable to make all kinds of strange phenomena appear in our night sky. But the number if beings capable of doing so on a whim, multiplied by the chance they'd be interested in such things, might be very very small without breaking any of our current expectations about biology and physics. Finally, I'd like to address the simulation argument. There are two extreme ends of the simulation scenario spectrum. At the one extreme, we're talking about an artificial reality made especially for us, humans. This would be the popular "Matrix"-style simulation. No scientific argument I've heard so far makes it a convincing model for the reality we live in, except as a possible explanation for the Fermi paradox. At the other end of the spectrum, we have a full simulated universe. It's hard to argue for or against that notion, simply because either way it fits with our observable reality. The catch is of course that it's a neutral proposition with no impact on us at all. This variant does not offer any explanation for the Fermi paradox. As I see it, the simulation argument as pertinent to the Fermi problem offers two options, neither of which are intellectually appealing: one is a borderline-untenable just-so make-believe world where all rules are an illusion and anything can happen, and the other one is virtually undistinguishable from our "normal" world, up to and including an absence of any obvious explanation for the Fermi paradox.