The glossed over Great Filter is space is fucking huge and physics is mean.

It takes a great effort to get a coherent radio signal to hit a system many light years away. Leaked radio emissions just don't reach very far. Even high powered radar is extremely narrow beams coming from a spinning planet orbiting a star that itself is flying through space. The odds that beam crosses some system specifically listening for it is extremely low and the odds of a reoccurrence is ridiculously low.

The dark forest just doesn't make sense. A sufficiently large telescope can get spectra from terrestrial planets. If you have some killer space fleet you'll send it off to any planet where you find short-lived industrial emissions (CFCs etc). There's no need to wait for radio emissions from a planet with biomarkers. It also presumes its practical to send a space fleet to go destroy anyone.

It's far more likely the odds of any two technological civilizations existing at the same "time" at detectable ranges is extremely low. Species also don't tend to take over galaxies because it requires unattainable amounts of power and resources much better used to live happily in their own little corner.

Interesting!

I've always had an intuitive feeling that theories like The Great Filter theory was a pretty arrogant simplification of "actual reality" beyond our narrow biological lenses and even narrower western definition of "life" or even spatial dimensions and time.

Just because some western scientist with only 350+ years of somewhat advanced tools, math and imagination can't see "something" doesn't mean something isn't there - we don't even know what "there" is, or who "we" are.

Math and science is an awesome "thing", but the ridiculous existential pop-science extrapolations from simple equations is laughable if not sinister, especially in light of the paradigmatic shifts in science and worldview over just the last couple of centuries.

I tend to agree, I don't think we have a good grasp on what life will be like in 50 years let alone 1000 or 10,000. My personal guesses are that we will continue to make improvements in efficiency and so will produce very little leakage of communications or even heat making us nearly invisible over vast distances. Sociologically, I think we'll be very different; population growth may approach 0 while lifespan increases dramatically so we'll continue to explore the universe but will do so remotely since we just won't have the numbers to physically colonize other star systems. Even the timescale on which we live may change drastically, perception of time isn't even fixed when it comes to biology there are other species that have much faster or slower perception of time and once we being to modify our biology and augment it by integrating with digital systems we'll be able to control that sense. Who can predict what other technological advances are on the horizon, for all we know alien probes or other technology could be as small as bacteria and might just be distributed through space as vast networks of dust clouds that harvest ambient chemical and solar energy and have transmission ranges measured in micrometers. How would we even detect such technology without physically going there and examining it up close?

Agreed. The Great Filter theory has weak assumptions that a) all ”living” systems evolve in a similar way as the biological systems on earth, and b) that this evolution ”advances” somehow towards space expansion.

Our biological lenses make it seem like the complex system we call ”life” is the only similarly complex system that is possible in the entire universe.

The Drake equation handles that case:

fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space

Right; the parameter that would be of interest is rather L = the length of time for which such civilizations release detectable signals into space.

Quoting Wikipedia: "Inserting the above minimum numbers into the equation gives a minimum N of 20. Inserting the maximum numbers gives a maximum of 50,000,000. Drake states that given the uncertainties, the original meeting concluded that N ≈ L, and there were probably between 1000 and 100,000,000 planets with civilizations in the Milky Way Galaxy."

As I understand it, at the time it was estimated that a civilization would broadcast during its existence, from the time radio communications started until the fall of civilization (thus the Great Filter).

Now, from our sample size of one, it looks like L would rather be on the order of 100 years (in our case, not because we are trying to hide in the Dark Forest, but because we don't want to waste energy beaming Dallas reruns into space for no good reason).

The drake equation handle nothing, because all parameters are pure speculation

When dealing with unknown unknowns any theory can be logical.

Maybe extra-terrestrials are more like lumberjacks chopping down trees. Except these lumber jacks avoid *any tree with a bird's nest in it*. Then, we should be as visible as possible.

So should we be quiet (ala Dark Forest), or loud? Depends on how you model extra-terrestrials.

Isn't some sort of game theory going to suggest we be quiet then? Because if they exterminate birds nests, we want to be quiet, and if they intentionally avoid bird's nests, they probably will look for them closer before chopping us down.

Hmm, so I am not sure I see why that would be more likely. It sounds like you're saying that exterminators are less effective at detection than lumberjacks--whether by effort or some other reason.

I think you could just as logically conclude the opposite: maybe lumberjacks don't need to exterminate to survive, so they do not put as much effort in, since they are just avoiding us altruistically.

But more generally, this is the sort of problem I have with speculation on unknown unknowns: It's fun to do, but I dont recommend changing any of our decisions based on it because we simply do not know.

I don't think any explanation is "better" or "worse" than the great filter, as we only have our example. There's nothing suggesting that we are alone in the universe, but also nothing suggesting that we aren't alone. We can formulate whatever hypothesis we want but it won't change reality. Either there's something out there or there isn't. Lots of people thinking the great filter or Drake's equation is real won't affect what is or isn't out there. We just don't know, and it's mostly a waste of time to think about it.

I feel like the second is the most likely. Combine that with challenging the proposition that intelligent life would ever choose to colonize the galaxy to the extent that it would be blatantly obvious and I think you have a pretty solid position from which to argue that it won't be easy to detect other civilizations.

the density of intelligent life cannot be bounded from below with only the one point of data that we have.