Comment by snakeyjake | Hacker News Reader

Comment by snakeyjake | Hacker News Reader

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I don't understand.

I feel like I'm going crazy.

If there was an identical civilization residing on an identical earth orbiting an identical sun at the distance of our closest celestial neighbor, there is an exact and precise 0.0% chance that we would be able to detect them.

We wouldn't be able to detect them optically or electromagnetically.

There's no room for debate, we cannot resolve enough detail at that distance and our (and therefore their) highest-output EM emissions would fall below the noise floor. We probably wouldn't even be able to tell the composition of their atmosphere besides "uh there's a little methane, some oxygen, and some nitrogen in the extreme upper layers".

It may be possible to send low data rate pulses between the two systems if high-gain high-power communications equipment is purposefully designed and installed on both planets and used to do so. Like two globe-spanning networks of high-power high-gain highly directional transmitters and receivers that are synced up to allow for continuous operation as both we and they rotate on a frequency ideal for punching through the magnetosphere, transiting space, and differentiating itself from the gigantic broadband emitters (the suns) adjacent to us.

But neither we nor the hypothetical other-humans are doing any of that.

But all of these supposedly smart people are like "where are the aliens? we're looking but they're not there!"

We can't even detect ourselves at the distance of our nearest neighbor!

I agree with you. But here's how it goes:

The universe is quite old. Civilizations could have arisen billions of years ago. It stands to reason that one or more of them would expand aggressively and attain a very high level of technological development, with Dyson Spheres and other artificial megastructures. This could include unnatural-looking star arrangements, technosignatures in stars, etc.

The people who make these assumptions also assume, generally, that humanity will one day attain such a state. And in the not terribly distant future, at that. (Thousands rather than millions or billions of years.)

Yet we don't see ANY evidence for any of this sort of thing. It's not that there are no civilizations at all, it's that, as far as we can tell, there are zero great star-faring civilizations -- no Rulers of the Cosmos.

So why not? They've had billions of years. And any explanation (like "they're just not interested") has to apply universally, to ALL such civilizations.

The most parsimonious explanations are:

The Zoo ("they, being unfathomably more advanced than us, don't want us to see them,")

The Great Filter ("something makes such life extraordinarily unlikely. This something -- the filter -- might be in our future.")

The notion that ALL such civilizations are too wise to expand at this stage of the evolution of the cosmos ("the vacuum is too warm and it makes life/computation less efficient, so let's hibernate a few billion/trillion years until things cool down," or "we have attained enlightenment and don't need Dyson Spheres".)

New Physics. ("We wouldn't even know them if we saw them. They might be able to convert waste heat to matter, etc.")

Another explanation:

Interstellar travel takes so long that any lifeform attempting it would be extinct by the time it arrived. Accordingly, intelligent lifeforms don't attempt it (and lifeforms lacking intelligence can't). We don't see VN probes because they're pointless from the POV of the sending civilization: by the time the probe's return signal reached home, the sending civilization would be extinct, and it knows it, so it doesn't bother.

We're at a stage in our development where just one lifetime ago, we didn't know other stars had planets, we didn't know there were other galaxies, and no human had ever been to space. We're still wide-eyed about the idea of space travel. But really, space travel is so difficult and expensive that almost any other use of resources has a better ROI. In a coupla hundred years we'll have calmed down (if we're still around).

Why no VN probes? Perhaps we don't know what to look for; it's pretty anthropomorphic to imagine they're going to look like Voyager 2. Or perhaps VN probes are just silly; there's no point in sending a probe to a distant star, if we'll all be extinct before it arrives.

> it's pretty anthropomorphic to imagine they're going to look like Voyager 2

i think that's why everyone was so interested in that asteroid that was behaving just a little bit unlike every other rock: https://en.wikipedia.org/wiki/%CA%BBOumuamua

Although the prose and storytelling is . . non-optimal . . I found Stross' explanation for the Fermi problem extremely convincing, from the novel Accelerando[1]. I think it's sort-of called the Bandwidth Explanation. Basically, the apparent lack of intelligent life in the universe is an illusion created by a shortage of bandwidth.

I'm going to try and work through it here.

As a civilization spreads, the outer nodes get "dumber" as the speed of light begins to cut into bandwidth/response. So agents get much more bang for their buck increasing their complexity while staying inside the light-second (or light-hour, with caching) sphere, right up until computational complexity is nearing the atomic level (i.e., "computronium").

So you get these planetary-sized shells of computronium, bound by the bandwidth limit of C. Human-equivalent intelligence gets a simulation space that's larger than a few hundred thousand Earths[0]. I'm probably not explaining it all that well, but Accelerando is free on the internet[1]. Like I said - not amazing literature, but pretty neat ideas.

The sad part of all this is that civilizations reach this hard halt where they've converted their systems into computronium - they come to a sudden halt, and no way to press on outwards, as they're all held in thrall to the light sphere.

[0] I challenge the notion of "simulation space" or even the notion that "downloaded humans" would stay human for very long (they wouldn't). Another problem: Stross' system is a little bit magical in terms of its infrastructure, because a fog of undifferentiated laser-connected micro-computers is going to have terrible latency across a 1 AU distance, and there's no way for a central authority to route things. But Stross is way smarter than I am . . so who knows?

[1] https://www.antipope.org/charlie/blog-static/fiction/acceler...

[1.a] Unrelated, but check out "A Colder War", also downloadable. CIA Cold War shenanigans meets Cthulhu! Features some obscure Cambrian species. This sent me down a rabbit hole of learning about the incredible early animals of our planet's history.

> This could include unnatural-looking star arrangements, technosignatures in stars, etc.

If humans saw an unnatural-looking star arrangement I would expect them to expand a lot of energy trying to come up with an explanation as to why this star arrangement had formed naturally?

Semi-Zoo: We, seeing something that could be explained as alien, will explain it in some other way.

I posit that out intrinsic drive to explain everything as though it's origin was from a thinking intelligence similar to our own is what causes us to misunderstand a great deal about our reality, and more specifically, about the possibility of alien intelligences.

We do this, for example, with our pet dogs, ascribing anthropomorphic qualities to their behavior. While it may be true that a dog can experience emotion, they do not (likely) experience it the way we do.

When it comes to these ideas about an alien civ traversing the cosmos (or staying home) we can only think about it in terms of the arguably tiny box that is our perspective. While this position has proven pretty useful to us so far, unless we learn to remove ourselves from the box, our explanations on the grander scale of galactic civilization and technologies beyond our understanding will be perpetually deficient. Insert Sagan's quote about advanced tech looking like magic here, I guess.

I think we are getting there, though. We have some interesting thinkers in the world right now, and more surely to come with future generations. It just bothers me that this thread seems to be full of some really limited and unprovable ideas that are being presented as unassailable. So far our greatest explanation as to why we don't have any alien buddies is The Great Filter, and that's a about as structurally sound as wet tissue. Important to remember that we have a long, long way to go and it would be my hope that we achieve the ability to think like something other than ourselves.

Dogs are mammal, come from social wolves, dogs live in complex human social structures, so on the other hand, it's likely their emotions are not extremely different to our own.

Humans can't even expand on planet Earth without conflict, the idea of a pan-galactic civilization in harmony with a very narrow focus on expanding doesn't seem too realistic to me

(building any electronics that resist radiation and last more than 50 yrs is a very complicated process as well)

One under-explored option with radiation resistant electronics IMO is to scale it up for robustness. It's impractical if we want to launch it from a gravity well, but if it could be built in space, there a lot of space, in space...

Also, the processing needn't be fast at all if going vast distances. There's a lot of time to complete a calculation. Lot's of time and lots of room for redundancy. Same with fuel, yes the rocket equation is wicked, but if you could just get more of it from an asteroid or whatever, just get more of it. Huge, slow burners with "CPUs" a mile wide.

> This could include unnatural-looking star arrangements, technosignatures in stars, etc.

> New Physics. ("We wouldn't even know them if we saw them. They might be able to convert waste heat to matter, etc.")

How do we even know what to look for? Why would we think that something we've only understood for 100-200 years is in any way a meaningful signature for billion year old civilizations?

We might as well be looking for the presence of flint flakes. That at least was state of the art technology for thousands of years.

> The people who make these assumptions also assume, generally, that humanity will one day attain such a state.

So another option is that there is some reason it's impossible to leave the solar system. Maybe there's something just outside the solar system which we cannot prepare for and won't overcome. Perhaps any life form will run into this issue, which we may never know about, and they stay in one star system.

"The Great Filter" is the only non-egotistical, and therefore IMO the only valid explanation. Even then, people still believe in egotistical great filters such as global thermonuclear war.

We already have evidence of an extinction-level event (Chicxulub impact) 66 million years ago. A strong enough solar flare would eradicate all life in extra-terrestrial colonies. We are just lucky to be alive.

> "The Great Filter" is the only non-egotistical, and therefore IMO the only valid explanation.

That's not how I see it. The Great Filter implies, and quite strongly, that the Filter is in our past -- and, as such, it's extremely egotistical. For, ultimately, the implication is that we may quite literally be unique.

It's also not at all clear that something like the Chicxulub impact would result in the extinction of humanity. Unlike dinosaurs, we're able to adapt with technological solutions, such that at least a breeding population would survive such a catastrophic event. (This applies broadly, to other technological societies.)

Granted, a supernova could go off somewhere in the neighborhood, but this is a low-likelihood event, and thus cannot be a Filter. The Filter, after all, has to apply universally.

I think that the most parsimonious explanation is new physics. There's nothing egotistical in the notion that we don't understand everything there is to understand about how science and technology might progress, and looking for infrared waste heat and the technosignatures we're already familiar with, at our present level of development... this might, for obvious reasons, be totally futile.

> It stands to reason that...

No, it doesn't! The scale of the universe is huge, as in HUGE! There is simply no way a microscopic bug like us can influence anything at an inter-stellar distance.

Even if we never leave our system, it's at least possible that we could build a Dyson Swarm or something similar around our own Sun, which would make it look like a strangely -- possibly unnaturally -- occluded star to distant observers. We've spotted one of those already, and we still don't know exactly what we're looking at: https://en.wikipedia.org/wiki/Tabby%27s_Star

"Our present technology is entirely adequate for both transmitting and receiving messages across immense interstellar distances. For example, if the 1,000-foot radio telescope at the Arecibo observatory in Puerto Rico were to transmit information at the rate of one it (binary digit) per second with a bandwidth of one hertz, the signal could be received by an identical radio telescope anywhere in the galaxy. By the same token, the Arecibo telescope could detect a similar signal transmitted from a distance hundreds of times greater than our estimate of 300 light-years to the nearest extraterrestrial civilization."

- Carl Sagan and Frank Drake, "The Search for Extraterrestrial Intelligence" https://www.scientificamerican.com/article/the-search-for-ex...

(Of course, one could make the counterargument that we don't have Arecibo anymore...)

This is (was) true, but only if the distant end has an identical or better aricebo pointed at us…

…several (or several thousand) years into the future. And even then tracking difficulties and the sheer vastness of space would make the chances of success near-zero.

Due to having a fixed dish with only a movable antenna feed the available look angles of aricebo are limited.

In all likelihood the aliens looking for us have a mega-aricebo in a random valley that is perfectly capable of receiving our signals but it is positioned one degree off-axis from the angle needed to receive us and they are as puzzled as we are as to why they are not hearing anything either.

> We wouldn't be able to detect them optically or electromagnetically

Please could you provide a link that supports this assertion? We can detect gases in exoplanets?

my money is on Zoo, for the reason that:

if you were surveying a planet, and the dominant species regularly engages in assymetrical warfare against every other species it encounters.... would you pay them a visit?

we're stuck on a literal planet of Predators

worse than a Zoo though, would be a Lab: were we made for a purpose by someone else to test a hypothesis? or even worse... what if we are the control group?

>We wouldn't be able to detect them optically or electromagnetically.

We can have have radio (electromagnetic) communication between the Earth and the Moon just fine.

Distance from Earth to Alpha Centauri is about 110 million times the distance to moon. And then remember inverse-square law. Which makes things quite a bit worse.

The inverse square law only applies to omnidirectional antennas though: but stars have known positions, so any transmitter in the galaxy would be focused.

Even laser beams spread with distance, and these are vast distances.

How do you imagine focusing "any transmitter in the galaxy" to converge at a distance of, say, 200 light years?

Any rough calculations on the method, focusing array size?

Which is why Alpha Centauri is not our closest celestial neighbor as the moon is closer.

By celestial neighbor I meant proxima centauri.

The moon is our celestial roommate.

Light needs four years to travel from Earth to our nearest star, Proxima Centauri.

Light need 1.3 seconds on average to travel from Earth to the Moon.

Do you still think your comment makes any sense?

>Do you still think your comment makes any sense?

Yes, because the nearest celestial neighbor is the moon and the nearest star is the sun. I don't see how Proxima Centauri is relevant here.

Perhaps their comment didn't possess the greatest technical merit but there is no need to be rude like that.

That's a fair bit closer.

It would be farther as the moon has a smaller radius than the second Earth that would be placed where the moon is.

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