Why do we assume extraterrestrials might want to visit us?

Seeing the insane complexity of the human condition (look at the amount of scientific disciplines we come up with) and thinking "nay, this won't be interesting to a higher mind" feels awfully dismissive.

sure, depending on the leap of sophistication we may appear like... rocks, I guess? But I can't even begin to conceptualize to what in comparison we'd appear like rocks. Anything of that complexity probably is multiple magnitudes beyond our comprehension anyway, and therefore not really part of the discussion

When the European powers explored the pacific they wrote off a lot of islands as being devoid of anything useful. Now a few hundred years later these islands, mostly untouched by humans, are a gold mine for various niches of biology. Human presence is still infrequent enough that the seagulls don't seem to notice.

Even if we are as the aliens were 2 millions years ago, there must be something of interest in what we do? I mean, we'd be interested in life 2 billion years ago. I find it more likely that they just don't want to interfere.

[0] https://en.wikipedia.org/wiki/Ant_colony_optimization_algori...

Even if ETs study ants generally, there's nothing unique about us to give us a greater than 1/(large number) chance of being studied.

Not only that we've incorporated armies of scientists in to the public realm to advise on such envoirnmental/biodiversity policy issues. It's possible an Interstate Freeway project may not happen because an bunch of endangered ants live along its planned route.

In the same way an ant might stumble across a human building or notice a human above the grass, you would think if life was so prevalent in our galaxy that there would be some sign of their technology.

https://youtube.com/user/AntsCanada

Which is actually what would make us more interesting, not less.

From Wikipedia for "ant": "More than 12,500 of an estimated total of 22,000 species have been classified."

From our human perspective, we are interested in ants. Everybody has seen ants. Everybody is curious about ants.

From an ant perspective, humans scarcely exist. There are 10,000 ant species that don't have a relationship with humans sufficient to deserve classification, let alone a name.

(I also want to wonder aloud why extra-terrestrials would be more interested in humans than in ants)

It doesn't end well for ants.

I think the answer is far less clear in that scenario.

It would be absurd to conclude the absence of entomologists just because most individual ants go unobserved.

They could also operate on a completely different timescale. For example, shrews' metabolism is way faster than ours. Sequoias are way slower. There's no reason an alien should perceive time on the same scale we do.

We know that Neanderthals may have had bigger brains, and may have been pushed to extinction by homo sapiens. A bigger brain will require more food and take longer to develop, potentially putting Neanderthals at an evolutionary disadvantage to humans.

Assuming the laws of Physics do not vary throughout the universe and that evolution, if "run more than once" will eventually lead to similar outcomes, that could mean aliens capable of space travel are not significantly more intelligent than us, they've just had longer to develop technology.

And given their apparent tendency to crash their spaceships while visiting earth, you might have a reasonable case for "alien idiots"...

>"We may be a phenomenon as uninteresting to them as ants are to us; after all, when we’re walking down the sidewalk we rarely if ever examine every ant along our path." Is it helpful to ascribe human-like motives to an alien species? Projecting our thought patterns on an alien species will not get us anywhere. There could be numerous reasons or no reason in particular why an alien lifeform might visit us: they are cataloging lifeforms, they are interested in 'ants' like EO Wilson, they might want to harvest resources on our planet, etc.

> "But better yet, we could get in touch with Proxima b and entice the locals to visit and share a water-based drink with us." There's humor mixed in this statement, so I'm not sure if Avi Loeb is being entirely serious. I take the opposite stand of "don't broadcast our presence to aliens". It's common sense that if you're out in the wild, you don't draw attention to yourself.

The Invaders divide sentient life into three tiers - species like themselves that evolve in gas giants, cetaceans, and vermin; we're in the third category.

[0] https://en.wikipedia.org/wiki/Eight_Worlds

Very true. A lot of our behaviors and instincts are based on how we procreate and the environment we live in. For example if you live forever or don’t have the pressure to procreate you will have a totally different perspective on the universe.

Lifeforms that have developed differently most likely would have motivations we can’t even fathom to understand.

The first chronicles the development of sentient, space-capable spiders. The sequel follows the development of octopuses. I found both to be quick, easy reads - perfect for vacation or a rainy weekend. In both, the psychology of the species, and how humans can relate, is a plot point.

I think that most people (who think about such things) realize that extraterrestrials, if they exist, may well be more alien than we can even imagine.

But it's fun to imagine things, so we try anyway :)

Sort of like the premise of “They’re made of meat”: https://web.archive.org/web/20190501130711/http://www.terryb...

Or imagine they were psychopathic sadists, like the Affront in that Ian Banks novel.

As it is right now we're doing human cargo culting, most of which is indoctrinating people into believing things that are not true - sooo YMMV?

I think this is unlikely. It seems to me that some amount of curiosity would be a prerequisite for being able to make discoveries that lead to technological progress. Although I suppose it is possible such progress could be made through some kind of evolutionary mechanism as opposed to individual intellect.

This is already known not to be the case, the Breakthrough Starshot project is expensive, but merely expensive.

It’d be easier for it to travel great distances than organic life, it’d be possible for a variety of organic life to arrive at creating it, it may be hard for organic life to solve the control problem to limit it, etc.

IMHO a prerequisite to the survival of civilization is the recognition that the interests of civilizations can be, and often are, at odds with the interests of genes, and so we are necessarily in active conflict with the genes that made us. The best example of this is birth control, which is an obvious existential threat to the reproductive fitness of our genes. So genes that build brains that have an instinctive revulsion to birth control will, all else being equal, reproduce better than genes that build brains that don't have this revulsion. In the absence of active intervention, the result will be overpopulation.

For a civilization to succeed long-term it has to recognize that it is necessarily in conflict with the genes that produced its individual members, because otherwise the genes will win.

[1] https://en.wikipedia.org/wiki/The_Evolution_of_Cooperation

This is true. But even if just a small fraction of civilizations engaged in interstellar expansion, they'd quickly subsume the galaxy on geological timescales. Darwin applies just as much across the stars as it does in a tide pool. As long as there's even a small amount of competition, it will push every player to aggressively expand.

The only way out is either 1) technological civilization almost never evolve anywhere. 2) Virtually every technological civilization winds up eschewing interstellar expansion. Or 3) a single player previously won the game, and used its dominant position to benevolently stop the game.

https://www.nature.com/articles/s43247-020-00057-8

https://phys.org/news/2018-06-advanced-civilization-universe...

that, through the use of models and simulations, come to the conclusion that we are dang lucky to have evolved on the Earth at all.

While I don't know that I was ever a believer in the Earth being visited by ETs, I always thought that we wound find evidence of intelligent life elsewhere in the galaxy any day now. For the reasons above, I'm less and less convinced of that with every passing year.

This makes a big assumption: that our inability to solve these problems is rooted in a lack of intelligence (collectively or individually). I don't think that's the case at all. Solutions to these problems are widely known, and most educated people support them, at least in theory.

The problem isn't with our intelligence, it's with our incentives. Climate change is a tragedy of the commons (as are other environmental degradation issues, such as loss of biodiversity). Each of us would benefit if everyone cooperated (a nice environment for each of us), but each of us also benefits when we individually defect (cheaper energy for our various needs). As a result, we predictably end up with the suboptimal outcome of (almost-)everybody-defects.

What's the way out of the dilemma? It's clearly not a matter of getting smarter. I don't think it's an issue we can solve with moral pleading either: we've been trying that for decades. But what if we could change the game and remove the incentives to defect? * We could implement a carbon tax, incentivizing firms and consumers to use carbon-neural energy sources. * We could subsidize clean energy, incentivizing the same. * We could invest as much money as possible in reducing the cost of clean energy sources, eventually removing the need for ongoing tax/subsidy policies.

If non-polluting energy sources are cheaper, more widely available, and easier to use than polluting sources, no one would ever choose the latter. No heightened intelligence required.

For as far as we know, they've observed us, and have long moved on, finding us entirely uninteresting, which seems to be the one explanation we love to overlook, but given we are humans with big egos, love to make ourselves out to be more important than we actually are.

It's possible we are one of those trillion species being simulated, and our pogs are currently being scrutinized.

Would extraterrestrials who communicate with pheremones, or touch, or don't communicate at all (ala "Blindsight") have any concept of music? If they can "hear", does their sensory range overlap ours? Is it compatible with our notion of musical scales? Does whatever passes for a nervous system operate at a similar timescale to ours?

Food and clothing seem like more of a stretch- even within earth's biosphere many substances humans can eat are poisonous to other animals, and vice versa. Vast differences in bodyplan would almost certainly make our clothing useless to an alien race, and the materials we use could easily be incompatible with their biology.

Even if aliens were substantially similar psychologically, minor changes in biology could result in completely different societies. What would our world look like with humans who reproduced asexually, or in triads? Where we produce our own food via photosynthesis or symbiosis? Where we didn't sleep, or different populations hibernated in their own cycles?

Overall I'm inclined to believe that cultural exchange with an intelligent extraterrestrial species would be harder and less productive than cultural exchange with parrots.

Space is vast. The strength of communication signals drops off quickly with distance. All life is subject to the laws of thermodynamics.

The Fermi paradox was proposed in 1950 during a time of rapid growth and empire. At that time, radio communications were powerful, and it seemed like they would only get more powerful as our civilization advanced. But that's not what happened. The key to better communication is not more power, but better noise reduction. Since WW2, our radio signals have become weaker and weaker and our receivers smaller as we transmit information more efficiently. Ideally we would transmit signals with the bare minimum amount of energy needed for them to be reliably received by the intended receiver. Any civilization that wants to not waste energy (read all of them) would do the same.

Because power drops off with distance, a more sensitive receiver is required to receive a message at a greater distance than the one intended, and this required improvement to sensitivity increases rapidly with greater distance.

Your cellphone communicates with an antenna approximately 2 meters in length with a maximum range of about 70 kilometers. An antenna of the same technological capability able to pick up your cellphone signal at 1 lightyear would need to be 2900 km in length. At 100 lightyears, you would need an antenna over 37,000 km long.

If you can bounce a signal off satellites, you can communicate with any point on earth - thus the most powerful radio transmissions we need to send for our own utility need to be detectable by a 4 meter dish 30000 km away in geostationary orbit. To detect such a transmission at 1 lightyear requires a receiver 203 km in diameter, at 100 lightyears a dish 2600 km in diameter. Beyond 2000 light years, you need a dish larger than Earth. If you need to communicate any further away than that, you're using highly directional beamed communication between planets which won't be detectable unless the receiver just happens to also be along that beam line.

Thus to detect a radio signal from another civilization using a telescope we could conceivably fit on our planet, one of the following must be true: the transmission must be from a relatively nearby world (0.16% of the milky way in range if they are our technological peers, less if they are more advanced than us), the transmission must use orders of magnitude more power than is necessary for communication (either they are using dramatically less advanced technology or intentional broadcast), or we need to detect highly focused beamed communication (either we get incredibly lucky or its an intentional message directed at us). It would be presumptuous to assume that aliens would set up a colony conveniently close to us, that in our mere 100 years of radio use have already greatly surpassed them, that they have maintained an active beacon for long enough that we would happen to see it, or that they would be trying to communicate with us specifically (especially given that any civilization more than a few dozen light years away would have no way of knowing that there is intelligent life on Earth.

There are of course other means of detecting life besides radio communication. Perhaps we may see pollutants in another world's atmosphere - but we have only directly detected a few thousand exoplanets thus far and observed the atmospheres of only a tiny fraction of those. Perhaps we could detect megastructures like dyson spheres - but to know what we are looking for requires a lot of assumptions about how they are built and we don't even know if they can be built. Really any sign of intelligence detectable over interstellar distances other than radio waves is purely speculative.

The assumption that evidence should be commonplace is poorly founded. Unless the universe were teeming with civilizations at a similar technology level to our own, we shouldn't expect to see anything at all.

I did not get your last sentence though. Could you elaborate?

At the moment, the only thing I can imagine that would be like that would be a deep space probe that has been traveling for thousands of years, moving so fast it can't actually slow down and make contact. What if Oumuamua was one of those, or the melted slag remains of that? We'll never know.

Popular culture skews our expectations towards two-legged creatures flying on saucers, roughly our size, but forms of intelligent life can manifest in radically different ways at micro and macro levels.

Perhaps, what looks like a sand particle to us might be a complex microorganism, in a complex interconnected self-regulating network, with no physical artifacts of "civilisation". Those microorganisms would also be able to form "mega-structures" by mutating the environment around them, just not at the pace and scale we are accustomed to.

I've never found this argument particularly compelling, as it seems too simplistic and ignores a vast number of possible confounding variables such as stars not being equally amenable to colonization, or even equidistant to each other, and the likely stability of civilizations over such timescales.

It seems far more likely to me that any civilization that colonizes another star sees diminishing returns given the risk and reaches some limit rather than seeking infinite, exponential expansion.

>The fact that we are not getting signals from the considerable number of stars that are within a reasonable distance is concerning. It does point to a great filter that we are not seeing or understanding. Or at least an enormous misconception about our universe.

For one thing, the observable universe contains billions of galaxies, which means the vast majority of stars are unreasonably distant.

Our understanding of physics changes constantly!

https://www.sciencedirect.com/science/article/abs/pii/S00945...

Do you know that early in the development of trains people were sure it would be physically impossible for humans to travel over 30 mph or so? They thought something would happen with the air pressure or something.

Our understanding of physics changes.

Wormholes tho

Commerce. If we use our experience as a basis here, this is the #1 interest that would lure alien explorers to this neck of the woods. Commerce is what got us to cross the Atlantic: looking for routes, buyers, suppliers, riches and land. All science-first approach ("they should come to study us") is so 20th century utopism.

But without really being sure what matters to aliens the most, commerce, tourism or science, makes it hard to lure them. We sent Voyager with curiosity in mind: songs, poems, language samples, pictures... But we could have sent instead a list/sample of our prime minerals, water supplies, preferred payment methods and our "1-800 number" for contact. Scientists can be so un-enterpreneurial sometimes!

Now, what then could get their attention and provoke a visit?

Become a menace.

Without really being sure what matters to aliens makes it tough to envision a way to get them really interested on the 3rd rock enough to launch a mission or send signals. So the most effective (and reckless...) is to become a menace, or at least a nuisance, to them. Fiction has played around with that idea, nuclear capability being the trigger that got them to notice or outraged enough to wipe us out...

Let's say we develop a gravitational wave cannon capable of making Sirius shoot over as a billiard ball into Procyon. Oh, now that would get their attention!

Heck, this begs the question of why the hell would an intelligent alien species even send their meat bags into space, when they can just upload their consciousness into a machine and have it do their bidding, without any of the limitations of biological systems.

https://en.wikipedia.org/wiki/Uncontacted_peoples

Go to the ant, thou sluggard;

Consider her ways, and be wise