Where aliens could be watching us

> Intelligence in this context means the ability to develop the tools necessary to detect other unusual planets.

What if instead of attempting to detect planets, they just spam the universe with their space-hardened eggs, and hope that eventually they’ll smack into something habitable? Seems a lot more productive than analyzing incoming UV rays for thousands of years, then spending who knows how long to figure out how to get to the ones we suspect are interesting.

We are concerned with disseminating our discoveries and keeping in touch with the folks back home. But a non-hierarchical intelligence (by whatever hand-wavey metric you want to use for “intelligence”) might be more concerned with simply existing in as many places in which it can survive in as possible, whether Mom and Dad know about it or not.

This isn’t science fiction: I’d estimate there’s 1e10 spore-producing mushrooms on Earth on any given day. (That’s only a couple steps away from a wild-ass guess, but hear me out.) One mushroom can produce over a billion spores per day, 1e9. That’s 1e19 “eggs” every single day, and that number hasn’t changed significantly for thousands of years. It’s a staggering number.

This is science fiction: Imagine mushrooms are aliens who originally came from a planet with a more turbulent atmosphere, one which promotes more ejections of tiny spores into space. Imagine that their spores are drastically more long-lived and more spaceworthy (the Earth ones already do pretty well).

This isn’t science fiction: Mushrooms (well, fungi) have a symbiotic relationship with an overwhelming majority of plants. They are crucial to forests; there’s a viable hypothesis that forests only exist because mushrooms “decided” to farm trees. That decision, if the hypothesis is correct, played a huge role in the development of humans and therefore big telescopes.

Even if they’re native earthlings (they probably are), could they represent an intelligence whose comprehension of their environment, existential goals, mode of communication, etc. is too far outside of what we are used to in order to recognize them as being intelligent?

To bring it back around to what GP wrote, fungi do pay attention to humans, an analogue for “watching” us. They “hear” our footsteps and send hyphae to investigate, because we often track tasty things from our shoes onto their rooftops. If we cannot even speculatively judge a homegrown lifeform’s intelligence, why do we think we’ll stumble across an alien species that makes more sense to us? Those odds seem even less in our favor.

I'm not sure what this has to do with a communications link though. It's not like we need as much energy as a star, we can use a directional link like a laser. Sure it'd still need to be massive but while I don't have the math in front of me, it seems like something we could build.

If we had to overpower the Sun to communicate, we wouldn't use radio on Earth either.

It's like why we sent human envoys during the era when communication speeds were limited by horses and ships.

ET has probably given up on long range radio for their local comms, just as we have. The bulk of our comms go through waveguides (electrical cables and optical fibers). Even our radio comms have relatively short range, and are designed to be virtually indistinguishable from noise. It's as if we've wrapped ourselves in a primitive Dyson sphere.

Tachyons are fictional, there's no reason to assume they exist. Gravitational waves require exceptionally large amounts of energy to generate; we can't transmit with them, and for a more advanced civilization which does have that capability, using the same amount of energy for a focused/directional EM transmission would be much easier to detect; because gravitational waves (unlike EM) radiate equally in all directions but EM can be directed to a particular recipient. Neutrinos are similar to EM but worse, as their transmission/power characteristics are pretty much the same but it's very difficult to detect them.