There’s a lot of energy expenditure needed to make the kinds of broadcasts you discuss, and even then, it won’t go far—aiming for specific targets with relatively high probability of reception helps a bit, but not much. Given that, this all seems low value compared to even short term benefits that we could get with the same effort or at the same cost.
Concretely I guess current tech can get a message out to a few targets at 10^3 to 10^6 light years distance. ASI can use many physical probes near light speed, accelerated using energy from a Dyson swarm, so I’d guess it’s a few years behind only. I don’t expect there to be aliens within 10^6 lys, nor do we know which stars, and it’s again unlikely that they happen to be in the thin window of technological development where a warning message from us helps them.
There’s a lot of energy expenditure needed to make the kinds of broadcasts you discuss, and even then, it won’t go far—aiming for specific targets with relatively high probability of reception helps a bit, but not much. Given that, this all seems low value compared to even short term benefits that we could get with the same effort or at the same cost.
Concretely I guess current tech can get a message out to a few targets at 10^3 to 10^6 light years distance. ASI can use many physical probes near light speed, accelerated using energy from a Dyson swarm, so I’d guess it’s a few years behind only. I don’t expect there to be aliens within 10^6 lys, nor do we know which stars, and it’s again unlikely that they happen to be in the thin window of technological development where a warning message from us helps them.
And the receiver won’t know where to look, and we don’t know where to send it, so given attenuation, even 10^4 light years seems pretty optimistic.