But what is feasible is to send the messages simply claiming that we are sentient, we want to be reconstructed
Clever. Issue: Any signal we send may only intersect the expanding frontier of the nearest alien civilization 0.2-1 billion years later; i. e., at a distance 0.2-2 billion light-years away. Can we send a signal that could actually be picked up?
Let’s suppose the alien civilization is nice, vast (spans many galaxies by the time the signal reaches it), and is specifically listening for these types of “reconstruct-us” messages, sent from distant low-tech low-power civilizations facing extinction/genocide. Intuitively, it should be relatively cheap for them to build coordinated arrays of receivers spanning galaxy-sized volumes, with a correspondingly ridiculous effective surface area. We could further assume there’s a civilization like this in any direction we could point.[1]
Suppose we had $10 million to spend on the project, and had 2 years until we’re unable to broadcast. How much information would we be able to transmit?
I don’t know how to calculate it off the top of my head, so I went and asked LLMs. Their answers varied wildly between models and samples, but they usually said that ~100 GB was achievable. Here’s one of GPT-5′s answers; I’d love if someone sanity-checked that.
That should be enough information to reconstruct us, I think, if we use dense compression and send high-quality data? (Not reconstructing any specific person, of course, but the general shape of the human mind and human values.)
Neat. This is the only desperate Hail Mary plan I’ve heard that actually sounds plausible. I’d donate a modest amount to that.
This isn’t all that many assumptions. It’s basically just “the grabby-alien model is approximately correct” and “probability that any given alien civilization is nice”. If sending such messages is feasible, the nice alien civilizations are pretty likely to be listening to them.
Clever. Issue: Any signal we send may only intersect the expanding frontier of the nearest alien civilization 0.2-1 billion years later; i. e., at a distance 0.2-2 billion light-years away. Can we send a signal that could actually be picked up?
Let’s suppose the alien civilization is nice, vast (spans many galaxies by the time the signal reaches it), and is specifically listening for these types of “reconstruct-us” messages, sent from distant low-tech low-power civilizations facing extinction/genocide. Intuitively, it should be relatively cheap for them to build coordinated arrays of receivers spanning galaxy-sized volumes, with a correspondingly ridiculous effective surface area. We could further assume there’s a civilization like this in any direction we could point.[1]
Suppose we had $10 million to spend on the project, and had 2 years until we’re unable to broadcast. How much information would we be able to transmit?
I don’t know how to calculate it off the top of my head, so I went and asked LLMs. Their answers varied wildly between models and samples, but they usually said that ~100 GB was achievable. Here’s one of GPT-5′s answers; I’d love if someone sanity-checked that.
That should be enough information to reconstruct us, I think, if we use dense compression and send high-quality data? (Not reconstructing any specific person, of course, but the general shape of the human mind and human values.)
Neat. This is the only desperate Hail Mary plan I’ve heard that actually sounds plausible. I’d donate a modest amount to that.
(Aside: relevant Sam Hughes short story.)
This isn’t all that many assumptions. It’s basically just “the grabby-alien model is approximately correct” and “probability that any given alien civilization is nice”. If sending such messages is feasible, the nice alien civilizations are pretty likely to be listening to them.
https://www.youtube.com/watch?v=_OpxrtUwjNw—This is a little fan project I did of that short story, as a sort of a radio play. I’ve never had it be relevant to a conversation before!