A common question about UFOs is “why now?” As in, UFOs could have arrived at any point in Earth’s history; why would they happen to arrive in the 20th or 21st centuries?
One reason could be that they were attracted by our 1900s radio broadcasts or nuclear tests, but I think it’s more likely they’ve always been around and we only recently had the technology to detect them.
If you consider that for most of human history, “sensing” was limited to humans’ sensory organs, then it wouldn’t matter how long they’d been here if we couldn’t easily see or hear them. Telescopes emerging in the 1600s raised our detection capability, but in a pre-industrial, and more importantly, pre-digital world, the rate of improvement was slow.
However, in recent decades we’ve been developing exponentially, with sensing-relevant technologies like transistor density, memory capacity, and photon capture doubling every 1-2 years. As progress speeds upwards, the rate of improvement is proportional to the likelihood of detection, because each marginal advancement provides a new chance to detect ETs.
Compared to our stagnant past, we’re more likely than ever before to reach the technological level required for ET detection.
That said, indefinite exponential growth only means detecting the previously undetectable is more likely than in the past, but not necessarily more likely than in the future.
If it’s an S-Curve, not an Exponential
S-curves that eventually flatten can look like exponentials at first. Individual technologies will eventually plateau as they hit physical limits; for example, a camera can do no better than capturing every single photon that enters its aperture.
Overlapping S-curves of related technologies can keep progress going, but even when aggregated, a technological domain is likely to eventually slow. If sensor technology is really an S-curve, then where we are now, in the steep part, is the most likely time for us to find extraterrestrials ever.
The upshot of all this is that one planet’s inhabitants are most likely to detect another when:
Its prior history was characterized by universally low technological development.
Its technology is currently improving exponentially.
It has recently begun to pick up equivocal evidence of other civilizations.
It seems we are in this position now, so we should expect to find aliens around now, if ever.
Because it’s clearly possible to advance technology much further, there’s no reason for aliens to wait for signs there’s something interesting in a particular place instead of simply unconditionally colonizing everything that can be reached. Not taking over some of the things is a choice, but there’s no reason for not already being here (for a very long time) if possible to reach, regardless of the signs there’d be life/civilization here. Such aliens can’t be detected at all yet if they don’t want to be.
A different possibility is a technologically bounding AGI takeover that enforces zones of thought (a permanent ban on superintelligence), so that the aliens are forced to engage in a retro space opera, not being allowed stronger tech for an absurdly long time. I’m positing AGIs as the enforcement authority since evolved life is probably insufficiently robust to maintain such a ban indefinitely, while it’s probably feasible to make AGIs that maintain such a rule literally forever (when the AGIs don’t have corrigibility, don’t find feedback on this issue from their evolved builders compelling). In this case, not interfering is again a choice, and being here now even more strongly requires unconditional colonization rather than response to observations, because it would take the technologically stunted aliens too long to notice and respond (unless the overseeing AGIs provide digital transportation/reconstruction services and have already low-key colonized everything within reach).
The technologically capped aliens fit the poorly-hiding-spaceships stereotype, they could even mostly withdraw in response to ambiguous detection a few decades ago and thus get much harder to find even with better modern tech. The hypothesis of aliens being purely fictional is still much stronger, but I don’t think the way the world works makes the technology-capping AGIs so impossible that it’s not worth considering at all. AI companies being allowed to keep working towards superintelligence becomes evidence against as the work progresses further.