According to an astrophysicist, David Kipping, the initial traces of extraterrestrial life would also be extremely dissimilar, too, as noises of their larger category. The line reflects a contradictory scenario: the initial verified signal of another race can be like the one that happened by accident, short, strong, and non-recursive that of an afterimage, generated by the presence of a previous signal, instead of a stable light to communicate with.
Astronomy constantly instructs us that first discoveries are determined not by what is common but by what is perceivable. Among the earliest exoplanets, e.g. were found around pulsars where exquisitely regular pulsations are used to make tiny orbital tugs visible; now thousands of exoplanets are known, but less than ten of them are pulsar worlds. Even the sky of a night, is a selection effect in place, as the small fraction of stars that have evolved into giants (under one percent of stellar numbers) makes up one-third of the naked-eye stellar numbers, as these are the luminous ones that can be seen at a distance.
The “Eschatian Hypothesis” by Kipping builds upon that well-known detection bias to technosignatures. Insofar as civilizations live most of their history in relatively silent technological phases, then telescopes searching a large galaxy will selectively observe the infrequent times when a society becomes visible appear, due to emitting much more energy, or due to temperature effects, become narrowband, organized or discrete. Kipping would argue that, given a toy model, a civilization that lives only a thousandth of its life, but during this period, is noisy, would be more likely to be detected than a quiet civilization that lives a long time, but during that short interval, puts to that short period a fraction of one percent of its total lifetime energy output. That is a very extreme tradeoff with physics: it is aimed at periods of instability, high rates of industrial activity, or even conscious campaigns of broadcasting, which is not persistent enough to become a regular target.
Such framing alters the classical SETI lore. The strange Wow! signal of 1977 has always been in this inconvenient middle ground between interesting and impossible to verify: a powerful, narrowband burst of 72 seconds which has not been observed since. Subsequent searches did not find any repeat, and subsequent work suggested natural causes, such as superradiance of neutral hydrogen clouds caused by exotic astrophysical conditions. Considering the non-repetition is not a disqualifier but a sign under an eschatian perspective: a non-repetition can be precisely what an element of detection bias would force humankind to regard as the first instance of our species that could ever have come into existence: the first instance of our species that can ever have existed.
The pipeline problem already involves modern SETI practice: large numbers of candidate events can be seen in data by humans, in numbers much larger than can be explored. The citizen-science program SETI@home has filtered Arecibo observations taken between the year 1999 and 2020 and has counted 12 billion candidate narrowband signal with this filtering but upon automated screening and hand inspection it has then narrowed it down to a small number of potential candidates worth reexamination. The FAST telescope of China has been employed to check up the final candidates, which demonstrates a fundamental limitation that dictates any search: a survey can be exceptionally sensitive and yet be overwhelmed by local radiofrequency noise, data-processing decisions and the capacity of human attention.
That fact pushes SETI towards the approach that Kipping proposes: agnostic anomaly detection. The search is broadened to transients that act strangely in flux, spectrum, repetition, or apparent motion-events which can no longer be explained by current astrophysical theories-instead of seizing a few channels that are likely to be the points investigated. This methodology also accommodates an enlarging zoo of natural impostors which might appear unnatural on the surface, such as fast radio bursts (FRBs). FRBs have been found to produce energy as powerful as the Sun in seconds, and repeaters may have elaborate structures; one particularly studied repeater was a frequency drift similar to a “cosmic slide whistle,” and this makes nature and its generation of signals sound engineered.
There are changing tools that fit the hypothesis. Wide-field surveys like Vera C. Rubin Observatory are constructed to be observable what varies, not what remains luminous as part of a large time-domain sample with a sparse record of short-lived aberrations before they fade. At radio wavelengths, SETI groups are also busy increasing the search space in less noisy manners, such as considering stellar bycatch, the hidden stars that will enter the field of view of a radio telescope even when they are not the target, decreasing human selection bias on the location of transmitters being where they are supposed to be.
Provided the eschatian logic is true, then the first technosignature would not be representative of galactic civilization. It would be the kind of outlier that machines cannot disregard some engineered-looking event that momentarily exceeds the noise of the universe, and is then seen by the astronomers with the more difficult job of determining whether the universe just played another natural game, or whether the technology has ultimately served to leave a high-energy manifestation behind, a momentary, high-energy trace.
