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\begin{document}

\title{Millisecond Pulsars as Standards: Timing, Positioning and Communication}



\author[1]{Clément Vidal}%
\affil[1]{Vrije Universiteit Brussel}%


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  \date{June 10, 2024}


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\begin{abstract}
Millisecond Pulsars (MSPs) are likely to be or to become a timing,
navigation, and metadata communication standard across the galaxy.
Regarding timing, they provide a parallel clock to terrestrial ones, are
based on macroscopic neutron stars behavior instead of quantum
processes, and they will remain ticking longer than any clock we can
construct on Earth. Regarding navigation, X-ray MSPs provide all the
necessary ingredients for a Pulsar Positioning System that has many
similarities with GPS. In astronautics, X-ray pulsar-based navigation
(XNAV) uses a time-of-arrival navigation method comparable to GPS,
accurate down to about 100 meters. Regarding metadata communication,
MSPs would be a natural metadata coding choice for any galactic
communication effort. On Earth, any letter or email contains metadata
information about where it comes from, where it goes, and when it was
written. We can expect that similar conventions exist for any potential
galactic communication. Most messages are likely to be galacto-tagged
and pulsar-time-stamped by reference to MSPs. This simple remark opens a
simplified SETI search. Given any suspicious message we want to decode,
the first step becomes to attempt to decode not the message itself, but
its metadata (Vidal 2017). GPS is a technological breakthrough that
enables many others: one needs only to think about all the
location-based services (LBS) that it has unlocked in our modern
societies. The realm of potential galactic LBS is an area totally
unexplored, and may well be a key to find technosignatures of many
kinds. Is GPS a technology? The answer is an obvious yes. Now imagine
that we would find around an exoplanet's orbit well-distributed
timekeeping devices with an accuracy comparable with atomic clocks,
beaming timing information that can be used as a positioning system,
just like GPS. Would not we be compelled to check if it is a
technosignature? This is exactly the current situation with MSPs, but on
a galactic scale. This is why I have proposed ways to test whether the
pulsar positioning system is actually an instance of galactic
engineering (Vidal 2019). Seeking such a galactic technosignature proof
is actually searching for a distributed signal, instead of searching for
a localized signal around one particular star or planet. If the search
program succeeds, it would lead to the discovery of extraterrestrial
intelligence, through their engineered timing and navigation system.
References: Vidal, C. 2017. ``Millisecond Pulsars as Standards: Timing,
Positioning and Communication.'' Proceedings of the International
Astronomical Union 13 (S337): 418--19. doi:10.1017/S1743921317008596.
https://arxiv.org/abs/1711.06036. (where this poster was first
presented) Vidal, C. 2019. ``Pulsar Positioning System: A Quest for
Evidence of Extraterrestrial Engineering.'' International Journal of
Astrobiology 18 (3): 213--34. doi:10.1017/S147355041700043X.
https://arxiv.org/abs/1704.03316.%
\end{abstract}%



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