arXiv subjects

John Gertz

Publications and source records attributed to John Gertz.

12 recordsLinked to original sources

arXiv2023

Interstellar Diplomacy

The Defense Department and NASA are investigating the possibility that aliens are currently surveilling Earth. This aligns with some search-for-extraterrestrial-intelligence (SETI) theorists who have concluded that ET's best strategy for opening a channel of communication is to send artificially intelligent probes to our Solar System for that purpose. This is a golden age for traditional SETI, which is currently well funded, with most of the world's radio telescopes now engaged in the hunt. One way or another, contact with aliens may be imminent. There has been no planning among nations for the aftermath of a first detection. This paper advocates for such planning and diplomacy.

physics.pop-ph↗

arXiv2023

Strategies for the Detection of ET Probes Within Our Own Solar System

Arguments are reviewed in support of the hypothesis that ET would more likely send physical probes to surveil our Solar System and communicate with Earth than to communicate from afar with interstellar radio, infrared or laser beacons. Although the standard SETI practice of targeting individual stars or galaxies with powerful telescopes might detect a foreground local probe by serendipity, an intentional hunt for those probes would entail a different set of strategies, most notably sacrificing sensitivity (needed to detect a very faint and very distant signal) in exchange for a widened field-of-view (because a local signal can be reasonably hypothesized to be relatively bright). This paper suggests a number of strategies to detect local ET probes.

physics.pop-ph↗

arXiv2023

The Search for Deliberate Interstellar SETI Signals May Be Futile

For more than 60 years, the predominant SETI search paradigm has entailed the observation of stars in an effort to detect alien electromagnetic signals that deliberately target Earth. However, this strategy is fraught with challenges when examined from ETs perspective. Astronomical, physiological, psychological, and intellectual problems are enumerated. Consequently, ET is likely to attempt a different strategy in order to best establish communications. It will send physical AI robotic probes that would be linked together by a vast interstellar network of communications nodes. This strategy would solve most or all problems associated with interstellar signaling.

physics.pop-ph↗

arXiv2022

Engineering an Interstellar Communications Network by Deploying Relay Probes

We develop a model for an interstellar communication network that is composed of relay nodes that transmit diffraction-limited beams of photons. We provide a multi-dimensional rationale for such a network of communication in lieu of interstellar beacons. We derive a theoretical expression for the bit rate of communication based on fundamental physics, constrained by the energy available for photons and the diffraction of the beam that dilutes the information by the inverse square law. We find that meter-scale probes are severely limited in their bit rate, under 1 Gbps, over distances of a light year. However, that bit rate is proportional to the 4th power of the size of the optics that transmit and receive the photons, and inversely proportional to the square of the distance between them, thus favoring large optics and short separations between nodes. The optimized architecture of interstellar communication consists of a network of nodes separated by sub-light-year distances and strung out between neighboring stars.

physics.pop-ph↗

arXiv2021

Reviewing METI: A Critical Analysis of the Arguments

There is an ongoing debate pertaining to the question of whether Earth should initiate intentional and powerful radio transmissions to putative extra-terrestrial (ET) civilizations in the hope of attracting ET's attention. This practice is known as METI (Messaging to ET Intelligence) or Active SETI. The debate has recently taken on a sense of urgency, as additional proponents have announced their intention to commence de novo transmissions as soon as they become funded and acquire the needed time on a powerful transmitter such as Arecibo. Arguments in favor of METI are reviewed. It is concluded that METI is unwise, unscientific, potentially catastrophic, and unethical.

physics.pop-ph↗

arXiv2021

ET Probes: Looking Here as Well as There

Almost all SETI searches to date have explicitly targeted stars in the hope of detecting artificial radio or optical transmissions. It is argued that extra-terrestrials (ET) might regard sending physical probes to our own Solar System as a more efficient means for sending large amounts of information to Earth. Probes are more efficient in terms of energy and time expenditures; may solve for the vexing problem of Drake's L factor term, namely, that the civilization wishing to send information may not coexist temporally with the intended recipient; and they alleviate ET's reasonable fear that the intended recipient might prove hostile. It is argued that probes may be numerous and easier to find than interstellar beacons.

physics.pop-ph↗

arXiv2021

Post-Detection SETI Protocols & METI: The Time Has Come To Regulate Them Both

Regulations governing METI are weak or non-existent. Post-detection SETI protocols are non-binding and too general. Vastly increased SETI capabilities, Chinese involvement in the field, and an intensified effort by METI-ists to initiate radio transmissions to the stars are among reasons cited for urgency in addressing the question of appropriate regulations. Recommendations include regulations at the agency level and laws at the national level as well as international treaties and oversight.

physics.pop-ph↗

arXiv2021

Nodes: A Proposed Solution to Fermi's Paradox

Within the SETI community, a school of thought holds that ET might prefer to send information physically in so-called "probes," rather than by radio or optical beacon, in effect, a message in a bottle. In this paper, a related solution to Fermi's Paradox (also known as the "Great Silence") is proposed whereby ET civilizations aggregate knowledge into a system of "nodes," interspersed throughout the galaxy. Each node explores and serves the local star systems, detecting through its exploration non-technological life, and enlisting newly emergent technological civilizations, such as ourselves, into its central system. Each node would download information to new member civilizations and upload information from those civilizations, passing it along to its immediately adjacent nodes, such that new information would pass through the entire galaxy at near light speed. The most local node would not be directly detectible by us until it signaled Earth in response to a detection of its artificial electromagnetic (EM) leakage. This is because Earth would not be in the narrow beam of the signal pathways between our local node and its adjacent nodes, nor between the local node and other local civilizations, while the spillover signal strength of far distant nodes would be too weak to be detectable. Thus, the Great Silence of the galaxy is simply the result of the fact that Earth is not currently situated within a communications pathway in an otherwise well interconnected galaxy.

physics.pop-ph↗

arXiv2021

ET Probes, Nodes, and Landbases: A Proposed Galactic Communications Architecture and Implied Search Strategies

Land-based beacons, information laden probes sent into our solar system, and more distal communication nodes have each been proposed as the most likely means by which we might be contacted by ET. Each method, considered in isolation from ET's point of view, has limitations and flaws. An overarching galactic communication architecture that tethers together probes, nodes, and land bases is proposed to be a better overall solution. From this more efficient construct flows several conclusions: (a) Earth has been thoroughly surveilled, (b) Earth will be contacted in due course, (c) SETI beyond half the distance that Earth's EM has reached (~35-50 LY) is futile, and (d) the very quiescence of the galaxy paradoxically implies that that Drake's N = many, and that there is a system of galactic governance. Search strategies are proposed to detect the described probe-node-land base communications pathway.

physics.pop-ph↗

arXiv2021

Oumuamua and Scout ET Probes

Numerous advantages may accrue to ET from the use of probes for the conveyance of information relative to the alternative of beaming information electromagnetically from its home star system. However, probes would benefit from a trans-galactic communications network to transmit information back to their progenitor civilization(s) and throughout the Galaxy. A model for such trans-galactic communications has previously been proposed, comprised of probes linked together by relay nodes. The current paper refines that model, specifying two types of probes or nodes, both part of a communications lattice. The first type of cellular probe (CP) is statically associated with individual stars, and the second type is a scout CP that traverses the galaxy surveying successive star systems rather than permanently residing within any one of them. CPs would communicate with adjacent CPs and, ultimately, through the network of CPs, with their progenitor civilization(s). The question of whether Oumuamua is such a flyby scout CP is considered. Search strategies for CPs are suggested.

physics.pop-ph↗

arXiv2021

There's No Place Like Home (in Our Own Solar System): Searching for ET Near White Dwarfs

The preponderance of white dwarfs in the Milky Way were formed from the remnants of stars of the same or somewhat higher mass as the Sun, i.e., from G-stars. We know that life can exist around G-stars. Any technologically advanced civilization residing within the habitable zone of a G-star will face grave peril when its star transitions from the main sequence and successively enters sub-giant, red giant, planetary nebula, and white dwarf stages. In fact, if the civilization takes no action it will face certain extinction. The two alternatives to passive extinction are (a) migrate away from the parent star in order to colonize another star system, or (b) find a viable solution within one's own solar system. It is argued in this paper that migration of an entire biological population or even a small part of a population is virtually impossible, but in any event, far more difficult than remaining in one's home solar system where the problem of continued survival can best be solved. This leads to the conclusion that sub-giants, red giants, planetary nebula, and white dwarfs are the best possible candidate targets for SETI observations. Search strategies are suggested.

physics.pop-ph↗

arXiv2021

The Drake Equation at 60: Reconsidered and Abandoned

Each of the individual factors of the Drake Equation is considered. Each in turn is either abandoned or redefined and finally reduced to a single new factor, fd, the fraction of technological life that is detectable by any means. However, neither the Drake Equation, nor its replacement, can actually solve for N. Only a vibrant SETI program and, ultimately, contact with an alien civilization might result in the determination of N.

physics.pop-ph↗