Related papers: The Sustainability Solution to the Fermi Paradox
It is well-known that the chances of success of SETI depend on the longevity of technological civilizations or, more broadly, on the duration of the signs of their existence, or technosignatures. Here, we re-examine this general tenet in…
The link between black holes and star formation allows us to draw a connection between black holes and the places and times extraterrestrial intelligences (ETIs) had a greater chance of emerging. Within the context of the gap paradigm for…
Current evidence suggests that the cosmological constant is not zero, or that we live in an open universe. We examine the implications for the future under these assumptions, and find that they are striking. If the Universe is cosmological…
According to the "hard-steps" model, the origin of humanity required "successful passage through a number of intermediate steps" (so-called "hard" or "critical" steps) that were intrinsically improbable with respect to the total time…
Although big bang cosmology effectively models even the most puzzling observational data, it offers no insight into why the cosmological expansion should occur at all. In this paper it is suggested that a finite Universe poses particular…
The Optical Search for Extraterrestrial Intelligence (OSETI) attempts to detect collimated, narrowband pulses of electromagnetic radiation. These pulses may either consist of signals intentionally directed at the Earth, or signals between…
Searching for signatures of cosmic-scale archaeological artifacts such as Dyson spheres or Kardashev civilizations is an interesting alternative to conventional SETI. Uncovering such an artifact does not require the intentional transmission…
Are we alone? It is a compelling question that human beings have confronted for centuries. The search for extraterrestrial life is a broad range of quests for finding simple forms of life up to intelligent beings in the Universe. The…
The Search for Extraterrestrial Intelligence (SETI) is a research activity that started in the late 1950s, predating the arrival of "Big History" and "Astrobiology" by several decades. Many elements first developed as part of the original…
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…
Recently, a spatially extended excess of gamma rays collected by the Fermi-LAT from the inner region of the Milky Way has been detected by different groups and with increasingly sophisticated techniques. Yet, any final conclusion about the…
The Search for Extraterrestrial Intelligence (SETI) has thus far failed to provide a convincing detection of intelligent life. In the wake of this null signal, many "contact pessimistic" hypotheses have been formulated, the most famous of…
The existence of multiple regions of space beyond the observable Universe (within the so-called "multiverse") where the vacuum energy density takes different values, has been postulated as an explanation for the low non-zero value observed…
The search for extraterrestrial intelligence by looking for signals from advanced technological civilizations has been ongoing for some decades. We suggest that it could possibly be made more efficient by focusing on stars from which the…
Can scientific discovery be made arbitrarily easy by choosing the right representation, collecting enough data, and deploying sufficiently powerful algorithms? This paper argues that the answer is fundamentally negative. We introduce the…
We report the detection of whisky in the atmosphere of the extrasolar super-Earth planet GJ 1132b from transmission spectroscopic data. It is seen both in atmospheric absorption as well as in chromospheric emission, the latter probably due…
Triple-star systems exhibit a phenomenon known as the Triple Evolution Dynamical Instability (TEDI), in which mass loss in evolving triples triggers short-term dynamical instabilities, potentially leading to collisions of stars, exchanges,…
Explaining the well established observation that the expansion rate of the universe is apparently accelerating is one of the defining scientific problems of our age. Within the standard model of cosmology, the repulsive 'dark energy'…
The METI risk problem refers to the uncertain outcome of sending transmissions into space with the intention of messaging to extraterrestrial intelligence (METI). Here, I demonstrate that this uncertainty is undecidable by proving that that…
The consensus that complexity begets stability in ecosystems was challenged in the seventies, a result recently extended to ecologically-inspired networks. The approaches assume the existence of a feasible equilibrium, i.e. with positive…