Related papers: The Drake Equation as a Function of Spectral Type …
We use a statistical model to investigate the detectability (defined by the requirement that they are in causal contact with us) of communicating civilizations within a volume of the universe surrounding our location. If the civilizations…
In this paper we address the cosmic frequency of technological species. Recent advances in exoplanet studies provide strong constraints on all astrophysical terms in the Drake Equation. Using these and modifying the form and intent of the…
We critically investigate some evolutionary aspects of the famous Drake equation, which is usually presented as the central guide for the research on extraterrestrial intelligence. It is shown that the Drake equation tacitly relies on…
This paper develops a detailed quantitative model which uses the Drake equation and an assumption of an average maximum radio broadcasting distance by an communicative civilization to derive a minimum civilization density for contact…
Speculation about the existence of advanced forms of life in the Universe and in our galaxy, has been since ever a subject of fascination and discussion in fiction, as well as in astrophysics, biology and philosophy. The well-known Fermi's…
The Drake equation has been used many times to estimate the number of observable civilizations in the Galaxy. However, the uncertainty of the outcome is so great that any individual result is of limited use, as predictions can range from a…
The Drake Equation has proven fertile ground for speculation about the abundance, or lack thereof, of communicating extraterrestrial intelligences (CETIs) for decades. It has been augmented by subsequent authors to include random variables…
In the 20th century the scientific search for extraterrestrial intelligence began, and the Drake equation was proposed to estimate the number of extraterrestrial species humanity could attempt to detect, N. This paper discusses the need to…
The search for extraterrestrial intelligence (SETI) has been heavily influenced by solutions to the Drake Equation, which returns an integer value for the number of communicating civilisations resident in the Milky Way, and by the Fermi…
In evaluating the number of technological civilizations N in the Galaxy through the Drake formula, emphasis is mostly put on the astrophysical and biotechnological factors describing the emergence of a civilization and much less on its the…
The Drake equation pertains to the essentially equilibrium situation in a population of communicative civilizations (CCs) of the Galaxy, but it does not describe dynamical processes which can occur in it. Both linear and non-linear…
The number N of detectable (i.e. communicating) extraterrestrial civilizations in the Milky Way galaxy is usually done by using the Drake equation. This equation was established in 1961 by Frank Drake and was the first step to quantifying…
This paper presents the proportional evolutionary time hypothesis, which posits that the mean time required for the evolution of complex life is a function of stellar mass. The "biological available window" is defined as the region of a…
Probabilistic arguments about the existence of technological life beyond Earth traditionally refer to the Drake equation to draw possible estimates of the number of technologically advanced civilizations releasing, either intentionally or…
The data recently accumulated by the Kepler mission have demonstrated that small planets are quite common and that a significant fraction of all stars may have an Earth-like planet within their Habitable Zone. These results are combined…
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,…
We explore how questions related to developing a sustainable human civilization can be cast in terms of astrobiology. In particular we show how ongoing astrobiological studies of the coupled relationship between life, planets and their…
The intuition suggested by the Drake equation implies that technology should be less prevalent than biology in the galaxy. However, it has been appreciated for decades in the SETI community that technosignatures could be more abundant,…
The ease of interstellar rocket travel is an issue with implications for the long term fate of our own and other civilizations and for the much-debated number of technological civilizations in the Galaxy. We show that the physical barrier…
Previous critiques of the Drake Equation have highlighted its deterministic nature, implying that the number of civilizations is the same at all times. Here, I build upon earlier work and present a stochastic formulation. The birth of…