The Drake equation is a probabilistic argument used to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy.
Extraterrestrial life refers to life occurring outside of Earth which did not originate on Earth. Such hypothetical life might range from simple prokaryotes to beings with civilizations far more advanced than humanity. The Drake equation speculates about the existence of intelligent life elsewhere in the universe. The science of extraterrestrial life in all its forms is known as exobiology.
The Fermi paradox is named after Italian-American physicist Enrico Fermi and refers to the apparent contradiction between the lack of evidence for and various high probability estimates of the existence of extraterrestrial civilizations elsewhere in the Milky Way galaxy.
The search for extraterrestrial intelligence (SETI) is a collective term for scientific searches for intelligent extraterrestrial life, for example, monitoring electromagnetic radiation for signs of transmissions from civilizations on other planets.
The technological singularity is a hypothetical point in the future when technological growth becomes uncontrollable and irreversible, resulting in unfathomable changes to human civilization.
Extraterrestrial intelligence refers to hypothetical intelligent extraterrestrial life. The question of whether other inhabited worlds might exist has been debated since ancient times. The modern form of the concept emerged when the Copernican Revolution demonstrated that the Earth was a planet revolving around the Sun, and other planets were conversely, other worlds. The question of whether other inhabited planets or moons exist was a natural consequence of this new understanding. It has become one of the most speculative questions in science and is a central theme of science fiction and popular culture.
The zoo hypothesis speculates on the assumed behavior and existence of technically-advanced extraterrestrial life and the reasons they refrain from contacting Earth. It is one of many theoretical explanations for the Fermi paradox. The hypothesis is that alien life intentionally avoids communication with Earth, and one of its main interpretations is that it does so to allow for natural evolution and sociocultural development, avoiding interplanetary contamination, similarly to people observing animals at a zoo. The hypothesis seeks to explain the apparent absence of extraterrestrial life despite its generally accepted plausibility and hence the reasonable expectation of its existence.
The Great Filter, in the context of the Fermi paradox, is whatever prevents non-living matter from undergoing abiogenesis, in time, to expanding lasting life as measured by the Kardashev scale. The concept originates in Robin Hanson's argument that the failure to find any extraterrestrial civilizations in the observable universe implies the possibility something is wrong with one or more of the arguments from various scientific disciplines that the appearance of advanced intelligent life is probable; this observation is conceptualized in terms of a "Great Filter" which acts to reduce the great number of sites where intelligent life might arise to the tiny number of intelligent species with advanced civilizations actually observed. This probability threshold, which could lie behind us or in front of us, might work as a barrier to the evolution of intelligent life, or as a high probability of self-destruction. The main counter-intuitive conclusion of this observation is that the easier it was for life to evolve to our stage, the bleaker our future chances probably are.
In science fiction, uplift is a developmental process to transform a certain species of animals into more intelligent beings by other, already-intelligent beings. This is usually accomplished by cultural, technological, or evolutional interventions like genetic engineering but any fictional or real process can be used. The earliest appearance of the concept is in H. G. Wells' 1896 novel The Island of Doctor Moreau, and more recently appears in David Brin's Uplift series and other science fiction works.
Communication with extraterrestrial intelligence or CETI is a branch of the search for extraterrestrial intelligence that focuses on composing and deciphering interstellar messages that theoretically, could be understood by another technological civilization. This field of study once was known as exosemiotics. The best-known CETI experiment of its kind was the 1974 Arecibo message composed by Frank Drake.
In futures studies and the history of technology, accelerating change is a perceived increase in the rate of technological change throughout history, which may suggest faster and more profound change in the future and may or may not be accompanied by equally profound social and cultural change.
Moravec's paradox is the discovery by artificial intelligence and robotics researchers that, contrary to traditional assumptions, high-level reasoning requires very little computation, but low-level sensorimotor skills require enormous computational resources. The principle was articulated by Hans Moravec, Rodney Brooks, Marvin Minsky and others in the 1980s. As Moravec writes, "it is comparatively easy to make computers exhibit adult level performance on intelligence tests or playing checkers, and difficult or impossible to give them the skills of a one-year-old when it comes to perception and mobility".
Neocatastrophism is the hypothesis that life-exterminating events such as gamma-ray bursts have acted as a galactic regulation mechanism in the Milky Way upon the emergence of complex life in its habitable zone. It is proposed as an explanation of Fermi's paradox since it provides a mechanism which would have delayed the otherwise expected advent of intelligent beings in the local galaxy nearby to Earth. This is an avenue to explain why none so far have been detected by humans.
Metalaw is “the entire sum of legal rules regulating relationships between different races in the universe.” It is a concept of space law closely related to the scientific Search for Extraterrestrial Intelligence (SETI). The idea is an elaboration of Immanuel Kant's Categorical imperative "Act only according to that maxim whereby you can at the same time will that it should become a universal law."
The cultural impact of extraterrestrial contact is the corpus of changes to terrestrial science, technology, religion, politics, and ecosystems resulting from contact with an extraterrestrial civilization. This concept is closely related to the search for extraterrestrial intelligence (SETI), which attempts to locate intelligent life as opposed to analyzing the implications of contact with that life.
The Eerie Silence: Renewing Our Search for Alien Intelligence is a 2010 science text by Paul Davies, chair of the SETI: Post-Detection Science and Technology Taskgroup of the International Academy of Astronautics. The Eerie Silence explores the possibilities of intelligent extraterrestrial life, and its potential consequences.
In astrobiology and planetary astrophysics, the galactic habitable zone is the region of a galaxy in which life might most likely develop. More specifically, the concept of a galactic habitable zone incorporates various factors, such as metallicity and the rate of major catastrophes such as supernovae, to calculate which regions of the galaxy are more likely to form terrestrial planets, initially develop simple life, and provide a suitable environment for this life to evolve and advance. According to research published in August 2015, very large galaxies may favor the birth and development of habitable planets more than smaller galaxies such as the Milky Way. In the case of the Milky Way, its galactic habitable zone is commonly believed to be an annulus with an outer radius of about 10 kiloparsecs and an inner radius close to the Galactic Center.
Breakthrough Listen is a project to search for intelligent extraterrestrial communications in the Universe. With $100 million in funding and thousands of hours of dedicated telescope time on state-of-the-art facilities, it is the most comprehensive search for alien communications to date. The project began in January 2016, and is expected to continue for 10 years. It is a component of Yuri Milner's Breakthrough Initiatives program. The science program for Breakthrough Listen is based at Berkeley SETI Research Center, located in the Astronomy Department at the University of California, Berkeley.
