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Dark Forest Hypothesis
The dark forest hypothesis is the conjecture that many alien civilizations exist throughout the universe, but they are both silent and paranoid. In this framing, it is presumed that any space-faring civilization would view any other intelligent life as an inevitable threat, and thus destroy any nascent life that makes itself known. As a result, the electromagnetic spectrum would be relatively quiet, without evidence of any intelligent alien life, as in a "dark forest" filled with "armed hunter(s) stalking through the trees like ghosts". Background There is no reliable or reproducible evidence that aliens have visited or attempted to contact Earth. No transmissions and little evidence of intelligent extraterrestrial life has been detected or observed. This runs counter to the knowledge that the universe is filled with a very large number of planets, some of which likely hold conditions hospitable for life. Life typically expands until it fills all available niches. These contra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conjecture
In mathematics, a conjecture is a conclusion or a proposition that is proffered on a tentative basis without proof. Some conjectures, such as the Riemann hypothesis (still a conjecture) or Fermat's Last Theorem (a conjecture until proven in 1995 by Andrew Wiles), have shaped much of mathematical history as new areas of mathematics are developed in order to prove them. Important examples Fermat's Last Theorem In number theory, Fermat's Last Theorem (sometimes called Fermat's conjecture, especially in older texts) states that no three positive integers a, ''b'', and ''c'' can satisfy the equation ''a^n + b^n = c^n'' for any integer value of ''n'' greater than two. This theorem was first conjectured by Pierre de Fermat in 1637 in the margin of a copy of '' Arithmetica'', where he claimed that he had a proof that was too large to fit in the margin. The first successful proof was released in 1994 by Andrew Wiles, and formally published in 1995, after 358 years of effort by mathe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Brin
Glen David Brin (born October 6, 1950) is an American scientist and author of science fiction. He has won the Hugo,Who's Getting Your Vote? , October 29, 2008, '''' , and s. His novel '' |
Astronomical Controversies
Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole. Astronomy is one of the oldest natural sciences. The early civilizations in recorded history made methodical observations of the night sky. These include the Babylonians, Greeks, Indians, Egyptians, Chinese, Maya, and many ancient indigenous peoples of the Americas. In the past, astronomy included disciplines as diverse as astrometry, celestial navigation, observational astronomy, and the making of calendars. Nowadays, professiona ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Hypotheses
Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole. Astronomy is one of the oldest natural sciences. The early civilizations in recorded history made methodical observations of the night sky. These include the Babylonians, Greeks, Indians, Egyptians, Chinese, Maya, and many ancient indigenous peoples of the Americas. In the past, astronomy included disciplines as diverse as astrometry, celestial navigation, observational astronomy, and the making of calendars. Nowadays, p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypotheses
A hypothesis (plural hypotheses) is a proposed explanation for a phenomenon. For a hypothesis to be a scientific hypothesis, the scientific method requires that one can test it. Scientists generally base scientific hypotheses on previous observations that cannot satisfactorily be explained with the available scientific theories. Even though the words "hypothesis" and "theory" are often used interchangeably, a scientific hypothesis is not the same as a scientific theory. A working hypothesis is a provisionally accepted hypothesis proposed for further research in a process beginning with an educated guess or thought. A different meaning of the term ''hypothesis'' is used in formal logic, to denote the antecedent of a proposition; thus in the proposition "If ''P'', then ''Q''", ''P'' denotes the hypothesis (or antecedent); ''Q'' can be called a consequent. ''P'' is the assumption in a (possibly counterfactual) ''What If'' question. The adjective ''hypothetical'', meaning "havin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrobiology
Astrobiology, and the related field of exobiology, is an interdisciplinary scientific field that studies the origins, early evolution, distribution, and future of life in the universe. Astrobiology is the multidisciplinary field that investigates the deterministic conditions and contingent events with which life arises, distributes, and evolves in the universe. Astrobiology makes use of molecular biology, biophysics, biochemistry, chemistry, astronomy, physical cosmology, exoplanetology, geology, paleontology, and ichnology to investigate the possibility of life on other worlds and help recognize biospheres that might be different from that on Earth. The origin and early evolution of life is an inseparable part of the discipline of astrobiology. Astrobiology concerns itself with interpretation of existing scientific data, and although speculation is entertained to give context, astrobiology concerns itself primarily with hypotheses that fit firmly into existing scientific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drake Equation
The Drake equation is a probabilistic argument used to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way Galaxy. The equation was formulated in 1961 by Frank Drake, not for purposes of quantifying the number of civilizations, but as a way to stimulate scientific dialogue at the first scientific meeting on the search for extraterrestrial intelligence (SETI). The equation summarizes the main concepts which scientists must contemplate when considering the question of other radio-communicative life. It is more properly thought of as an approximation than as a serious attempt to determine a precise number. Criticism related to the Drake equation focuses not on the equation itself, but on the fact that the estimated values for several of its factors are highly conjectural, the combined multiplicative effect being that the uncertainty associated with any derived value is so large that the equation cannot be used to draw firm conclusions. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Dark Forest
''The Dark Forest'' () is a 2008 science fiction novel by the Chinese writer Liu Cixin. It is the sequel to the Hugo Award-winning novel '' The Three-Body Problem'' in the trilogy titled "''Remembrance of Earth's Past''", but Chinese readers generally refer to the series by the title of the first novel. The English version, translated by Joel Martinsen, was published in 2015. The novel's title comes from the dark forest hypothesis, coined by Liu in the novel, but described by astronomer and author David Brin as early as 1983 as a possible solution to the Fermi paradox. Plot The UN forms the Planetary Defense Council (PDC) to coordinate defensive efforts against the impending assault of the Trisolarans, who have launched a massive invasion fleet that will reach Earth in around 400 years. However, subatomic semi-artificial intelligences sent from Trisolaris (the book's name for the three-star system of Alpha Centauri), known as sophons, have already reached Earth; these conduct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liu Cixin
Liu Cixin (, pronounced ; born 23 June 1963) is a Chinese science fiction writer. He is a nine-time winner of China's Galaxy Award and has also received the 2015 Hugo Award for his novel '' The Three-Body Problem'' as well as the 2017 Locus Award for ''Death's End''. He is also a winner of the Chinese Nebula Award. In English translations of his works, his name is given as Cixin Liu. He is a member of China Science Writers Association and the vice president of Shanxi Writers Association. He is also called "Da Liu" ("Big Liu"). Life and career Liu was born on 23 June 1963 in Beijing and raised in Yangquan, Shanxi, where his parents had been sent to work in the mines. Due to the violence of the Cultural Revolution he was sent to live in his ancestral home in Luoshan County, Henan. Liu graduated from the North China University of Water Conservancy and Electric Power in 1988. He then worked as a computer engineer at a power plant in Shanxi province. Writing Liu's writing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Forge Of God
''The Forge of God'' is a 1987 science fiction novel by American writer Greg Bear. Earth faces destruction when an inscrutable and overwhelming alien form of life attacks. Plot The novel features scenes and events, including the discovery of a nearly-dead alien in the desert, who clearly says in English, "I'm sorry, but there is bad news," and the alien's subsequent interrogation and autopsy; the discovery of an artificial geological formation and its subsequent nuclear destruction by a desperate military; and the Earth's eventual destruction by the mutual annihilation of a piece of neutronium and a piece of antineutronium dropped into Earth's core. There is another alien faction at work, however, represented on Earth by small spider-like robots that recruit human agents through some form of mind control. They frantically collect all the human data, biological records, tissue samples, seeds, and DNA from the biosphere that they can and evacuate a handful of people from Earth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greg Bear
Gregory Dale Bear (August 20, 1951 – November 19, 2022) was an American writer and illustrator best known for science fiction. His work covered themes of galactic conflict ('' Forge of God'' books), parallel universes ('' The Way'' series), consciousness and cultural practices ('' Queen of Angels''), and accelerated evolution ('' Blood Music'', ''Darwin's Radio'', and '' Darwin's Children''). His most recent work was the 2021 novel ''The Unfinished Land''. Greg Bear wrote over 50 books in total. Early life Greg Bear was born in San Diego, California. He attended San Diego State University (1968–1973), where he received a Bachelor of Arts degree. At the university, he was a teaching assistant to Elizabeth Chater in her course on science fiction writing, and in later years her friend. Career Bear is often classified as a hard science fiction author because of the level of scientific detail in his work. Early in his career, he also published work as an artist, including il ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extensive-form Game
An extensive-form game is a specification of a game in game theory, allowing (as the name suggests) for the explicit representation of a number of key aspects, like the sequencing of players' possible moves, their choices at every decision point, the (possibly imperfect) information each player has about the other player's moves when they make a decision, and their payoffs for all possible game outcomes. Extensive-form games also allow for the representation of incomplete information in the form of chance events modeled as " moves by nature". Finite extensive-form games Some authors, particularly in introductory textbooks, initially define the extensive-form game as being just a game tree with payoffs (no imperfect or incomplete information), and add the other elements in subsequent chapters as refinements. Whereas the rest of this article follows this gentle approach with motivating examples, we present upfront the finite extensive-form games as (ultimately) constructed here. This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
