Fermi paradox....probability of the existence of extraterrestrial civilization and humanity's lack of contact with, or evidence for, such civilizations.make no photoshop
the absence of evidence for extraterrestrial intelligence. For the type ofestimation problem, see Fermi problem. For the music album, see Fermi Paradox (album). For the short story, see The Fermi Paradox Is Our Business Model.A graphical representation of the Arecibo message – Humanity's first
attempt to use radio waves to actively communicate its existence to alien civilizations. The Fermi paradox (or Fermi's paradox) is the apparent contradiction between high estimates of the probability of the existence of extraterrestrial civilization and humanity's lack of contact with, or evidence for, such civilizations.[1] The basic points of the argument,
made by physicists Enrico Fermi and Michael H. Hart, are:
• The Sun is a young star. There are billions of stars in the galaxy that are billions of years older;• Some of these stars likely have Earth-like planets[2] which, if the Earth is typical, may develop intelligent life;• Presumably some of these civilizations will develop interstellar travel, as Earth seems likely to do;• At any practical pace of interstellar travel, the galaxy can be completely colonized in just a few tens of millions of years.According to this line of thinking, the Earth should have already been colonized, or at least visited. But no convincing evidence of this exists.Furthermore, no confirmed signs of intelligence elsewhere have been spotted, either in our galaxy or the more than 80 billion other galaxies of
the observable universe. Hence Fermi's question "Where is everybody?"
brainu.org/files/wikipedia_fermi_paradox_information.pdf
Frank Drake in 1961 in an attempt to find a systematic means to evaluate the numerous probabilities involved in the existence of alien life. The speculative equation considers the rate of star formation in the galaxy; the fraction of stars with planets and the number per star that are habitable; the fraction of those planets that develop life; the fraction that develop intelligent life; the fraction that have detectable, technological intelligent life; and finally the length of time such communicable civilizations are detectable. The fundamental problem is that the last four terms are completely unknown, rendering statistical estimates impossible.There are two parts of the Fermi paradox that rely on empirical evidence—that there are many potential habitable planets, and that we see no evidence of life. The first point, that many suitable planets exist, was an assumption in Fermi's time that is gaining ground with the discovery of many exoplanets, and models predicting billions of habitable worlds in our galaxy..The second part of the paradox, that we see no evidence of extraterrestrial life, is also an active field of scientific research. This includes both efforts to find any indication of life,[36] and efforts specifically directed to finding intelligent life. These searches have been made since 1960, and several are ongoing?Those who think that intelligent extraterrestrial life is (nearly) impossible argue that the conditions needed for the evolution of life—or at least the evolution of biological complexity—are rare or even unique to Earth. Under this assumption, called the rare Earth hypothesis, a rejection of the mediocrity principle, complex multicellular life is regarded as exceedingly unusual.The Rare Earth hypothesis argues that the evolution of biological complexity requires a host of fortuitous circumstances, such as a galactic habitable zone, a central star and planetary system having the requisite character, the circumstellar habitable zone, a right sized terrestrial planet, the advantage of a giant guardian like Jupiter and a large natural satellite, conditions needed to ensure the planet has a magnetosphere and plate tectonics, the chemistry of the lithosphere, atmosphere, and oceans, the role of "evolutionary pumps" such as massive glaciation and rare bolide impacts, and whatever led to the appearance of the eukaryote cell, sexual reproduction and the Cambrian explosion.This is the argument that technological civilizations may usually or invariably destroy themselves before or shortly after developing radio or spaceflight technology. Possible means of annihilation are many,[68] including war, accidental environmental contamination, or poorly designed artificial intelligence. This general theme is explored both in fiction and in scientific hypothesizing. In 1966, Sagan and Shklovskii speculated that technological civilizations will either tend to destroy themselves within a century of developing interstellar communicative capability or master their self-destructive tendencies and survive for billion-year timescales.Self-annihilation may also be viewed in terms of thermodynamics: insofar as life is an ordered system that can sustain itself against the tendency to disorder, the "external transmission" or interstellar communicative phase may be the point at which the system becomes unstable and self-destructs.Another hypothesis is that an intelligent species beyond a certain point of technological capability will destroy other intelligent species as they appear. The idea that something, or someone, might be destroying intelligent life in the universe has been explored in the scientific literature. A species might undertake such extermination out of expansionist motives, paranoia, or aggression. In 1981, cosmologist Edward Harrison argued that such behavior would be an act of prudence: an intelligent species that has overcome its own self-destructive tendencies might view any other species bent on galactic expansion as a threat It has also been suggested that a successful alien species would be a superpredator, as are humans.New life might commonly die out due to runaway heating or cooling on their fledgling planets.On Earth, there have been numerous major extinction events that destroyed the majority of complex species alive at the time; the extinction of the dinosaurs is the best known example. These are thought to have been caused by events such as impact from a large meteorite, massive volcanic eruptions, or astronomical events such as gamma-ray bursts.[76] It may be the case that such extinction events are common throughout the universe and periodically destroy intelligent life, or at least its civilizations, before the species is able to develop the technology to communicate with other species.
Fermi paradox....probability of the existence of extraterrestrial civilization and humanity's lack of contact with, or evidence for, such civilizations.make no photoshop
the absence of evidence for extraterrestrial intelligence. For the type ofestimation problem, see Fermi problem. For the music album, see Fermi Paradox (album). For the short story, see The Fermi Paradox Is Our Business Model.A graphical representation of the Arecibo message – Humanity's first
attempt to use radio waves to actively communicate its existence to alien civilizations. The Fermi paradox (or Fermi's paradox) is the apparent contradiction between high estimates of the probability of the existence of extraterrestrial civilization and humanity's lack of contact with, or evidence for, such civilizations.[1] The basic points of the argument,
made by physicists Enrico Fermi and Michael H. Hart, are:
• The Sun is a young star. There are billions of stars in the galaxy that are billions of years older;• Some of these stars likely have Earth-like planets[2] which, if the Earth is typical, may develop intelligent life;• Presumably some of these civilizations will develop interstellar travel, as Earth seems likely to do;• At any practical pace of interstellar travel, the galaxy can be completely colonized in just a few tens of millions of years.According to this line of thinking, the Earth should have already been colonized, or at least visited. But no convincing evidence of this exists.Furthermore, no confirmed signs of intelligence elsewhere have been spotted, either in our galaxy or the more than 80 billion other galaxies of
the observable universe. Hence Fermi's question "Where is everybody?"
brainu.org/files/wikipedia_fermi_paradox_information.pdf
Frank Drake in 1961 in an attempt to find a systematic means to evaluate the numerous probabilities involved in the existence of alien life. The speculative equation considers the rate of star formation in the galaxy; the fraction of stars with planets and the number per star that are habitable; the fraction of those planets that develop life; the fraction that develop intelligent life; the fraction that have detectable, technological intelligent life; and finally the length of time such communicable civilizations are detectable. The fundamental problem is that the last four terms are completely unknown, rendering statistical estimates impossible.There are two parts of the Fermi paradox that rely on empirical evidence—that there are many potential habitable planets, and that we see no evidence of life. The first point, that many suitable planets exist, was an assumption in Fermi's time that is gaining ground with the discovery of many exoplanets, and models predicting billions of habitable worlds in our galaxy..The second part of the paradox, that we see no evidence of extraterrestrial life, is also an active field of scientific research. This includes both efforts to find any indication of life,[36] and efforts specifically directed to finding intelligent life. These searches have been made since 1960, and several are ongoing?Those who think that intelligent extraterrestrial life is (nearly) impossible argue that the conditions needed for the evolution of life—or at least the evolution of biological complexity—are rare or even unique to Earth. Under this assumption, called the rare Earth hypothesis, a rejection of the mediocrity principle, complex multicellular life is regarded as exceedingly unusual.The Rare Earth hypothesis argues that the evolution of biological complexity requires a host of fortuitous circumstances, such as a galactic habitable zone, a central star and planetary system having the requisite character, the circumstellar habitable zone, a right sized terrestrial planet, the advantage of a giant guardian like Jupiter and a large natural satellite, conditions needed to ensure the planet has a magnetosphere and plate tectonics, the chemistry of the lithosphere, atmosphere, and oceans, the role of "evolutionary pumps" such as massive glaciation and rare bolide impacts, and whatever led to the appearance of the eukaryote cell, sexual reproduction and the Cambrian explosion.This is the argument that technological civilizations may usually or invariably destroy themselves before or shortly after developing radio or spaceflight technology. Possible means of annihilation are many,[68] including war, accidental environmental contamination, or poorly designed artificial intelligence. This general theme is explored both in fiction and in scientific hypothesizing. In 1966, Sagan and Shklovskii speculated that technological civilizations will either tend to destroy themselves within a century of developing interstellar communicative capability or master their self-destructive tendencies and survive for billion-year timescales.Self-annihilation may also be viewed in terms of thermodynamics: insofar as life is an ordered system that can sustain itself against the tendency to disorder, the "external transmission" or interstellar communicative phase may be the point at which the system becomes unstable and self-destructs.Another hypothesis is that an intelligent species beyond a certain point of technological capability will destroy other intelligent species as they appear. The idea that something, or someone, might be destroying intelligent life in the universe has been explored in the scientific literature. A species might undertake such extermination out of expansionist motives, paranoia, or aggression. In 1981, cosmologist Edward Harrison argued that such behavior would be an act of prudence: an intelligent species that has overcome its own self-destructive tendencies might view any other species bent on galactic expansion as a threat It has also been suggested that a successful alien species would be a superpredator, as are humans.New life might commonly die out due to runaway heating or cooling on their fledgling planets.On Earth, there have been numerous major extinction events that destroyed the majority of complex species alive at the time; the extinction of the dinosaurs is the best known example. These are thought to have been caused by events such as impact from a large meteorite, massive volcanic eruptions, or astronomical events such as gamma-ray bursts.[76] It may be the case that such extinction events are common throughout the universe and periodically destroy intelligent life, or at least its civilizations, before the species is able to develop the technology to communicate with other species.