"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 written 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 a Fermi problem rather than as a serious attempt to nail down a"
"""communicative"" extraterrestrial life can be gleaned from the Drake equation, essentially an equation expressing the probability of intelligent life as the product of factors such as the fraction of planets that might be habitable and the fraction of planets on which life might arise: where: However, whilst the rationale behind the equation is sound, it is unlikely that the equation will be constrained to reasonable limits of error any time soon. The problem with the formula is that it is not usable to generate or support hypotheses because it contains factors that can never be verified. The first term, R*,"
"predicted to have a higher probability of hosting planets with complex life. The variables of the Drake equation are used to discuss the conditions in planetary systems where civilization is most likely to exist. Use of the equation to predict the amount of extraterrestrial life, however, is difficult; because many of the variables are unknown, the equation functions as more of a mirror to what its user already thinks. As a result, the number of civilizations in the galaxy can be estimated as low as 9.1 x 10 or as high as 156 million; for the calculations, see Drake equation."
"Drake and his colleagues in 1961 were: Inserting the above minimum numbers into the equation gives a minimum N of 20 (see: Range of results). Inserting the maximum numbers gives a maximum of 50,000,000. Drake states that given the uncertainties, the original meeting concluded that , and there were probably between 1000 and 100,000,000 civilizations in the Milky Way galaxy. This section discusses and attempts to list the best current estimates for the parameters of the Drake equation. Latest calculations from NASA and the European Space Agency indicate that the current rate of star formation in our galaxy is about"
"the Milky Way galaxy. The equation is best understood not as an equation in the strictly mathematical sense, but to summarize all the various concepts which scientists must contemplate when considering the question of life elsewhere. The Drake equation is: where: and Drake's proposed estimates are as follows, but numbers on the right side of the equation are agreed as speculative and open to substitution: formula_2 The Drake equation has proved controversial since several of its factors are uncertain and based on conjecture, not allowing conclusions to be made. This has led critics to label the equation a guesstimate, or"
"rates, the rare Earth hypothesis value of , Mayr's view on intelligence arising, Drake's view of communication, and Shermer's estimate of lifetime: gives: i.e., suggesting that we are probably alone in this galaxy, and possibly in the observable universe. On the other hand, with larger values for each of the parameters above, values of can be derived that are greater than 1. The following higher values that have been proposed for each of the parameters: Use of these parameters gives: Monte Carlo simulations of estimates of the Drake equation factors based on a stellar and planetary model of the Milky"
"against the dangers of nuclear warfare. As many skeptics have pointed out, the Drake equation can give a very wide range of values, depending on the assumptions, and the values used in portions of the Drake equation are not well-established. In particular, the result can be , meaning we are likely alone in the galaxy, or , implying there are many civilizations we might contact. One of the few points of wide agreement is that the presence of humanity implies a probability of intelligence arising of greater than zero. As an example of a low estimate, combining NASA's star formation"
"case that hopefully will be considered legitimate ten years later. Appearing on ""ABC Primetime"" in 2009, Romanek underwent hypnosis by R. Leo Sprinkle, a psychologist who specialized in alien abduction cases. During hypnosis, Romanek wrote out the Drake equation, which is a formula used to estimate the number of communicative extraterrestrial civilizations in our galaxy. It was suggested by Joe Nickell from the Center for Inquiry that this was done through simple memorization. In 2008, Romanek appeared on ""Larry King Live"", along with Jeff Peckman, former Denver Mayoral candidate endorsing Romanek's story as part of his campaign for a Denver"
"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. The Drake equation has been used by"
"Way have resulted in the number of civilizations varying by a factor of 100. The Drake equation can be modified to determine just how unlikely intelligent life must be, to give the result that Earth has the only intelligent life that has ever arisen, either in our galaxy or the universe as a whole. This simplifies the calculation by removing the lifetime and communication constraints. Since star and planets counts are known, this leaves the only unknown as the odds that a habitable planet ""ever"" develops intelligent life. For Earth to have the only civilization that has ever occurred in"
"broader astronomical context. In 2015, ""remains of biotic life"" were found in 4.1 billion-year-old rocks in Western Australia, when the young Earth was about 400 million years old. According to one of the researchers, ""If life arose relatively quickly on Earth, then it could be common in the universe."" In 1961, University of California, Santa Cruz, astronomer and astrophysicist Frank Drake devised the Drake equation as a way to stimulate scientific dialogue at a meeting on the search for extraterrestrial intelligence (SETI). The Drake equation is a probabilistic argument used to estimate the number of active, communicative extraterrestrial civilizations in"
"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 effect being that the uncertainty associated with any derived value is so large that the equation cannot be used to draw firm conclusions. The Drake equation is: where: and In September 1959, physicists Giuseppe Cocconi and Philip Morrison published an article in the journal ""Nature"" with the provocative title ""Searching for Interstellar Communications"". Cocconi and Morrison argued that radio telescopes had become sensitive enough to pick up transmissions"
"to the equation have been proposed. One line of modification, for example, attempts to account for the uncertainty inherent in many of the terms. Others note that the Drake equation ignores many concepts that might be relevant to the odds of contacting other civilizations. For example, David Brin states: ""The Drake equation merely speaks of the number of sites at which ETIs spontaneously arise. The equation says nothing directly about the contact cross-section between an ETIS and contemporary human society"". Because it is the contact cross-section that is of interest to the SETI community, many additional factors and modifications of"
"the Drake equation is not in the solving, but rather in the contemplation of all the various concepts which scientists must incorporate when considering the question of life elsewhere, and gives the question of life elsewhere a basis for scientific analysis. The Drake equation is a statement that stimulates intellectual curiosity about the universe around us, for helping us to understand that life as we know it is the end product of a natural, cosmic evolution, and for helping us realize how much we are a part of that universe. What the equation and the search for life has done"
"Frank Drake Frank Donald Drake (born May 28, 1930) is an American astronomer and astrophysicist. He is involved in the search for extraterrestrial intelligence, including the founding of SETI, mounting the first observational attempts at detecting extraterrestrial communications in 1960 in Project Ozma, developing the Drake equation, and as the creator of the ""Arecibo Message,"" a digital encoding of an astronomical and biological description of the Earth and its lifeforms for transmission into the cosmos. Born on May 28, 1930, in Chicago, Illinois, as a youth Drake loved electronics and chemistry. He reports that he considered the possibility of life"
"the Drake equation have been proposed. Seager stresses, “We’re not throwing out the Drake Equation, which is really a different topic,” explaining, “Since Drake came up with the equation, we have discovered thousands of exoplanets. We as a community have had our views revolutionized as to what could possibly be out there. And now we have a real question on our hands, one that’s not related to intelligent life: Can we detect any signs of life in any way in the very near future?” There is considerable disagreement on the values of these parameters, but the 'educated guesses' used by"
"the electron that can be approximated by a delta potential. The delta potential well is a limiting case of the finite potential well, which is obtained if one maintains the product of the width of the well and the potential constant while decreasing the well's width and increasing the potential. This article, for simplicity, only considers a one-dimensional potential well, but analysis could be expanded to more dimensions. The time-independent Schrödinger equation for the wave function of a particle in one dimension in a potential is where is the reduced Planck constant and is the energy of the particle. The"
"number of stars, is generally constrained within a few orders of magnitude. The second and third terms, ""f"", stars with planets and ""f"", planets with habitable conditions, are being evaluated for the star's neighborhood. Drake originally formulated the equation merely as an agenda for discussion at the Green Bank conference, but some applications of the formula had been taken literally and related to simplistic or pseudoscientific arguments. Another associated topic is the Fermi paradox, which suggests that if intelligent life is common in the universe, then there should be obvious signs of it. Another active research area in astrobiology is"
"Calvin, astronomer Su-Shu Huang, neuroscientist John C. Lilly, inventor Barney Oliver, astronomer Carl Sagan and radio-astronomer Otto Struve. These participants dubbed themselves ""The Order of the Dolphin"" (because of Lilly's work on dolphin communication), and commemorated their first meeting with a plaque at the observatory hall. The Drake equation amounts to a summary of the factors affecting the likelihood that we might detect radio-communication from intelligent extraterrestrial life. The last four parameters, , , , and , are not known and are very difficult to estimate, with values ranging over many orders of magnitude (see criticism). Therefore, the usefulness of"
"the probability of intelligent life arising on an Earth-like planet and communicating with us. His discussion is centered around the Drake Equation. Davies argues for a new search method for SETI, which would be less anthropocentric but at the same time scientifically eliminating various uninhabitable regions. He also discusses whether or not we have already received signals from extraterrestrials, but have not yet discovered them. In this chapter, Davies brings up an interesting theory about habitability on the Galactic Plane. The theory is as such: the Solar system moves up and down relative to the Galactic Plane, in a cycle"
"both optimists and pessimists, with wildly differing results. The first scientific meeting on the search for extraterrestrial intelligence (SETI), which had 10 attendees including Frank Drake and Carl Sagan, speculated that the number of civilizations was roughly equal to the lifetime in years, and there were probably between 1,000 and 100,000,000 civilizations in the Milky Way galaxy. Conversely, Frank Tipler and John D. Barrow used pessimistic numbers and speculated that the average number of civilizations in a galaxy is much less than one. Almost all arguments involving the Drake equation suffer from the overconfidence effect, a common error of probabilistic"
"estimate for the Lagrange multipliers formula_16 based on the particle velocities. It is worth mentioning that MSHAKE computes corrections on the constraint ""forces"", achieving better convergence. A final modificatio to the SHAKE algorithm is the P-SHAKE algorithm that is applied to very rigid or semi-rigid molecules. P-SHAKE computes and updates a pre-conditioner which is applied to the constraint gradients before the SHAKE iteration, causing the Jacobian formula_21 to become diagonal or strongly diagonally dominant. The thus de-coupled constraints converge much faster (quadratically as opposed to linearly) at a cost of formula_46. The M-SHAKE algorithm solves the non-linear system of equations"
"Natural Sciences (1984–88). He serves on the Board of Trustees of the SETI Institute. Drake Planetarium at Norwood High School in Norwood, Ohio is named for Drake and linked to NASA. Frank Drake Frank Donald Drake (born May 28, 1930) is an American astronomer and astrophysicist. He is involved in the search for extraterrestrial intelligence, including the founding of SETI, mounting the first observational attempts at detecting extraterrestrial communications in 1960 in Project Ozma, developing the Drake equation, and as the creator of the ""Arecibo Message,"" a digital encoding of an astronomical and biological description of the Earth and its"
"the Drake equation, which estimates the number of intelligent, communicating civilizations that exist in the Milky Way. There are exoplanets that are much closer to their parent star than any planet in the Solar System is to the Sun, and there are also exoplanets that are much farther from their star. Mercury, the closest planet to the Sun at 0.4 AU, takes 88 days for an orbit, but the shortest known orbits for exoplanets take only a few hours, e.g. Kepler-70b. The Kepler-11 system has five of its planets in shorter orbits than Mercury's, all of them much more massive"
"number of planetary-mass objects orbiting within the CHZ of each star. A low value lends support to the Rare Earth hypothesis, which posits that intelligent life is a rarity in the Universe, whereas a high value provides evidence for the Copernican mediocrity principle, the view that habitability—and therefore life—is common throughout the Universe. A 1971 NASA report by Drake and Bernard Oliver proposed the ""water hole"", based on the spectral absorption lines of the hydrogen and hydroxyl components of water, as a good, obvious band for communication with extraterrestrial intelligence that has since been widely adopted by astronomers involved in"
"12Ka period of the 800Ma evolution of life. The following discussion is adapted from Cramer. The Rare Earth equation is Ward and Brownlee's riposte to the Drake equation. It calculates formula_1, the number of Earth-like planets in the Milky Way having complex life forms, as: where: We assume formula_5. The Rare Earth hypothesis can then be viewed as asserting that the product of the other nine Rare Earth equation factors listed below, which are all fractions, is no greater than 10 and could plausibly be as small as 10. In the latter case, formula_1 could be as small as 0"
"unphysical assumption that the step potential is discontinuous. When the step function is replaced with a ramp that spans some finite distance ""w"", the probability of reflection approaches zero in the limit formula_21, where ""k"" is the wavenumber of the particle. The relativistic calculation of a free particle colliding with a step potential can be obtained using relativistic quantum mechanics. For the case of 1/2 fermions, like electrons and neutrinos, the solutions of the Dirac equation for high energy barriers produce transmission and reflection coefficients that are not bounded. This phenomenon is known as the Klein paradox. The apparent paradox"
"values. The Love number k is defined as the cubical dilation or the ratio of the additional potential (self-reactive force) produced by the deformation of the deforming potential. It can be represented as formula_10, where formula_11 for a rigid body. The Love number l represents the ratio of the horizontal (transverse) displacement of an element of mass of the planet's crust to that of the corresponding static ocean tide. In potential notation the transverse displacement is formula_12, where formula_13 is the horizontal gradient operator. As with ""h"" and ""k"", formula_14 for a rigid body. According to Cartwright, ""An elastic solid"
"that once a civilization has learned of a more advanced one, its longevity could increase because it can learn from the experiences of the other. The astronomer Carl Sagan speculated that all of the terms, except for the lifetime of a civilization, are relatively high and the determining factor in whether there are large or small numbers of civilizations in the universe is the civilization lifetime, or in other words, the ability of technological civilizations to avoid self-destruction. In Sagan's case, the Drake equation was a strong motivating factor for his interest in environmental issues and his efforts to warn"
"single year in Chicago is We can similarly calculate that the average piano tuner performs Dividing gives In 2009, the actual number of piano tuners in Chicago was about 290. A famous example of a Fermi-problem-like estimate is the Drake equation, which seeks to estimate the number of intelligent civilizations in the galaxy. The basic question of why, if there were a significant number of such civilizations, ours has never encountered any others is called the Fermi paradox. Scientists often look for Fermi estimates of the answer to a problem before turning to more sophisticated methods to calculate a precise"
"huge, far beyond what some consider acceptable or meaningful. One reply to such criticisms is that even though the Drake equation currently involves speculation about unmeasured parameters, it was intended as a way to stimulate dialogue on these topics. Then the focus becomes how to proceed experimentally. Indeed, Drake originally formulated the equation merely as an agenda for discussion at the Green Bank conference. The pessimists' most telling argument in the SETI debate stems not from theory or conjecture but from an actual observation: the presumed lack of extraterrestrial contact. A civilization lasting for tens of millions of years might"
"is generalized to the relativistic concept that humans are not privileged observers of the universe. Many prominent scientists, including Stephen Hawking have proposed that the sheer scale of the universe makes it improbable for intelligent life not to have emerged elsewhere. However Fermi's Paradox highlights 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. The Kardashev scale is a speculative method of measuring a civilization's level of technological advancement, based on the amount of energy a civilization is able to utilize. The Drake"
"of characters (as do all other X/Y formats). The message forms the image shown on the right when translated into graphics, characters, and spaces. Dr. Frank Drake, then at Cornell University and creator of the Drake equation, wrote the message with help from Carl Sagan, among others. The message consists of seven parts that encode the following (from the top down): Since it will take nearly 25,000 years for the message to reach its intended destination (and an additional 25,000 years for any reply), the Arecibo message is viewed as a demonstration of human technological achievement, rather than a real"