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In a recent paper (Maccone, 2011 [15]) and in a recent book (Maccone, 2012 [17]), this author proposed a new mathematical model capable of merging SETI and Darwinian Evolution into a single mathematical scheme. This model is based on exponentials and lognormal probability distributions, called “b-lognormals” if they start at any positive time b (“birth”) larger than zero. Indeed:
  • 1.Darwinian evolution theory may be regarded as a part of SETI theory in that the factor fl in the Drake equation represents the fraction of planets suitable for life on which life actually arose, as it happened on Earth.
  • 2.In 2008 (Maccone, 2008 [9]) this author firstly provided a statistical generalization of the Drake equation where the number N of communicating ET civilizations in the Galaxy was shown to follow the lognormal probability distribution. This fact is a consequence of the Central Limit Theorem (CLT) of Statistics, stating that the product of a number of independent random variables whose probability densities are unknown and independent of each other approached the lognormal distribution if the number of factors is increased at will, i.e. it approaches infinity.
  • 3.Also, in Maccone (2011 [15]), it was shown that the exponential growth of the number of species typical of Darwinian Evolution may be regarded as the geometric locus of the peaks of a one-parameter family of b-lognormal distributions constrained between the time axis and the exponential growth curve. This was a brand-new result. And one more new and far-reaching idea was to define Darwinian Evolution as a particular realization of a stochastic process called Geometric Brownian Motion (GBM) having the above exponential as its own mean value curve.
  • 4.The b-lognormals may be also be interpreted as the lifespan of any living being, let it be a cell, or an animal, a plant, a human, or even the historic lifetime of any civilization. In Maccone, (2012 [17, Chapters 6, 7, 8 and 11]), as well as in the present paper, we give important exact equations yielding the b-lognormal when its birth time, senility-time (descending inflexion point) and death time (where the tangent at senility intercepts the time axis) are known. These also are brand-new results. In particular, the σ=1 b-lognormals are shown to be related to the golden ratio, so famous in the arts and in architecture, and these special b-lognormals we call “golden b-lognormals”.
  • 5.Applying this new mathematical apparatus to Human History leads to the discovery of the exponential trend of progress between Ancient Greece and the current USA Empire as the envelope of the b-lognormals of all Western Civilizations over a period of 2500 years.
  • 6.We then invoke Shannon's Information Theory. The entropy of the obtained b-lognormals turns out to be the index of “development level” reached by each historic civilization. As a consequence, we get a numerical estimate of the entropy difference (i.e. the difference in the evolution levels) between any two civilizations. In particular, this was the case when Spaniards first met with Aztecs in 1519, and we find the relevant entropy difference between Spaniards an Aztecs to be 3.84 bits/individual over a period of about 50 centuries of technological difference. In a similar calculation, the entropy difference between the first living organism on Earth (RNA?) and Humans turns out to equal 25.57 bits/individual over a period of 3.5 billion years of Darwinian Evolution.
  • 7.Finally, we extrapolate our exponentials into the future, which is of course arbitrary, but is the best Humans can do before they get in touch with any alien civilization. The results are appalling: the entropy difference between aliens 1 million years more advanced than Humans is of the order of 1000 bits/individual, while 10,000 bits/individual would be requested to any Civilization wishing to colonize the whole Galaxy (Fermi Paradox).
  • 8.In conclusion, we have derived a mathematical model capable of estimating how much more advanced than humans an alien civilization will be when SETI succeeds.
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《Acta Astronautica》2007,60(8-9):780-782
In Acta Astronautica, Vol. 56, No. 5, March 2006, at ISSN0094-5765 there appears the article entitled “Will space actually be the Final Frontier of humankind?” written by Giancarlo Genta, and Michael Rycroft. This Acta Astronautica article requires amplification on the economic side. The writer of this article was personally present at the Apollo 11th launchings for the first landing on the Moon, by Buzz Aldrin and others. The Apollo 11 take off to the Moon, from Cape Carnival, did not leave the situation “so humankind seems forever to be bound to its own planet!” There was nothing pessimistic about the launch of Apollo 11. It is written that there was a lack of vision at that time, which is also not correct. The ‘Final Frontier’ myth was never mentioned on that occasion. At Apollo 11 we did take planet earth's “first faltering step for mankind” on the path towards a space faring civilization, exactly as these two authors later correctly mention. Now with the US Presidential initiatives “Moon, Mars and Beyond,” the authors suggested that it “will depend on social, political and economic issues rather than technological and scientific ones.” This Academy Note respectfully submits that all of these factors social, political and economic issues, plus psychological and scientific ones, instead of, “rather than technical and scientific ones” are going to be the determining factors of the speed of progress of the exploration of the entire universe, and particularly the sun in our Milky Way Galaxy. Russia and Ukraine are now on same, deep-space policy directions. The attention of the readers of this Academy Note is called to the current “Cosmic Collision” excellent presentation at the Hayden Planetarium, located at the Museum of National History in the City of New York. It shows the past, the present and the future of international humankind in exploring space and the creation of the universe, with particular reference to the protons of our sun, for our Milky Way Galaxy.  相似文献   

5.
Cirković MM 《Astrobiology》2004,4(2):225-231
We critically investigate some evolutionary aspects of the famous Drake equation, which is usually presented as the central guide for research on extraterrestrial intelligence. It is shown that the Drake equation tacitly relies on unverified assumptions on both the physicochemical history of our galaxy and the properties of advanced intelligent communities. In this manner, the conventional approach fails to take into account various evolutionary processes forming prerequisites for quantification of the Drake equation parameters. The importance of recent results of Lineweaver and collaborators on chemical build-up of inhabitable planets for the search for extraterrestrial intelligence is emphasized. Two important evolutionary effects are briefly discussed, and the resolution of the difficulties within the context of the phase-transition astrobiological models is sketched.  相似文献   

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A Monte Carlo computer model of extra-solar planetary formation and evolution, which includes the planetary geochemical carbon cycle, is presented. The results of a run of one million galactic disc stars are shown where the aim was to assess the possible abundance of both biocompatible and habitable planets. (Biocompatible planets are defined as worlds where the long-term presence of surface liquid water provides environmental conditions suitable for the origin and evolution of life. Habitable planets are those worlds with more specifically Earthlike conditions). The model gives an estimate of 1 biocompatible planet per 39 stars, with the subset of habitable planets being much rarer at 1 such planet per 413 stars. The nearest biocompatible planet may thus lie approximately 14 LY distant and the nearest habitable planet approximately 31 LY away. If planets form in multiple star systems then the above planet/star ratios may be more than doubled. By applying the results to stars in the solar neighbourhood, it is possible to identify 28 stars at distances of < 22 LY with a non-zero probability of possessing a biocompatible planet.  相似文献   

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Many important SETI terms are either ambiguously defined or interpreted by different experts differently. Based on the author's experience with astronautical terminology (IAA multilingual space dictionary) a summary of the usual problems connected with an uniform definition of fundamental terms is attempted. In the second part several examples are quoted from the SETI literature—including the terms ETI, SETI and METI themselves, the definition of a habitable zone, of alien life, of an extraterrestrial artifact, of the Drake equation, of the Fermi-paradox, etc. In the third part of the paper a new task for the SETI social sciences community is raised, namely to collect “Lasting Universal Terms”; i.e. terms the meaning of which did not change since millennia, are independent on geographic position and also on the terrestrial environment and biology. Such terms might be preferably used in interstellar communication. All these questions are related to the manner how we might think about ETI and SETI in new ways. The paper tries to summarize the problems connected with exact SETI terminology and its potential implications for the future.  相似文献   

9.
We present results from an initial survey of the 2(12)-1(11) transition of formaldehyde (H2CO) at 140.8 GHz in giant molecular clouds in the far outer Galaxy (RG >or= 16 kpc). Formaldehyde is a key prebiotic molecule that likely plays an important role in the development of amino acids. Determining the outermost extent of the H2CO distribution can constrain the outer limit of the Galactic Habitable Zone, the region where conditions for the formation of life are thought to be most favorable. We surveyed 69 molecular clouds in the outer Galaxy, ranging from 12 to 23.5 kpc in galactocentric radius. Formaldehyde emission at 140.8 GHz was detected in 65% of the clouds. The H2CO spectral line was detected in 26 of the clouds with RG > 16 kpc (detection rate of 59%), including 6 clouds with RG > 20 kpc (detection rate of 55%). Formaldehyde is readily found in the far outer Galaxy-even beyond the edge of the old stellar disk. Determining the relatively widespread distribution of H2CO in the far outer Galaxy is a first step in establishing how favorable an environment this vast region of the Galaxy may be toward the formation of life.  相似文献   

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Searching for signatures of cosmic-scale archeological artifacts such as Dyson spheres is an interesting alternative to conventional radio SETI. Uncovering such an artifact does not require the intentional transmission of a signal on the part of the original civilization. This type of search is called interstellar archeology or sometimes cosmic archeology. A variety of interstellar archeology signatures is discussed including non-natural planetary atmospheric constituents, stellar doping, Dyson spheres, as well as signatures of stellar, and galactic-scale engineering. The concept of a Fermi bubble due to interstellar migration is reviewed in the discussion of galactic signatures. These potential interstellar archeological signatures are classified using the Kardashev scale. A modified Drake equation is introduced. With few exceptions interstellar archeological signatures are clouded and beyond current technological capabilities. However SETI for so-called cultural transmissions and planetary atmosphere signatures are within reach.  相似文献   

12.
It is sometimes assumed that the rapidity of biogenesis on Earth suggests that life is common in the Universe. Here we critically examine the assumptions inherent in this if-life-evolved-rapidly-life-must-be-common argument. We use the observational constraints on the rapidity of biogenesis on Earth to infer the probability of biogenesis on terrestrial planets with the same unknown probability of biogenesis as the Earth. We find that on such planets, older than approximately 1 Gyr, the probability of biogenesis is > 13% at the 95% confidence level. This quantifies an important term in the Drake Equation but does not necessarily mean that life is common in the Universe.  相似文献   

13.
In the present work, we have derived an expression ML ? 4.738 M (M = 1.985 × 1033 g = mass of the Sun) giving the “limiting” value of the mass of a dense stellar matter, by introducing the concept of nuclear size correction in the theory of relativistic Thomas Fermi model for a compressed atom. We find that ML ? 5.1571 MChand =3.2750(MO)Prev [MCh and (MO)Prev denote respectively the Chandrasekhar and author's “limiting” masses]. By making a comparative study with those of previous results it has been shown that our present treatment would provide satisfactory results for the density ranges from ? ? 108 up to ? ? 1011g/cm3. Other results of cognate interest in the non-relativistic regime 103 < ? ? 105 (without the nuclear size effect) are presented. The astrophysical implications of the results are mentioned.  相似文献   

14.
The concept of logical existence is embedded in Lingua Cosmica, a formal linguistic system intended for use in interstellar communication between intelligent species in the Galaxy.  相似文献   

15.
The dynamics of modular structures is approached in this paper by means of the discrete Fourier transform. This method, applied to a structure with N bays and ring type boundary conditions, leads to N uncoupled systems of the size of a single bay. For other boundary conditions, it leads to a “spectrally resolved” eigenproblem, that is a form whose dominant terms in each field of frequency are evidenced. Approximate reduced models in narrow frequency fields can therefore be generated by using the “spectral condensation” technique. The method can be applied with general boundary conditions, but the present paper deals mostly with the “clamped edges” boundary condition and shows that numerical advantages can be obtained, particularly for the large space structures.  相似文献   

16.
The coronal mass ejections (CME) with small angular dimensions (d ≤ 10°) have the simplest form, much simpler than large CME. This fact simplifies the problem of analyzing the CME structure and studying their origin. On the basis of the analysis of the LASCO C2 (SOHO) data, we show in this paper that the motion of a CME having small dimensions proceeds within a magnetic tube (a ray with increased brightness) of the streamer belt and leads to an “explosion-like” increase in the angular dimensions (rapid expansion) of the tube. A hypothesis is put forward that a small CME represents a “plasmoid” (a plasma bunch bounded in space, with its own magnetic field) thrown into the base of the magnetic tube and moving along it away from the Sun.  相似文献   

17.
This paper presents the practice of the artist/researcher Ioannis Michaloudis. It showcases his use of a space technology nanomaterial, silica aerogel, and its potential in the cultural utilization of space. Since 2001, his projects have centered around the esthetic, sculptural and conceptual use of silica aerogel. For Michaloudis, this material is highly allegorical of what he terms ‘our breaking sky’. For the authors, the step towards space is a real ‘bridge moment’, analogous to the evolutionary progression of organisms from water to earth. In this current era of space exploration, it is clear that humans need to develop new organs and survival skills – or, cultivate new skies in response to the breaking of our atmosphere?s dome. It is also clear that science and art need to collaborate more productively. To this end, it is argued that allegory provides the link between imaginability, experiment and representation in both scientific and artistic practices. Etherospermia (εθεροσπερμ?α) is an invented word from ether and panspermia. The Etherospermia project pursues, allegorically, the creation of new atmospheres on other planets, in order to draw attention to the degradation and destruction of the earth?s protective veil. Imagine an astronaut who, during a space walk, scatters fragments of Michaloudis? silica aerogel as seed material to alter the atmospheres of other planets, making them habitable. The paper discusses nine artworks as a way of presenting the conceptual core of the etherospermia allegory.  相似文献   

18.
This paper discusses a multifaceted strategy to link NASA Minimal Functionality Habitable Element (MFHE) requirements to a compatible growth plan; leading forward to evolutionary, deployable habitats including outpost development stages. The discussion begins by reviewing fundamental geometric features inherent in small scale, vertical and horizontal, pressurized module configuration options to characterize applicability to meet stringent MFHE constraints.A proposed scenario to incorporate a vertical core MFHE concept into an expanded architecture to provide continuity of structural form and a logical path from “minimum” to “optimum” design of a habitable module.The paper describes how habitation and logistics accommodations could be pre-integrated into a common Hab/Log Module that serves both habitation and logistics functions. This is offered as a means to reduce unnecessary redundant development costs and to avoid EVA-intensive on-site adaptation and retrofitting requirements for augmented crew capacity. An evolutionary version of the hard shell Hab/Log design would have an expandable middle section to afford larger living and working accommodations.In conclusion, the paper illustrates that a number of cargo missions referenced for NASA’s 4.0.0 Lunar Campaign Scenario could be eliminated altogether to expedite progress and reduce budgets. The plan concludes with a vertical growth geometry that provides versatile and efficient site development opportunities using a combination of hard Hab/Log modules and a hybrid expandable “CLAM” (Crew Lunar Accommodations Module) element.  相似文献   

19.
Abstract

Spatial proximity terms, such as near and far, communicate information regarding the distance in which a “located” object can be found with respect to a “reference” object. The present paper investigates whether people take into account the location of an object extraneous to the located object and reference object pair, when setting the scale for proximity language judgements. Across three experiments participants rated the appropriateness of near and far to describe spatial scenes that included a third (distractor) object positioned the same distance as the located object from the reference object, but at varying distances from the located object. The results show that the presence of other spatial relations affects scale setting, resulting in differences in appropriateness ratings for those spatial terms.  相似文献   

20.
《Acta Astronautica》2013,82(2):478-483
Speculations about the existence of life beyond Earth are probably as old as mankind itself, but still there is no evidence – neither for its presence nor for its absence. Moreover, we neither know the necessary nor the sufficient conditions for life to emerge, sustain or evolve. The Drake equation famously quantifies our ignorance by writing the number of detectable civilizations as product of factors that get increasingly uncertain the further one goes to the right. As a result, the predictive power is poor, and it ultimately depends on the most uncertain factor. However, if we were able to derive a reasonable estimate, we would not need SETI experiments to tell us whether we are alone or not. What has changed substantially over human history is our ability to explore the Universe. Most significantly, radio transmission technology gives us the opportunity to communicate over interstellar distances, and we are now able to not only determine the population statistics of planets within the Milky Way, but even in principle to find biosignatures in their atmospheres. By finding life beyond Earth, we will learn how frequently it emerges. By finding signals from intelligent extra-terrestrial civilizations, we will get unprecedented insight into our biological, technological, and societal evolution. The Drake equation is not such a useful means for assessing the chances of success of SETI, but instead it provides the framework for using observational data in advancing towards understanding the origins of our existence and our role in the cosmos, and maybe to get a glimpse of our future.  相似文献   

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