|
Megatrajectory
In evolutionary biology, megatrajectories are the major evolutionary milestones and directions in the evolution of life. Posited by A. H. Knoll and Richard K. Bambach in their 2000 collaboration, "Directionality in the History of Life," Knoll and Bamback argue that, in consideration of the problem of progress in evolutionary history, a middle road that encompasses both contingent and convergent features of biological evolution may be attainable through the idea of the megatrajectory: We believe that six broad megatrajectories capture the essence of vectoral change in the history of life. The megatrajectories for a logical sequence dictated by the necessity for complexity level ''N'' to exist before ''N+1'' can evolve...In the view offered here, each megatrajectory adds new and qualitatively distinct dimensions to the way life utilizes ecospace. According to Knoll and Bambach, the six megatrajectories outlined by biological evolution thus far are: #the origin of life to the "Last ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intelligence Principle
Steven J. Dick (born October 24, 1949, Evansville, Indiana) is an American astronomer, author, and historian of science most noted for his work in the field of astrobiology. Dick served as the Chief Historian for the National Aeronautics and Space Administration from 2003 to 2009 and as the Baruch S. Blumberg NASA/Library of Congress Chair in Astrobiology from 2013 to 2014. Before that, he was an astronomer and historian of science at the United States Naval Observatory in Washington, DC, from 1979 to 2003. Career Steven J. Dick received a Bachelor of Science in astrophysics from Indiana University in 1971. In 1977, he earned a Master of Arts and a Ph.D. in the history and philosophy of science. For 24 years, Dick worked as an astronomer and historian of science for United States Naval Observatory in Washington, D.C., including three years at the Naval Observatory's Southern Hemisphere station in New Zealand. There he was part of a team using transit telescopes and astrographs t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technology
Technology is the application of knowledge to reach practical goals in a specifiable and reproducible way. The word ''technology'' may also mean the product of such an endeavor. The use of technology is widely prevalent in medicine, science, industry, communication, transportation, and daily life. Technologies include physical objects like utensils or machines and intangible tools such as software. Many technological advancements have led to societal changes. The earliest known technology is the stone tool, used in the prehistoric era, followed by fire use, which contributed to the growth of the human brain and the development of language in the Ice Age. The invention of the wheel in the Bronze Age enabled wider travel and the creation of more complex machines. Recent technological developments, including the printing press, the telephone, and the Internet have lowered communication barriers and ushered in the knowledge economy. While technology contributes to econom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Uplift
Star lifting is any of several hypothetical processes by which a sufficiently advanced civilization (specifically, one of Kardashev scale, Kardashev-II or higher) could remove a substantial portion of a star's matter which can then be re-purposed, while possibly optimizing the star's energy output and lifespan at the same time. The term appears to have been coined by David Criswell. Stars already lose a small flow of mass via solar wind, coronal mass ejections, and other natural processes. Over the course of a star's life on the main sequence this loss is usually negligible compared to the star's total mass; only at the end of a star's life when it becomes a red giant or a supernova is a large proportion of material ejected. The star lifting techniques that have been proposed would operate by increasing this natural Plasma (physics), plasma flow and manipulating it with magnetic fields. Stars have deep gravity wells, so the energy required for such operations is large. For exampl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Nanotechnology
Molecular nanotechnology (MNT) is a technology based on the ability to build structures to complex, atomic specifications by means of mechanosynthesis. This is distinct from nanoscale materials. Based on Richard Feynman's vision of miniature factories using nanomachines to build complex products ( including additional nanomachines), this advanced form of nanotechnology (or ''molecular manufacturing'') would make use of positionally-controlled mechanosynthesis guided by molecular machine systems. MNT would involve combining physical principles demonstrated by biophysics, chemistry, other nanotechnologies, and the molecular machinery of life with the systems engineering principles found in modern macroscale factories. Introduction While conventional chemistry uses inexact processes obtaining inexact results, and biology exploits inexact processes to obtain definitive results, molecular nanotechnology would employ original definitive processes to obtain definitive results. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artificial Intelligence
Artificial intelligence (AI) is intelligence—perceiving, synthesizing, and inferring information—demonstrated by machines, as opposed to intelligence displayed by animals and humans. Example tasks in which this is done include speech recognition, computer vision, translation between (natural) languages, as well as other mappings of inputs. The ''Oxford English Dictionary'' of Oxford University Press defines artificial intelligence as: the theory and development of computer systems able to perform tasks that normally require human intelligence, such as visual perception, speech recognition, decision-making, and translation between languages. AI applications include advanced web search engines (e.g., Google), recommendation systems (used by YouTube, Amazon and Netflix), understanding human speech (such as Siri and Alexa), self-driving cars (e.g., Tesla), automated decision-making and competing at the highest level in strategic game systems (such as chess and Go). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transhumanism
Transhumanism is a philosophical and intellectual movement which advocates the enhancement of the human condition by developing and making widely available sophisticated technologies that can greatly enhance longevity and cognition. Transhumanist thinkers study the potential benefits and dangers of emerging technologies that could overcome fundamental human limitations as well as the ethics of using such technologies. Some transhumanists believe that human beings may eventually be able to transform themselves into beings with abilities so greatly expanded from the current condition as to merit the label of posthuman beings. Another topic of transhumanist research is how to protect humanity against existential risks, such as nuclear war or asteroid collision. Julian Huxley was a biologist who popularised the term transhumanism in an influential 1957 essay. The contemporary meaning of the term "transhumanism" was foreshadowed by one of the first professors of futurology, a ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serbian Astronomical Journal
The ''Serbian Astronomical Journal'' is a biannual peer-reviewed scientific journal covering astronomy. The journal is the successor of the ''Bulletin Astronomique de Belgrade'' (1992–1998), which was formed by a merger of the ''Bulletin de l'Observatoire Astronomique de Belgrade'' (1936–1991) and the ''Publications of the Department of Astronomy'' (1969–1990). It has been published under the present title since 1998. It is published by the Astronomical Observatory Belgrade and the Department of Astronomy (Faculty of Mathematics, University of Belgrade). It publishes invited reviews, original scientific papers, preliminary reports, and professional papers over the entire range of astronomy, astrophysics, astrobiology, and related fields. Abstracting and indexing The ''Serbian Astronomical Journal'' is abstracted and indexed by Astrophysics Data System, Chemical Abstracts, Referativni Zhurnal, EBSCO databases EBSCO Information Services, headquartered in Ipswich, Massac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Astronomy (journal)
''New Astronomy'' is a peer-reviewed scientific journal covering topics in astronomy and astrophysics. The journal was established in 1996 and is currently published by Elsevier. Abstracting and indexing The journal is abstracted and indexed in the following databases: *Current Contents/Physics, Chemical, & Earth Sciences * INSPEC *SCISEARCH *Science Citation Index *Scopus According to the ''Journal Citation Reports'', the journal has a 2020 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as i ... of 1.325. References External links * Astronomy journals Elsevier academic journals English-language journals Publications established in 1996 {{astronomy-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolutionary Biology
Evolutionary biology is the subfield of biology that studies the evolutionary processes (natural selection, common descent, speciation) that produced the diversity of life on Earth. It is also defined as the study of the history of life forms on Earth. Evolution is based on the theory that all species are related and they gradually change over time. In a population, the genetic variations affect the physical characteristics i.e. phenotypes of an organism. These changes in the phenotypes will be an advantage to some organisms, which will then be passed onto their offspring. Some examples of evolution in species over many generations are the Peppered Moth and Flightless birds. In the 1930s, the discipline of evolutionary biology emerged through what Julian Huxley called the modern synthesis of understanding, from previously unrelated fields of biological research, such as genetics and ecology, systematics, and paleontology. The importance of studying Evolutionary biology is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation tends to exist within any given population as a result of genetic mutation and recombination. Evolution occurs when evolutionary processes such as natural selection (including sexual selection) and genetic drift act on this variation, resulting in certain characteristics becoming more common or more rare within a population. The evolutionary pressures that determine whether a characteristic is common or rare within a population constantly change, resulting in a change in heritable characteristics arising over successive generations. It is this process of evolution that has given rise to biodiversity at every level of biological organisation, including the levels of species, individual organisms, and molecules. The theory of evolution by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multicellular
A multicellular organism is an organism that consists of more than one cell, in contrast to unicellular organism. All species of animals, land plants and most fungi are multicellular, as are many algae, whereas a few organisms are partially uni- and partially multicellular, like slime molds and social amoebae such as the genus ''Dictyostelium''. Multicellular organisms arise in various ways, for example by cell division or by aggregation of many single cells. Colonial organisms are the result of many identical individuals joining together to form a colony. However, it can often be hard to separate colonial protists from true multicellular organisms, because the two concepts are not distinct; colonial protists have been dubbed "pluricellular" rather than "multicellular". There are also multinucleate though technically unicellular organisms that are macroscopic, such as the xenophyophorea that can reach 20 cm. Evolutionary history Occurrence Multicellularity has evolved ind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eukaryote
Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacteria and Archaea (both prokaryotes) make up the other two domains. The eukaryotes are usually now regarded as having emerged in the Archaea or as a sister of the Asgard archaea. This implies that there are only two domains of life, Bacteria and Archaea, with eukaryotes incorporated among archaea. Eukaryotes represent a small minority of the number of organisms, but, due to their generally much larger size, their collective global biomass is estimated to be about equal to that of prokaryotes. Eukaryotes emerged approximately 2.3–1.8 billion years ago, during the Proterozoic eon, likely as flagellated phagotrophs. Their name comes from the Greek εὖ (''eu'', "well" or "good") and κάρυον (''karyon'', "nut" or "kernel"). Euka ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
