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Triarchic theory of intelligence

The Triarchic Theory of Intelligence or Three Forms of Intelligence, formulated by psychologist Robert Sternberg, aims to go against the psychometric approach to intelligence and take a more cognitive approach, which leaves it to the category of the cognitive-contextual theories. The three meta components are also called triarchic components.

Sternberg's definition of human intelligence is "(a) mental activity directed toward purposive adaptation to, selection and shaping of, real-world environments relevant to one's life". Thus, Sternberg viewed intelligence as how well an individual deals with environmental changes throughout their lifespan. Sternberg's theory comprises three parts: componential, experiential and practical.

Sternberg's theory has since been expanded and advanced in the book Experiential Intelligence by Soren Kaplan.

Different components of information processing
Sternberg associated the workings of the mind with a series of components. These components he labeled the metacomponents, performance components, and knowledge-acquisition components.

The metacomponents are executive processes used in problem solving and decision making that involve the majority of managing our mind. They tell the mind how to act. Metacomponents are also sometimes referred to as a homunculus. A homunculus is a fictitious or metaphorical "person" inside our head that controls our actions, and which is often seen to invite an infinite regress of homunculi controlling each other.

Sternberg's next set of components, performance components, are the processes that actually carry out the actions the metacomponents dictate. These are the basic processes that allow us to do tasks, such as perceiving problems in our long-term memory, perceiving relations between objects, and applying relations to another set of terms.

The last set of components, knowledge-acquisition components, are used in obtaining new information. These components complete tasks that involve selectively choosing relevant information from a mix of information, some of it relevant and some of it irrelevant. These components can also be used to selectively combine the various pieces of information they have gathered. Gifted individuals are proficient in using these components because they are able to learn new information at a greater rate.

Whereas Sternberg explains that the basic information processing components underlying the three parts of his triarchic theory are the same, different contexts and different tasks require different kinds of intelligence.

Componential – analytical subtheory
This form of intelligence focuses on academic proficiency.

Sternberg associated the componential subtheory with analytical giftedness. This is one of three types of giftedness that Sternberg recognizes. Analytical giftedness is influential in being able to take apart problems and being able to see solutions not often seen. Unfortunately, individuals with only this type are not as adept at creating unique ideas of their own. This form of giftedness is the type that is tested most often.

Experiential – creative subtheory
This form of intelligence focuses on "capacity to be intellectually flexible and innovative.

The experiential subtheory is the second stage of the triarchic theory. This stage deals mainly with how well a task is performed with regard to how familiar it is. Sternberg splits the role of experience into two parts: novelty and automation.

A novel situation is one that has not been experienced before. People that are adept at managing a novel situation can take the task and find new ways of solving it that the majority of people would not notice.

A process that has been automated has been performed multiple times and can now be done with little or no extra thought. Once a process is automatized, it can be run in parallel with the same or other processes. The problem with novelty and automation is that being skilled in one component does not ensure that you are skilled in the other.

The experiential subtheory also correlates with another one of Sternberg's proposed types of giftedness. Synthetic giftedness is seen in creativity, intuition, and a study of the arts. People with synthetic giftedness are not often seen with the highest IQs because there are not currently any tests that can sufficiently measure these attributes, but synthetic giftedness is especially useful in creating new ideas to create and solve new problems. Sternberg also associated another one of his students, "Barbara", to the synthetic giftedness. Barbara did not perform as well as Alice on the tests taken to get into school, but was recommended to Yale University based on her exceptional creative and intuitive skills. Barbara was later very valuable in creating new ideas for research.

Practical - contextual subtheory
Sternberg's third subtheory of intelligence, called practical or contextual, "deals with the mental activity involved in attaining fit to context". Through the three processes of adaptation, shaping, and selection, individuals create an ideal fit between themselves and their environment. This type of intelligence is often referred to as "street smarts."

Adaptation occurs when one makes a change within oneself in order to better adjust to one's surroundings. For example, when the weather changes and temperatures drop, people adapt by wearing extra layers of clothing to remain warm.

Shaping occurs when one changes their environment to better suit one's needs. A teacher may invoke the new rule of raising hands to speak to ensure that the lesson is taught with least possible disruption.

The process of selection is undertaken when a completely new alternate environment is found to replace the previous, unsatisfying environment to meet the individual's goals. For instance, immigrants leave their lives in their homeland countries where they endure economical and social hardships and go to other countries in search of a better and less strained life.

The effectiveness with which an individual fits to his or her environment and contends with daily situations reflects degree of intelligence. Sternberg's third type of giftedness, called practical giftedness, involves the ability to apply synthetic and analytic skills to everyday situations. Practically gifted people are superb in their ability to succeed in any setting. An example of this type of giftedness is "Celia". Celia did not have outstanding analytical or synthetic abilities, but she "was highly successful in figuring out what she needed to do in order to succeed in an academic environment. She knew what kind of research was valued, how to get articles into journals, how to impress people at job interviews, and the like". Celia's contextual intelligence allowed her to use these skills to her best advantage. Sternberg also acknowledges that an individual is not restricted to having excellence in only one of these three intelligences. Many people may possess an integration of all three and have high levels of all three intelligences.

Practical intelligence is also a topic covered by Malcolm Gladwell in his book Outliers: The Story of Success.

Criticism
Psychologist Linda Gottfredson criticises the unempirical nature of triarchic theory. Further, she argues it is absurd to assert that traditional intelligence tests are not measuring practical intelligence, given that they show a moderate correlation with income, especially at middle age when individuals have had a chance to reach their maximum career potential, and an even higher correlation with occupational prestige, and that IQ tests predict the ability to stay out of jail and stay alive (all of which qualifies as practical intelligence or "street smarts"). Gottfredson claims that what Sternberg calls practical intelligence is not a broad aspect of cognition at all but simply a specific set of skills people learn to cope with a specific environment (task specific knowledge).

There is evidence to suggest that certain aspects of creativity (i.e. divergent thinking) are separable from analytical intelligence, and are better accounted for by the cognitive process of executive functioning. More specifically, task-switching and interference management are suggested to play an important role in divergent thinking. A more recent meta-analysis found only small correlations between IQ and creativity.

title: Triarchic theory of intelligence


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PEAR

The PHP Extension and Application Repository, or PEAR, is a repository of PHP software code. Stig S. Bakken founded the PEAR project in 1999 to promote the re-use of code that performs common functions. The project seeks to provide a structured library of code, maintain a system for distributing code and for managing code packages, and promote a standard coding style. Though community-driven, the PEAR project has a PEAR Group which serves as the governing body and takes care of administrative tasks. Each PEAR code package comprises an independent project under the PEAR umbrella. It has its own development team, versioning-control and documentation.

PEAR packages
A PEAR package is distributed as a gzipped tar file. Each archive consists of source code written in PHP,. Many PEAR packages can readily be used by developers as ordinary third party code via simple include statements in PHP. More elegantly, the PEAR package manager which comes with PHP by default may be used to install PEAR packages so that the extra functionality provided by the package appears as an integrated part of the PHP installation. Unlike the Comprehensive Perl Archive Network (CPAN) archives,, PEAR packages do not have implicit dependencies so that a package's placement in the PEAR package tree does not relate to code dependencies. Rather, PEAR packages must explicitly declare all dependencies on other PEAR packages.

The PEAR base classes contain code for simulating object-oriented destructors and consistent error-handling. Packages exist for many basic PHP functions including authentication, caching, database access, encryption, configuration, HTML, web services and XML.

PEAR means “PHP Extension and Application Repository.” It is a framework and distribution system for reusable PHP components. It extends PHP and gives a higher level of programming for all web developers. PEAR is divided into three different classes that are: PEAR Core Components, PEAR Packages, and PECL Packages. The PEAR Packages include functionality giving for authentication, networking, and file system features and tools for working with HTML and XML templates.

PEAR package manager
The PEAR package manager provides a standardized way to install, uninstall, or upgrade with new PEAR packages or PECL extensions. Before installing a package it can also be instructed to take care of package dependencies so all the extra needed packages are installed too.

The PEAR package manager is run from the command line using the  command. Usually it is therefore only the server administrator who can alter the installed base of PEAR and PECL extensions. On PHP installations running on Linux, the PEAR package manager is ready for usage by default, but on Windows the PEAR package manager is only available after running a batch file called.

PEAR2 Pyrus
With Pyrus an attempt was undertaken to redesign and improve PEAR from the ground up for PHP 5.3 or newer. Pyrus can be used to install packages from PEAR channels. The last release is from March 2011 and its development might have been discontinued due to the popularity of Composer.

PEAR and Composer
With Composer there is an alternative available for managing packages for a PHP project. Composer also supports the installation of PEAR packages. Some people  of the PHP community argue for replacing PEAR in favor of composer.

PECL
The PHP Extension Community Library (PECL), (pronounced 'pickle' ) is conceptually very similar to PEAR, and indeed PECL modules are installed with the PEAR Package Manager. PECL contains C extensions for compiling into PHP. As C programs, PECL extensions run more efficiently than PEAR packages. PECL includes modules for XML-parsing, access to additional databases, mail-parsing, embedding Perl or Python in PHP scripts and for compiling PHP scripts. PECL spun off from the PEAR Project in October 2003. Originally it was called the PEAR Extension Code Library, but it now operates independently of PEAR.

PECL extensions are documented alongside standard extensions within the PHP Manual, so there is no special manual for PECL extensions. Also, several extensions began their development cycle in PECL and ended up in core (the distributed PHP source) and in many of these cases the PECL versions become unmaintained.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: PEAR


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Peter M. Bowers

Peter M. Bowers (May 15, 1918 – April 27, 2003) was an aeronautical engineer, airplane designer, and a journalist and historian specializing in the field of aviation.

An engineer for planemaker Boeing for over 35 years, Bowers is famed in the aviation community for his role as a military and general aviation historian and writer, and designer of the popular Bowers Fly Baby homebuilt aircraft design.

Personal and early life
Bowers lived in Seattle, Washington, for most of his life.

Bowers's first ride in an aircraft was in 1928, at the age of 10. He began intensively designing and building aircraft models, which led to requests for plans and articles about them from editors of model airplane magazines—his first article appearing in 1938 in Air Trails.

Bowers took a course in aeronautical engineering at the Boeing School of Aeronautics in Seattle, then enrolled as an Engineering Cadet in the Army Air Corps. During World War II, and after, Bowers spent five years in the U.S. Army Air Forces as a maintenance and intelligence officer, before his discharge in 1947.

Aeronautical career
Following his 1947 discharge from the military, Bowers went to work for The Boeing Company in Seattle, eventually becoming an aeronautical and research engineer for the company, and remained with the company for 36 years.

Bowers learned to fly in 1948, and by 1962 had reportedly logged over 3,000 hours of flight time, mostly in sailplanes, homebuilt aircraft, antique aircraft, and "other romantic types"—becoming "an internationally-known consultant on aviation history and sport flying."

Bowers's designing and building of model aircraft evolved into developing actual, full-size aircraft.

In 1961, to commemorate the 50th anniversary of the first trans-continental flight, Bowers crafted a reproduction of the Wright Brothers' Vin Fiz Flyer (first plane to fly across the U.S.). The plane was built to airworthy standards, and flown as a towed glider, before becoming a display in the San Diego Air and Space Museum.

Starting in the 1950s, and culminating in 1962, Bowers designed a noted homebuilt aircraft, the Bowers Fly Baby (winner of the 1962 Design Contest of the Experimental Aircraft Association—one of the most successful homebuilt designs, eventually built by over 500 homebuilders)

Bowers also designed and built the Namu II, and also completed and flew a Detroit G1 Gull primary glider.

Under its Fly Baby entry, Jane's All The World's Aircraft, 1964–1965, says of Bowers:

Mr. Peter Bowers, an aeronautical engineer with Boeing in Seattle, is a principal source of detailed information on vintage aircraft in the United States, and has provided much of the data for a number of replicas of 1914-18 War aircraft now under construction or flying. He is currently engaged on a redesign of the Fokker D.VIII monoplane of 1918 in association with Herr Rheinhold Platz, the original designer, with a view to starting a replica building program.

A full-scale Fokker Triplane replica of this period has been under construction by Mr. Bowers for nearly five years. At least six others are known to be under construction from plans that he has provided.

Another aircraft built by Mr. Bowers is a full-scale replica of the Wright Model EX of 1911, the first aeroplane to cross the American continent. This machine was tested as a towed sailplane in the Autumn of 1961 and is to be powered by a converted "B" Ford automobile engine from a 1938 Funk monoplane.

In addition to this work on replicas, Mr. Bowers has designed and built a single-seat light aircraft known as the Fly Baby...

Bowers was the founding president of the EAA's Chapter 26, in the Seattle area.

Aviation media career
One of the principal U.S. aviation historians of the 20th century, Bowers wrote or co-authored over 40 aviation books, and several hundred magazine and journal articles. His first articles, about his model airplane designs, appeared in Air Trails magazine in 1938. By the time his plans for his full-sized airplane, the Fly Baby, began appearing in the EAA magazine Sport Aviation, in 1963, he had already published his first books about aircraft.

Bowers was an avid aviation photographer—particularly noted for photography of historic aircraft—accumulating over 25,000 negatives in his collection by 1962. The photos further supported his publications. The collection became known as one of the largest such collections in the nation, and is now in the archives of the Museum of Flight in Seattle. Bowers wrote a text on the subject, A Complete Guide to Aviation Photography (TAB Books, 1980), which was reprinted in several subsequent editions.

In the 1960s, Bowers was among a small handful of writers chronicling U.S. military aviation. He served as a contributing editor for Sentry Publications' twin magazine titles Wings and Airpower, drawing on the lifetime of aviation photographs of his own, and of a vast archive collected through his employment at Boeing.

Bowers was a member of the first board of directors of the American Aviation Historical Society (AAHS), and a principal contributor to the AAHS Journal from its first issue in 1956 until the late 1960s.

Starting in 1972, Bowers wrote over 800 articles detailing historic aircraft for a column in General Aviation News called "Of Wings and Things." Bowers was a fixture of the newspaper for decades, until his death in 2003.

Awards and recognition

 * 1962: Winner of the Experimental Aircraft Association's 1962 Design Contest (reportedly the only one ever held ), for his Bowers Fly Baby
 * 1968: Dr. August Raspet Memorial Award, Experimental Aircraft Association, for Outstanding Contribution to the Advancement of Light Aircraft
 * 1968: service to the EAA award.
 * 2002: Books with Swanborough recommended, by Air and Space Magazine, as two top sources on early American military aircraft.
 * 2017: Stearman book identified as one of three "quasi-classic" histories of the man and the planes by HistoryNet.com

Death
Bowers died in 2003 from cancer.

Publications
During his career, Bowers authored or co-authored over 40 books on aviation subjects, and over 800 magazine and journal articles. This is a partial list.

Magazines & Journals

 * Air Trails
 * AOPA Pilot
 * Sport Aviation, Experimental Aircraft Association (EAA)
 * AAHS Journal, American Aviation Historical Society
 * Air Classics
 * Airpower (Sentry Publications)
 * Wings (Sentry Publications)
 * Western Flyer (1972, began his aviation history column "Of Wings and Things")
 * General Aviation News ("Of Wings and Things" column, continued. His columns are partially compiled in the book Of Wings & Things, Vol. 1: 1972-1979, 2000)

Books
Bowers authored or co-authored over 40 aviation books, including a dozen about aircraft of Boeing (or about aircraft of companies that Boeing acquired).

Aviation generally

 * Soaring guide, with Robert L. Parks, 1966
 * Soaring in America, 2nd Ed., Soaring Society of America, Inc. 1967
 * Modern Aviation Library Vol. 2 No. 202, with Don Downie, Robert T. Smith, Harold Krier, 1979
 * A Complete Guide to Aviation Photography, 1st ed., March 1980, (6th ed., 1988), TAB Books, Blue Ridge, Pennsylvania, ISBN 0-8306-0924-5

Aircraft generally

 * Antique Plane Guide, Modern Aircraft Series, Sports Car Press, NY, 1962; 1981
 * Yesterday's Wings, 1974
 * Pedigree of Champions: Boeing since 1916 (6th ed.), May 1985, The Boeing Company, Seattle, Washington, LOC: 85–71915.
 * The DC-3: 50 Years of Legendary Flight, May 1, 1986
 * Curtiss Aircraft, 1907-1947, 1987
 * Unconventional Aircraft, April 1, 1990
 * Scale Aircraft Drawings: World War 2, Vol. 2, 1991
 * Lockheed Constellation: Design, Development, and Service History of all Civil and Military Constellations, Super Constellations, and Starliners, with Curtis K. Stringfellow, December 1, 1991
 * Triplanes: A Pictorial History of the World's Triplanes and Multiplanes, with Ernest R. McDowell, 1993
 * Wings of Stearman: The Story of Lloyd Stearman and the Classic Stearman Biplanes, Historic Aircraft Series, December 1, 1998, ASIN : B08GKTCCSH
 * Of Wings & Things, Vol. 1: 1972–1979, 2000
 * America's Outstanding Aircraft of World War II: Plus Odd Aircraft, October 15, 2011
 * Scale Aircraft Drawings, September 10, 2021
 * Stearman Guidebook: Book 1: American Aircraft Series, with Mitch Mayborn

Civilian aircraft

 * Guide to Homebuilts, Modern Aircraft Series, Sports Car Press, NY, 1962; 1984
 * Fly Baby Builders Manual, 1964
 * Flying the Boeing Model Eighty, 1984

Military aircraft

 * The Sixty Best Airplanes of World War One (60), 1960
 * World War Two: Outstanding U.S. Aircraft Plus Odd Aircraft, 1961
 * Aircraft Profile series, Profile Publications Ltd. (U.K.):
 * Aircraft Profile No. 14: The Boeing P-26A, 1965
 * Aircraft Profile No. 37: The Curtiss JN-4, 1965
 * Aircraft Profile No. 45: The Curtiss Army Hawks, 1965
 * Aircraft Profile No. 2: The Boeing P-12E, 1966
 * Aircraft Profile No. 79: The Nieuport N.28C-I, 1966
 * Aircraft Profile No. 80: The Curtiss Hawk 75, 1966
 * Aircraft Profile No. 83: The Boeing B-47, 1966
 * Aircraft Profile No. 97: The American DH4, 1966
 * Aircraft Profile No. 116: The Curtiss Navy Hawks, 1966
 * Aircraft Profile No. 245: Boeing B-52A/H Stratofortress, ASIN: B0007BNZS6, 1972

 * Fortress in the Sky: The Story of Boeing's B-17, 1976
 * United States Navy Aircraft Since 1911, with Gordon Swanborough, Naval Institute Press, Annapolis, MD, 1976 (Second Edition, 1982)
 * 50th Anniversary: Boeing B-17 Flying Fortress, 1935-1985, 1985
 * United States Military Aircraft Since 1909, with Gordon Swanborough, Smithsonian Institution Press,  August 1, 1989
 * United States Navy Aircraft Since 1911, with Gordon Swanborough, Naval Institute Press, 1990
 * Scale Aircraft Drawings: Volume I - World War I and Volume II - World War II, 1991
 * Boeing B-29 Superfortress - Warbirdtech Vol 14, April 14, 1999
 * Buzz Numbers, with W. David Menard, July 11, 2006
 * The Fokkers of World War I: Hobby Helpers Library, No. 150, with Air Progress magazine, October 13, 2012

title: Peter M. Bowers


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PECL

The abbreviation PECL can refer to:

 * PHP Extension Community Library, a repository of extensions for the PHP programming language
 * Positive emitter-coupled logic, a family of digital integrated circuits
 * Principles of European Contract Law, a scholarly restatement of the contract law of European legal systems

title: PECL


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IBM 1410

The IBM 1410, a member of the IBM 1400 series, was a decimal computer with a variable word length that was announced by IBM on September 12, 1960 and marketed as a midrange business computer. It was withdrawn on March 30, 1970.

Overview
The 1410 was similar in design to the very popular IBM 1401, but it had one major difference. Addresses were five characters long and allowed a maximum memory of 80,000 characters, much larger than the 16,000 characters permitted by the 1401's three-character addresses. However, the 1410 could also be run in what was termed "1401 compatibility mode". This was accomplished in hardware - the machine literally turned into a 1401 with the flip of a switch. In addition, with care, it was possible to write source code in the Autocoder assembler language that could be used on either system, as nearly all 1401 instructions had exact 1410 equivalents, and had the same mnemonics.

The later IBM 7010 used the same architecture as the 1410, but was implemented with 7000 series technology (see IBM 700/7000 series), and supported up to 100,000 characters of storage.

title: IBM 1410


text:
Albedo (disambiguation)

Albedo is a measure of reflectivity.

Albedo may also refer to:

Arts, entertainment, and media

 * Albedo (Ben 10), a character in the Ben 10 franchise.
 * Albedo, a character from the video game Genshin Impact.
 * Albedo, a character from the light novel and anime series Overlord
 * Albedo, a character in the video game series Xenosaga
 * Albedo 0.39, a 1976 album by the artist Vangelis
 * Albedo Anthropomorphics, a comic book anthology
 * Albedo (role-playing game), derived from the comics
 * Albedo One, an Irish horror, fantasy, and science fiction magazine founded in 1993

Other uses

 * Albedo (alchemy), a stage of alchemical progression
 * Albedo, the mesocarp of a fruit

title: Albedo (disambiguation)


text:
Titular bishop

A titular bishop in various churches is a bishop who is not in charge of a diocese. By definition, a bishop is an "overseer" of a community of the faithful, so when a priest is ordained a bishop, the tradition of the Catholic, Eastern Orthodox and Oriental Orthodox churches is that he be ordained for a specific place. There are more bishops than there are functioning dioceses. Therefore, a priest appointed not to head a diocese as its diocesan bishop but to be an auxiliary bishop, a papal diplomat, or an official of the Roman Curia is appointed to a titular see.

Catholic Church
In the Catholic Church, a titular bishop is a bishop who is not in charge of a diocese. Examples of bishops belonging to this category are coadjutor bishops, auxiliary bishops, bishops emeriti, vicars apostolic, nuncios, superiors of departments in the Roman Curia, and cardinal bishops of suburbicarian dioceses (since they are not in charge of the suburbicarian dioceses). Most titular bishops hold the title to a titular see. Assigning titular sees serves two purposes. Since part of being a bishop means being the head of a Christian church, titular sees serve that purpose for bishops without a diocese. At the same time, the office of titular bishop memorializes ancient Churches, most of which were suppressed because they fell into the hands of non-Christian conquerors. For this reason the former terminology was not "titular bishop" but "bishop in infidel regions" (in partibus infidelium). In recent times the names of titular sees are drawn also in numerous cases from those of former dioceses which were absorbed into other dioceses or expanded and hence moved to larger towns and cities.

Since 1970, there are two more exceptions. Diocesan bishops who resign their see or are transferred to a non-diocesan appointment are no longer habitually transferred to a titular see. Instead, they take the title Bishop (or Archbishop) Emeritus of the last see. Also, coadjutors are no longer named to titular sees, instead taking the title Coadjutor Bishop (or Coadjutor Archbishop) of the see they will inherit. In other cases titular bishops still take a titular see.

Beginning in 2019, titular sees are no longer being assigned to new Vicars Apostolic.

When Francis Green was named Coadjutor Bishop of Tucson, Arizona, in 1960, his official title remained "Titular Bishop of Serra" until he succeeded Daniel James Gercke later that same year. However, when Gerald Kicanas became Coadjutor Bishop of Tucson in 2001, he ceased being Titular Bishop of Bela. He remained a titular bishop until he succeeded Manuel Moreno in 2003, but his official title changed from "Titular Bishop of Bela" to "Coadjutor Bishop of Tucson."

Cardinal Bishops of suburbicarian dioceses are also titular bishops, but unlike others, they hold titles to existing dioceses, namely one or more of the suburbicarian sees near Rome. While they do not govern their see, they are obliged to give it their patronage. Angelo Sodano, as Cardinal Bishop of Albano, was titular bishop of the see, while Bishop Marcello Semeraro is its actual diocesan bishop. The Cardinal Dean is by tradition Cardinal Bishop of Ostia, in addition to the suburbicarian see he previously held.

Occasionally, the transfer of a diocesan bishop to a titular see has been used by the Holy See to strip of responsibilities a bishop whose behavior was disapproved. For instance, in 1995, Jacques Gaillot, known for his activism on Catholic-sensitive social and political topics (such as support for contraception and abortion), was transferred from the see of Évreux in France to Partenia, a titular see in Algeria, instead of becoming Bishop Emeritus of Évreux.

Eastern Orthodox Church
Titular bishops and titular metropolitans are often appointed in the Eastern Orthodox Church. In Ecumenical Patriarchate of Constantinople, titular bishops and metropolitans are usually appointed with titles of former dioceses in the regions of Thrace, Asia Minor and Pontus (now Turkey), that were often active until the Greek-Turkish population exchange of 1923. In Serbian Orthodox Church, titular bishops are usually appointed to serve as auxiliary bishops, assisting diocesan bishops in various fields of diocesan administration.

title: Titular bishop


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James Fisher (Manitoba politician)

James Fisher (November 6, 1840 – March 8, 1927) was a politician in Manitoba, Canada. He may have served as leader of the parliamentary opposition in the Legislative Assembly of Manitoba for a brief period in the mid-1890s.

Born at Glenquaich in Perthshire, Scotland, Fisher moved to Canada West (now Ontario) in his youth. He was educated at the University of Toronto, and was a member of that body's Senate.

In July 1875, Fisher contested a federal by-election in Perth North for the Liberals, losing to Conservative Andrew Monteith by 20 votes. He was defeated in the same riding in the general election of 1878.

Fisher subsequently moved to Winnipeg, where he practised law and was a member of the University of Manitoba Council. In 1886, he ran for the provincial riding of Russell as a Liberal, losing to Conservative Edward Leacock by eight votes. He was easily elected in his second attempt for the seat, in the Liberal landslide victory of 1888.

Fisher soon lost confidence in the government of Thomas Greenway, and crossed the floor to the opposition. He was re-elected without opposition in 1892, and appears to have served as the de facto leader of the opposition from 1894 to 1896. He did not identify himself as a Conservative, but sat among their ranks in parliament.

Fisher was re-elected in 1896, but did not contest the election of 1899. In 1897, while still serving as a Member of the Legislative Assembly (MLA), he served in a Hudson's Bay Expedition unit.

title: James Fisher (Manitoba politician)


text:
Talk:Relativistic rocket

Relativistic Rocket Problem
I will present a credible theoretical design for a relatavistic, or semi-relatavistic rocket here. For now I will use algebra & geometry based newtonian physics to describe such a rocket. A calculas based version of this description may also be presented here in a future improved version of this article.* Improvements to the article may be made by other editors here if the nature  of their work is good, and correct. Let all editors feel free to correct what ever spelling errors, spacing errors, or puntuation errors may be found in this article. Tmayes1965

Please excuse my clumsy editing. This is my first contribution here, and I don't know much about the markup and conventions. I was trying to find the tag for attaching a signature with time and date, but I'll just type them in.

 * 1) Please kill "relatavistic", "relavistic". relativistic please.
 * 2) 2nd paragraph contains two conflicting definitions of "relativistic rocket"

I have now fixed this contradiction.*tim
 * 3) Punctuation is messed up. Please put a space after commas and periods, not before.
 * 4) "wickipedia"?! "cruising velocity"?!!

Article begun by OneRock on 7/23/04.

Somewhere, I have a numerical Fortran solution (or did I write that in Basic) of the general-relativistic rocket problem on a 5 1/4 floppy, which I can no longer access. It ran quite well on my old TRS-80 with no hard drive. I don't think I have the will to solve it again, but I am curious whether anyone else has such a program.

In case you want to duplicate my work, here's what it involves:

First, you must postulate the existence of a propulsion mechanism with specific parameters. My imaginary rocket was propelled by a laser which converts matter and antimatter to a light beam with 100% efficiency. (Onerock 19:40, 28 Jul 2004 (UTC)) I propose this engine as an absolute upper limit on what can plausibly be done without violating widely accepted physical principles.) The program user was asked to specify the mass and thrust of the engine. P.S.: Exploring this site, I see that Eugen Sänger proposed a nuclear photonic rocket long before the discover of the laser.

Second, you must determine the rate at which fuel must be consumed to deliver the required thrust. In the case of the laser drive, thrust is equal to the power of the laser divided by the speed of light. Begin with thrust (force), solve for power, and covert to mass--using E= Mc^2.

Third, you must attach your laser drive engine to a vehicle, and set up the problem of incrimentally calculating velocity after a short time interval. If you do this in a general relativity format, the solution will be valid all the way to relativistic speeds. (See correction below.)

I originally attempted to obtain a classical formula for the result, but I was thwarted by an integral of a form I never encountered in three years of Integral Calculus. Does anyone know how to solve an integral of the following form?

Integral from A to [the integral from A to B of F(x) dx] of G(x) dx.

Sorry I can't be more specific about that integral without tackling the rocket problem anew.

Interestingly, it turns out that such a rocket could take you across the galaxy and back in a few years (on the traveler's clock)---if not for some rather daunting obstacles. First, you would need to start your journey with a matter-anitmatter fuel supply with about as much mass as Earth's Moon. All that mass would come in very handy as a shield against the inevitable collision with a grain of sand which would explode like an atomic bomb. The travelers would have to be frozen in a solid block of ice to withstand the high G-forces. And of course, the Earth might not be here when you return a few years older but hundreds of thousands of Earth-years later.

(Onerock 19:40, 24 Jul 2004 (UTC)) Yesterday, I wrote, impromptu, during my 1-hour daily internet slot (Tuesday thru Saturday at the public library). Today’s message has been written at a more leisurely pace at home.

I hypothesized the 100% efficient matter-antimatter laser-drive engine, not because it is feasible, but because I believe it places an absolute upper limit on what can plausibly be achieved without violating any widely accepted principles of physics. This is not Star Trek; it is real physics. If you want feasible results, you need only reduce the efficiency of the engine and its power to mass ratio. I’m afraid today’s lasers are many orders of magnitude too wimpy to get you to the corner drug store, let alone the far side of the galaxy.

Correction: It is not necessary to apply, or even know, the general relativity formulas. As the time interval, Delta-T, approaches zero, general relativity reduces to special relativity. Consequently, my numerical approach does not rely on such esoteric concepts as curved four-dimensional space.

Apply special-relativity formulas to calculate changes in position, velocity, mass and time for a short time interval, Delta-T. Plug the new values back into the algorithm, and the result after many short intervals should be exactly equal to that predicted by general relativity formulas for the total interval—provided that you chose a small enough Delta-T.

Start with a fairly large Delta-T (perhaps one hour); repeat with smaller values of Delta-T until successive calculations yield the same result within tolerable limits.

Relativistic effects are detectible at much lower velocities if you use double precision math; I’m not sure how much difference that makes. Lower precision with smaller Delta-T’s will probably yield the same result; I’m not sure which method takes more computing time. I used double precision, which yielded an accurate result in a few minutes of TRS-80 computer time for a trip across the galaxy. Today’s PC is a thousand times faster.

Calculations must be kept within a single reference frame. Mix your coordinate systems and the results will be invalid.

From the traveler’s point of view: My hypothetical engine’s thrust is constant; remaining fuel mass decreases at a constant rate; and acceleration increases in inverse proportion to the ship’s total mass with fuel. There is no relativistic mass to consider because the ship and fuel are stationary in the traveler’s coordinates. Due to this simplicity, it is probably easier to calculate the Earth’s position in the traveler’s coordinates, rather than the other way around.

From an Earthling’s point of view: I’m not sure if thrust is increasing or decreasing. Since the relativistic mass of the engine is increasing, we might expect it to produce more light, but the thrust would be diminished in proportion to the red shift of the retreating light source. Conservation of mass-energy requires that the total of kinetic energy plus relativistic mass of the ship (including fuel) decreases by an amount equal to the total energy imparted to the laser beam since the beginning of the trip. I’m pretty sure I didn’t write my old program from this point of view; it’s too confusing.

I recommend that you calculate Earth’s parameters in traveler’s coordinates, but output spaceship parameters in Earth coordinates. With each millisecond on the traveler’s clock, you calculate the time on Earth; then for each hour on Earth, you find the corresponding time on the traveler’s clock and apply special relativity formulas to convert the other parameters. (At least I think that’s sort of the way it’s done. It’s been a very long time since I did it.)

Further comments:

How much acceleration does it take, and for how long, to reach relativistic speeds? Suppose you accelerate at one G in one direction for 355 Earth days. The Newtonian formulas put your speed at just over the speed of light. I’m too lazy to look up the formulas and do the math, but I’d guess general relativity puts your speed at roughly half of light speed.

In case you’re wondering, this laser-drive engine is no kid’s toy. A laser gun having a recoil force of 1000 Newton (i.e. 225 lb.) would consume fuel at a rate of 1000 Newton ¸ c = 1/3 microgram per second. The power of the beam would be 1000 Newton times c = 300 trillion Watt—approximately 100 times the most powerful nuclear power plant on Earth. (Hope I did that correctly in my head.) I wonder if the astronomical phenomenon of gamma-ray bursts might be our passage thru the exhaust of such a space ship in a distant galaxy.

In traveler’s coordinates, the distance across our galaxy decreases as the relative velocity increases. That is why, from the traveler’s point of view, it may take only a few years to cross a distance of 100,000 light-years without traveling faster than light. When the ship is stationary at each end of the journey, the width of the galaxy is 100,000 light-years; mid-way through the trip, the galaxy is only a few light-years across. When Einstein said you can’t travel faster than light, he meant relative to any object in your immediate vicinity. While you are accelerating, even at very modest rates, distant galaxies (both fore and aft) grow nearer or farther at many times the speed of light—without moving! Ain’t language funny!

(Onerock 19:40, 28 Jul 2004 (UTC))I moved my comments re. Twins Paradox to the appropriate forum.

199.250.57.32Onerock 7/29//04

It may be argued that fuel can be collected along the way. Unfortunately, any potential fuel that may be encountered along the way will be coming at you very close to light speed. Collecting fuel will be the furthest thing from your mind, since its momentum would slow you down—besides which, any collision with it would vaporize you. A more feasible way to conserve fuel is to chuck your excess engines into the matter-antimatter reactor when acceleration reaches the max allowable. In that case, most of the mass of the engines may be considered as fuel mass.

I may have found that old 5 1/4" floppy; the label just says “Batch Files”. I’ll see if I can find someone with an operational B-drive to read it. Some of the program is coming back to me, now.

The program should be initiated by user input specifying the following: Mass of the ship, Mass of cargo and crew, Mass of fuel, Mass of one engine, Thrust of one engine, Number of engines, Distance to destination. You may assume 100% efficiency or input a lower figure; calculate fuel consumption accordingly. You may also want to specify a maximum allowable deceleration so you won’t apply the brakes hard enough to crush the frozen bodies of the crew. You may set the initial velocity at zero (relative to the Sun) or get fancy and factor in the Earth’s solar-orbital velocity and the Sun’s galactic-orbital velocity, as well as an escape-velocity correction for the gravity of Earth and Sun. Similar corrections can be made for the gravity at your destination, if you already know what’s there—fat chance.

Use Newtonian formulas to calculate position, mass, time and velocity of the ship (s, m, t, v) after one δT in ship coordinates, which are initially the same as Earth (no-prime) coordinates. a = thrust / (rest mass); v = a·δT;  s = v·δT / 2;  t = t + δT. That gives you position, time and velocity of the 1-prime coordinate system. Note that you are not using relativistic mass to calculate acceleration because you will always calculate acceleration in the ship’s coordinates, not Earth coordinates.

Next use Newtonian formulas to calculate the position, mass, time and velocity of the ship (s', m', t', v') after a second δT in 1-prime coordinates; a' = thrust / (rest mass); v' = a·δT;  s' = v·δT / 2;  t' = t + δT. That gives you the position, time and velocity of the 2-prime (next) coordinate system in 1-prime (present) coordinates.

Using special-relativity, calculate the position, time and velocity of the two-prime (next) coordinate system in Earth (zero-prime) coordinates. I think the velocity formula is v (i.e., velocity of next coordinate system relative to Earth) = (v + v') / (1+ v×v' / c2). I haven’t yet found the position and time formulas. Anybody here know them? I think the answer might be found under the heading of Lorenz transformation http://en.wikipedia.org/wiki/Lorentz_transformation or Poincare transformations http://en.wikipedia.org/wiki/Poincar%E9_group.

You will loop back to calculate a new s', m', t', and v', and repeat the same steps n times to get the position, mass, time and velocity of the ship in Earth coordinates after n δT’s. Before looping back, however, you must determine whether it is time to begin coasting.

You will need to begin coasting and turn the ship around when the remaining fuel is just sufficient to stop the ship at its destination. To calculate the deceleration trajectory, you must run time backwards from touchdown at the destination. In forward time, the arrival fuel mass will decrease, and acceleration will increase until it reaches the max allowable value. From then on, you will convert one engine at a time to fuel, and adjust your thrust, acceleration and fuel consumption accordingly. You will run out of fuel upon arrival.

However, you will be doing these calculations in reverse time; so arrival fuel mass begins at zero and increases, acceleration decreases until one additional engine can be created from fuel mass without exceeding max acceleration. In reverse time, you have negative fuel consumption as you accelerate toward Earth. You begin with the minimum number of engines needed to produce maximum acceleration; you convert fuel mass to engines each time your acceleration decreases below maximum.

Coasting must begin at the point where both velocity and fuel mass accumulated in reverse time relative to the destination are equal to velocity and fuel remaining in forward time relative to Earth. The program should alternate between the departure trajectory from Earth and arrival trajectory at the destination—in leap-frog fashion. Each time the velocity in one direction increases beyond the other, you compare fuel masses; if the arrival fuel mass is greater, then it is past time to begin coasting.

That concludes one iteration of the program. You should loop back to the beginning and repeat the calculation using a smaller δT—perhaps half as large. When two consecutive iterations yield the same result, withing tolerance limits, you output the resulting trajectory. The output should, at least, describe the duration of the journey in both Earth coordinates and in ship coordinates. It might also tell the time, location and mass at the beginning and end of coasting in both Earth and ship coordinates and the number of engines remaining at touchdown.

The program I am describing is one dimensional. A sensible space traveler would probably go the long way—following an arc well outside the plane of the galaxy’s disk—to hopefully avoid colliding with dark matter.

The program also ignores the effects of gravitational bodies, such as Earth the Sun the galaxy, etc. If you hypothesize a really peppy spacecraft, say ten G’s at liftoff, and you’re only going to Alpha Centauri and back, those gravitational fields will not greatly alter your trajectory. A little more realistically, you will begin with a tremendous mass of fuel (perhaps equal to the Moon’s mass) and very small acceleration; it may take a significant portion of your fuel to overcome the gravity of the Earth and Sun. You may need to spiral once or twice around the Sun before heading into deep space. At the other end of the trip, your fuel mass is greatly reduced, so gravitational fields are insignificant by comparison to your maxxed-out deceleration.

If you wish to make a round trip, you will have to take with you the ability to replenish your matter-antimatter fuel supply at the turn-around point. You’ll probably want to carry only the most basic tools and the information needed to build from there to a functional antimatter production facility. Bear in mind, you’ll be a few years older when you return to Earth, but Earth will be about 200,000 years older, so what’s the point of returning? How many dark ages will have ensued? Will the master race be silicon-based descendants of our computers or will it be an intelligent cockroach? I doubt if either will be friendly to a 21st Century human.

Since any information obtained by such a journey would be unavailable even to the descendants of those who remain behind, who would be willing to pay the bill? Would those making the trip have to pick up the tab before leaving Earth. The more people going, the greater the expense. So a very few people would have to enslave the rest and leave them behind after milking them dry. The cost of this project would make the pyramids of Egypt look like an item on an employee’s expense voucher.

Has anyone read this yet?

 * I've read as much as I can :) Anyway, there was a science fiction story many years back about a space faring race that created highways by collapsing suitable stars into black holes, turning all the resulting energy into laser beams that were bent into loops by the created blackholes.  The idea was that to travel through space one simply dipped a mirror into these beams and got an immediate thrust.  The beam also cleared the path of any debris.  The reason I'm posting this is the fact that your calculations assume that the reaction mass-energy is carried with the ship, but in fact beaming the energy out makes the limit somewhat less useful. njh 05:30, 31 December 2005 (UTC)

Cleanup
This needs lots of cleanup such as spelling, italic variables, consistent symbols for variables, superscripts, and capitalization for starters. Plus it needs to be broken up into sections and otherwise wikified. Gene Nygaard 01:59, 28 January 2006 (UTC)
 * Not just consistent variables but conventional ones, too, and other things like leading zeros. Gene Nygaard 02:01, 28 January 2006 (UTC)

Be more specific about what things you think need changing, and state justification for change"? If you see any actual spelling, puntuation, or grammar errors you are welcome to fix them.?
 * puntuation->punctuation
 * (there are a lot of errors in this article, I just haven't had the time to go through and fix them - perhaps you could run the whole thing through a spell chequer and fix the worst offenders) njh 08:54, 6 February 2006 (UTC)
 * (there are a lot of errors in this article, I just haven't had the time to go through and fix them - perhaps you could run the whole thing through a spell chequer and fix the worst offenders) njh 08:54, 6 February 2006 (UTC)
 * (there are a lot of errors in this article, I just haven't had the time to go through and fix them - perhaps you could run the whole thing through a spell chequer and fix the worst offenders) njh 08:54, 6 February 2006 (UTC)

Relativistic rocket formulas
I've put a bunch of formulas at User:Wwoods/Relativistic rocket formulas. I collected or worked them out several years ago, so I don't have the derivations at hand, but for most of them it shouldn't be to hard to verify them. —wwoods 22:36, 10 February 2006 (UTC)
 * You give some data for a rocket accelerating at constant rate, but it is more relevant, especiall to this article, to correctly apply the rocket equation that takes into account the depletion of propellant during thrust. DonPMitchell (talk) 00:13, 5 July 2008 (UTC)

Additions by Tmayes1965
A long series of paragraphs have been added to this article by the above user, describing the design of a theoretical relativistic rocket. While there are a number of useful points on design considerations that would need to be taken into account, as it stands the additions are much more a prescription for the design on an individual rocket. Sentences such as "It would have a rotating crew habitat" or "There would be an array of high energy lasers, particle beams and some missiles mounted on the starship" are nothing more than crystal ball gazing. Would it make more sense to try and selectively eliminate passages that refer to non-critical design features, move the whole section to a new article on this ""beam core" pion rocket" or just wipe the entire section and try to rebuild a few useful points of consideration, such as the need for sheilding at the bow of the craft? Icelight 01:18, 7 June 2006 (UTC)

Addition/Correction/Question - Andy Stangeland 02 Oct 2006
In the article it mentions that "Gamma rays can be reflected by some materials such as beryllium." This is counter to every other discussion about gamma rays that I've seen. Other sites have said that only theoretical, quantum engineered materials, could deflect a gamma ray. Additionally, I can't find any other resource that says that gamma rays can be deflected. High energy X-rays (lower than gamma rays) can be deflected or refracted at small angles, but the only information I've found on gamma rays said it could be stopped with 2 inches of lead or tungsten. (CRC) Never anything about deflection though.

Nonsense
This whole article is quite a nonsense. It is not useful to derive from the special theory of relativity, since it is obvious from conversation of momentum that a relativic velocity never can be reached by a rocket. From the law of conversation of momentum one easly derives
 * $$ m \ \frac{dv}{dt} + dm \ v_e = 0 $$

for the velocity $$v$$ of the rocket of mass $$m$$ and the velocity $$v_e$$ of the exhaust gases. This leads to

 * $$ dv = v_{e} \frac{dm}{m} $$

and finally by integrating
 * $$ v = v_{e} \ln\left(\frac{m(t=0)}{m(t)}\right). $$

Moreover the relativistic calculation is just wrong, since as an example, there is not a uniform velocity $$v_e$$ of the exhaust gases. The velecity $$v_e$$ is only constant relative to the rocket but not in any frame which is not accelerated. —Preceding unsigned comment added by 84.169.245.54 (talk • contribs) 25 November 2006

 * The relativistic rocket equation is
 * $$ \tanh^{-1}\frac{v(t)}{c} = \frac{v_e}{c} \ln\left(\frac{m_0}{m(t)}\right). $$
 * For $$v \ll c$$, this reduces to the non-relativistic version:
 * $$ v(t) = v_e \ln\left(\frac{m_0}{m(t)}\right). $$

 * The exhaust "velocity", $$v_e$$, is a figure of merit for a rocket, not necessarily the speed of anything.
 * —wwoods 21:33, 26 November 2006 (UTC)

 * Ok, one may define an exhaust velocity just as the ratio of the disired total momentum the space vehicle finally gains to the mass of the propellant. This ratio can indeed be regarded as a figure of merit for a space vehicle and has the dimension of a velocity, but is not the speed of anything. This is in contrast to the classical derivation of the rocket equation, since here $$v_e$$ is in fact the velocity of the exhausted gases measued in the rest frame of the rocket.

Additions by 71.124.2.194
I reverted these additions:

 * It should be noted that any electrical source can be used to have an effective exhaust velocity of nearly $$c$$ using a linear acelerator.

This is not true because you have to include the energy source's fuel ...

 * The implication of this is that even a $$c$$ exhaust velocity needs a fuel ratio of 99.9997%; effectively making a 50 ton spaceship require 2 million tons of fuel to have 0.5$$c$$ final velocity. Being able to decelerate also would mean 4x the fuel mass.

The calculation is obviously flawed.

Icek 05:46, 28 December 2006 (UTC)

Pion Engine
The section on pion engines is bogus. The device describe would vaporize in a microsecond under exposure to the levels of radiation described there. Even with chemical rocket engines, a key problem is cooling. Designs for antimatter engines (even ones funded by the infamous NIAC) almost always ignore the simple fact that no form of matter known to man can exist in a solid state when exposed to such enormous radiation flux. DonPMitchell 22:34, 24 October 2007 (UTC)

 * The section on pion drive should be deleted. It is just someone's pseudo-scientific ramblings that belong on their talk page or a blog, not in an encyclopedia.
 * 1. Gamma rays are almost impossible to collimate
 * 2. Beryllium is not a "gamma ray reflector"
 * 3. proton-antiproton collions doesn't just produce pions
 * 4. pumping liquid hyrogen, are you going to pump liquid antihydrogen too?
 * 5. The engine and nozzle and such would evaporate in a nanosecond, when the annililation of bulk quantities of antimatter begins.
 * 6. There is plenty of nonsense about antimatter drives elsewhere in wikipedia

This whole article could be replaced with a summation of the very clear discussion of relativistic rockets in Taylor and Wheeler's book "Spacetime Physics" DonPMitchell (talk) 00:21, 5 July 2008 (UTC)

 * The cooling problems encountered by conventional rockets arise from the contact between the hot expanding propellent and the inside of the engine combustion chamber and nozzle. A pion rocket or antimatter induced heating/fission/fusion engine redirects the products of these reactions using a magnetic nozzle, which cannot be heated. The mass to energy conversions that would occur during the reactions would be intense enough for all the radiation produced to be gamma rays, and very energetic ones since we're talking about proton annihilation and π0 meson decay. As long as the walls of the engine are not impossibly thick or made of too dense metal, the attenuation coefficient will allow most rays to pass right through and exit into space without inducing heat. Obviously this stops being true for the ridiculously large amounts of antimatter -1kg per second, was it ?- and thrust described in the original section, as the gamma rays would be so densely emitted that even the minuscule fraction of them that would interact with the engine materials would melt them.

 * Antimatter induced heating, fission, and fusion engines (or a combination thereof such as the ICAN or AIMSTAR) using pelletized propellent will cause a sudden increase in temperature within the pellet or droplet, leading to gamma ray-producing reactions almost immediately; there will be no time for the reaction mass to thermally radiate the energy input away.

 * Such engines designed for uninterrupted annihilation are the only kind that could have a radiated heat problem. Solid and gas core antimatter rockets are conventional rockets operating at conventional power levels, only using unconventional fuel. They would not generate immoderate amounts of heat. Plasma core antimatter and annihilation powered continuous fusion rockets (such as C. Pellegrino's "valkyrie") have the potential to thermally radiate through whatever contains the reaction mass, but they don't have the time to do so either. Unlike what happens during confined fusion or ionization, the particles are heated suddenly around the annihilation reactions (so much that they fuse in the case of the fusion rocket) and they (along with reaction products, also in the case of the fusion rocket) all exit the engine carrying their heat with them. It's a lot like some extreme form of evaporative cooling.

 * My point is, the cooling problem does not exist but these rockets would irradiate everything. 82.65.175.49 (talk) 10:09, 5 February 2012 (UTC)

 * Ok, i rewrote some of the article, removed the dead first reference, and added some new ones which authors were mentioned in the article. Also removed the bogus "1kg of antimatter for X Newtons of thrust" part, the redundant description of magnetic containment, and that link to the vacuum flask(!) article. It still needs to be written in an organized way by a real expert, but at least it should be accurate now. 82.251.149.7 (talk) 23:51, 5 February 2012 (UTC)

Bogus or not, the pion section should be rewritten to make it clear that this is a highly hypothetical concept. Currently it reads as if it were an existing, working technology. Nobody even knows if pion engines are possible.--114.181.225.100 (talk) 23:10, 25 March 2017 (UTC)

Fuel
It may be worth noting that the only onboard fuel that would be required would the amount necessary to get to a noticeably relativistic velocity. After that point, the radiation energy from the forward direction (from stars or even from cosmic background radiation) would be blue-shifted to the point where it would be providing all the energy needed for further acceleration. 68.39.154.196 (talk) 15:18, 4 October 2008 (UTC)

No. Absorbing such radiation would slow the spacecraft down, due to conservation of momentum. The blue shift comes from its speed in the first place. You don't get something for nothing. 131.111.185.8 (talk) 16:01, 21 January 2011 (UTC)

 * This article is really bad. Apparently none of the editors understand the difference between rocket fuel and rocket propellant. Confusing the two is rampant here. Fuel is the energy source; propellant is the "stuff" (atoms, electrons, photons) which a rocket expels in order to gain momentum. It also does, imho, a really bad job of separating the useful physical properties (of the various parts of the system) from parameters used (mostly in comparisons by hobbyists, I'd guess) to compare properties. Ve & Isp for instance. I understand that the clowns who established the field used these and that they are so entrenched in the field's literature that they need to be discussed, but I also think that most kids, after taking high school physics, are NOT familiar with them while they are quiet familiar with the concepts of mass, velocity, acceleration, and momentum. I suggest that the introductory discussion confine itself to concepts which most readers will be familiar with before jumping to other, and unnecessary, concepts.67.140.181.214 (talk) 18:39, 22 March 2018 (UTC)

Table on specific impulse needs references
Where do the values in the table about specific impulse come from? In particular, I can find no research article in which it was calculated that electron-positron annihilation with a "hemispherical absorbing shield" results in a 0.25c specific impulse. Also note that the values for eta and I_sp/c as reported in the table have apparently no connection with the formula for I_sp given in terms of eta, as given in the article just before the table appears. [For example, the table says that for the pion engine, eta is 0.56. However, if you plug eta = 0.56 into the equation given for I_sp, you would get I_sp = 0.898c. What is going on? If the I_sp is reduced due to "energy losses," this needs to be explicitly and clearly stated.]

Please give references for the data in the table.

Also, at the moment Reference (1) is nothing but a broken link.

Nullinfinity (talk) 22:49, 23 June 2009 (UTC)

Specific Impulse
I_sp is defined as:

I_sp = g0 * v_e

Where g0 is acceleration due to gravity at earth's surface. This doesn't significantly affect the derivation, but either each I_sp has to be replaced with a v_e or every v_e needs to be multiplied by g0. — Preceding unsigned comment added by 129.22.124.89 (talk) 00:25, 5 July 2014 (UTC)

External links modified
Hello fellow Wikipedians,

I have just added archive links to 2 one external links on Relativistic rocket. Please take a moment to review my edit. If necessary, add after the link to keep me from modifying it. Alternatively, you can add to keep me off the page altogether. I made the following changes:
 * Attempted to fix sourcing for http://scientium.com/diagon_alley/commentary/bowden_essays/sotm/starship/rockets.htm
 * Added archive https://web.archive.org/20120118144444/http://thefutureofthings.com:80/articles/33/new-antimatter-engine-design.html to http://thefutureofthings.com/articles/33/new-antimatter-engine-design.html

When you have finished reviewing my changes, please set the checked parameter below to true to let others know.

Cheers. —cyberbot II  Talk to my owner :Online 01:22, 19 October 2015 (UTC)

 * Fixed one link:.
 * The scientium source was used to back largely inrrelevant information, and does not appear to have been a wp:reliable source. Removed: . - DVdm (talk) 07:12, 19 October 2015 (UTC)

"By applying the Lorentz transformation on the acceleration"
The article mentions a Lorentz transformation, but those are not valid for an accelerating frame. The proper time arclength gives the same t' = (1/a)sinh(at) relation on a hyperbolic motion worldline, however. Should this be changed? -AkariAkaori (talk) 08:03, 21 April 2017 (UTC)
 * I have removed the "on the acceleration" part (which I already had changed to "to the acceleration" in my copy edit), but the transformation can be applied because the non-rocket frame is inertial. The standard Lorentz transformation (with c=1) between the rest frame $$(x',t')$$ and the "instantaneously comoving inertial" frame the rocket $$(x,t)$$ at rocket time t is given by:
 * $$dt' = \gamma(t) \ ( dt + v(t) \ dx )$$
 * $$dx' = \gamma(t) \ ( dx + v(t) \ dt )$$
 * No problem. DVdm (talk) 08:25, 21 April 2017 (UTC)

 * I just noticed above the Lorentz transformation part to derive $$\Delta v = c \tanh \left(\frac {I_{sp}}{c} \ln \frac{m_0}{m_1} \right).$$ it is already stated that $$\frac{\Delta v}{c} = \tanh\left[\frac{at}{c}\right]$$ (which would already give us delta-v without needing to find rest time), are these part of the same train of thought or should they be in different subsections like the different derivations for the classical rocket equation are? AkariAkaori (talk) 07:41, 22 April 2017 (UTC)

 * No idea. I hadn't seen that article Tsiolkovsky rocket equation before. - DVdm (talk) 08:47, 22 April 2017 (UTC)

 * Please note that Delta-V/c = tanh((Ve/C)(ln(m0/m1)) is given (derived) in the UCR article The Relativistic Rocket which as of 25/1/2018 is easily found on the web (and has persisted for over 10 yrs).

Difficult
This article's lead claims:"Achieving relativistic velocities is difficult, requiring advanced forms of spacecraft propulsion that have not yet been adequately developed." Plainly speaking: this is false. First, we need to carefully frame the issue. While "atom smashers" are able to accelerate massive objects (H, Pb, & Xe (LHC); H, Al, Au, Cu, U (RHIC)) to near light speed (protons were accelerated to 0.99999999c at the LHC) with a GREAT deal of difficulty there is no recorded event in which any macroscopic object has been accelerated to near light speed. Nor is the attainment of such velocity possible with any known or reasonably straightforward improvements of known technology; that is it is not "difficult" it is (currently) impossible. Claiming is is "difficult" is false and misleading because in fact it may never be accomplished. (This is using the reasonable constraints that a rocket vehicle carries its own fuel (energy) and propellant.) "have not yet been adequately developed" is another misleading, but factually correct statement. In fact, there are very good {evidence based) reasons to believe attaining relativistic velocities with rockets in the kilogram to kilotonne range is not possible; no evidence contradicts this. I am changing this profoundly misleading sentence to:"There is no known technology capable of accelerating a rocket to relativistic velocities. Relativistic rockets require enormous advances in spacecraft propulsion, energy storage, and engine efficiency which may or may not ever be possible."71.31.150.130 (talk) 15:40, 25 January 2018 (UTC)

 * I agree with the edit. An extra book source would be welcome. - DVdm (talk) 15:51, 25 January 2018 (UTC)

 * This is not quite accurate. There are many theoretically possible designs that would allow such engines, and there has been some research into photonic thrusters, which (due to their 'exhaust' velocity literally being the speed of light), can absolutely be used to accelerate to relativistic speeds assuming a large enough energy supply. Current photonic thrusters have been able to exert forces on the order of millinewtons with power inputs of a few kilowatts and so it is entirely feasible that with enough resources this idea could be scaled up to practical sizes. 131.227.33.141 (talk) 18:39, 7 March 2018 (UTC)

title: Talk:Relativistic rocket


text:
Category:Wiki concepts

These are community or technical concepts associated with wikis.

title: Category:Wiki concepts


text:
Hyangak

Hyangak, literally "indigenous/native music, folks music" is a traditional form of Korean court music with origins in the Three Kingdoms period (57 BC – 668 AD). It is often accompanied by traditional folk dances of Korea, known as hyangak jeongjae. These dances are performed in front of audiences—as opposed to the square dance more familiar to Westerners, which is primarily for the participants' enjoyment.

One important hyangak piece is Yeomillak (hangul: 여민락; hanja: 與民樂). Few hyangak pieces are performed in Chinese style; these include Pollyeong, Haeryeong (hangul: 해령; hanja: 解令), and Poheoja

History
During the Unified Silla Period, Hyangak began to be used as a symmetrical concept with dangak. At that time, Hyangak included both native music from the Korean Peninsula and foreign music that had been adopted before the unified Silla Dynasty.

The literature of the Goryeo Dynasty often referred to Korean traditional court music as 'Sokak' rather than 'Hyangak'. During the Goryeo Dynasty, the musical instruments Of Hyangak were composed of Samhyeon and Samjook, which were handed over from the unified Silla, and foreign instruments such as janggu, haegeum, and flute.

In the Joseon Dynasty, Hyangak, and Dangak were influenced musically by one another. Hyangak, the early Joseon Dynasty, was part of a project to honor the historical legitimacy of Joseon and the new dynasty. Since the mid-sized Joseon Dynasty, the contents of the music have changed as the music changed like Hyangak, and the distinction between Hyanggak and Dangak was blurred even when using musical instruments.

title: Hyangak


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List of quantum field theories

This is a list of quantum field theories. The first few sections are organized according to their matter content, that is, the types of fields appearing in the theory. This is just one of many ways to organize quantum field theories, but reflects the way the subject is taught pedagogically.

Scalar field theory
Theories whose matter content consists of only scalar fields
 * Klein-Gordon: free scalar field theory
 * φ4 theory
 * Sine-Gordon
 * Toda field theory

Spinor field theory
Theories whose matter content consists only of spinor fields
 * Dirac theory: free spinor field theory
 * Thirring model
 * Nambu–Jona-Lasinio model
 * Gross–Neveu model

Gauge field theory
Theories whose matter content consists only of gauge fields
 * Yang–Mills theory
 * Proca theory
 * Chern–Simons theory

Interacting theories

 * Spinor and scalar
 * Yukawa model
 * Scalar and gauge
 * Scalar electrodynamics
 * Scalar chromodynamics
 * Yang–Mills–Higgs
 * Spinor and gauge
 * Quantum electrodynamics (QED)
 * Schwinger model (1+1D case of QED)
 * Quantum chromodynamics (QCD)
 * Scalar, spinor and gauge
 * Standard Model

Sigma models

 * Chiral model
 * Non-linear sigma model
 * Wess–Zumino–Witten model

Supersymmetric quantum field theories

 * Wess–Zumino model
 * Supersymmetric Yang–Mills
 * Seiberg–Witten theory
 * Super QCD (sQCD)

Superconformal quantum field theories

 * N = 4 supersymmetric Yang–Mills theory
 * ABJM superconformal field theory
 * 6D (2,0) superconformal field theory

String theories
Theories studied in the branch of quantum field theory known as string theory. These theories are without supersymmetry.
 * Polyakov action
 * Nambu-Goto action
 * Bosonic string theory

Other quantum field theories

 * Kondo model (s-d model)
 * Minimal model (Virasoro minimal model)

Branches of quantum field theory

 * String theory
 * Conformal field theory
 * Supersymmetry
 * Topological quantum field theory
 * Noncommutative quantum field theory
 * Local quantum field theory (also known as Algebraic quantum field theory or AQFT)

title: List of quantum field theories


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Titular

Titular may refer to:

Arts, entertainment, and media

 * Title character in a narrative work, the character referred to in its title

Religion

 * Titular (Catholicism), a cardinal who holds a titulus, one of the main churches of Rome
 * Titular bishop, a bishop who is not in charge of a diocese
 * Titular church, a church in Rome assigned or assignable to one of the cardinals
 * Titular see, an episcopal see of a former diocese that no longer functions

Other uses

 * Titular nation, the single dominant ethnic group in the state, typically after which the state was named
 * Titular ruler, a person in an official position of leadership who possesses few, if any, actual powers

title: Titular


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Category:Aston Martin vehicles

This category contains articles about Aston Martin vehicles.

title: Category:Aston Martin vehicles


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Electra (Pleiad)

In Greek mythology, Electra (Ἠλέκτρα 'amber' ) was one of the Pleiades, the seven daughters of Atlas and Pleione. She lived on the island of Samothrace. She had two sons, Dardanus and Iasion (or Eetion), by Zeus.

Electra was connected with the legend of the Palladium, the sacred statue, which became the talismanic protector of Troy. Electra, along with the rest of the Pleiades, were transformed into stars by Zeus. By some accounts she was the one star among seven of the constellation not easily seen because, since she could not bear to look upon the destruction of Troy, she hid her eyes, or turned away; or in her grief, she abandoned her sisters and became a comet.

Family
The Pleiades were said to be the daughters of Atlas, who was the son of the Titan Iapetos. Gantz, pp. 212–213; Hesiod, Catalogue of Women fr. 118 Most [= Hesiod fr. 169* MW = Schol. on Pindar Nemian 2.17]; Simonides, fr. 555 Campbell; Lycophron, 72–80; Apollonius Rhodius, Argonautica 1.916; Catasterismi 23 (Hard 2015, p. 86); Diodorus Siculus, 5.48.2; Hyginus, De Astronomica 2.21.2 (Hard 2015, p. 88), Fabulae 155, 192 & 250; Conon, Narrations (from the Bibliotheca of Photius) 21 (Greek with facing French translation; English translation by Brady Kiesling at ToposText); Ovid, Fasti, 4.31–32, 4.166–178, 5.83–84; Apollodorus, 3.10.1, 3.12.1 No early source mentions their mother, but according to some late accounts she was the Oceanid Pleione. Hyginus' De Astronomica says that Electra and her six sisters were called the Pleiades because, according to the 1st-century BC Greek scholar and historian Alexander Polyhistor, they were the daughters of Pleione. De Astronomica also says that, according to Musaeus, their mother was instead an Oceanid named Aithra, explaining that they were called the Pleiades because there were more (pleion in Greek) of them than their sisters the Hyades. According to the mythographer Apollodorus, the Pleiades were born to Pleione "at Cyllene" (Mount Cyllene?) in Arcadia.

On the island of Samothrace, Electra had, by Zeus, a son Dardanus who left Samothrace and founded the city of Dardanus in the Troad. Through Dardanus, Electra was the progenitor of the Trojan royal line. She also had another son, by Zeus, Iasion (also called Eetion), who, because of an outrage against Demeter (or her statue ), was blasted by Zeus' thunderbolt. The logographer Hellanicus also makes Electra the mother, by Zeus, of Harmonia the wife of Cadmus, although usually Harmonia is the daughter of Ares and Aphrodite. Nonnus also makes Electra the mother of Emathion, who succeeded his brother Dardanus as king of Samothrace.

According to an Italian tradition, Electra was the wife of the Etruscan king Corythus. Her sons Dardanus and Iasion were born in Italy, with Iasion being the son of Electra and Corythus, and Dardanus being the son of Electra and Zeus.

Mythology
There are two stories involving Electra. One concerns the Palladium, the sacred statue of Pallas Athena, considered to be the divine protector of Troy (and later Rome). According to Apollodorus, Electra, seeking protection from Zeus, took refuge at the divine statue, but Zeus in his anger threw the statue from heaven. It landed near Troy, where Ilus, the founder of Troy, found the statue and built a temple to house and honor it. According to another version of the story Electra herself gave the statue to Dardanus as protection for Troy.

Another story involving Electra, concerns her, and her six sisters transformation into stars. The reason for their transformation varied. According to one account, the Pleiades were being pursued by the huntsman Orion, intent on rape, but Zeus took pity on the sisters and placed them among the stars. And by way of explanation for the fact that only six of the seven stars in the constellation were readily visible, it was said that Electra, unable to behold the destruction of Troy, hid her eyes, or turned away; or, in another version, Electra, in mourning, let down her hair, and left her sisters altogether and became a "long haired star" (i.e. a "comet").

Early
A constellation called the Pleiades is mentioned in Homer's Iliad and Odyssey and Hesiod's Works and Days, however none of the stars are named. Hesiod calls the stars the Atlageneis, possibly meaning "born from Atlas", although linguistic considerations suggests that the epithet refers to some geographic location. The lyric poet Simonides of Ceos (c. 556–468 BC), is the first (datable) source to connect the name of the star-cluster with the seven daughters of Atlas.

The names of the seven Pleiades are first attested in a scholion on Pindar, which quotes three hexameter lines from an unattributed poem, probably from the Hesiodic corpus:
 * lovely Taygete and dark-eyed Electra,
 * Alcyone and Asterope and godly Celaeno,
 * Maia and Merope, whom splendid Atlas begot.

Electra is also mentioned in the Hesiodic Catalogue of Women, where apparently she was said to be the mother of Dardanus and Eetion. The fifth-century Greek logographer Hellanicus of Lesbos provides more details. According to Hellanicus, Electra (called Electryone by Hellanicus) lived on Samothrace, where the locals called her Strategis. She had two sons by Zeus, Dardanus, and Eetion, who was also called Iasion. She also had a daughter Harmonia by Zeus, who was the bride of Cadmus, the founder of Thebes, and that because of this, the Thebans named one of the city gates (the Electran gates) after her.

The story of Electra and her sisters being transformed into stars may also have been told somewhere in the Epic Cycle. A scholion to the Iliad mentions the Pleiades escape from Orion by catasterism and says the following about Electra:
 * They say that Electra, being unwilling to watch the sack of Ilion [i.e. Troy] because it was a foundation of her descendants, left the place where she had been set as a star, so that whereas they had previously been seven, they became six. The story is found in the Cyclic poets.

Late
De Astronomica is a Latin astronomical guide, attributed to Hyginus (died AD 17), containing the most complete surviving ancient compendium of astral mythology. It gives the following account of why only six of the seven Pleiades can be seen:
 * The Pleiades are said to be seven in number, but no one can see more than six of them. It has been suggested by way of explanation that, of the seven, six went to bed with immortals—while the other is indicated to have been the wife of Sisyphos. ... She [Merope] was placed among the stars thanks to her other sisters, but because she married a mortal, her star is faint.
 * According to other accounts, it is Electra who cannot be seen, for the following reason. The Pleiades led the chorus of the stars, so it is thought, but after the fall of Troy and the destruction of all who ere descended from her through Dardanos, Electra was overcome by grief and abandoned the company of her sisters to establish herself on the circle known as the arctic, and at long intervals she can be seen in mourning with her hair unloosed; for that reason she has come to be called a comet (long-haired star).

The Latin poet Ovid, in his poem the Fasti (c. AD 8), gives a similar account, but with a different explanation regarding Electra:

 * Seven are they [the Pleiades] usually called, but six they usually are; whether it be that six of the sisters were embraced by gods (for they say that Sterope lay with Mars, Alcyone and fair Celaeno with Neptune, and Maia, Electra, and Taygete with Jupiter); the seventh, Merope, was married to a mortal man, to Sisyphus, and she repents of it, and from shame at the deed she alone of the sisters hides herself; or whether it be that Electra could not brook to behold the fall of Troy, and so covered her eyes with her hand.

The mythographer Apollodorus (first or second century AD), discussing the "legend" of the Palladium", says that "Electra, at the time of her violation, took refuge at the image, and Zeus threw the Palladium along with Ate into the Ilian country; and Ilus built a temple for it, and honored it."

Nonnus, in the third book of his Dionysiaca (c. fifth century AD), has the wandering Cadmus land on Samothrace where he will find his bride to be, Electra's foster-daughter Harmonia. He arrives at the palace, "that masterly work of Hephaistos, which the industrious god once built for Electra as a bride", where he is received by Electra, the queen of Samothrace, and her son Emathion, who, with the departure of his brother Dardanus, is now "sole king". In answer to Electra's questioning, Cadmus tells her of the woeful abduction of his sister Europa, by Zeus, and order of his father Agenor to find his sister or never return home. Nonnus has Electra try to console Cadmus with the following speech:
 * "My guest, let sister and country and father pass into the whirlpool of Forgetfulness and un-remembering silence! For this is the way men's life runs on, bringing trouble upon trouble; since all that are born of mortal womb are slaves by necessity to Fate the Spinner. I am witness, queen though I am, if I was ever born myself one of those Pleiads, seven girls whom our mother once carried under her heart in labour, seven times having called Eileithyia at her lying-in to lighten the pangs of birth after birth—I am witness! for my house is far from my father's; no Sterope is near me, no Maia my companion, nor sister Celaino beside me at my hearth; I have not dandled up and down sister Taygete's Lacedaimon at my breast nor held the merry boy on my cherishing arm; I do not see Alcyone's house hard by, or hear Merope herself speak some heartwarming word! Here is something besides which I lament even more—in the bloom of his youth my own son has left his home, just when the down was on his cheek, my Dardanos has gone abroad to the bosom of the Idaian land; he has given the firstling crop of his hair to Phrygian Simoeis, and drunk the alien water of river Thymbrios. And away by the boundary of Libya my father still suffers hardship, old Atlas with chafing shoulders bowed, upholding the seven-zoned vault of the sky.
 * "Still and all with these great sufferings I feed a comfortable hope, by the promises of Zeus, that with my other sisters I shall pass from the earth to the stars' Atlantean vault, and dwell in heaven myself a star with my sisters six.

title: Electra (Pleiad)


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Kentucky River Museum

The Kentucky River Museum is located in Boonesborough, Kentucky, in Fort Boonesborough State Park.

Established in 2002, the museum occupies the former lock operator's home and storage and maintenance building for Lock 10, one of fourteen locks on the Kentucky River which were originally built by the U.S. Army Corps of Engineers. The ten uppermost ones (locks 5 through 14) are now operated by the Kentucky River Authority.

title: Kentucky River Museum