text:
Manchester Metropolitan University

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Manchester Metropolitan University
Logo of the Manchester Metropolitan University
Motto Many Arts, Many Skills
Type Public
Established 1970 (as Manchester Polytechnic)
1992 (gained university status)
Endowment £1.0 m (2015)[1]
Chancellor Peter Mandelson[2]
Vice-Chancellor Malcolm Press[3]
Students 31,355 (2014/15)[4]
Undergraduates 25,810 (2014/15)[4]
Postgraduates 5,545 (2014/15)[4]
Other students
200 FE[5]
Location Manchester, England, UK
53.47053, −2.23872
Campus All Saints, Birley Fields, Crewe
Colours Blue, turquoise, burgundy, gold
Affiliations University Alliance
Association of Commonwealth Universities
Association of MBAs

Manchester Metropolitan University (often referred to as MMU, Man Met or Manchester Met) is a public university located in Manchester, England. It was established in 1970 as Manchester Polytechnic and gained university status in 1992. Its headquarters and central campus are in the city of Manchester, and there are additional facilities in Cheshire. The university has its roots in the Manchester Mechanics' Institution (1824) and the Manchester School of Design (1838).[6]

Manchester Metropolitan University receives approximately 52,000 applications every year, making it the second most applied-to university in the UK after the University of Manchester.[7] It is the fifth largest university in the UK in terms of student numbers. It is an accredited member of the Association of MBAs, a member of the University Alliance, the Association of Commonwealth Universities, the North West Universities Association, Association to Advance Collegiate Schools of Business and the European University Association.

The university is home to the Manchester School of Art and the Manchester School of Theatre. Together with the University of Manchester, Manchester Metropolitan University also jointly administers the Manchester School of Architecture (MSA) with MSA students classified as students of both universities.

The university developed from mergers of various colleges with various specialisms, including Technology, Art and Design, i.e. Manchester Mechanics' Institution (1824) and Manchester School of Design (1838). Later, Schools of Commerce (founded 1889), Education (f. 1878) and Domestic Science (f. 1880) were added along with colleges at Didsbury, Crewe, Alsager and the former Domestic and Trades College (f. 1911), latterly Hollings College.

The painter L. S. Lowry attended Manchester School of Art in the years after the First World War where he was taught by the noted impressionist Adolphe Valette.[6] It became Manchester Polytechnic in 1970. On 1 January 1977, the polytechnic merged with the Didsbury College of Education and Hollings College, and on 1 January 1983 with City of Manchester College of Higher Education. In 1987 the institution became a founding member of the Northern Consortium. Having previously been a local authority institution, the polytechnic became a corporate body on 1 April 1989, as allowed by the terms of the Education Reform Act 1988.

It was granted university status as "Manchester Metropolitan University" by the Privy Council on 15 September 1992 under the provisions of the Further and Higher Education Act 1992. The university absorbed Crewe and Alsager College of Higher Education on 1 October 1992 and the Manchester School of Physiotherapy in 2004.[8]

Manchester School of Physiotherapy: The Manchester School of Physiotherapy (MSOP) was a higher education institution based in Manchester, United Kingdom. It provided undergraduate and postgraduate degree programmes within Physiotherapy and additionally offered NVQ level qualifications for unqualified Physiotherapy Support Workers. The School of Physiotherapy was affiliated to the Victoria University of Manchester and all degree level courses were validated and conferred by this institution.[9]

The School was officially formed in 1991, through the amalgamation of the Manchester Royal Infirmary (M.R.I.) and the Withington Hospital Schools of Physiotherapy. From these two institutions it can date its history back to 1911 and during the 1980s via its M.R.I. routes, became the first NHS School of Physiotherapy to offer a three-year undergraduate honours degree programme.[8] The Manchester School of Physiotherapy was based at the Manchester Royal Infirmary and from 1993, was housed within purpose built accommodation converted from the hospital's former outpatient department. The academic building consisted of two large raked lecture theatres, a number of practical rooms, a gymnasium, seminar rooms, a library, office facilities and a student common room.

In 2004 the Manchester School of Physiotherapy officially joined the Manchester Metropolitan University (MMU) and initially became known as the Department of Physiotherapy. It was at this point the last NHS School of Physiotherapy to join a UK higher education institution.[8] It subsequently became the Department of Health Professions and is currently based at the Birley Fields Campus of MMU in Hulme.[10] All students now have their degrees conferred from the Manchester Metropolitan University.

The final cohort of Manchester School of Physiotherapy students graduated in 2005, with their degrees being conferred by the University of Manchester.

Manchester Royal Infirmary School of Physiotherapy Badge

Exercise and Sports Science Building at Cheshire Campus.
The All Saints Building on the All Saints Campus, Chorlton-on-Medlock
The administration building of the Didsbury Campus

The university was previously located on seven sites, five in Manchester (All Saints, Aytoun, Didsbury, Elizabeth Gaskell, and Hollings) and two in Cheshire (Alsager and Crewe), and has rationalised its estate, reducing the number of sites to two. The university has moved the work of the Alsager campus to Crewe. The Aytoun campus closed in 2012 when a new Business School opened on the All Saints Campus. Since 2011, the university has been engaged in a £350 million investment programme involving the largest physical change to its estate since its foundation. In 2014 the Elizabeth Gaskell, Hollings and Didsbury campuses were closed and the faculties moved to All Saints and the new Birley campus[11]

All Saints Campus[edit]

Statue of John Dalton by William Theed outside the university's building in Chester Street

All Saints campus is one of the university's 2 campuses.

The Faculty of Humanities, Languages and Social Science is split between the Geoffrey Manton and Mabel Tylecote buildings. The Geoffrey Manton Building accommodates the English, History and Economic History, Information and Communications, Politics and Philosophy, and Sociology departments. The Languages departments are housed in the Mabel Tylecote Building.[12]

The John Dalton Building, on Chester Street is the home of the Faculty of Science and Engineering.[13] It comprises four schools: the School of Healthcare Sciences, the School of Computing, Mathematics & Digital Technology, the School of Engineering, and the School of Science and The Environment. To the rear of the John Dalton Building is JD tower, housing the university's main science laboratories including IRM,[14] the Institute for Biomedical Research into Human Movement and Health.

The Manchester School of Art on the All Saints Campus is composed of four departments: The Manchester School of Architecture (operated jointly with the University of Manchester Faculty of Humanities); Department of Art; Department of Design; Department of Media.[15] The faculty houses the Holden Gallery which has a continuous programme of exhibitions and is open free to the public.[16] The university has invested in improving the Manchester School of Art building granting £35 million to facilitate three changes including: a new building for the faculty, refurbishment of the workshops and renovation of the studios. In 2014 the building was nominated for the Stirling Prize.[17][18]

New premises costing £75 million for the Faculty of Business and Law have been built on All Saints Campus and the Business School re-located to this building from the Aytoun Campus in 2012.[19] It will house more than 5,000 students and 250 staff.[20] The new building is an original architectural concept with three towers under a single glass roof.[citation needed] Green credentials are an integral part of the building's design which incorporates solar panels and heat pumps to power the building and a rain water recycling scheme.[20] The Manchester Law School is in the Sandra Burslem building which opened in 2003.

The university library, renamed the Sir Kenneth Green Library, is on the All Saints campus. It houses a number of special collections mainly relating to the fine and applied arts, like the Laura Seddon Greeting Card Collection, a collection of 32,000 Victorian and Edwardian greeting cards.[21] The library is in the All Saints Building where it occupies three floors. It was planned as a single central library in 1972 but after the mergers with the Didsbury College of Education and Hollings College it became a central library and administrative centre for seven library sites. From 1975 a catalogue was produced with the aid of the Birmingham Libraries Co-operative Mechanisation Project.[22] From 1992 the library was part of the Consortium of Academic Libraries in Manchester (CALIM) which was extended in 2002 to become NoWAL, the North West Academic Libraries.[23]

The John Dalton Tower and John Dalton West on the All Saints Campus

The Hollings Faculty offers undergraduate and postgraduate programmes in food, clothing, and hospitality studies and related fields. Formerly in Fallowfield, the faculty is now housed in the Righton Building on the All Saints campus, a former department store.

Cheshire Campus[edit]

The second campus is based in Crewe, Cheshire. The Pro-Vice-Chancellor of the Cheshire campus is Professor Christine Horrocks. [24]

The Cheshire campus is home to over 2,000 students from around the world, supported by over 400 staff across 150 undergraduate and postgraduate courses in the arts, business, education, humanities and sport science. [25]

Academic staff regularly win Students’ Union teaching awards and departments on campus have numerous accreditations from professional bodies. [26][27]The strong regional, national and international links mean that graduates at the campus have had a wealth of opportunities to work with industry professionals, from Paralympic and Olympic athletes and artists to business leaders and high-profile practitioners in health, welfare and social care. [28][29][30][31]

MMU announced on Friday 25th November 2016 following a board meeting it looked to close the Crewe campus by summer 2019. The decision was made following a independent review conducted by financial advisory firm Deloitte, MMU cited a poor intake in students as a main reason for closure.[32][33]

Birley Campus[edit]

2014 saw the opening of a highly environmentally sustainable £140 million development situated on the Birley Fields site in Hulme, Manchester, creating a central location for the Faculties of Education and Health following the closure of the Didsbury and Elizabeth Gaskell campuses. Alongside the academic building there is student accommodation for up to 1200 students comprising ultra-modern, environmentally sustainable townhouses and traditional student apartments.

In common with most universities in the United Kingdom, Manchester Metropolitan University is headed formally by the Chancellor, currently Lord Mandelson but led by the Vice-Chancellor, currently Professor Malcolm Press. There are two deputy Vice-Chancellors.

The University's Board of Governors is responsible for determining the educational character and mission of the University. It also falls to the Board of Governors to ensure that the University's resources are used in line with the University's Article of Government. It also safeguards the University's assets and approves the annual estimates of income and expenditure.[35]

The Board of Governors is responsible for broad policy but the Vice-Chancellor, along with the Executive and Directorate, is responsible for overall management, policy implementation, organisation, operations and direction of the University.[36]

In December 2014, it was announced that Malcolm Press[3] had been appointed to succeed John Brooks[37] as Vice Chancellor on 1 June 2015.[38]

University structure[edit]

The University is organised into eight faculties:

  • Manchester School of Art
  • Health, Psychology and Social Care
  • Humanities, Languages and Social Science
  • Science and Engineering
  • Business and Law
  • Cheshire Campus
  • Faculty of Education
  • Hollings Faculty

The Manchester School of Theatre is a drama school, which trains students to become professional actors. The course offered is a BA (Hons) in Acting. The school is a member of Drama UK, which means the course is a nationally acclaimed programme. Students who complete the course successfully are eligible for full Equity status. The school has links with many local theatres and television companies, such as Granada and the BBC. Graduates from the school of theatre include Amanda Burton, Steve Coogan, Richard Griffiths, Graham Fellows, Julie Walters and Burn Gorman.

In the session 2014/15, the University had 31,355 students, making it the seventh largest university in the UK (out of 165).[4] The University employs 4,400 staff, comprising almost 1,500 full-time teaching staff, 700 part-time teaching staff and 2,200 support staff.[39]

In the financial year ended 31 July 2011, Manchester Metropolitan University had a total income of £248,028,000 (2009/10 - £243,606,000) and a total expenditure of £213,103,000 (2009/10 - £220,221,000).[39] The University's collects £106,857,000 from tuition fees and education contracts (2009/10 - £101,640,000) and attracts £4,992,000 in research grants and contracts (2009/10 - £4,414,000). Income from other sources totalled £31,371,000 (2009/10 - 30,524,000).[39]

Academic profile[edit]

Admissions and ranking[edit]

(2016/17, national)
(2016/17, world)
(2016/17, national)
(2016/17, world)
(2017, national)
The Guardian[45]
(2017, national)
Times/Sunday Times[46]
(2017, national)

UCAS statistics show that the University received 58,752 applications in 2011 and granted places to 9,083 students.[47] Its student population stands at 35,165[48] and The Complete University Guide shows that the University has a ratio of enrolled male to female students standing at 42:58.[49]

The University admits undergraduate students who have achieved a broad range of UCAS tariff points, with an average of 343.7[50]

In terms of academic rigour, in 2012 government statistics show 0.5% of students gaining a First Class Honours degree, 35% gaining a 2:1, 5% gaining a 2:2, and 55% gaining a 3rd or a pass.[51] According to The Complete University Guide's teaching quality inspections, the publication places the university within the top 20 in the UK. [52] The university is also ranked fourth of the new universities in attracting research funds from the Higher Education Funding Council for England.[52]

MMU has eight research institutes:

  • Dalton Research Institute (DRI)
  • Education and Social Research Institute (ESRI)
  • Healthcare Science Research Institute (HSRI)
  • Institute of Humanities and Social Science Research (HSSR)
  • Institute for Performance Research (IPR)
  • Manchester Institute for Research and Innovation in Art and Design (MIRIAD)
  • Research Institute for Business and Management (RIBM)
  • Research Institute for Health and Social Change (RIHSC)

Students' union[edit]

Main article: The Union MMU

The students' union has buildings on both campuses. The Students' Union exists to represent all members at the Manchester Metropolitan University and students on accredited external courses. The union is controlled by the Union Officers Group formed of six students and recent graduates of the university, elected by the students to control the Union on their behalf. A shop especially designed to cater to the university students has also been set up inside the Students' Union.

The students' union will be moving, in January 2015, to a new purpose built building on Higher Cambridge Street, next to Cambridge and Cavendish Halls of Residence.

International partnerships[edit]

The university has developed international relationships with the following institutions:[53] American Hotel Academy, Brasov, Romania, University of Nicosia, Cyprus, University of Economics, Prague, Aalborg University, Denmark, Blaise Pascal University, Clermont-Ferrand, École Supérieure de Commerce de Montpellier, Montpellier and University of Savoy, France.

In Germany, Hochschule Bochum, Bochum and Viadrina European University, Frankfurt (Oder).

In Italy, University of Padua, Padova. In Lithuania, ISM University of Management and Economics, Vilnius. In Spain, Pablo de Olavide University, Seville, University of Murcia and University of Seville.

In the Netherlands, Radboud University Nijmegen

In Australia, Deakin University, Geelong, Melbourne, Warrnambool, Victoria, Flinders University, Adelaide, University of Technology, Sydney, University of Newcastle, Newcastle.

In Hong Kong, Hong Kong Baptist University and, Bridgewater State University,

In the USA, Buffalo State College, East Carolina University, Louisiana State University, Texas Tech University and University of North Carolina.

In Canada, Ryerson University.

Notable alumni[edit]

This partial list of alumni of Manchester Metropolitan University includes some who attended institutions which became part of present-day MMU.

  1. ^ "Financial Statements Year Ended 31 July 2015" (PDF).
  2. ^
  3. ^ a b PRESS, Prof. Malcolm Colin. Who's Who. 2015 (online Oxford University Press ed.). A & C Black, an imprint of Bloomsbury Publishing plc.  (subscription required)
  4. ^ a b c d "2014/15 Students by HE provider, level, mode and domicile" (XLSX). Higher Education Statistics Agency. Retrieved 19 January 2016.
  5. ^ "Table 0a – All students by institution, mode of study, level of study, gender and domicile 2006/07" (Microsoft Excel spreadsheet). Higher Education Statistics Agency. Retrieved 11 April 2008.
  6. ^ a b "About Manchester Metropolitan University". Retrieved 30 August 2012.
  7. ^ "The Times Good University Guide 2015: Most Applications". The Good University Guide. London. Retrieved 16 August 2014. (subscription required)
  8. ^ a b c "School of Physiotherapy launched | News & Events | Manchester Metropolitan University". Retrieved 2015-11-02.
  9. ^ Brian S. Pullan; Michele Abendstern. A History of the University of Manchester, 1973-90. Retrieved 2015-11-02.
  10. ^ "Department of Health Professions · Manchester Metropolitan University". Retrieved 2015-11-02.
  11. ^ "Campus Redevelopments". Retrieved 15 February 2011.
  12. ^ "The Faculty of Humanities, Languages and Social Science". MMU. Retrieved 16 February 2012.
  13. ^ "Faculty of Science and Engineering". MMU. Retrieved 26 April 2012.
  14. ^ "IRM". MMU. Retrieved 26 April 2012.
  15. ^ "The Faculty of Art and Design". MMU. Retrieved 16 February 2012.
  16. ^ "The Holden Gallery". MMU. Retrieved 16 February 2012.
  17. ^ "New Spaces. New Facilities. New building.". Retrieved 2015-11-02.
  18. ^ "Manchester School of Art". Retrieved 2015-11-02.
  19. ^ "Accounts 0066" (PDF). Retrieved 2015-11-02.
  20. ^ a b "Campus Redevelopment". Retrieved 2015-11-02.
  21. ^ MMU Library Electronic Services Development Team. "MMU Special Collections". Retrieved 15 July 2015.
  22. ^ Rogerson, Ian (1978) "Library", in: The Making of a Polytechnic Building: All Saints Building. Manchester: Manchester Polytechnic; pp. 34–36
  23. ^ "Nowal". Retrieved 15 July 2015.
  24. ^, MMU Cheshire Web Officer -. "Meet the team | Cheshire Campus". Retrieved 2016-05-04.
  25. ^, MMU Cheshire Web Officer -. "Who we are and what we do | Cheshire Campus". Retrieved 2016-05-04.
  26. ^, MMU Cheshire Web Officer -. "News Article | News & Events | Department of Business & Management | Cheshire Campus". Retrieved 2016-05-04.
  27. ^, Cheshire Web Officer -. "About Us | Department of Exercise & Sport Science | Cheshire Campus". Retrieved 2016-05-04.
  28. ^, Web Team, Marketing, Communications & Development,. "Sarah Storey's world record warmly welcomed | News & Events | Manchester Metropolitan University". Retrieved 2016-05-04.
  29. ^, MMU Cheshire Web Officer -. "News Archive Article | MMU Cheshire". Retrieved 2016-05-04.
  30. ^, MMU Cheshire Web Officer -. "News Archive Article | MMU Cheshire". Retrieved 2016-05-04.
  31. ^, MMU Cheshire Web Officer -. "News Article | Cheshire Campus". Retrieved 2016-05-04.
  32. ^
  33. ^
  34. ^ "Birley Fields Proposals". MMU. Retrieved 16 February 2012.
  35. ^ "Board of Governors". MMU. Retrieved 15 February 2012.
  36. ^ "Executive". MMU. Retrieved 15 February 2012.
  37. ^ BROOKS, Prof. John Stuart. Who's Who. 2014 (online Oxford University Press ed.). A & C Black, an imprint of Bloomsbury Publishing plc.  (subscription required)
  38. ^ Morgan, John (2014-12-12). "Manchester Met appoints Malcolm Press as next v-c". Times Higher Education. Retrieved 2015-11-02.
  39. ^ a b c "MMU Financial Statements Year Ended 31 July 2011" (PDF). Retrieved 2015-11-02.
  40. ^ "QS World University Rankings 2016/17 - United Kingdom". Quacquarelli Symonds Ltd. Retrieved 7 September 2016.
  41. ^ "QS World University Rankings 2016/17". Quacquarelli Symonds Ltd. Retrieved 7 September 2016.
  42. ^ "World University Rankings 2016-17 - United Kingdom". Times Higher Education. Retrieved 21 September 2016.
  43. ^ "World University Rankings 2016-17". Times Higher Education. Retrieved 21 September 2016.
  44. ^ "University League Table 2017". The Complete University Guide. Retrieved 25 April 2016.
  45. ^ "University league tables 2017". The Guardian. 23 May 2013. Retrieved 23 May 2016.
  46. ^ "The Times and Sunday Times University Good University Guide 2017". Times Newspapers. Retrieved 23 September 2016.
  47. ^ "Applications (choices) and accepted applicants to each UCAS member university and college 2011". Retrieved 2015-11-02.
  48. ^ "Unistats| THE MANCHESTER METROPOLITAN UNIVERSITY". Retrieved 2015-11-02.
  49. ^ "Manchester Metropolitan University". Retrieved 2015-11-02.
  50. ^ "University league table 2015 - the complete list". the Guardian. Retrieved 15 July 2015.
  51. ^ "Degree results show what class of degree students achieved". Retrieved 15 February 2012.
  52. ^ a b "Manchester Metropolitan University". Retrieved 24 June 2012.
  53. ^ "About Manchester Metropolitan University". Retrieved 2015-11-02.
  54. ^ "FREE LUNCH—Korean Barbecue With Daley - Myspace". Myspace. Retrieved 15 July 2015.
  55. ^ "A happy homecoming for graduate Vernon Kay". The Bolton News. Newsquest Media Group. 10 July 2009. Retrieved 8 October 2012.
  56. ^ Barry, Chris (13 August 2004). "Pure passion drives David". Manchester Evening News. Retrieved 1 March 2015.

External links[edit]


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text:
From Wikipedia, the free encyclopedia
Jump to: navigation, search
Norethandrolone structure.png
Clinical data
Trade names Nilevar, Pronabol
AHFS/ International Drug Names
Routes of
ATC code A14AA09 (WHO)
Legal status
Legal status
Synonyms Noretandrolone; CB-8022
CAS Number 52-78-8 YesY
PubChem (CID) 5858
ChemSpider 5649 YesY
UNII P7W01638W6 YesY
KEGG D07127 YesY
ECHA InfoCard 100.000.140
Chemical and physical data
Formula C20H30O2
Molar mass 302.451 g/mol
3D model (Jmol) Interactive image

Norethandrolone (INN, BAN) (brand names Nilevar, Pronabol), also known as 17α-ethyl-19-nortestosterone or 17α-ethyl-19-norandrost-4-en-17β-ol-3-one, as well as ethylnandrolone or ethylnortestosterone, is a synthetic androgenic-anabolic steroid (AAS) and progestogen of the 17α-alkylated and 19-nortestosterone groups.[1] It was synthesized at G. D. Searle & Company in 1953 and was originally studied as a progestin, along with norethisterone and noretynodrel, but ultimately was not marketed as such.[2] In 1955, it was re-examined for testosterone-like activity and was found to have similar anabolic activity to testosterone but only one-sixteenth the androgenic potency.[2][3]

Norethandrolone was introduced in the United States as an AAS in 1965 under the trade name Nilevar[4] but was withdrawn from the market in the 1980s due to concerns of cholestatic jaundice.[3] Norethandrolone is now only marketed in Australia, France, and Switzerland, and as with all 17α-alkylated oral steroids, long-term use in high doses may result in elevated liver enzymes and consequently cirrhosis.[5] It is used in the treatment of muscle wasting,[3] patients with severe burns, after severe trauma, and for certain forms of aplastic anemia.

See also[edit]

  1. ^ J. Elks (14 November 2014). The Dictionary of Drugs: Chemical Data: Chemical Data, Structures and Bibliographies. Springer. pp. 885–. ISBN 978-1-4757-2085-3.
  2. ^ a b Charles D. Kochakian (6 December 2012). Anabolic-Androgenic Steroids. Springer Science & Business Media. pp. 380–. ISBN 978-3-642-66353-6.
  3. ^ a b c Walter Sneader (23 June 2005). Drug Discovery: A History. John Wiley & Sons. pp. 206–. ISBN 978-0-471-89979-2.
  4. ^ W., Llewellyn. (2005). Anabolics. p. 156.
  5. ^ D., Lednicer. (2011). Steroid Chemistry at Glance. Wiley. p. 67.

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text:
Nusrat Bhutto

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Mother of Democracy
مادر جمہوریت

Begum Nusrat Bhutto
بیگم نصرت بھٹو
Tariq Bhatti & Mohtarma Nusrat Bhutto (cropped).jpg
(بیگم نصرت بھٹو (مادر جمہوریت
2nd Chairperson of Pakistan Peoples Party
In office
4 April 1979 – 10 January 1984
Preceded by Zulfikar Ali Bhutto
Succeeded by Benazir Bhutto
First Lady of Pakistan
In office
20 December 1971 – 5 July 1977
Succeeded by Shafiq Jahan Zia-ul-Haq
Personal details
Born Nusrat Ispahani
(1929-03-23)23 March 1929
Esfahan, Iran
Died 23 October 2011 (aged 82)
Dubai, United Arab Emirates
Nationality Pakistani, Iranian
Political party Pakistan People's Party
Spouse(s) Zulfikar Ali Bhutto
Children Benazir, Murtaza, Shahnawaz
Religion Shia Islam

Nusrat Bhutto (Urdu: بیگم نصرت بھٹو, Sindhi: بیگم نصرت ڀٽو; Kurdish: بێگوم نوسره‌ت بوتو; born Nusrat Ispahani; March 23, 1929 – October 23, 2011) was an Iranian-Pakistani public figure who served as Pakistan's first lady between 1971 until the 1977 coup, and as a senior member of the federal cabinet between 1988 and 1990.

Born in Isfahan to an upper-class Shia Persian family which had settled in Mumbai before moving to Karachi after the Partition of India. Ispahani joined a paramilitary women's force in 1950, but left a year later when she married Zulfikar Ali Bhutto. She moved to Oxfordshire with her husband who than was pursuing his legal education. She returned to Pakistan alongside Bhutto who went on to serve as the Foreign Minster. After her husband founded Pakistan Peoples Party, Ispahani worked to lead party's women’s wing.[1]

After Bhutto was elected as the Prime Minister in 1971, Ispahani became the First Lady of Pakistan and remained so until her husband's removal in 1977. She immediately succeeded her husband as the leader of the Peoples Party, and, while under house arrest, fought an unsuccessful legal battle to prevent her husband's execution. After Bhutto's execution, Ispahani, along with her children, went into exile to London, from where in 1981 she co-founded the Movement for the Restoration of Democracy, a nonviolent opposition to Zia's regime.[2]

Ispahani returned to Pakistan in 1988, as the party's national leader she campaigned for her daughter, Benazir's, election to the premiership. After the People's Party's victory in 1988, she joined Benazir's cabinet as a minister without portfolio while representing Larkana District in the National Assembly.[3] She remained in the cabinet until Benazir's government was dismissed in 1990. Afterwards, during a family dispute between her son, Murtaza, and her daughter, Benazir, Ispahani favoured Murtaza leading Benazir to sack Ispahani as the party leader.[4] Ispahani stopped talking to the media and refrained from political engagement's after the assassination of her son Murtaza in 1996 during a police encounter, during her daughter's second government.[5][6]

Ispahani moved to Dubai in 1996, suffering from Alzheimer's disease, she was kept out of public eye's by Benazir, until she made headline's in 23 October 2011 when she died.[7] Ispahani's body was flown to Pakistan, and was buried next to the grave of her husband Zulfikar at Garhi Khuda Bakhsh two day's later. In Pakistan, Ispahani is remembered for her contribution to empowerment of women in Pakistan and for advocating for democracy in Pakistan, for which she is dubbed as "Mādar-e-Jamhooriat" (English "Mother of Democracy"), a title she was honored with by the parliament following her death.[8]

See also: Bhutto family

Nusrat Ispahani was born on 23 March 1929 in Esfahan, Iran, hailing from the wealthy Hariri family. She had Kurdish descent.[2][9] Her father was a wealthy Iranian businessman who initially lived in Bombay and the moved to Karachi, Pakistan before the independence of Pakistan in 1947.[2] Before emigrating to Pakistan, Nusrat attended and was educated at the University of Isfahan where she obtained a Bachelor of Arts (B.A.) in Humanities in 1950.[2] Nusrat met Zulfikar Ali Bhutto in Karachi where they got married on 8 September 1951.[2] She was Zulfikar Ali Bhutto's second wife, and they had four children together: Benazir, Murtaza, Sanam and Shahnawaz. With the exception of Sanam, she outlived her children. Benazir's widower and Nusrat's son-in-law Asif Ali Zardari was the President of Pakistan from 9 September 2008 till 8 September 2013.

Family and political career[edit]

Nusrat Bhutto at a wedding.

As first lady from 1973 to 1977,[2] Nusrat Bhutto functioned as a political worker and accompanied her husband on a number of overseas visits. In 1979, after the trial and execution of her husband, she succeeded her husband as leader of the Pakistan Peoples Party as chairman for life. She led the PPP's campaign against General Muhammad Zia-ul-Haq's regime. Alongside her daughter Benazir Bhutto, she was arrested numerous times and placed under house arrest and in prison in Sihala. Nusrat Bhutto was attacked by police with batons while attending a cricket match at Gaddafi Stadium in Lahore, when the crowd began to raise pro Bhutto slogans.

In 1982, ill with cancer, she was given permission to leave the country by the military government of Genera Zia-ul-Haq for medical treatment in London at which point her daughter, Benazir Bhutto, became acting leader of the party, and, by 1984, the party chairman.[10][11]

After returning to Pakistan in the late 1980s, she served two terms as a Member of Parliament to the National Assembly from the family constituency of Larkana, Sindh. During the administrations of her daughter Benazir, she became a cabinet minister and Deputy Prime Minister. In the 1990s, she and Benazir became estranged when Nusrat took the side of her son Murtaza during a family dispute but were later reconciled after Murtaza's murder. She lived the last few years of her life with her daughter's family in Dubai, United Arab Emirates and later suffered from the combined effects of a stroke and Alzheimer's disease.[2]

Illness and death[edit]

Bhutto was suspected of suffering from cancer in 1982, the year when she left Pakistan for medical treatment. For the last several years of her life, she had also been suffering from Alzheimer's disease.[12] In the mid-1990s, particularly after the death of her son Mir Murtaza Bhutto in 1996, she withdrew from public life. Party sources suggest this may also have coincided with the time that she began to show symptoms of Alzheimer’s.[citation needed]

According to her senior party leader, Bhutto's disease was so advanced that she was even unaware of the assassination of her daughter, Benazir. She used a ventilator until her last days. She died at age 82 in Dubai on 23 October 2011.[12] Her body was flown to her hometown of Garhi Khuda Bakhsh in Larkana District the next day, and was buried next to her husband and children in the Bhutto family mausoleum at a ceremony attended by thousands of mourners.

See also[edit]

  1. ^ Newspaper, From the (2011-10-24). "Nusrat Bhutto's death — end of an era". DAWN.COM. Retrieved 2016-10-30.
  2. ^ a b c d e f g "Bhutto".
  3. ^ "Begum Nusrat Bhutto: First Lady of Pakistan who fought to keep her". The Independent. 2011-10-28. Retrieved 2016-10-30.
  4. ^ Ali, Tariq (2007-12-13). "Daughter of the West". London Review of Books. pp. 3–9. ISSN 0260-9592. Retrieved 2016-10-30.
  5. ^ "Nusrat goes with many historic secrets". Retrieved 2016-10-30.
  6. ^ "Touched by tragedy: Exclusive extracts from Fatima Bhutto's new book - Times of India". The Times of India. Retrieved 2016-10-30.
  7. ^ Leading News (25 October 2011). "Mother of Democracy Nusrat Bhutto laid to rest". Pakistan Tribune. Retrieved 3 November 2011.
  8. ^ Gilani, MBBS, Syed Nazir. "Death in six instalments". Pakistan Observer. Retrieved 3 November 2011.
  9. ^ "Untitled Document".
  10. ^ "Miss Benazir Bhutto, the daughter of the former Prime Minister, Zulfikar Bhutto, and chairman of the Pakistan People's Party has been released from detention and has gone to Paris to be with her cancer-stricken mother". Financial Times. 11 January 1984.
  11. ^ Hall, Carla (4 April 1984). "The April of her freedom five years later, Benazir Bhutto's plea for Pakistan". Washington Post.
  12. ^ a b "Nusrat Bhutto: A tragic life". All Voices. 13 October 2011. Retrieved 26 June 2013.

External links[edit]

Party political offices
Preceded by
Zulfikar Ali Bhutto
Chairperson of the Pakistan Peoples Party
Benazir Bhutto was acting chairperson from 1982 to 1984

Succeeded by
Benazir Bhutto


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Portsmouth Naval Prison

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Portsmouth Naval Prison in 2006

Portsmouth Naval Prison is a former U.S. Navy and Marine Corps prison on the grounds of the Portsmouth Naval Shipyard (PNS) in Kittery, Maine. The building has the appearance of a castle. The reinforced concrete naval prison was occupied from 1908 until 1974.

Fort Sullivan and Camp Long[edit]

The island site was first used in 1775 during the Revolution when the New Hampshire militia, commanded by General John Sullivan, constructed an earthwork defense called Fort Sullivan atop the bluff. In conjunction with Fort Washington across the Piscataqua River on Pierce Island, it guarded the channel to Portsmouth. The militia withdrew about three years later. The fort was reactivated for the War of 1812 in 1814. In 1863, it was rebuilt to protect Portsmouth against attacks by the Confederate navy. After 1866, Fort Sullivan was dismantled. Camp Long, named for Secretary of the Navy John Long, was erected nearby during the Spanish–American War. From July 11 to mid-September in 1898, the stockade housed 1,612 Spanish prisoners, including Admiral Pascual Cervera, until returned to Spain.[1]

"Alcatraz of the East"[edit]

Prison from across river, c. 1913

When Camp Long was dismantled in 1901, the site became available for a naval prison. Constructed between 1905–1908, the brig was modeled after Alcatraz, set on an island with tidal currents to deter escape. Colonel Kelton of the Marine Corps was in command when the first Navy prisoners arrived in 1908. It would eventually house Marine inmates as well. The central crenellated tower, roofed in copper, was erected in 1912. Lieutenant Commander Thomas Osbourne assumed command in 1917. Called "the Father of Naval Corrections," Osbourne and 2 others went undercover in the prison to see what changes needed to be made, including living conditions. During World War I, the prison housed wartime convicts, reaching a maximum of 2,295 in 1918. Two wings were added—in 1942 the northeast wing, and in 1943 the unornamented southwest wing, dubbed "the Fortress," which rises sheer beside the rocky shore. Maximum occupancy reached 3,088 in 1945.[1]

Office of Naval Intelligence[edit]

After the German surrender ended World War II fighting in Europe on May 5, 1945, U-boats surrendering to United States naval forces were escorted to Portsmouth so engineers at the Portsmouth Naval Shipyard might study their design features. U-805, U-873, U-1228 and U-234 were towed to the Portsmouth Naval Shipyard between 15 and 19 May. The Office of Naval Intelligence (ONI) had interrogators available to question the submarine crewmen at the prison. The interrogations were classified at the time because of potential military value of information collected about German submarine, jet aircraft, ballistic missile, guided bomb, and nuclear weapons technology. U-234 had been bound for Japan carrying 1,232 lb (559 kg) of uranium oxide, a disassembled Messerschmitt Me 262 jet fighter, tons of prototypes and technical documents relating to new weapons, and several senior weapons technicians.[2] The commanding officer of U-873 had conducted submarine-launched ballistic missile experiments with his brother Ernst Steinhoff, who was Director for Flight Mechanics, Ballistics, Guidance Control, and Instrumentation at the Peenemünde Army Research Center. Kapitänleutnant Friedrich Steinhoff was slapped by a large, husky Marine guard until his face was swollen and bleeding, and died in a Charles Street Jail cell after two days of interrogation.[3] Despite subsequent declassification of documents, it is unclear if ONI realized Steinhoff's ballistic missile connections. Similar uncertainty remains about disposal of the uranium oxide aboard U-234.[4]

There was inadequate preparation to deal with the arriving U-boats. United States Navy prize crews scattered possessions of the U-boat crewmen as they searched for potential sabotage and intelligence information while the U-boats were en route to Portsmouth. Scattered documents and clothing were perceived as fire and access hazards while the U-boats awaited inspection by shipyard engineers. Material scattered aboard the U-boats was stockpiled in the prison entrance lobby where it was looted by prison guards. Decorations and personal possessions taken from U-boat crewmen were retained as souvenirs rather than returned to prisoners of war as required by the Geneva Convention.[5]

Cold War[edit]

The brig was used throughout the Korean War and almost to the end of the Vietnam War. During warmer months, it was not uncommon for boats navigating the river to hear shouts and whistles coming from within barred windows of "the Fortress." In 1974 the Department of Defense developed a three-tiered, regional correctional facility plan. Inmates would be placed depending on the service, sentence length, geographical location, and treatment programs. First-tier offenders are those with sentences less than a year, second-tier up to 7 years. Male convicts from all the services sentenced to punitive discharge and incarceration longer than 7 years are confined at the third-tier — the maximum-security U. S. Disciplinary Barracks at Fort Leavenworth, Kansas. The Portsmouth Naval Prison, built to be a modern correctional facility for a navy which had once disciplined by flogging and capital punishment, was rendered obsolete. After containing about 86,000 military inmates over its 66-year operation, the brig closed in 1974, its maintenance thereafter contributing to shipyard overhead.The Navy briefly used the prison in the early 1980s to train military corrections officers. Volunteer Inmates from the Rockingham County Jail were sometimes used.

In popular culture[edit]

In the 1973 movie The Last Detail, Seaman Larry Meadows (Randy Quaid) is escorted by petty officers Billy "Badass" Buddusky (Jack Nicholson) and Mule Mulhall (Otis Young) to the Portsmouth Naval Prison. Meadows has been sentenced to 8 years confinement for trying to steal $40 from a charity box. But because of his harsh sentence, the guards feel sorry for Meadows. They decide to show the naive sailor the time of his life before arriving on Seavey's Island (where another location substitutes for the actual brig).

In W.E.B. Griffin's novel "Semper Fi," Corporal Kenneth "Killer" McCoy is assigned to transport prisoners from San Diego, California to the Portsmouth Naval Prison.

The prison is referred to in Stephen King's 1982 novella The Body, later filmed as Stand by Me.

The prison and shipyard locations were used to depict a Russian shipyard in the 1978 TV Movie The Defection of Simas Kudirka starring Alan Arkin. [6]

The building was previously one of 14 structures the Portsmouth Naval Shipyard had considered for outleasing and renovation. Local developer Joseph Sawtelle estimated the cost to renovate the immense edifice into civilian office space, including removing lead paint and asbestos, would cost more than $10 million. But plans to adapt the prison were halted a month after Sawtelle's death in 2000, and abandoned altogether after military base security was tightened following the terrorist attacks of September 11, 2001 in New York City and Washington D.C.[7] In 2008, it was considered as a home for the Air Force Cyber Command.

  • Blair, Clay Hitler's U-Boat War: The Hunted 1942-1945 Random House (1998) ISBN 0-679-45742-9
  • Paterson, Lawrence Black Flag: The Surrender of Germany's U-Boat Forces MBI Publishing (2009) ISBN 0760337543

  1. ^ a b "History of Fort Sullivan". Archived from the original on 2004-12-17. Retrieved 2006-09-08.
  2. ^ Blair pp.692&693
  3. ^ Paterson pp.55-57&60
  4. ^ Blair pp.689&694
  5. ^ "Report of the Naval Inspector General Regarding Irregularities Connected with the Handling of Surrendered German Submarines". U-boat Archive. Retrieved 2012-10-05.
  6. ^ http://www.imdb.com/title/tt0077418/
  7. ^ Fabrizio, Richard (2001-02-25). "Naval prison plans dead in the water". Portsmouth Herald. Retrieved 2006-09-08.  External link in |work= (help)

External links[edit]

Coordinates: 43°04′34″N 70°43′52″W / 43.0761°N 70.7311°W / 43.0761; -70.7311


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Position circle

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A position circle is a circle that can be measured both from a chart and from the surface of the earth for the purpose of position fixing. The circles can be measured by sextant. Two overlapping position circles can be used to give a position fix.

See also[edit]


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Renaissance dance

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Renaissance dances belong to the broad group of historical dances.

During the Renaissance period, there was a distinction between country dances and court dances. Court dances required the dancers to be trained and were often for display and entertainment, whereas country dances could be attempted by anyone. At Court, the formal entertainment would often be followed by many hours of country dances which all present could join in. Dances described as country dances such as Chiarantana or Chiaranzana remained popular over a long period - over two centuries in the case of this dance. A Renaissance dance can be likened to a ball.

Knowledge of court dances has survived better than that of country dances as they were collected by dancing masters in manuscripts and later in printed books. The earliest surviving manuscripts that provide detailed dance instructions are from 15th century Italy. The earliest printed dance manuals come from late 16th century France and Italy. The earliest dance descriptions in England come from the Gresley manuscript c.1500 found in the Derbyshire Record Office, D77 B0x 38 pp 51–79. These have been recently published as "Cherwell Thy Wyne (Show your joy): Dances of fifteenth-century England from the Gresley manuscript".[1] The first printed English source appeared in 1652, the first edition of Playford.

The dances in these manuals are extremely varied in nature. They range from slow, stately dances (bassadance, pavane, almain) to fast, lively dances (galliard, coranto, canario). The former, in which the dancers' feet did not leave the ground were styled the dance basse while energetic dances with leaps and lifts were called the haute dance.[2] Some were choreographed, others were improvised on the spot.

French painting of the volta, from Penhurst Place, Kent, often wrongly assumed to be of Elizabeth I.

One dance for couples, a form of the galliard called lavolta, involved a rather intimate hold between the man and woman, with the woman being lifted into the air while the couple made a 34 turn. Other dances, such as branles or bransles, were danced by many people in a circle or line.

Fifteenth-century Italian dance[edit]

Our knowledge of 15th-century Italian dances comes mainly from the surviving works of three Italian dance masters: Domenico da Piacenza, Antonio Cornazzano and Guglielmo Ebreo da Pesaro. Their work deals with similar steps and dances, though some evolution can be seen. The main types of dances described are bassa danze and balletti. These are the earliest European dances to be well-documented, as we have a reasonable knowledge of the choreographies, steps and music used.

  1. ^ Ann and Paul Kent DHDS,2013 ISBN 978-0-9540988-1-0
  2. ^ Liza Picard (2005). Elizabeth's London. Macmillan. p. 215. ISBN 978-0-312-32566-4.

  • Ebreo, Guglielmo (1993). On the practice or art of dancing (orig. pub. 1463) edited by Barbara Sparti. Oxford: Clarendon Press. ISBN 0-19-816574-9.
  • Caroso, Fabritio (1986). Courtly Dance of the Renaissance - a new translation and edition of Nobilta di Dame (orig. pub. 1600) edited by Julia Sutton. New York: Dover Publications Inc. ISBN 0-486-28619-3.
  • A William Smith (1995). Fifteenth-century dance and music: the complete transcribed Italian treatises and collections in the tradition of Domenico da Piacenza (vol 1). Stuyvesant, NY: Pendragon Press. ISBN 0-945193-25-4.
  • A William Smith (1995). Fifteenth-century dance and music: the complete transcribed Italian treatises and collections in the tradition of Domenico da Piacenza (vol 2). Stuyvesant, NY: Pendragon Press. ISBN 0-945193-57-2.
  • Date Van Winkler Keller; Genevieve Shimer (1990). The Playford Ball 103 Early English Country Dances As Interpreted by Cecil Sharp and his Followers. A Cappella Books and the Country Dance and Song Society. ISBN 1-55652-091-3.

External links[edit]

Modern performance[edit]

Many groups exist that recreate historical music and dance from the Renaissance period


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Rift Valley Province

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Rift Valley Province
Mkoa wa Bonde la Ufa
Former Province
Rift Valley
Rift Valley
Location in Kenya.
Location in Kenya.
Coordinates: 0°30′N 36°0′E / 0.500°N 36.000°E / 0.500; 36.000Coordinates: 0°30′N 36°0′E / 0.500°N 36.000°E / 0.500; 36.000
Country  Kenya
No. of Counties: 14
Capital Nakuru
 • Total 182,505.1 km2 (70,465.6 sq mi)
Population (2009)
 • Total 10,006,805
 • Density 55/km2 (140/sq mi)
Time zone EAT (UTC+3)

Rift Valley Province (Swahili: Mkoa wa Bonde la Ufa) of Kenya, bordering Uganda, was one of Kenya's 8 provinces, before the Kenyan general election, 2013. Rift Valley Province was the largest and one of the most economically important provinces in Kenya. It was dominated by the Kenya Rift Valley which passes through it and gives the province its name. According to the 2009 Census, the former province covered an area of 182,505.1 square kilometres (45,098,000 acres; 70,465.6 sq mi) and would have had a population of 10,006,805,[1][2] making it the largest and most populous province in the country. The bulk of the provincial population is a strip between former Nairobi and Nyanza Province. The capital was the town of Nakuru.

As of March 2013 after the Kenyan general election, 2013, the Province was divided into counties and Rift Valley Province was no more.[3]

Code County Former Province Area (km2) Population
Census 2009
23 Turkana Rift Valley 71,597.8 855,399 Lodwar
24 West Pokot Rift Valley 8,418.2 512,690 Kapenguria
25 Samburu Rift Valley 20,182.5 223,947 Maralal
26 Trans Nzoia Rift Valley 2,469.9 818,757 Kitale
27 Uasin Gishu Rift Valley 2,955.3 894,179 Eldoret
28 Elgeyo-Marakwet Rift Valley 3,049.7 369,998 Iten
29 Nandi Rift Valley 2,884.5 752,965 Kapsabet
30 Baringo Rift Valley 11,075.3 555,561 Kabarnet
31 Laikipia Rift Valley 8,696.1 399,227 Nanyuki
32 Nakuru Rift Valley 7,509.5 1,603,325 Nakuru
33 Narok Rift Valley 17,921.2 850,920 Narok
34 Kajiado Rift Valley 21,292.7 687,312 Kajiado
35 Kericho Rift Valley 2,454.5 752,396 Kericho
36 Bomet Rift Valley 1,997.9 730,129 Bomet
Totals 182,505.1 10,006,805 -

Map of Kenya, showing its provinces

The Great Rift Valley runs south through Kenya from Lake Turkana in the north and has several unique geographical features, including the Elgeyo escarpment which is a popular tourist attraction.

Apart from the Rift Valley itself, the area has other important geographic features such as: the extinct volcanoes Mount Longonot and Mount Suswa and Lake Baringo, Lake Bogoria, Lake Magadi, Lake Nakuru, Lake Naivasha, the Suguta Valley, and Lake Turkana.

A large part of Kenya is underlain by Precambrian basement, while the Kenya rift basin (a typical extensional basin) hosts Tertiary volcanics that cover Mesozoic sediments (Recently these sediments have been considered for oil exploration).[4] The sedimentary basins evolved along the Anza trough during the Late Paleozoic to Early Tertiary times through extension tectonics during the major Gondwanaland breakup. In the Miocene Period the region underwent intermittent uplift and subsidence along major boundary faults accompanied by the large outpouring of lava flows. The Anza trough intersects the modern rift valley in the area of Lake Turkana. Rifting still continues today; primarily in the north, where active volcanoes are more plentiful.

The highlands provide adequate rainfall for farming and agriculture which is the economic base of the residents of the Rift Valley. Tea from the highlands in the Kericho district enjoy a worldwide reputation, but horticulture is an important part of the district's economy and cattle raising is also practised to a large extent.

The full economic potential of the Rift Valley region is, however, far from fully exploited, though the current growth in population and improved education may change this in a near future. People in the province are still mostly rural, but urbanisation is gradually increasing; new cities and towns contain the rural-urban migration and, provided the right policies are instituted, the Rift Valley province will be able to emerge as a national economic and cultural hub.

The people of the Rift Valley are a mesh work of different ethnic identities, and the Kalenjin and the Maasai are two of the best known ethnic groups. Most of Kenya's top runners comes from the Kalenjin community. The Maasai people have the most recognizable cultural identity, both nationally and internationally, and serve as Kenya's international cultural symbol.

See also[edit]

External links[edit]

Media related to Rift Valley Province at Wikimedia Commons


text:
Thane (disambiguation)

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Thane is a city in Maharashtra, India.

  • Thegn, a retainer or official of a king or nobleman in medieval England and Scandinavia or a class of aristocracy, spelled thane in Shakespearean English
  • Thane (Scotland), a hereditary non-military tenant of the Crown in medieval Scotland

Other uses[edit]

See also[edit]


text:
Tom Gomes

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Tom Gomes (born February 5, 1978) is a former drummer for the metalcore bands Aftershock, Catchthirteen, and Killswitch Engage.[1]

He joined Killswitch Engage after the recording of their 2002 record Alive or Just Breathing, and performed with the band during their Road Rage tour of the United Kingdom and their performance at Ozzfest, in 2002 and 2003 respectively. He then left the band and was replaced by Blood Has Been Shed drummer Justin Foley. Gomes was with the band during the departure of former vocalist Jesse Leach and the entry of his replacement, Howard Jones, and also participated in the writing of the song "When Darkness Falls". Gomes also appears on the band's re-recorded version of "Fixation on The Darkness", which featured Jones' vocals on the bands re-release of Alive or Just Breathing.

He is now in the rock band 'Something Of A Silhouette'. Differing from his hardcore roots in Aftershock and Killswitch Engage, Something Of A Silhouette sounds more melodic and dark. His girlfriend Sara Saffery sings in the band as well. He also started a project with former Aftershock vocalist Toby Dutkiewicz, who is Adam Dutkiewicz's brother as well as the owner of Devil's Head Recordings. This project is more similar to Gomes previous metalcore acts. Tom Gomes also appears as a guest drummer for 36 Crazyfists album Rest Inside the Flames on the song "We Cannot Deny". Tom co-wrote the music for the song along with 36 Crazyfists guitarist Steve Holt.


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Transit of Venus, 2004

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A photograph taken at 15:39 Hong Kong time (07:39 UTC) from Tuen Mun, New Territories, Hong Kong.

The second most recent transit of Venus observed from Earth took place on June 8, 2004. The event received significant attention, since it was the first Venus transit after the invention of broadcast media. No human alive at the time had witnessed a previous Venus transit since that transit occurred on December 6, 1882.

European Southern Observatory (ESO) and the European Association for Astronomy Education (EAAE) launched the VT-2004 project, together with the Institut de Mécanique Céleste et de Calcul des Éphémérides (IMCCE) and the Observatoire de Paris in France, as well as the Astronomical Institute of the Academy of Sciences of the Czech Republic. This project had 2,763 participants all over the world, including nearly 1,000 school classes. The participants made a measurement of the astronomical unit (AU) of 149 608 708 km ± 11 835 km[1] which had only a 0.007% difference to the accepted value.

Where the 2004 transit was visible

The entire transit was visible from Europe, most of Asia, and almost all of Africa. The beginning was visible before sunset from easternmost Asia and Australia. The end was visible after sunrise from the westernmost fringe of Africa, eastern North America, and much of South America. The transit was not visible at all from western North America, southern South America, Hawaii, or New Zealand. The regions from which the transit were visible are shown on the map to the right.

The following table and image give times for various events (respectively, first contact, second contact, the midpoint, third contact and fourth contact) during the transit on June 8, 2004 for a hypothetical observer at the center of the Earth. Due to parallax, times observed at different points on Earth may differ from the following by as much as ±7 minutes.

Times (UTC) for observations
of the transit on June 8, 2004
05:13:29 05:32:55 08:19:44 11:06:33 11:25:59
The path of Venus across the Sun (moving left to right)

See also[edit]

External links[edit]


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Twin paradox

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"Clock problem" redirects here. For mathematical problems involving the positions of the hands on a clock face, see Clock angle problem.

In physics, the twin paradox is a thought experiment in special relativity involving identical twins, one of whom makes a journey into space in a high-speed rocket and returns home to find that the twin who remained on Earth has aged more. This result appears puzzling because each twin sees the other twin as moving, and so, according to an incorrect[1][2][3] and naive[4][5] application of time dilation and the principle of relativity, each should paradoxically find the other to have aged more slowly. However, this scenario can be resolved within the standard framework of special relativity: the travelling twin's trajectory involves two different inertial frames, one for the outbound journey and one for the inbound journey, and so there is no symmetry between the spacetime paths of the two twins. Therefore, the twin paradox is not a paradox in the sense of a logical contradiction.

Starting with Paul Langevin in 1911, there have been various explanations of this paradox. These explanations "can be grouped into those that focus on the effect of different standards of simultaneity in different frames, and those that designate the acceleration [experienced by the travelling twin] as the main reason...".[6] Max von Laue argued in 1913 that since the traveling twin must be in two separate inertial frames, one on the way out and another on the way back, this frame switch is the reason for the aging difference, not the acceleration per se.[7] Explanations put forth by Albert Einstein and Max Born invoked gravitational time dilation to explain the aging as a direct effect of acceleration.[8]

Time dilation has been verified experimentally by precise measurements of atomic clocks flown in aircraft and satellites. For example, gravitational time dilation and special relativity together have been used to explain the Hafele–Keating experiment.[A 1][A 2] It was also confirmed in particle accelerators by measuring time dilation of circulating particle beams.[A 3]

In his famous paper on special relativity in 1905, Albert Einstein deduced that when two clocks were brought together and synchronized, and then one was moved away and brought back, the clock which had undergone the traveling would be found to be lagging behind the clock which had stayed put.[A 4] Einstein considered this to be a natural consequence of special relativity, not a paradox as some suggested, and in 1911, he restated and elaborated on this result as follows (with physicist Robert Resnick's comments following Einstein's):[A 5][9]

If we placed a living organism in a box ... one could arrange that the organism, after any arbitrary lengthy flight, could be returned to its original spot in a scarcely altered condition, while corresponding organisms which had remained in their original positions had already long since given way to new generations. For the moving organism, the lengthy time of the journey was a mere instant, provided the motion took place with approximately the speed of light.

If the stationary organism is a man and the traveling one is his twin, then the traveler returns home to find his twin brother much aged compared to himself. The paradox centers on the contention that, in relativity, either twin could regard the other as the traveler, in which case each should find the other younger—a logical contradiction. This contention assumes that the twins' situations are symmetrical and interchangeable, an assumption that is not correct. Furthermore, the accessible experiments have been done and support Einstein's prediction.

In 1911, Paul Langevin gave a "striking example" by describing the story of a traveler making a trip at a Lorentz factor of γ = 100 (99.995% the speed of light). The traveler remains in a projectile for one year of his time, and then reverses direction. Upon return, the traveler will find that he has aged two years, while 200 years have passed on Earth. During the trip, both the traveler and Earth keep sending signals to each other at a constant rate, which places Langevin's story among the Doppler shift versions of the twin paradox. The relativistic effects upon the signal rates are used to account for the different aging rates. The asymmetry that occurred because only the traveler underwent acceleration, is used to explain why there is any difference at all, because "any change of velocity, or any acceleration has an absolute meaning".[A 6]

Max von Laue (1911, 1913) elaborated on Langevin's explanation. Using Minkowski's spacetime formalism, Laue went on to demonstrate that the world lines of the inertially moving bodies maximize the proper time elapsed between two events. He also wrote that the asymmetric aging is completely accounted for by the fact that the astronaut twin travels in two separate frames, while the Earth twin remains in one frame, and the time of acceleration can be made arbitrarily small compared with the time of inertial motion.[A 7][A 8][A 9] Eventually, Lord Halsbury and others removed any acceleration by introducing the "three-brother" approach. The traveling twin transfers his clock reading to a third one, traveling in the opposite direction. Another way of avoiding acceleration effects is the use of the relativistic Doppler effect (see What it looks like: the relativistic Doppler shift below).

Neither Einstein nor Langevin considered such results to be problematic: Einstein only called it "peculiar" while Langevin presented it as a consequence of absolute acceleration.[A 10] Both men argued that, from the time differential illustrated by the story of the twins, no self-contradiction could be constructed. In other words, neither Einstein nor Langevin saw the story of the twins as constituting a challenge to the self-consistency of relativistic physics.

Specific example[edit]

Consider a space ship traveling from Earth to the nearest star system: a distance d = 4 light years away, at a speed v = 0.8c (i.e., 80 percent of the speed of light).

(To make the numbers easy, the ship is assumed to attain full speed immediately upon departure-even though it would actually take close to a year accelerating at 1 g to get up to speed.)

The parties will observe the situation as follows:[10][11]

The Earth-based mission control reasons about the journey this way: the round trip will take t = 2d/v = 10 years in Earth time (i.e. everybody on Earth will be 10 years older when the ship returns). The amount of time as measured on the ship's clocks and the aging of the travelers during their trip will be reduced by the factor , the reciprocal of the Lorentz factor. In this case ε = 0.6 and the travelers will have aged only 0.6 × 10 = 6 years when they return.

The ship's crew members also calculate the particulars of their trip from their perspective. They know that the distant star system and the Earth are moving relative to the ship at speed v during the trip. In their rest frame the distance between the Earth and the star system is εd = 0.6d = 2.4 light years (length contraction), for both the outward and return journeys. Each half of the journey takes 2.4/v = 3 years, and the round trip takes 2 × 3 = 6 years. Their calculations show that they will arrive home having aged 6 years. The travelers' final calculation is in complete agreement with the calculations of those on Earth, though they experience the trip quite differently from those who stay at home.

If twins are born on the day the ship leaves, and one goes on the journey while the other stays on Earth, they will meet again when the traveler is 6 years old and the stay-at-home twin is 10 years old. The calculation illustrates the usage of the phenomenon of length contraction and the experimentally verified phenomenon of time dilation to describe and calculate consequences and predictions of Einstein's special theory of relativity.

Resolution of the paradox in special relativity[edit]

The paradoxical aspect of the twins' situation arises from the fact that at any given moment the travelling twin's clock is running slow in the earthbound twin's inertial frame, but based on the relativity principle one could equally argue that the earthbound twin's clock is running slow in the travelling twin's inertial frame.[12][13][14] One proposed resolution is that the earthbound twin is at rest in the same inertial frame throughout the journey, while the travelling twin is not: in the simplest version of the thought-experiment the travelling twin switches at the midpoint of the trip from being at rest in an inertial frame with velocity in one direction (away from the earth) to being at rest in an inertial frame with velocity in the opposite direction (towards the earth).

Role of acceleration[edit]

Although some solutions attribute a crucial role to the acceleration of the travelling twin at the time of the turnaround,[12][13][14][15] others note that the effect also arises if one imagines separate outward-going and inward-coming travellers, who pass each other and synchronize their clocks at the point corresponding to "turnaround" of a single traveller. In this version, physical acceleration of the travelling clock plays no direct role;[16][17][18] "the issue is how long the world-lines are, not how bent".[19] The length referred to here is the Lorentz-invariant length or "proper time interval" of a trajectory which corresponds to the elapsed time measured by a clock following that trajectory (see Section Difference in elapsed time as a result of differences in twins' spacetime paths below). In Minkowski spacetime, the travelling twin must feel a different history of accelerations from the earthbound twin, even if this just means accelerations of the same size separated by different amounts of time,[19] however "even this role for acceleration can be eliminated in formulations of the twin paradox in curved spacetime, where the twins can fall freely along space-time geodesics between meetings".[6]

Relativity of simultaneity[edit]

Minkowski diagram of the twin paradox. There is a difference between the trajectories of the two twins: the trajectory of the ship is equally divided between two different inertial frames, while the Earth-based twin stays in the same inertial frame.

For a moment-by-moment understanding of how the time difference between the two twins unfolds, one must understand that in special relativity there is no concept of absolute present. For different inertial frames there are different sets of events that are simultaneous in that frame. This relativity of simultaneity means that switching from one inertial frame to another requires an adjustment in what slice through spacetime counts as the "present". In the spacetime diagram on the right, drawn for the reference frame of the Earth-based twin, that twin's world line coincides with the vertical axis (his position is constant in space, moving only in time). On the first leg of the trip, the second twin moves to the right (black sloped line); and on the second leg, back to the left. Blue lines show the planes of simultaneity for the traveling twin during the first leg of the journey; red lines, during the second leg. Just before turnaround, the traveling twin calculates the age of the Earth-based twin by measuring the interval along the vertical axis from the origin to the upper blue line. Just after turnaround, if he recalculates, he will measure the interval from the origin to the lower red line. In a sense, during the U-turn the plane of simultaneity jumps from blue to red and very quickly sweeps over a large segment of the world line of the Earth-based twin. When one transfers from the outgoing inertial frame to the incoming inertial frame there is a jump discontinuity in the age of the Earth-based twin.[12][13][17][20][21]

A non space-time approach[edit]

As mentioned above, an "out and back" twin paradox adventure may incorporate the transfer of clock reading from an "outgoing" astronaut to an "incoming" astronaut, thus entirely eliminating the effect of acceleration. Also, according to the so-called "clock postulate", physical acceleration of clocks doesn't contribute to the kinematical effects of special relativity. Rather, the time differential between two reunited clocks is produced purely by uniform inertial motion, as discussed in Einstein's original 1905 relativity paper,[16] as well as in all subsequent kinematical derivations of the Lorentz transformations.

Because spacetime diagrams incorporate Einstein's clock synchronization (with its lattice of clocks methodology), there will be a requisite "jump in simultaneity" in the calculation made by a "suddenly returning astronaut" who inherits a "new meaning of simultaneity" in keeping with a new clock synchronization dictated by the transfer to a different inertial frame, as explained in Spacetime Physics by John A. Wheeler.[20]

If, instead of incorporating Einstein's clock synchronization (lattice of clocks), the astronaut (outgoing and incoming) and the Earth-based party regularly update each other on the status of their clocks by way of sending radio signals (which travel at light speed), then all parties will note an incremental buildup of asymmetry in time-keeping, beginning at the "turn around" point. Prior to the "turn around", each party regards the other party's clock to be recording time differently from his own, but the noted difference is symmetrical between the two parties. After the "turn around", the noted differences are not symmetrical, and the asymmetry grows incrementally until the two parties are reunited. Upon finally reuniting, this asymmetry can be seen in the actual difference showing on the two reunited clocks.[22]

The equivalence of biological aging and clock time-keeping[edit]

All processes—chemical, biological, measuring apparatus functioning, human perception involving the eye and brain, the communication of force—everything, is constrained by the speed of light. There is clock functioning at every level, dependent on light speed and the inherent delay at even the atomic level. Biological aging, therefore, is in no way different from clock time-keeping.[23] This means that biological aging would be slowed in the same manner as a clock.

What it looks like: the relativistic Doppler shift[edit]

In view of the frame-dependence of simultaneity for events at different locations in space, some treatments prefer a more phenomenological approach, describing what the twins would observe if each sent out a series of regular radio pulses, equally spaced in time according to the emitter's clock.[17] This is equivalent to asking, if each twin sent a video feed of themselves to each other, what do they see in their screens? Or, if each twin always carried a clock indicating his age, what time would each see in the image of their distant twin and his clock?

Shortly after departure, the traveling twin sees the stay-at-home twin with no time delay. At arrival, the image in the ship screen shows the staying twin as he was 1 year after launch, because radio emitted from Earth 1 year after launch gets to the other star 4 years afterwards and meets the ship there. During this leg of the trip, the traveling twin sees his own clock advance 3 years and the clock in the screen advance 1 year, so it seems to advance at 13 the normal rate, just 20 image seconds per ship minute. This combines the effects of time dilation due to motion (by factor ε=0.6, five years on earth are 3 years on ship) and the effect of increasing light-time-delay (which grows from 0 to 4 years).

Of course, the observed frequency of the transmission is also 13 the frequency of the transmitter (a reduction in frequency; "red-shifted"). This is called the relativistic Doppler effect. The frequency of clock-ticks (or of wavefronts) which one sees from a source with rest frequency frest is

when the source is moving directly away. This is fobs = 13frest for v/c = 0.8.

As for the stay-at-home twin, he gets a slowed signal from the ship for 9 years, at a frequency 13 the transmitter frequency. During these 9 years, the clock of the traveling twin in the screen seems to advance 3 years, so both twins see the image of their sibling aging at a rate only 13 their own rate. Expressed in other way, they would both see the other's clock run at 13 their own clock speed. If they factor out of the calculation the fact that the light-time delay of the transmission is increasing at a rate of 0.8 seconds per second, both can work out that the other twin is aging slower, at 60% rate.

Then the ship turns back toward home. The clock of the staying twin shows "1 year after launch" in the screen of the ship, and during the 3 years of the trip back it increases up to "10 years after launch", so the clock in the screen seems to be advancing 3 times faster than usual.

When the source is moving towards the observer, the observed frequency is higher ("blue-shifted") and given by

This is fobs = 3frest for v/c = 0.8.

As for the screen on Earth, it shows that trip back beginning 9 years after launch, and the traveling clock in the screen shows that 3 years have passed on the ship. One year later, the ship is back home and the clock shows 6 years. So, during the trip back, both twins see their sibling's clock going 3 times faster than their own. Factoring out the fact that the light-time-delay is decreasing by 0.8 seconds every second, each twin calculates that the other twin is aging at 60% his own aging speed.

Light paths for images exchanged during trip
Left: Earth to ship.              Right: Ship to Earth.
Red lines indicate low frequency images are received
Blue lines indicate high frequency images are received

The xt (space–time) diagrams at left show the paths of light signals traveling between Earth and ship (1st diagram) and between ship and Earth (2nd diagram). These signals carry the images of each twin and his age-clock to the other twin. The vertical black line is the Earth's path through spacetime and the other two sides of the triangle show the ship's path through spacetime (as in the Minkowski diagram above). As far as the sender is concerned, he transmits these at equal intervals (say, once an hour) according to his own clock; but according to the clock of the twin receiving these signals, they are not being received at equal intervals.

After the ship has reached its cruising speed of 0.8c, each twin would see 1 second pass in the received image of the other twin for every 3 seconds of his own time. That is, each would see the image of the other's clock going slow, not just slow by the ε factor 0.6, but even slower because light-time-delay is increasing 0.8 seconds per second. This is shown in the figures by red light paths. At some point, the images received by each twin change so that each would see 3 seconds pass in the image for every second of his own time. That is, the received signal has been increased in frequency by the Doppler shift. These high frequency images are shown in the figures by blue light paths.

The asymmetry in the Doppler shifted images[edit]

The asymmetry between the Earth and the space ship is manifested in this diagram by the fact that more blue-shifted (fast aging) images are received by the ship. Put another way, the space ship sees the image change from a red-shift (slower aging of the image) to a blue-shift (faster aging of the image) at the midpoint of its trip (at the turnaround, 5 years after departure); the Earth sees the image of the ship change from red-shift to blue shift after 9 years (almost at the end of the period that the ship is absent). In the next section, one will see another asymmetry in the images: the Earth twin sees the ship twin age by the same amount in the red and blue shifted images; the ship twin sees the Earth twin age by different amounts in the red and blue shifted images.

Calculation of elapsed time from the Doppler diagram[edit]

The twin on the ship sees low frequency (red) images for 3 years. During that time, he would see the Earth twin in the image grow older by 3/3 = 1 years. He then sees high frequency (blue) images during the back trip of 3 years. During that time, he would see the Earth twin in the image grow older by 3 × 3 = 9 years. When the journey is finished, the image of the Earth twin has aged by 1 + 9 = 10 years.

The Earth twin sees 9 years of slow (red) images of the ship twin, during which the ship twin ages (in the image) by 9/3 = 3 years. He then sees fast (blue) images for the remaining 1 year until the ship returns. In the fast images, the ship twin ages by 1 × 3 = 3 years. The total aging of the ship twin in the images received by Earth is 3 + 3 = 6 years, so the ship twin returns younger (6 years as opposed to 10 years on Earth).

The distinction between what they see and what they calculate[edit]

To avoid confusion, note the distinction between what each twin sees and what each would calculate. Each sees an image of his twin which he knows originated at a previous time and which he knows is Doppler shifted. He does not take the elapsed time in the image as the age of his twin now.

  • If he wants to calculate when his twin was the age shown in the image (i.e. how old he himself was then), he has to determine how far away his twin was when the signal was emitted—in other words, he has to consider simultaneity for a distant event.
  • If he wants to calculate how fast his twin was aging when the image was transmitted, he adjusts for the Doppler shift. For example, when he receives high frequency images (showing his twin aging rapidly) with frequency , he does not conclude that the twin was aging that rapidly when the image was generated, any more than he concludes that the siren of an ambulance is emitting the frequency he hears. He knows that the Doppler effect has increased the image frequency by the factor 1 / (1 − v/c). Therefore, he calculates that his twin was aging at the rate of

when the image was emitted. A similar calculation reveals that his twin was aging at the same reduced rate of εfrest in all low frequency images.

Simultaneity in the Doppler shift calculation[edit]

It may be difficult to see where simultaneity came into the Doppler shift calculation, and indeed the calculation is often preferred because one does not have to worry about simultaneity. As seen above, the ship twin can convert his received Doppler-shifted rate to a slower rate of the clock of the distant clock for both red and blue images. If he ignores simultaneity, he might say his twin was aging at the reduced rate throughout the journey and therefore should be younger than he is. He is now back to square one, and has to take into account the change in his notion of simultaneity at the turnaround. The rate he can calculate for the image (corrected for Doppler effect) is the rate of the Earth twin's clock at the moment it was sent, not at the moment it was received. Since he receives an unequal number of red and blue shifted images, he should realize that the red and blue shifted emissions were not emitted over equal time periods for the Earth twin, and therefore he must account for simultaneity at a distance.

Viewpoint of the traveling twin[edit]

During the turnaround, the traveling twin is in an accelerated reference frame. According to the equivalence principle, the traveling twin may analyze the turnaround phase as if the stay-at-home twin were freely falling in a gravitational field and as if the traveling twin were stationary. A 1918 paper by Einstein presents a conceptual sketch of the idea.[A 11] From the viewpoint of the traveler, a calculation for each separate leg, ignoring the turnaround, leads to a result in which the Earth clocks age less than the traveler. For example, if the Earth clocks age 1 day less on each leg, the amount that the Earth clocks will lag behind amounts to 2 days. The physical description of what happens at turnaround has to produce a contrary effect of double that amount: 4 days' advancing of the Earth clocks. Then the traveler's clock will end up with a net 2-day delay on the Earth clocks, in agreement with calculations done in the frame of the stay-at-home twin.

The mechanism for the advancing of the stay-at-home twin's clock is gravitational time dilation. When an observer finds that inertially moving objects are being accelerated with respect to themselves, those objects are in a gravitational field insofar as relativity is concerned. For the traveling twin at turnaround, this gravitational field fills the universe. In a weak field approximation, clocks tick at a rate of t' = t (1 + Φ / c2) where Φ is the difference in gravitational potential. In this case, Φ = gh where g is the acceleration of the traveling observer during turnaround and h is the distance to the stay-at-home twin. The rocket is firing towards the stay-at-home twin, thereby placing that twin at a higher gravitational potential. Due to the large distance between the twins, the stay-at-home twin's clocks will appear to be sped up enough to account for the difference in proper times experienced by the twins. It is no accident that this speed-up is enough to account for the simultaneity shift described above. The general relativity solution for a static homogeneous gravitational field and the special relativity solution for finite acceleration produce identical results.[24]

Other calculations have been done for the traveling twin (or for any observer who sometimes accelerates), which do not involve the equivalence principle, and which do not involve any gravitational fields. Such calculations are based only on the special theory, not the general theory, of relativity. One approach calculates surfaces of simultaneity by considering light pulses, in accordance with Hermann Bondi's idea of the k-calculus.[25] A second approach calculates a straightforward but technically complicated integral to determine how the traveling twin measures the elapsed time on the stay-at-home clock. An outline of this second approach is given in a separate section below.

Difference in elapsed time as a result of differences in twins' spacetime paths[edit]

The following paragraph shows several things:

  • how to employ a precise mathematical approach in calculating the differences in the elapsed time
  • how to prove exactly the dependency of the elapsed time on the different paths taken through spacetime by the two twins
  • how to quantify the differences in elapsed time
  • how to calculate proper time as a function (integral) of coordinate time

Let clock K be associated with the "stay at home twin". Let clock K' be associated with the rocket that makes the trip. At the departure event both clocks are set to 0.

Phase 1: Rocket (with clock K') embarks with constant proper acceleration a during a time Ta as measured by clock K until it reaches some velocity V.
Phase 2: Rocket keeps coasting at velocity V during some time Tc according to clock K.
Phase 3: Rocket fires its engines in the opposite direction of K during a time Ta according to clock K until it is at rest with respect to clock K. The constant proper acceleration has the value −a, in other words the rocket is decelerating.
Phase 4: Rocket keeps firing its engines in the opposite direction of K, during the same time Ta according to clock K, until K' regains the same speed V with respect to K, but now towards K (with velocity −V).
Phase 5: Rocket keeps coasting towards K at speed V during the same time Tc according to clock K.
Phase 6: Rocket again fires its engines in the direction of K, so it decelerates with a constant proper acceleration a during a time Ta, still according to clock K, until both clocks reunite.

Knowing that the clock K remains inertial (stationary), the total accumulated proper time Δτ of clock K' will be given by the integral function of coordinate time Δt

where v(t) is the coordinate velocity of clock K' as a function of t according to clock K, and, e.g. during phase 1, given by

This integral can be calculated for the 6 phases:[26]

Phase 1
Phase 2
Phase 3
Phase 4
Phase 5
Phase 6

where a is the proper acceleration, felt by clock K' during the acceleration phase(s) and where the following relations hold between V, a and Ta:

So the traveling clock K' will show an elapsed time of

which can be expressed as

whereas the stationary clock K shows an elapsed time of

which is, for every possible value of a, Ta, Tc and V, larger than the reading of clock K':

Difference in elapsed times: how to calculate it from the ship[edit]

In the standard proper time formula

Δτ represents the time of the non-inertial (travelling) observer K' as a function of the elapsed time Δt of the inertial (stay-at-home) observer K for whom observer K' has velocity v(t) at time t.

To calculate the elapsed time Δt of the inertial observer K as a function of the elapsed time Δτ of the non-inertial observer K', where only quantities measured by K' are accessible, the following formula can be used:[18]

where a(τ) is the proper acceleration of the non-inertial observer K' as measured by himself (for instance with an accelerometer) during the whole round-trip. The Cauchy–Schwarz inequality can be used to show that the inequality Δt > Δτ follows from the previous expression:

Using the Dirac delta function to model the infinite acceleration phase in the standard case of the traveller having constant speed v during the outbound and the inbound trip, the formula produces the known result:

In the case where the accelerated observer K' departs from K with zero initial velocity, the general equation reduces to the simpler form:

which, in the smooth version of the twin paradox where the traveller has constant proper acceleration phases, successively given by a, −a, −a, a, results in[18]

where the convention c = 1 is used, in accordance with the above expression with acceleration phases Ta = Δt/4 and inertial (coasting) phases Tc = 0.

A rotational version[edit]

Twins Bob and Alice inhabit a space station in circular orbit around a massive body in space. Bob suits up and exits the station. While Alice remains inside the station, continuing to orbit with it as before, Bob uses a rocket propulsion system to cease orbiting and hover where he was. When the station completes an orbit and returns to Bob, he rejoins Alice. Alice is now younger than Bob.[27] In addition to rotational acceleration, Bob must decelerate to become stationary and then accelerate again to match the orbital speed of the space station.

Explanation in terms of Mach's principle[edit]

A minority of physicists also favor some version of Mach's principle, which would imply that the difference between accelerated motion and inertial motion can only be defined relative to the rest of the matter in the universe, often referred to as motion relative to the "fixed stars". For example, A.P. French writes, regarding the twin paradox: "Note, though, that we are appealing to the reality of A's acceleration, and to the observability of the inertial forces associated with it. Would such effects as the twin paradox exist if the framework of fixed stars and distant galaxies were not there? Most physicists would say no. Our ultimate definition of an inertial frame may indeed be that it is a frame having zero acceleration with respect to the matter of the universe at large."[28]

See also[edit]

Primary sources[edit]

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  2. ^ Hafele, J. C.; Keating, R. E. (July 14, 1972). "Around-the-World Atomic Clocks: Observed Relativistic Time Gains". Science. 177 (4044): 168–170. Bibcode:1972Sci...177..168H. doi:10.1126/science.177.4044.168. PMID 17779918.
  3. ^ Bailey, H.; et al. (1977). "Measurements of relativistic time dilatation for positive and negative muons in a circular orbit". Nature. 268 (5618): 301–305. Bibcode:1977Natur.268..301B. doi:10.1038/268301a0.
  4. ^ Einstein, Albert (1905). "On the Electrodynamics of Moving Bodies". Annalen der Physik. 17 (10): 891. Bibcode:1905AnP...322..891E. doi:10.1002/andp.19053221004.
  5. ^ Einstein, Albert (1911). "Die Relativitäts-Theorie". Naturforschende Gesellschaft, Zürich, Vierteljahresschrift. 56: 1–14.
  6. ^ Langevin, P. (1911), "The evolution of space and time", Scientia, X: 31–54  (translated by J. B. Sykes, 1973).
  7. ^ von Laue, Max (1911). "Zwei Einwände gegen die Relativitätstheorie und ihre Widerlegung (Two Objections Against the Theory of Relativity and their Refutation)". Physikalische Zeitschrift. 13: 118–120.
  8. ^ von Laue, Max (1913). Das Relativitätsprinzip (The Principle of Relativity) (2 ed.). Braunschweig, Germany: Friedrich Vieweg. OCLC 298055497.
  9. ^ von Laue, Max (1913). "Das Relativitätsprinzip (The Principle of Relativity)". Jahrbücher der Philosophie. 1: 99–128.
  10. ^ "We are going to see this absolute character of the acceleration manifest itself in another form." ("Nous allons voir se manifester sous une autre forme ce caractère absolu de l'accélération."), page 82 of Langevin1911
  11. ^ Einstein, A. (1918) "dialog about objections against the theory of relativity", Die Naturwissenschaften 48, pp. 697–702, 29 November 1918

Secondary sources[edit]

  1. ^ Crowell, Benjamin (2000). The Modern Revolution in Physics (illustrated ed.). Light and Matter. p. 23. ISBN 978-0-9704670-6-5.  Extract of page 23
  2. ^ Serway, Raymond A.; Moses, Clement J.; Moyer, Curt A. (2004). Modern Physics (3rd ed.). Cengage Learning. p. 21. ISBN 978-1-111-79437-8.  Extract of page 21
  3. ^ Bell, John L. (2016). Oppositions and Paradoxes: Philosophical Perplexities in Science and Mathematics. Broadview Press. p. 87. ISBN 978-1-77048-603-4.  Extract of page 87
  4. ^ D'Auria, Riccardo; Trigiante, Mario (2011). From Special Relativity to Feynman Diagrams: A Course of Theoretical Particle Physics for Beginners (illustrated ed.). Springer Science & Business Media. p. 541. ISBN 978-88-470-1504-3.  Extract of page 541
  5. ^ Ohanian, Hans C.; Ruffini, Remo (2013). Gravitation and Spacetime (3rd ed.). Cambridge University Press. p. 176. ISBN 978-1-139-61954-7.  Extract of page 176
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  10. ^ Jain, Mahesh C. (2009). Textbook Of Engineering Physics, Part I. PHI Learning Pvt. p. 74. ISBN 8120338626.  Extract of page 74
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  17. ^ a b c Kogut, John (2000). Introduction to Relativity. Burlington, MA: Harcourt Academic Press. p. 35. ISBN 0124175619.
  18. ^ a b c E. Minguzzi (2005) - Differential aging from acceleration: An explicit formula - Am. J. Phys. 73: 876-880 arXiv:physics/0411233 (Notation of source variables was adapted to match this article's.)
  19. ^ a b Maudlin, Tim (2012). Philosophy of physics : space and time. Princeton: Princeton University Press. pp. 77–83. ISBN 9780691143095.
  20. ^ a b Wheeler, J., Taylor, E. (1992). Spacetime Physics, second edition. W. H. Freeman: New York, pp. 38, 170-171.
  21. ^ Einstein, A., Lorentz, H.A., Minkowski, H., and Weyl, H. (1923). Arnold Sommerfeld. ed. The Principle of Relativity. Dover Publications: Mineola, NY. p. 38.
  22. ^ William Geraint Vaughan Rosser (1991). Introductory Special Relativity, Taylor & Francis Inc. USA, pp. 67-68.
  23. ^ Taylor, Edwin F.; Wheeler, John Archibald (1992). Spacetime Physics (2nd, illustrated ed.). W. H. Freeman. p. 150. ISBN 978-0-7167-2327-1.
  24. ^ Jones, Preston; Wanex, L.F. (February 2006). "The clock paradox in a static homogeneous gravitational field". Foundations of Physics Letters. 19 (1): 75–85. arXiv:physics/0604025Freely accessible. Bibcode:2006FoPhL..19...75J. doi:10.1007/s10702-006-1850-3.
  25. ^ Dolby, Carl E. & Gull, Stephen F (2001). "On Radar Time and the Twin 'Paradox'". American Journal of Physics. 69 (12): 1257–1261. arXiv:gr-qc/0104077Freely accessible. Bibcode:2001AmJPh..69.1257D. doi:10.1119/1.1407254.
  26. ^ C. Lagoute and E. Davoust (1995) The interstellar traveler, Am. J. Phys. 63:221-227
  27. ^ Michael Paul Hobson, George Efstathiou, Anthony N. Lasenby (2006). General Relativity: An Introduction for Physicists. Cambridge University Press. p. 227. ISBN 0-521-82951-8.  See exercise 9.25 on page 227.
  28. ^ French, A.P. (1968). Special relativity. W.W. Norton, New York. p. 156. ISBN 0-393-09804-4.

Further reading[edit]

The ideal clock

The ideal clock is a clock whose action depends only on its instantaneous velocity, and is independent of any acceleration of the clock. Wolfgang Rindler (2006). "Time dilation". Relativity: Special, General, and Cosmological. Oxford University Press. p. 43. ISBN 0-19-856731-6.

Gravitational time dilation; time dilation in circular motion

External links[edit]