| 词条 | John Moffat (physicist) |
| 释义 |
| name = John Moffat | image = John_Moffat_2007.jpg | image_size = 220px | caption = Moffat in 2007 | birth_date = {{birth date and age|1932|05|24|df=y}} | birth_place = Copenhagen, Denmark | death_date = | death_place = | residence = Denmark, United Kingdom, Canada | citizenship = | ethnicity = | field = Physics | work_institutions = University of Toronto Perimeter Institute for Theoretical Physics, Waterloo | alma_mater = Trinity College, Cambridge | doctoral_advisor = Fred Hoyle and Abdus Salam | doctoral_students = | known_for = Gravitation Quantum field theory Variable speed of light | prizes = | signature = }} John W. Moffat (born 24 May 1932)[1] is a Danish-born British-Canadian physicist. He is currently Professor Emeritus in physics at the University of Toronto[2] and is also an adjunct Professor in physics at the University of Waterloo and a resident affiliate member of the Perimeter Institute for Theoretical Physics. Moffat is best known for his work on gravity and cosmology, culminating in his nonsymmetric gravitational theory and scalar–tensor–vector gravity (now called MOG), and summarized in his 2008 book for general readers, Reinventing Gravity. His theory explains galactic rotation curves without invoking dark matter. He proposes a variable speed of light approach to cosmological problems. The speed of light c may have been more than 30 orders of magnitude higher during the early moments of the Big Bang. His recent work on inhomogeneous cosmological models purports to explain certain anomalous effects in the CMB data, and to account for the recently discovered acceleration of the expansion of the universe. Moffat has proposed a new nonlocal variant of quantum field theory, that is finite at all orders and hence{{Citation needed|date=March 2013}} dispenses with renormalization. It also generates mass without a Higgs mechanism. Early life and educationMoffat was born in Copenhagen, Denmark, the son of a Scottish father, George Moffat, and Danish mother, Esther (née Winther). His father, a musician from Glasgow, was performing in a night club in Copenhagen when he met Esther, a dancer. They married three weeks later. In 1938, on the eve of the Second World War, John's father moved the family to London, correctly predicting that Denmark would be invaded by Germany. In later 1939, during the Blitz, the 7-year-old John was evacuated to Glasgow to live with his grandparents. But he failed to thrive in Glasgow, struggling academically, so after a year he returned to his parents, and all three moved to Bristol, where his father got a job searching ships for German spies. In Bristol, they lived close to the factory that manufactured the Bristol F2 Fighters. Air raids were frequent as the Battle of Britain intensified in 1940. One day, they went to the boardwalk at Weston-super-Mare to escape the raids in Bristol, only to have German planes appear overhead. As Moffat recalled in his memoir, Einstein Wrote Back:
The trauma from the bombing and the air-raids stayed with him for a lifetime, Moffat wrote:
When John was 7 or 8, his father took him to a psychiatrist in London because he insisted on reading sentences and clocks backward. The psychiatrist told his father that he was a genius. John, overhearing, did not think the word meant much for his future. After the war, the family moved back to Denmark, where John's father started an import-export business. He contracted tuberculosis from one of his employees and became seriously ill for a year, and the family struggled to get by. Interest in physicsAs a teenager, Moffat quit school at 16 to become an artist. He gave up after living for a time in Paris with no income. Upon returning to Copenhagen, he became interested in the cosmos and began teaching himself mathematics and physics. The University of Copenhagen allowed anyone to check out books from its libraries, and he made such quick progress that within a year he began working on problems of general relativity and unified field theory. When Moffat was about 20 years old, he wrote a letter to Albert Einstein, informing the great physicist that he was working on one of his theories. "Dear Professor . . . I would be eternally indebted if you could find time to read my work," he began.
Einstein's initial reply:
Moffat's correspondence with Einstein and meeting with Bohr drew the attention of officials at the British consulate in Copenhagen, and he was invited to study at Cambridge.[3] In 1958, he was awarded a Ph.D. without a first degree at Trinity College, Cambridge. He was supervised by Fred Hoyle and Abdus Salam. Variable speed of light: theory and controversyIn 1992, John Moffat proposed that the speed of light was much larger in the early universe, in which the speed of light had a value of more than 1030 km/s.[2] He published his "variable speed of light" (VSL) theory in two places—on the Los Alamos National Laboratory's (LANL) online archive, Nov. 16, 1992,[4] and in a 1993 edition of International Journal of Modern Physics D.[5][6] The scientific community mostly ignored VSL theory[5] until in 2001, University of New South Wales astronomer John Webb and peers detected experimental evidence from telescopic observations that the cosmological fine structure constant—which contains the speed of light—may have been different than its present value in the very early Universe.[7] The observations supported Moffat's VSL theory—and started a race for primacy that began in 1998. That year, five years after Moffat had published his VSL papers, João Magueijo of Imperial College in London, and collaborators Andrew Albrecht of the University of California at Davis and John D. Barrow of Cambridge University, published a strikingly similar idea in the more prestigious journal, Physical Review D, which had rejected Moffat's paper years earlier.[2] Informed of the omission, Magueijo credited Moffat with an entire chapter in Magueijo's 2002 book, Faster Than the Speed of Light: The story of a scientific speculation.[2][8] The controversy reignited, however, when during a worldwide publicity tour for Magueijo's book, the author neither credited Moffat nor corrected numerous erroneous press accounts—in such magazines as Discover,[9] Publisher's Weekly,[10] Seed Magazine and the Christian Science Monitor.[11] In efforts to portray Magueijo as a "brash, young scientific upstart," dozens of publications attributed VSL theory entirely to Magueijo and his co-authors, leaving Moffat—in his late sixties by this time—out.[5][6] Moffat expressed displeasure about the re-emergent omissions, urging reporters to check their facts, but to no avail.[5][6] Stories emerged about the book tour media omissions in March and July 2003, written by a science journalist, Michael Martin, who had earlier attributed VSL theory to Moffat in a 2001 UPI article about Webb's astronomical discoveries.[12] Discover Magazine writer Tim Folger acknowledged the omissions in his story and apologized. In response to a reader letter from Henry van Driel of the University of Toronto Department of Physics, Folger wrote, "Professor van Driel is absolutely right—John Moffat did develop a varying speed of light theory several years before João Magueijo, and I regret not including that information in my story."[13] Months later, as other reports picked up on the reignited dispute,[14] Magueijo reiterated Moffat's primacy in VSL theory.[5][6] In September 2004, Discover Magazine's Tim Folger followed through on a promise he had made during the controversy to "write a story about John Moffat."[15] The two physicists became friends, publishing a joint paper in 2007 in the journal General Relativity and Gravitation.[16] Modified gravity theoryContinuing Einstein's search for a unified field theory, Moffat proposed a nonsymmetric gravitational theory that, like Einstein's unified field, incorporated a symmetric field (gravity) and an antisymmetric field. Unlike Einstein, however, Moffat made no attempt to identify the latter with electromagnetism, instead proposing that the antisymmetric component is another manifestation of gravity. As investigation progressed, the theory evolved in a variety of ways; most notably, Moffat postulated that the antisymmetric field may be massive. The current version of his modified gravity (MOG) theory, which grew out of this investigation, modifies Einstein's gravity with the addition of a vector field, while also promoting the constants of the theory to scalar fields. The combined effect of these fields modifies the strength of gravity at large distances when large masses are involved, successfully accounting for a range of astronomical and cosmological observations. The resulting theory describes well, without invoking dark matter, the rotation curves of galaxies[17] and the mass profiles of X-ray galaxy clusters.[18] Non-local quantum field theoryIn 1990, Moffat proposed a finite, non-local quantum field theory. The theory was developed extensively by Evens, Moffat, Kleppe and Woodard in 1991. In subsequent work, Moffat proposed this theory as an alternative to the standard electroweak unification of electromagnetism and the weak nuclear interactions. Moffat's theory is a quantum field theory with a non-local term in the field Lagrangian. The theory is gauge invariant and it is finite to all orders of perturbation theory. For the standard model it can solve the Higgs boson mass hierarchy naturalness problem.[19] It also leads to a finite quantum gravity theory. PublicationsBooks
Selected articles
See also
References1. ^{{cite news | title = Birthdays | newspaper = The Guardian | pages = 55 | publisher = Guardian News & Media | date = 11 October 2014}} 2. ^1 2 3 {{cite news |title=Einstein's respectful heretic |author=Peter Calamai |url=https://www.thestar.com/ScienceTech/article/121906 |newspaper=Toronto Star |date=27 November 2005 |accessdate=21 May 2011 |deadurl=yes |archiveurl=https://web.archive.org/web/20121024061405/http://www.thestar.com/ScienceTech/article/121906 |archivedate=24 October 2012 |df=dmy-all }} 3. ^{{cite news|title=Modern-day Einsteins search for the Holy Grail|url=http://www.canada.com/story_print.html?id=52dae348-83e0-439e-a3fd-01346201e282&sponsor=|accessdate=25 March 2016|work=The Ottawa Citizen|publisher=Canada.com|date=20 November 2005}}{{dead link|date=November 2017 |bot=InternetArchiveBot |fix-attempted=yes }} 4. ^{{cite journal| first = J. W. | last = Moffat | arxiv = gr-qc/9211020 | title = Superluminary Universe: A Possible Solution to the Initial Value Problem in Cosmology | doi=10.1142/S0218271893000246 | volume=2 | journal=International Journal of Modern Physics D | pages=351–365| bibcode=1993IJMPD...2..351M }} 5. ^1 2 3 4 Michael Martin (24 March 2003)[https://archive.today/20130125021312/http://business.highbeam.com/4341/article-1G1-98954289/cold-toronto-physicist-once-ridiculed-theory-gains-acceptance "In From the Cold: A Toronto physicist's once-ridiculed theory gains acceptance"] Maclean's {{webarchive|url=https://web.archive.org/web/20110810062718/http://www2.macleans.ca/ |date=10 August 2011 }} 6. ^1 2 3 Michael Martin (1 July 2003) "In the Shadow of the Speed of Light" {{webarchive|url=https://web.archive.org/web/20111007224241/http://www.weeklyscientist.com/ws/articles/Moffat.htm |date= 7 October 2011 }}, St. Louis Journalism Review 7. ^{{cite journal|author1=J.K. Webb |author2=M.T. Murphy |author3=V.V. Flambaum |author4=V.A. Dzuba |author5=J.D. Barrow |author6=C.W. Churchill |author7=J.X. Prochaska |author8=A.M. Wolfe |title=Further Evidence for Cosmological Evolution of the Fine Structure Constant| journal = Phys. Rev. Lett. |volume=87|date=2001|pages=091301|doi=10.1103/PhysRevLett.87.091301|pmid=11531558|issue=9|bibcode=2001PhRvL..87i1301W|arxiv=astro-ph/0012539}} 8. ^{{cite book |title=The trouble with physics |last=Smolin |first=Lee |date=2006 |publisher=Mariner Books |location= |isbn=978-0-618-91868-3 |page=230 |pages= |url=https://books.google.com/books?id=d6MIUlxY-qwC&pg=PA230 |accessdate=21 May 2011}} 9. ^Tim Folger (April, 2003) "Was Einstein Wrong?" Discover Magazine 10. ^Judith Rosen (1 January 2003) "Physics Brat: First-time author takes on Einstein" Publisher's Weekly 11. ^Lori Valigra (30 January 2003) "New theory on light weighs heavily on scientists: A brash young theoretical physicist claims Einstein was wrong" Christian Science Monitor 12. ^Michael Martin (17 August 2001) "That Speed of Light Varies Long Suspected"{{dead link|date=February 2019|bot=medic}}{{cbignore|bot=medic}} United Press International 13. ^Reader Letters (June 2003) Discover Magazine 14. ^Dan Falk (Nov. 08, 2003) [https://www.theglobeandmail.com/news/technology/science/maverick-physicist/article427150/ "Maverick Physicist"] Toronto Globe and Mail 15. ^Tim Folger (Sept. 4, 2004) "Einstein's Grand Quest for a Unified Theory" Discover Magazine 16. ^{{cite journal | first1 = J.W. | last1 = Moffat | first2 = J. | last2 = Magueijo | arxiv = 0705.4507 | title = Comments on "Note on varying speed of light theories" | journal = General Relativity and Gravitation | volume = 40 | pages = 1797–1806 | year = 2007| bibcode = 2008GReGr..40.1797M | doi = 10.1007/s10714-007-0568-2 }} 17. ^J. W. Moffat, S. Rahvar, The MOG weak field approximation and observational test of galaxy rotation curves; [https://arxiv.org/abs/1306.6383 arXiv:1306.6383] 18. ^[https://arxiv.org/abs/1309.5077 arXiv:1309.5077] 19. ^J. W. Moffat, Beyond The Standard Model; [https://arxiv.org/abs/hep-ph/9802228 arxiv:hep-ph/9802228] External links{{wikiquote}}
University of Toronto press releases re Moffat:
10 : 1932 births|Living people|Alumni of Trinity College, Cambridge|University of Toronto faculty|Canadian physicists|Relativity theorists|Cosmologists|Quantum gravity physicists|British physicists|People from Copenhagen |
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