A Brief History of Gravitational Waves
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Measurement of the Speed of Gravity
Measurement of the Speed of Gravity Yin Zhu Agriculture Department of Hubei Province, Wuhan, China Abstract From the Liénard-Wiechert potential in both the gravitational field and the electromagnetic field, it is shown that the speed of propagation of the gravitational field (waves) can be tested by comparing the measured speed of gravitational force with the measured speed of Coulomb force. PACS: 04.20.Cv; 04.30.Nk; 04.80.Cc Fomalont and Kopeikin [1] in 2002 claimed that to 20% accuracy they confirmed that the speed of gravity is equal to the speed of light in vacuum. Their work was immediately contradicted by Will [2] and other several physicists. [3-7] Fomalont and Kopeikin [1] accepted that their measurement is not sufficiently accurate to detect terms of order , which can experimentally distinguish Kopeikin interpretation from Will interpretation. Fomalont et al [8] reported their measurements in 2009 and claimed that these measurements are more accurate than the 2002 VLBA experiment [1], but did not point out whether the terms of order have been detected. Within the post-Newtonian framework, several metric theories have studied the radiation and propagation of gravitational waves. [9] For example, in the Rosen bi-metric theory, [10] the difference between the speed of gravity and the speed of light could be tested by comparing the arrival times of a gravitational wave and an electromagnetic wave from the same event: a supernova. Hulse and Taylor [11] showed the indirect evidence for gravitational radiation. However, the gravitational waves themselves have not yet been detected directly. [12] In electrodynamics the speed of electromagnetic waves appears in Maxwell equations as c = √휇0휀0, no such constant appears in any theory of gravity. -
Of the American Mathematical Society August 2017 Volume 64, Number 7
ISSN 0002-9920 (print) ISSN 1088-9477 (online) of the American Mathematical Society August 2017 Volume 64, Number 7 The Mathematics of Gravitational Waves: A Two-Part Feature page 684 The Travel Ban: Affected Mathematicians Tell Their Stories page 678 The Global Math Project: Uplifting Mathematics for All page 712 2015–2016 Doctoral Degrees Conferred page 727 Gravitational waves are produced by black holes spiraling inward (see page 674). American Mathematical Society LEARNING ® MEDIA MATHSCINET ONLINE RESOURCES MATHEMATICS WASHINGTON, DC CONFERENCES MATHEMATICAL INCLUSION REVIEWS STUDENTS MENTORING PROFESSION GRAD PUBLISHING STUDENTS OUTREACH TOOLS EMPLOYMENT MATH VISUALIZATIONS EXCLUSION TEACHING CAREERS MATH STEM ART REVIEWS MEETINGS FUNDING WORKSHOPS BOOKS EDUCATION MATH ADVOCACY NETWORKING DIVERSITY blogs.ams.org Notices of the American Mathematical Society August 2017 FEATURED 684684 718 26 678 Gravitational Waves The Graduate Student The Travel Ban: Affected Introduction Section Mathematicians Tell Their by Christina Sormani Karen E. Smith Interview Stories How the Green Light was Given for by Laure Flapan Gravitational Wave Research by Alexander Diaz-Lopez, Allyn by C. Denson Hill and Paweł Nurowski WHAT IS...a CR Submanifold? Jackson, and Stephen Kennedy by Phillip S. Harrington and Andrew Gravitational Waves and Their Raich Mathematics by Lydia Bieri, David Garfinkle, and Nicolás Yunes This season of the Perseid meteor shower August 12 and the third sighting in June make our cover feature on the discovery of gravitational waves -
Hendrik Antoon Lorentz's Struggle with Quantum Theory A. J
Hendrik Antoon Lorentz’s struggle with quantum theory A. J. Kox Archive for History of Exact Sciences ISSN 0003-9519 Volume 67 Number 2 Arch. Hist. Exact Sci. (2013) 67:149-170 DOI 10.1007/s00407-012-0107-8 1 23 Your article is published under the Creative Commons Attribution license which allows users to read, copy, distribute and make derivative works, as long as the author of the original work is cited. You may self- archive this article on your own website, an institutional repository or funder’s repository and make it publicly available immediately. 1 23 Arch. Hist. Exact Sci. (2013) 67:149–170 DOI 10.1007/s00407-012-0107-8 Hendrik Antoon Lorentz’s struggle with quantum theory A. J. Kox Received: 15 June 2012 / Published online: 24 July 2012 © The Author(s) 2012. This article is published with open access at Springerlink.com Abstract A historical overview is given of the contributions of Hendrik Antoon Lorentz in quantum theory. Although especially his early work is valuable, the main importance of Lorentz’s work lies in the conceptual clarifications he provided and in his critique of the foundations of quantum theory. 1 Introduction The Dutch physicist Hendrik Antoon Lorentz (1853–1928) is generally viewed as an icon of classical, nineteenth-century physics—indeed, as one of the last masters of that era. Thus, it may come as a bit of a surprise that he also made important contribu- tions to quantum theory, the quintessential non-classical twentieth-century develop- ment in physics. The importance of Lorentz’s work lies not so much in his concrete contributions to the actual physics—although some of his early work was ground- breaking—but rather in the conceptual clarifications he provided and his critique of the foundations and interpretations of the new ideas. -
Einstein's Mistakes
Einstein’s Mistakes Einstein was the greatest genius of the Twentieth Century, but his discoveries were blighted with mistakes. The Human Failing of Genius. 1 PART 1 An evaluation of the man Here, Einstein grows up, his thinking evolves, and many quotations from him are listed. Albert Einstein (1879-1955) Einstein at 14 Einstein at 26 Einstein at 42 3 Albert Einstein (1879-1955) Einstein at age 61 (1940) 4 Albert Einstein (1879-1955) Born in Ulm, Swabian region of Southern Germany. From a Jewish merchant family. Had a sister Maja. Family rejected Jewish customs. Did not inherit any mathematical talent. Inherited stubbornness, Inherited a roguish sense of humor, An inclination to mysticism, And a habit of grüblen or protracted, agonizing “brooding” over whatever was on its mind. Leading to the thought experiment. 5 Portrait in 1947 – age 68, and his habit of agonizing brooding over whatever was on its mind. He was in Princeton, NJ, USA. 6 Einstein the mystic •“Everyone who is seriously involved in pursuit of science becomes convinced that a spirit is manifest in the laws of the universe, one that is vastly superior to that of man..” •“When I assess a theory, I ask myself, if I was God, would I have arranged the universe that way?” •His roguish sense of humor was always there. •When asked what will be his reactions to observational evidence against the bending of light predicted by his general theory of relativity, he said: •”Then I would feel sorry for the Good Lord. The theory is correct anyway.” 7 Einstein: Mathematics •More quotations from Einstein: •“How it is possible that mathematics, a product of human thought that is independent of experience, fits so excellently the objects of physical reality?” •Questions asked by many people and Einstein: •“Is God a mathematician?” •His conclusion: •“ The Lord is cunning, but not malicious.” 8 Einstein the Stubborn Mystic “What interests me is whether God had any choice in the creation of the world” Some broadcasters expunged the comment from the soundtrack because they thought it was blasphemous. -
Ripples in Spacetime
editorial Ripples in spacetime The 2017 Nobel prize in Physics has been awarded to Rainer Weiss, Barry C. Barish and Kip S. Thorne “for decisive contributions to the LIGO detector and the observation of gravitational waves”. It is, frankly, difficult to find something original to say about the detection of gravitational waves that hasn’t been said already. The technological feat of measuring fluctuations in the fabric of spacetime less than one-thousandth the width of an atomic nucleus is quite simply astonishing. The scientific achievement represented by the confirmation of a century-old prediction by Albert Einstein is unique. And the collaborative effort that made the discovery possible — the Laser Interferometer Gravitational-Wave Observatory (LIGO) — is inspiring. Adapted from Phys. Rev. Lett. 116, 061102 (2016), under Creative Commons Licence. Rainer Weiss and Kip Thorne were, along with the late Ronald Drever, founders of the project that eventually became known Barry Barish, who was the director Last month we received a spectacular as LIGO. In the 1960s, Thorne, a black hole of LIGO from 1997 to 2005, is widely demonstration that talk of a new era expert, had come to believe that his objects of credited with transforming it into a ‘big of gravitational astronomy was no interest should be detectable as gravitational physics’ collaboration, and providing the exaggeration. Cued by detections at LIGO waves. Separately, and inspired by previous organizational structure required to ensure and Virgo, an interferometer based in Pisa, proposals, Weiss came up with the first it worked. Of course, the passion, skill and Italy, more than 70 teams of researchers calculations detailing how an interferometer dedication of the thousand or so scientists working at different telescopes around could be used to detect them in 1972. -
I. I. Rabi Papers [Finding Aid]. Library of Congress. [PDF Rendered Tue Apr
I. I. Rabi Papers A Finding Aid to the Collection in the Library of Congress Manuscript Division, Library of Congress Washington, D.C. 1992 Revised 2010 March Contact information: http://hdl.loc.gov/loc.mss/mss.contact Additional search options available at: http://hdl.loc.gov/loc.mss/eadmss.ms998009 LC Online Catalog record: http://lccn.loc.gov/mm89076467 Prepared by Joseph Sullivan with the assistance of Kathleen A. Kelly and John R. Monagle Collection Summary Title: I. I. Rabi Papers Span Dates: 1899-1989 Bulk Dates: (bulk 1945-1968) ID No.: MSS76467 Creator: Rabi, I. I. (Isador Isaac), 1898- Extent: 41,500 items ; 105 cartons plus 1 oversize plus 4 classified ; 42 linear feet Language: Collection material in English Location: Manuscript Division, Library of Congress, Washington, D.C. Summary: Physicist and educator. The collection documents Rabi's research in physics, particularly in the fields of radar and nuclear energy, leading to the development of lasers, atomic clocks, and magnetic resonance imaging (MRI) and to his 1944 Nobel Prize in physics; his work as a consultant to the atomic bomb project at Los Alamos Scientific Laboratory and as an advisor on science policy to the United States government, the United Nations, and the North Atlantic Treaty Organization during and after World War II; and his studies, research, and professorships in physics chiefly at Columbia University and also at Massachusetts Institute of Technology. Selected Search Terms The following terms have been used to index the description of this collection in the Library's online catalog. They are grouped by name of person or organization, by subject or location, and by occupation and listed alphabetically therein. -
Could Minkowski Have Discovered the Cause of Gravitation Before Einstein?
2 Could Minkowski have discovered the cause of gravitation before Einstein? Vesselin Petkov Abstract There are two reasons for asking such an apparently unanswer- able question. First, Max Born’s recollections of what Minkowski had told him about his research on the physical meaning of the Lorentz transformations and the fact that Minkowski had created the full-blown four-dimensional mathematical formalism of space- time physics before the end of 1907 (which could have been highly improbable if Minkowski had not been developing his own ideas), both indicate that Minkowski might have arrived at the notion of spacetime independently of Poincaré (who saw it as nothing more than a mathematical space) and at a deeper understanding of the basic ideas of special relativity (which Einstein merely postulated) independently of Einstein. So, had he lived longer, Minkowski might have employed successfully his program of regarding four- dimensional physics as spacetime geometry to gravitation as well. Moreover, Hilbert (Minkowski’s closest colleague and friend) had derived the equations of general relativity simultaneously with Ein- stein. Second, even if Einstein had arrived at what is today called Einstein’s general relativity before Minkowski, Minkowski would have certainly reformulated it in terms of his program of geometriz- ing physics and might have represented gravitation fully as the man- ifestation of the non-Euclidean geometry of spacetime (Einstein re- garded the geometrical representation of gravitation as pure math- ematics) exactly like he reformulated Einstein’s special relativity in terms of spacetime. 1 Introduction On January 12, 1909, only several months after his Cologne lecture Space and Time [1], at the age of 44 Hermann Minkowski untimely left this world. -
Towards a Theory of Gravitational Radiation Or What Is a Gravitational Wave?
Recent LIGO announcement Gravitational radiation theory: summary Prehistory: 1916-1956 History: 1957-1962 Towards a theory of gravitational radiation or What is a gravitational wave? Paweł Nurowski Center for Theoretical Physics Polish Academy of Sciences King’s College London, 28 April 2016 1/48 Recent LIGO announcement Gravitational radiation theory: summary Prehistory: 1916-1956 History: 1957-1962 Plan 1 Recent LIGO announcement 2 Gravitational radiation theory: summary 3 Prehistory: 1916-1956 4 History: 1957-1962 2/48 Recent LIGO announcement Gravitational radiation theory: summary Prehistory: 1916-1956 History: 1957-1962 LIGO detection: Its relevance the first detection of gravitational waves the first detection of a black hole; of a binary black-hole; of a merging process of black holes creating a new one; Kerr black holes exist; black holes with up to 60 Solar masses exist; the most energetic process ever observed important test of Einstein’s General Theory of Relativity new window: a birth of gravitational wave astronomy 3/48 Recent LIGO announcement Gravitational radiation theory: summary Prehistory: 1916-1956 History: 1957-1962 LIGO detection: Its relevance the first detection of gravitational waves the first detection of a black hole; of a binary black-hole; of a merging process of black holes creating a new one; Kerr black holes exist; black holes with up to 60 Solar masses exist; the most energetic process ever observed important test of Einstein’s General Theory of Relativity new window: a birth of gravitational wave astronomy -
Science & ROGER PENROSE
Science & ROGER PENROSE Live Webinar - hosted by the Center for Consciousness Studies August 3 – 6, 2021 9:00 am – 12:30 pm (MST-Arizona) each day 4 Online Live Sessions DAY 1 Tuesday August 3, 2021 9:00 am to 12:30 pm MST-Arizona Overview / Black Holes SIR ROGER PENROSE (Nobel Laureate) Oxford University, UK Tuesday August 3, 2021 9:00 am – 10:30 am MST-Arizona Roger Penrose was born, August 8, 1931 in Colchester Essex UK. He earned a 1st class mathematics degree at University College London; a PhD at Cambridge UK, and became assistant lecturer, Bedford College London, Research Fellow St John’s College, Cambridge (now Honorary Fellow), a post-doc at King’s College London, NATO Fellow at Princeton, Syracuse, and Cornell Universities, USA. He also served a 1-year appointment at University of Texas, became a Reader then full Professor at Birkbeck College, London, and Rouse Ball Professor of Mathematics, Oxford University (during which he served several 1/2-year periods as Mathematics Professor at Rice University, Houston, Texas). He is now Emeritus Rouse Ball Professor, Fellow, Wadham College, Oxford (now Emeritus Fellow). He has received many awards and honorary degrees, including knighthood, Fellow of the Royal Society and of the US National Academy of Sciences, the De Morgan Medal of London Mathematical Society, the Copley Medal of the Royal Society, the Wolf Prize in mathematics (shared with Stephen Hawking), the Pomeranchuk Prize (Moscow), and one half of the 2020 Nobel Prize in Physics, the other half shared by Reinhard Genzel and Andrea Ghez. -
Spacetime Warps and the Quantum World: Speculations About the Future∗
Spacetime Warps and the Quantum World: Speculations about the Future∗ Kip S. Thorne I’ve just been through an overwhelming birthday celebration. There are two dangers in such celebrations, my friend Jim Hartle tells me. The first is that your friends will embarrass you by exaggerating your achieve- ments. The second is that they won’t exaggerate. Fortunately, my friends exaggerated. To the extent that there are kernels of truth in their exaggerations, many of those kernels were planted by John Wheeler. John was my mentor in writing, mentoring, and research. He began as my Ph.D. thesis advisor at Princeton University nearly forty years ago and then became a close friend, a collaborator in writing two books, and a lifelong inspiration. My sixtieth birthday celebration reminds me so much of our celebration of Johnnie’s sixtieth, thirty years ago. As I look back on my four decades of life in physics, I’m struck by the enormous changes in our under- standing of the Universe. What further discoveries will the next four decades bring? Today I will speculate on some of the big discoveries in those fields of physics in which I’ve been working. My predictions may look silly in hindsight, 40 years hence. But I’ve never minded looking silly, and predictions can stimulate research. Imagine hordes of youths setting out to prove me wrong! I’ll begin by reminding you about the foundations for the fields in which I have been working. I work, in part, on the theory of general relativity. Relativity was the first twentieth-century revolution in our understanding of the laws that govern the universe, the laws of physics. -
How the Green Light Was Given for Gravitational Wave Search
HOW THE GREEN LIGHT WAS GIVEN FOR GRAVITATIONAL WAVE SEARCH C DENSON HILL AND PAWELNUROWSKI Abstract. The recent detection of gravitational waves by the LIGO/VIRGO team [1] is an incredibly impressive achievement of experimental physics. It is also a tremendous success of the theory of General Relativity. It confirms the existence of black holes; shows that binary black holes exist; that they may collide and that during the merging process gravitational waves are produced. These are all predictions of General Relativity theory in its fully nonlinear regime. The existence of gravitational waves was predicted by Albert Einstein in 1916 within the framework of linearized Einstein theory. Contrary to common belief, even the very definition of a gravitational wave in the fully nonlinear Einstein theory was provided only after Einstein's death. Actually, Einstein had arguments against the existence of nonlinear gravitational waves (they were erroneous but he did not accept this), which virtually stopped develop- ment of the subject until the mid 1950s. This is what we refer to as the Red Light for gravitational waves research. In the following years, the theme was picked up again and studied vigor- ously by various experts, mainly Herman Bondi, Felix Pirani, Ivor Robinson and Andrzej Trautman, where the theoretical obstacles concerning gravita- tional wave existence were successfully overcome, thus giving the Green Light for experimentalists to start designing detectors, culminating in the recent LIGO/VIRGO discovery. In this note we tell the story of this theoretical breakthrough. Particular attention is given to the fundamental 1958 papers of Trautman [19, 20], which seem to be lesser known outside the circle of General Relativity experts. -
Gravitational Waves from Supernova Core Collapse Outline Max Planck Institute for Astrophysics, Garching, Germany
Gravitational Waves from Supernova Core Collapse Outline Max Planck Institute for Astrophysics, Garching, Germany Harald Dimmelmeier [email protected] Gravitational Waves from Supernova Core Collapse: What could the Signal tell us? Work done at the MPA in Garching Dimmelmeier, Font, M¨uller, Astron. Astrophys., 388, 917{935 (2002), astro-ph/0204288 Dimmelmeier, Font, M¨uller, Astron. Astrophys., 393, 523{542 (2002), astro-ph/0204289 Source Simulation Focus Session, Center for Gravitational Wave Physics, Penn State University, 2002 Gravitational Waves from Supernova Core Collapse Max Planck Institute for Astrophysics, Garching, Germany Motivation Physics of Core Collapse Supernovæ Physical model of core collapse supernova: Massive progenitor star (Mprogenitor 10 30M ) develops an iron core (Mcore 1:5M ). • ≈ − ≈ This approximate 4/3-polytrope becomes unstable and collapses (Tcollapse 100 ms). • ≈ During collapse, neutrinos are practically trapped and core contracts adiabatically. • At supernuclear density, hot proto-neutron star forms (EoS of matter stiffens bounce). • ) During bounce, gravitational waves are emitted; they are unimportant for collapse dynamics. • Hydrodynamic shock propagates from sonic sphere outward, but stalls at Rstall 300 km. • ≈ Collapse energy is released by emission of neutrinos (Tν 1 s). • ≈ Proto-neutron subsequently cools, possibly accretes matter, and shrinks to final neutron star. • Neutrinos deposit energy behind stalled shock and revive it (delayed explosion mechanism). • Shock wave propagates through