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A history of research

Chiang-Mei Chen1 & James M. Nester1,2

1Department of Physics, National Central University, Taiwan 2LeCosPA, National Taiwan University, Taiwan [email protected], [email protected]

12 July 2016 @ GSROC GR101, NTNU, Taipei A history of gravitational wave research

Outline

Mainly a brief (and inadequate) history of the development of the theory Early history: Einstein, Eddington Einstein & Rosen (1937) Theoretical disputes: skeptics & non-skeptics binary pulsar Weber and bar detectors Laser interferometry and LIGO GW150914 References: D. Kennefick: Traveling at the Speed of Thought: Einstein and the quest for gravitational waves (Princeton Univ Press, 2007) H. Collins: Gravity’s Shadow: the search for gravity waves (U of Chicago Press, 2004) Collected Papers of (CPAE) http://einsteinpapers.press.princeton.edu A history of gravitational wave research

Forerunners

Clifford (1876): Curvature waves: “I hold that (1) small portions of space are in fact of a nature analogous to little hills on a surface which is on average flat; namely that the ordinary laws of geometry are not valid for them. (2) That the property of being curved or distorted is continually being passed on from one portion of space to another after the manner of a wave. ...” Poincare´ (1908) speculated about (special) relativistic gravity, with gravitational waves of acceleration that propagated at speed c Nordstrom¨ (1913): a relativistic scalar theory of gravity, with waves that propagate at speed c: Einstein & Fokker (1914): R = 24πGT & Weyl = 0. A history of gravitational wave research

Einstein’s predictions: 1916, 1918

AE to Schwarzschild, 19 Feb 1916, Doc 194 CPAE, Vol. 8 [http://einsteinpapers.press.princeton.edu]: “Since then [Nov 4], I have handled Newton’s case differently according to the final theory.—Thus there are no gravitational waves analogous to light waves. This is probably also related to the one-sidedness of the sign of scalar T , incidently. (Nonexistence of the “dipole”.)” de Sitter (1916) gave AE the hint, AE June 1916, a paper predicting GWs, includes the quadruple formula magnitude 1/24π, several mistakes, including confusing h¯µν and hµν correspondence with Nordstrom¨ (1918) −→ AE 1918, magnitude 1/80π, 3 types of waves, 2 recognized as coordinate waves, carry no energy Eddington (1922): curvature propagation, corrects AE by a factor of 2: 1/40π. A history of gravitational wave research

Do gravitational waves carry energy?

This has been debated since the beginning. The issue of gravitational energy is not so simple. Einstein used his pseudotensor, and found energy propagation Many objected to the pseudotensor including Schrodinger,¨ Bauer, Levi-Civita From the work of Hilbert, Klein and Nother it was established that there is no proper energy density Eddington & Pauli both argued that gravitational energy was non-localizable. Nowadays it is regarded as quasi-local—associated with a closed 2-surface. There are 2 issues: (1) no unique expression, (2) depends on the reference frame they are both addressed in our Hamiltonian boundary approach A history of gravitational wave research A history of gravitational wave research

Do gravity waves exist?: not accepted by Phys Rev

From Kennefick Ch 5 In 1936 Einstein submitted with a paper to Phys Rev entitled “Do gravity waves exist” which apparently came to a surprising conclusion: gravitational plane waves cannot exist. The Phys Rev editor [Tate] received a detailed referee report [see Appendix A in Kennefick Traveling at the speed of thought] He sent it to Einstein with the mild request that he “would be glad to have your reaction to the various comments and criticisms the referee has made” A history of gravitational wave research

Einstein wrote back Dear Sir, We (Mr Rosen and I) had sent you our manuscript for publication and had not authorized you to show it to specialists before it is printed. I see no reason to address the—in any case erroneous—comments of your anonymous expert. On the basis of this incident I prefer to publish the paper elsewhere. Tate replied that he regretted Einstein’s decision to withdraw the paper but stated that he would not set aside the the journal’s review procedure. Einstein’s annoyance was such that he never published in Phys Rev again. In fairness to Einstein, such a review procedure was not then used by the German journals he had been using in the past. A history of gravitational wave research

Einstein submitted the paper to the Journal of the Franklin Institute and it was accepted By then Rosen had gone to Russia. Einstein’s new assistant, Infeld, received a visit from H.P. Robertson (recently it came to light that he was the referee) who persuaded Infeld of problems in the paper. When Infeld went to tell Einstein, Einstein said that he himself had just discovered some problems. He had to modify the talk he had prepared for the next day. The paper was revised in proof to have the opposite of its original conclusion: it showed the existence of cylindrical gravity waves. Published as “On Gravitational Waves” They were looking for an exact plane wave solution, but actually found cylindrical waves. [they had been found earlier: Beck 1925, Baldwin & Jeffery 1926] Rosen did not know of the revision or publication (a friend had sent him a newspaper clipping) and meanwhile had also found some error but was not happy with the revisions. He published a paper in a Soviet journal in 1937 arguing that GWs do not exist because of a singularity in the solution. In 1955 at a conference he argued that gravitational waves cannot transport energy. In 1979 he published a paper “Does Gravitational Radiation Exist?” A history of gravitational wave research some theory

Since Faraday and Maxwell we think in terms of interaction fields, local action and propagating fields Maxwell’s electrodynamics is now our prototype the electromagnetic analogy J.J. Thompson argument Landau & Lifshitz derivation of the Einstein A history of gravitational wave research

Berne 1955, Chapel Hill 1957

Berne 1955: Synge, Pirani, geodesic deviation/tidal force Chapel Hill 1957 (Cecile DeWitt-Morette & Bryce DeWitt) Bondi waving two dumbbells : “Mr. Smith” () and . gravitational waves carrying energy, unlike EM, not dipole but rather quadrupole Pirani, Trautman, Robinson A history of gravitational wave research skeptics and non-skeptics

regarding the EM analogy a/o carrying energy, free fall binary systems skeptics: Eddington, Rosen, Infeld, Havas, Bondi, Cooperstock, Pereira non-skeptics: Landau, Wheeler, Pirani binary rate of energy loss, 2.5 order post-Newtonian, Einstein-Infeld-Hoffman complicated calculations issues include (i) advanced vs retarded vs half advanced–half retarded (ii) boundary conditions many different answers, some gain energy, Bondi: inductive energy transport Newtonian and GR A modern example: Io tidal heating Bondi news A history of gravitational wave research quadrupole formula

quadrupole formula: controversial Infeld, Goldberg, Havas, Fock, Peres, Trautman, Plebansky, Burke & Thorne, Walker & Will, Damour, Anderson boundary conditions, radiation reaction 2 approaches: PPN (slow) Linearized (fast) would binary stars radiate gravitational waves? quasars, collapse, black holes, pulsars 1967, A history of gravitational wave research binary pulsar

binary pulsar PSR B1913+16 (1974), Taylor & Hulse Nobel Prize (1993) indirect evidence for GW, fits the quadrupole formula A history of gravitational wave research

Christodoulou 2009

Christodoulou in 2009 proved that asymptotically flat vacuum initial data could be such that it would in the future form a trapped surface thus GWs could be focused to form a trapped surface and thus a so certainly gravity waves carry energy since they can condense and act like a “mass” (Wheeler had asked him to try to show this about 40 years earlier) A history of gravitational wave research resonant mass detectors

room temperature bars: Weber Joseph Weber 1960 1969 claim many other groups cyrogenic bars spheres were also proposed MTW Section 37.3: 8 types of mechanical detectors A history of gravitational wave research

Laser interferometers

MTW p 1014: “...or by laser interferometry. Several features of such detectors are explored in exercises 37.6 and 37.7. As shown in exercise 37.7, such detectors have so low a sensitivity that they are of little experimental interest.” History: Weber, Ray Weiss, Forward, Schutz, Thorne, Drever LIGO, VIRGO Kennefick (2007) “Today it is widely expected that the first direct detection of gravitational waves will take place within the decade” p1 A history of gravitational wave research

GW150914

GW150914 It offers direct evidence for (i) gravitational waves, propagating waves of curvature (ii) black holes (iii) binary black holes (iv) black hole coalescence some constraints on (i) the speed of the wave, (ii) limits on massive gravity, (iii) polarizations (iv) on certain types of proposed Lorentz violations seems to be consistent with orthodox theory A history of gravitational wave research conclusion

Thank you for your attention and patience. A history of gravitational wave research

A final thought

Gravity is the universal attractive interaction, A history of gravitational wave research

A final thought

Gravity is the universal attractive interaction, moreover it connects all of existence together and is the prime cause of the order in the cosmos A history of gravitational wave research

A final thought

Gravity is the universal attractive interaction, moreover it connects all of existence together and is the prime cause of the order in the cosmos gravity is like  A history of gravitational wave research

A final thought

Gravity is the universal attractive interaction, moreover it connects all of existence together and is the prime cause of the order in the cosmos gravity is like 

Is there a deeper meaning to this similarity? I think so. With appreciation for your attention.