Part 1 - The Professors Faulty Gravity - A Rejoinder
Defending a Pioneering 'Big Science' Astronomical Project and Promoting Science in TT Education.
We visit The Advanced Laser Interferometer Gravitational-Wave Observatory - LIGO
Part 2 - Aftermath - The Song in Space-Time - (Below)
What happened next - After the above was written.
How the history of gravitation wave science, made a huge step into the unknown
This rejoinder is dedicated to our most precious resource, the curious of our young women and men of Trinidad and Tobago.
tobagojo - San Fernando, Trinidad, TT. 7th October 2015.
Startled by the TT NEWSDAY, 30th September 2015, by-lineGravity waves search is doomed to failure ; I read on in accumulative dismay to the put-down, as expressed by Professor Stephan Gift, Faculty of Engineering, UWI, to one of he worlds most sophisticated and exciting scientific astronomical instruments, Advanced LIGO, as its 2015 US$200 million (TT$1,250m) upgrade is now called; following its reactivation on 18th September.
As a supporter of youth education, as we try in our panyard, and particularly for any project that inspires the engagement of students to follow the advancement of technology and science, much in the interdisciplinary way that the LIGO project is doing; I was curious to follow the Professors arguments and ready to engage in constructive discussion, based on any reasonable scientific principals, or on any relevant points that the Professor would make, concerning his doubts as to this projects eventual success.
At a present accumulated coat of US$620 million (TT$3,875m) The Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) is actually two individual physical installations, 3,030 kilometres (1,883 miles) apart. Both comprise two 4 km-long (2.5 mile) arms, perpendicular to each other, with vacuum tubes down which a split LASER beam is fired to ricochet as many as 50 times off mirrors on the super-quiet-suspended 'test masses' at the arms ends, before the recombined beam is measured for telling wave changes. One facility is at the Livingston observatory in Louisiana and the other at the Hanford observatory in Washington state, USA. (There is an option for a further facility to be built in India, but the funding awaits approval.). They comprise the most unusual and scientifically inspirational astronomical telescopes in the world. They also comprise one of the worlds most challenging to implement and are the most sensitive scientific instruments, ever.
Mainly funded by the US National Science Foundation, LIGO is an initial collaboration by a team of scientists from the US's CAL Tech and MIT, that has grown to over some 200 participants; which now includes teams from Germany, the U.K. and Australia.
Prior to its September 2015 restart, lead scientist Vern Sandberg of Hanford labs is quoted to having stated "The one thing I personally like about LIGO is it's used every bit of physics I know, from the most arcane solid-state and surface physics to lasers, electronics, quantum mechanics - everything." Seen as a long term 'big-science' project due to its outlandish aims and stringent 'sci-fi' specifications, LIGO was planned as a multi-staged experiment, proving and improving its systems and applied technologies as it went along, and upping its sensitivity in stages to arrive at that 'sci-fi' theoretical threshold of detection, somewhere down the time-line. Conceived on paper in 1992, sod-turned in 1998, outfitting started in 1999, seeing 'first light' in 2001, starting science in 2002 and ran tests and science to 2004 before retooling. Restarted in 2005 and ran tests and science to 2007 for next retooling. Restarted in 2009 and ran tests and science to 2010, the planned date for the Advanced LIGO upgrade. Up to that time, no cosmological phenomenon that could produce gravitational waves had been detected.
Advanced LIGO 2015 however, is perceived by the scientific community to have now matured to that theoretical threshold of detection, where the 'real' has now just about caught up with the 'sci-fi'. Additionally, suffering the usual 'wood from the trees' - 'signal to noise' syndrome at the sensitivity to which LIGO is to operate; scientists have had to subdue or work around some eight (8) principle 'noise' sources that could contaminate their data. Of note as an amusing aside, but not so for the 'engineering efforts needed to circumvent it', are 'seismic' events like a heavy vehicle hitting pot-holes some kilometres away from the detectors; it's a good thing that there are no LIGO's near San Fernando, where the exposed LOK-JOINT man-hole covers would no doubt promote a 'seismic catastrophe' for the machine.
To illustrate the degree of sensitivity of the Advanced LIGO instruments, designed to detect an 'in-spiral chirp' imposed by 'gravitational wave' distortion on 'space-time' by a pair of merging 'neutron stars' at an astronomical distance of some 60 Mega Parsecs (nearly 200 million light years away); requires a detection resolution of the change in length of the LASER beam bouncing around in the arms of the instruments, in the order of 1 part in 1022. In hopefully understandable layman's mathematical terms; that's 1 part in 10,000,000,000,000,000,000,000 ( One part in ten thousand, billion, billion! ) Sorry about that if it's a bit over-the-top, but at least we tried.
To crown it all off, if only to inspire some geeky TT girls and boys about science projects; to plan, administer, document, test, model, synchronise and control the instruments, sift 'noise', extract signal, and data-log the science, the LIGO's use a collection of 'mouth-watering' super-computers running in the basement.
Well, with all of that rattling around in my mind, I read on into the Professors article with continued dismay. What continued to be revealed was a thinly veiled unease of jealousy over the cost in expenditure required to support such 'big science' and a depreciating harangue about, if successful, the project initiators could receive a Nobel Prize. To counter that, in my view, 'big science' needs focussed investment in relevant technologies to arrive at new horizons; and if you get a 'Nobel' along the way, which incidentally is a conferred honour near impossible to predict, my goodness, you've done all the hard work to deserve one.
But what really got my goat, or my catfish, or whatever other TT spin one can put on it; was first, his floored philosophical interpretation of a quote by a LIGO researcher, where he penned:
(The Researcher) "If nature shows a little bit of cooperation, we will make history."
(The Professor) However nature does not follow the desires or dictates of men, but as history has shown is more likely to reveal her secrets to those who observe her with an open mind and go where the evidence leads.
Oh, come on Professor, that's a null statement. The researcher is already open minded, tracking the evidence and using the best tools at hand to probe the natural 'secrets' of the cosmos; and further, is only pointing out (i.e. he/she alludes to the fact) that scientists have to contend with the problems of 'noise' that the natural environment of the cosmos presents as problems to be overcome, before any successful outcome can even be in sight.
The Professors next statement is the real 'corker'; or at best a Sargasso seaweed annoyance, or at worst, equivalent to a TT Steelband Panorama's adjudicators' results. It's the Professors faulty gravity; where he states:
(The Professor) I have for the past several years followed the evidence and have concluded that, contrary to scientific orthodoxy, relativity theory is wrong. I contend therefore that these researchers are looking for a phenomenon that simply does not exist and despite their entreaties to nature, I am of the view that LIGO will end its latest search in another disappointing failure.
I knew beforehand, at the start of this rejoinder, that it would be a long and hard slog.
The above statement by the Professor had me wondering what "evidence" he had been "following" for "several years" as, his overall article was running a bit thin on the science but weighed heavy on the harangue; and did not quite match with what I had been "following". I thus concluded that the statement needed just two answers. One to address 'relativity' and the other to address 'failure'. Kindly bear with me, as I attempt to make the best from a sour 'fish broth'.
I would like to start with 'failure', a tricky little concept, one that can generate the pretty little roundabout of words like: You can never fail if you don't try to succeed.
So has LIGO 'failed' in its overall 15 years of expensive existence; with its 9 years of intermittent science, with no positive results since from as far back as 2010? Lets jump that roundabout and think. It's still a little too early to tell, but the odds are, that it will more than likely succeed. Why? It has some incredibly good no-nonsense scientific pioneers behind it, and in addition, a team of some of the worlds leading and upcoming scientists and engineers nursing their baby to maturity. Scientists and babies? Oh yes, scientists mind babies, passionately nurture them to maturity, then send them to the stars. Their children have visited all the planets, and some are even walking upon them, and astonishing us with what they have found. Babies are what scientists do best, it's their life's work, and LIGO is no different.
But leaving all that cosy rhetoric aside, we need briefly touch on a few real characters whom may lead us to appreciate just what LIGO is trying to find. While acknowledging generally the significant contribution of the team of specialist who have helped put LIGO together, we need note two mathematicians whose work is inspirational to the building of this unusual gravitational-wave telescope. The American physicist, known as a relativist, Dr. Kim S. Thorne, a member of the LIGO team; and his side kick, the British theoretical physicist Prof. Stephen Hawkins. While stretching a phrase without need to batting an eye; Thorne and Hawkins may be considered the Bat Man and Robin Hood of gravitational-wave physics. You could even throw in an Iron Man as well, although his 'Sci-Fi' technologies are a little more advanced than we have here today; but it is Iron Man's eccentric personal character and lime-juice whit that can be used as a fair description of the bond of brotherly playfulness that these two, Thorne and Hawkins, professionally share and enjoy together.
Hawkins, the wizard at Cambridge, sadly biologically infirmed to be the whispering synthesized voice behind the spectacles on the roving wheel-chair, is world famous for his A Brief History of Time, and is master of black-hole physics among much else; and has recently warned us to be very careful with our 'Artificial Intelligence' research. Thorne, not far behind (he'd like that!) with these matters, is noted also for his Black Holes & Time Warps. Thorne is blushingly famous for having helped his friend astrophysicist Prof. Carl Sagan, leader of NASA's Mariner, Viking and Voyager planetary missions, writer of Cosmos and in need of help to get some 'essentially correct science' to transport the heroin, the assertive Eleanor Arroway, in Sagan's 'Sci-Fi' epic Contact, safely through the 26 light-years round-trip from Earth to Vega. Thorn pursued the calculations and evidenced that an Einstein-Rosen/Flamm 'wormhole', though speculatively futuristic, was assuredly the best way to go. So while giving Sagan and Hollywood a solid new toy; he also opened up a new field of enquiry in gravitational physics. Thorne is an inspiring teacher and is one of the lead theoretical architects behind the LIGO project. Seeking "to detect and study astrophysical gravitational waves and use data from them for research in physics and astronomy" is LIGO's prime objective.
Although already sighted by some of the world great telescopes, the likes of ESO's ALMA, La Silla and VLT; WM Keck and Subaru; and NASA's Spitzer and the famous Hubble Space Telescopes; neutron stars, black-holes and supernovae and their remnants are familiar, though somewhat rare, cosmic entities. LIGO's task is more difficult and long-term; as it is trying to record the dynamics of their formation, or where applicable, their collisions. These dynamic events are even less frequent, and very rarely observed, so LIGO needs to listen long. With astronomers and astrophysicists conceding recently that they have only 'seen' about 10% to 15% of the known material of the cosmos, LIGO's unique properties may bring new light to this area of research. As the missing 'dark matter' is known to have gravitational properties, which is just up LIGO's street, who knows what new entities LIGO may find.
Apart from NASA's US$10 billion (TT$62.5 billion ≈ TT National Budget 2016) 6.5 meter (21.3ft) diameter, 18 segment, James Webb Space Telescope, scheduled for launch in 2018, the optical technical leading edge companion to the gravitational-wave Advanced LIGO 2015; one would be hard pressed to find a project as thoroughly inspirational as LIGO. LIGO, for the first time, opening the worlds eyes with a new lens into the gravitational-wave spectrum. How much more challenging can you get?
Through the internet, and as hopefully now promised with even better connectivity, the curious of our citizens of TT are inspired from a wider world. Although we have no NASA or LIGO's here in TT, our young women and men, from the panyards, the Primaries, the Secondaries, the Trinities, the St Mary's, the QRC, the Convents, the ASJA's, the UTT's and the UWI's all have a right to dream. They need inspirations like LIGO, and once inspired, who knows what some of them may bring home to TT.
We do not need Professors, with little good reason, telling us it's no good to try.
LIGO - Advanced Laser Interferometer Gravitational-Wave Observatory - L1 (Livingston)
A view of one of the 4 km-long (2.5 mile) arms of the US National Science Foundations Advanced LIGO Facility, Livingston, Louisiana, USA. LIGO uses a Dual Recycled, Fabry-Perot Michelson Interferometer (DRFPMI) developed collaboratively at GEO600.
Relativity is real and as right as the science community can understand it; but as will be shown, you don't need to take my word for it. It may, in time, be superseded by a better rendering; much as Newton's theories of motion were appended by 'relativity' as a special case. But Newton was not wrong either; his theories, after some 339 years, are still confidently used by science and engineering today, and are considered only to have been updated by Einstein's 'relativity'; and this only for some extreme conditions of motion and mass. For a layman to accept 'relativity' however, needs a little story that embodies the traditions of the 'scientific principal', an idea set by the considered father of 'science', the Italian scholar Galileo Galilei, in 1632; a quality apparently surprisingly lacking in an undisputedly accredited Professor of Engineering.
Many are perhaps familiar with the story of the young Swiss patent office clerk, who enjoyed contemplating the city's large clock, who in 1905 published a scientific paper on Special Relativity, and whose name was Albert Einstein. The thesis postulated that the speed of light was as fast as anything could go; and relative to an observer placed on an artefact approaching that speed, time would slow, the artefact would shrink in length while simultaneously increasing in mass. The thesis was 'special' because it only dealt with objects at rest, or moving in a straight line. The thesis also championed the idea of space-time; the underlying fabric of the cosmos. Although the thesis was a serious game changer for physics, Einstein remained in public obscurity as these ideas were so esoteric that only a handful of keen mathematicians and physicists understood what he was on about.
The unfamiliar part of the story continues with Einstein not having much luck with his game changers as, when he presented his theory of General Relativity, first presented in three lectures at the Prussian Academy of Science, in Berlin, around the 25 November 1915; Germany was at war (WWI - 1915 to 1918). The thesis was later published in Berlin in 1916, from which it struggled to impact on a wider world, because of the war. The 'general' in the new theory opened the discussions to now consider all or dynamic matter; it deals with matter in motion, changing direction, accelerating, gravitational fields. The theory brought on the concept that the force of gravity is equivalent to an accelerating mass, and synonymous to curved space-time. Mass induces a curve in space-time that implies a gravitational field. Light, that travels in space-time, will bend with it if space-time is bent! Thus mass will bend light!
Scientists are a wily bunch at the best of times, and detest political impediments that separate them from new ideas in science; word was getting out that somebody was bending light; this was ridicules off course!. But anyone who can bend light is definitely worth a second thought; and so the word spread.
We pause briefly in this story to report one of those oddly really surreal moments in scientific history, because it involves a still un-famous Einstein. In 1917, using quantum theory, Einstein published a paper on the behaviour of excited electrons and how they would behave, giving off photons, as they became un-excited. He cited that they could be stimulated to de-excite. Yes, Light Amplification by Stimulated Emission of Radiation, LASER's, are a spin-of from Einstein's theoretical pigeon; one that took 43 years to fly into the light in 1960. Just incidentally, they are a critical LIGO component.
Continuing in 1917, but this time across the channel to Britain; the British Astronomer Royal, Sir Frank Dyson a member of The Royal Society (RS), was aware of Einstein's new 'relativity' and was pondering by what scientific method of experiment it could be proven. If mass bent light, then the sun, a great mass, should also bend light. The light of what? The stars of course! Dyson then suggested that a solar eclipse, due in 1919, would be the ideal opportunity to test this theory. A solar eclipse obscures the direct glare of the sun, allowing far stars, aligned close to the sun's rim, to now be seen. If the gravity of the sun could bend their light; a picture of the far stars before an eclipse, compared with a picture of the far stars during an eclipse, should show a displacement in the position of the stars. It could all be precisely measured, and calculations made to test the theory. Piece of cake; except there was a war on. Undaunted, Dyson started planning an expedition anyway.
Luckily, the war appeared ended with the Armistice of 10th November 1918, which had halted the fighting, allowing consideration to the funding of a scientific expedition to be forthcoming. Dyson had determined that the best view for this eclipse would be from Principe Island, off the west coast of Africa; and to have a back-up in case of poor weather, at Sobrol in northern Brazil. In December 1918 reference plates (photographs on glass) were made of the stars in the position of the expected eclipse.
For the solar eclipse of 29th May 1919, the Cambridge astronomer Arthur Stanley Eddington of the RS would lead the Principe group and the Greenwich Observatory would send C.R. Davidson and team to Sobrol. Both teams had good viewing, and the solar eclipse was successfully photographed from both locations.
The plates were developed abroad, and Eddington, who had taken reference plates with him, knew the result. He telegraphed to the RS with the news. On the 3rd June 1919 the first scientific confirmation of Einstein's General Relativity came in to Britain and spread like wildfire; as a consequent message from the mathematician Littlewood of the RS to the philosopher mathematician Bertrand Russell records:
Before any public announcements, all the data had to come in from the field, and further measurements made to dispel any errors. Also the war was not yet officially over. However, The First World War ended on the 28th June 1919, just over 3 weeks after that fateful news. It was thought that a release of this news could bring some cheer to a battle worn Europe.
So virtually a year after the Armistice, it is recorded that on the 6th November 1919, at a joint meeting of the Royal Society and The Royal Astronomical Society at Birlington House, London, with The Times correspondent in attendance; the announcement was made in the proportions of 'a Greek drama', as described by the philosopher Alfred Whitehead who attended. To a packed hall awaiting in silence, J.J. Thompson the president of the Royal Society, rose to make the address, pausing to glance up at the portrait of Newton that hung above them. Thompson began "One of the greatest achievements in the history of human thought." Using euphemisms of Empire "It is not the discovery of an outlying Island, but a whole continent of new scientific ideas."
The Astronomer Royal, Sir Frank Dyson, then rose to outline the results from the Eddington and Davidson teams. In verification of Einstein's theory, he stated that the bending of light by the gravitational effect of the sun did not tally with the theory of Newton, but was in full accord and near exact agreement with Einstein's theory of General Relativity.
A lively debate then followed, as not everyone was in agreement; but it was clear that some heads of science were thoroughly convinced. Physicist J.J Thompson was noted to add that he was "confident that the Einstein theory must now be reasoned with, and that our conceptions of the universe must be fundamentally altered." At that point, the respected astronomer Sir Oliver Lodge, walked out of the meeting.
To the press however, bending of light by gravitation, upstaging Newton, was news indeed. The 7th November 1919 headlines of The Times read REVOLUTION IN SCIENCE. The worlds press then got on the bandwagon, and it was from that day on that Einstein became a world celebrity.
The year following, 1920, may be regarded as the year of 'Einstein hysteria', in which the essence of General Relativity and widely distorted and absurd versions about it, sprang up all over the place to heated debate, socio-didactic slang and satire. Einstein became a household name. By the end of that year, the only people who disagreed with General Relativity were; the unfortunate ignorant, the philosophically challenged, jealous physicists and radical anti-Semitic political opponents.
We now leave it up to our good Professor of Engineering to himself select to which of the above categories he may belong.
Jeremy G de Barry - tobagojo
PRO Hatters Steel Orchestra
06 October 2015
Both the Professor and myself were caught with using erroneous terminology; A gravity-wave = water wave; whence a wave in space-time = gravitational-wave, the correct usage.
The Professor was 75% wrong [3 in 4] ( e.g. The headline 'Gravity waves search is doomed to failure' should have read: 'Gravitational waves search is doomed to failure' ); whereas I managed 25% wrong usage [3 in 12]. - [Return]
I discovered the mistake in time to fully correct this internet transcript; however, should the article ever be published in any of the listed newspapers (low probability), it will contain the original transcription errors of use.
Part 2 - Aftermath - The Song in Space-Time
What happened next - After the above was written.
How the history of gravitation wave science, made a huge step into the unknown
Following the news that an unusual and expensive upgraded American telescope, called Advanced LIGO, had officially started on the 18th September 2015 it’s first new-sensitivity run to find gravitational waves, which it had previously been unable to detect since it had seen first light in 2001; a disgruntled and sceptical Professor Stephan Gift, Faculty of Engineering, University of the West Indies, published a paper in the TT NEWSDAY on 30th September 2015, with the by-line ‘Gravity waves search is doomed to failure’. The Professor, among other negatives, surmised that “…relativity theory is wrong. I contend ...that LIGO will end its latest search in another disappointing failure.”
Alarmed by the abject negativity of that article, the author communicated to The Editor of TT NEWSDAY (unpublished) and placed on the seetobago.org web an article written on the 6th October 2015 named ‘The Professors Faulty Gravity - A Rejoinder’. The author, supporting Einstein’s general relativity commented “…one would be hard pressed to find a project as thoroughly inspirational as LIGO. LIGO, for the first time, opening the worlds eyes with a new lens into the gravitational-wave spectrum. How much more challenging can you get?”
The following, is how the history of gravitation wave science, made a huge step into the unknown. Here we also find that; the Professor and his faulty gravity, got superlatively piped to the post; every-which-way you go. Ironically, as the ‘Professor’ was penning his harangue just before the 30th September; aLIGO had already made their stunning gravitational-wave discovery on the 14th September 2015. Hmmm!
UpDate: tobagojo - San Fernando, Trinidad, TT. 21st October 2017.
We in TT like song-forms, we invented some of them. They are deep-rooted in our Caribbean culture. The lyrics of our calypso, soca and chutney brighten our carnivals; and parang our Christmases, and some of those in turn get played on our indigenous steel drums by many of our culturally specific TT steelbands. However, curiously similar to our penchant for odd music-forms, at the 2015 updated Advanced Laser Interferometer Gravitational-wave Observatory (aLIGO 2015), over 1,000 highly skilled and committed technicians, engineers and scientist were also looking for a song-form. Albeit a theoretical song-form that they called ‘chirps’.These ‘chirps’ were not easy to invent. They were all the product of analyses of Einstein’s relativistic field equations that he developed in 1916 when he postulate the existence of gravitational waves, a year after he had composed his theory of General Relativity. Much later work by Kip Thorne in 1993 used the equations to describe how closely rotating binary black holes would generate strong gravitational waves, and how these waveforms would peak when the black holes eventually collided. That is the form of the ‘chirp’. From that time, to the refit at LIGO in 2015, these equations have been programmed into super-computers to realise the behaviour of as many interacting exotic cosmological heavy mass objects as the astrophysicists could think of that make all flavours of gravitational wave ‘chirps’. A ‘chirp’ being the audio translation of a specific type of detectable gravitational wave event.
It was in the late 1950's when Joseph Weber began his lonely course as the pioneer of gravitational wave research. By the mid 1960's, he had begun to inspire many researchers, but the expected results were not convincing, even into the early 1970's. However, by the mid 1970’s gravitational wave research was beginning to be taken seriously and proposals for a serious project to accomplish the feat arose in the mid 1980’s. It had now taken over 40 years of research into the intricate mathematics of Einstein’s general theory of relativity and the technical development and understanding of may new materials and technologies, across all disciplines of engineering and the sciences, to make all the equipment to find and to arrive at the templates for, a meaningful gravitational wave ‘chirp’. The LIGO Scientific Collaboration, which now included some 1,004 noted members from 15 contributing nations, and 133 internationally significant scientific institutions, having over the past years upgraded their LIGO facilities, were now ready to look for this odd song. The ‘song’ of two massive objects, way out in the cosmos, orbiting into collision.
As usual with the management of ‘big science’ projects, targets and time-lines had been set. As planed, after nearly 5 years of refit, a 3 - 10 times more sensitive aLIGO would start its upgraded run "O1" on 18th September 2015; to end again for upgrade on 12th January 2016. Run "O2" planned to start on 30th November 2016; to end 25th August 2017. Of the many things that could be of interest about aLIGO here, just two are highlighted for this dialogue. Mergers and chirps.
The first thing of interest here is the merger of two massive objects orbiting into collision. Targeting known astronomical phenomenon, the gravitational wave data sets that aLIGO was expected to have the best probability of finding was that for the merger of two closely rotating massive objects. In this case, the merger of two (binary) neutron stars. Although thousands of other gravitational wave inducing phenomenon have been investigated by the LIGO consortium, including the merger of binary black holes; binary neutron stars, because they were already identified by other and optical methods; the probability of these events were better known; at around 1 or 2 events a year; for the volume of space that aLIGO could at its limits be able to detect. So the merger of binary neutron stars were the objects that the now Advanced LIGO was first expected to find.
The second thing of interest here is about ‘chirps’. After all the high mathematics of astrophysics and relativity are as best considered for the merger of two massive astrophysical objects. It turns out that because of the relatively small size dimensions (10-150 km dia) of these incredibly massive objects, that the orbits they describe just before they touch, are incredibly small and tight. Typically in the order of a ~=>300km diameter circle. So to maintain orbit, their orbital speeds are very high. The last few moments of rotation before they crash together to fuse into one resultant object, can generally roughly be described in three stages as; the inspiral, the crash (merger) and the ringdown. The inspiral, because of their size and mass, is limited to be a rotation between around 100-200 revolutions per second. Because of their incredible masses (2-100 MSol), their gravitation ripples space-time, thus putting energy into space-time and loosing rotational kinetic energy, and thus causing them to get closer together. All of which rotation, constrained by the laws of physics for gravitationally bound masses in close orbit, to balance the required maths, means that they are moving at a velocity measured in fractions of the speed of light. When they touch and crash together, they exchange body fluids to become one entity. The event needs to reorganise all their intrinsic spin and kinetic rotational energy into one body, and for that system at that time, causing a maximal gravitational disturbance of space-time. The transfer converts some of their matter into gravitational wave energy in the process. So the received gravitational wave signal oscillates to a peak; generating a waveform of rising amplitude that raises in frequency from ~ 10Hz up to ~ 100Hz or so. The resultant entities mass then goes into ringdown; much like the ring of a bell, as the glob of matter reorganises itself into a sphere, under the influence of the extreme gravitational forces that its new mass dictates. The ringdown is a higher frequency event, though less gravitationally severe than the merger; and is estimated to be in the vibrational kHz range. So that’s the gravitational wave merger signal that, if found, can fortuitously be converted into the song of an audio ‘chirp’; as the signals lie within our audio frequency band.
Finally, the significance of the ‘All-Sky’ aspect of gravitational wave (GW) detection cannot be overstated. Event networking alerts with observatories seeing in other domains like neutrinos, gamma sources and the more line-of-sight instruments in the conventional electromagnetic (EM) spectrum, is an important facet of collaborative science. And it works in both directions, for significance of event confirmations. So it can be asked, which of these events and mergers detectable by GW methods could be observable with other telescopes?
Mergers of binary black holes (BBH’s) are not likely to be seen as there is no matter as we know it, to be gravitationally distorted; as emissions are contained within the event horizons; but we may yet have some surprises here. In that, are BH mergers always ‘perfect’? Around these conditions of highly distorted space-time, are there any turbulent points where the conditions of singularity brake down, and the merger leaks matter? On the other hand, as others have commented, if either or both black holes have a band of accretion material (matter) around them; the matter could generate gamma, x-ray, UV radiation as some of it is tidally squeezed when falling into the new larger black hole. On the other hand, grand firework displays, across the entire EM spectrum are expected for; black hole & neutron star and binary neutron star (BNS) mergers, (with or without accretion disks) as these mergers involve conventional matter. BNS mergers are currently postulated to generate gamma-ray bursts. Somewhere in there, neutrino events are also likely; particularly around any NS mergers; or events around any large novae. Like the creation of new NS’s and BH’s that ultimately will be GW detected.
UpDate: tobagojo - San Fernando, Trinidad, TT. 21st October 2017.
LIGO - Advanced Laser Interferometer Gravitational Wave Observatory - H1 (Hanford)
US National Science Foundations Advanced Laser Interferometer Gravitational Wave Observatory, Hanford, Washington, USA - 4 km arms. LIGO uses a Dual Recycled, Fabry-Perot Michelson Interferometer (DRFPMI) developed collaboratively at GEO600.
Caltech Media, Kathy Svitil, Ref: beckett
As would be expected, procedural preparations were well underway at the two LIGO facilities in the shakedown before the start of the much publicized Advanced LIGO observing run "O1"; to start on 18th September 2015; and to end 12th January 2016. Just around 2 weeks before the run "O1", aLIGO L1 at Livingston, Louisiana, and 3,030 kilometres (1,883 miles) away at aLIGO H1 at Hanford, Washington; both observatories were coming on-line, running system checks. By about a week before "O1" they were both fully functional and stabilised, and still running system checks. Then they had an unexpected bit of luck.
SILANCE IS HARD
What later became famously known as the GW150914 event; on the 14th September 2017 (GPS time 1126259462, or at 09:50:45 UTC) aLIGO L1 at Livingston first registered a signal, followed 6.9 (+0.5 −0.4) ms later, by H1 at Hanford. Gravitational Wave Astronomy had seen and recorded its first event. Surprised, suspicious and super-cautious, LIGO L1 and H1 went into overdrive. Knowing, besides the excitement, that it would take time to solidly confirm what and the character of the event that they had detected; and as well be responsible to continue the "O1" run; the tight LIGO and VIRGO consortium went into lockdown silence on what they had found, until all the science had been properly checked, and continued into the "O1" run as normal.
However, because LIGO/VERGO is essentially an ‘All-Sky’ survey tool, as part of a developing Advanced LIGO and VIRGO scientific collaboration operational GW ‘trigger’ protocol, a real-time network operates to alert selective established EM (Electro Magnetic) groups of astronomers to point their line-of-sight telescopes to observe for possible related transient gamma, X-ray, UV, optical or radio phenomenon. For the GW150914 event, as part of this exercise, the SWIFT orbiting high-energy observatory was queried within 48 hours, to look for gamma-ray bursts, but nothing positive resulted. A further developed of this GW ‘trigger’ protocol would lead to notable successes, some time later.
As the aLIGO researchers are members of a keen scientific community, spread far over the globe, following their unusual change in behaviour after the GW150914 event information lockdown, suspicion arose from those colleagues outside the group that they were onto something, and something big. Within two weeks of the event, speculative leaks began to appear in the social media. And the speculation got very near to the truth when a ‘LIGO_mole’ (or imitation, who knows?) sleuthed onto the networks. Rather than being phased by such revelations and also to some rather brutal criticisms of their scientific methodology in between, the LIGO consortium management stoically stood their ground, advising members to hanker down, remain vigilant, get their reports done; and adopted a ‘lets get the job done properly’ attitude. Silence is a hard thing, both ways; particularly to probing sensation seekers. It all played off handsomely. The probes never got their hands on the hard confirmation data they were seeking.
And now, all seemingly too soon, it was time to tell the world what aLIGO had found.
UpDate: tobagojo - San Fernando, Trinidad, TT. 22nd October 2017.
Windows on Gravity
THE PLACE Publicity day was the 11th February 2016 from the US Capitols National Press Club, 529 14th Street, NW, 13th Floor, Washington, DC 20045. All video linked to LIGO’s research principals at Caltech and MIT. The media conference was hosted by the National Science Foundation (NSF), one of aLIGO’s principal sponsors.
THE NSF The Director of the NSF, astrophysicist Dr. France Córdova, warmly opened with a welcome address to all, acknowledging the LIGO, VIRGO and GEO scientific collaboration, principal partners Caltech and MIT and the major international contributor groups, The Max Plank Society, the UK Science and Technology Facilities Council and the Australian Research Council. She then went on to comment that the NSF had taken a huge risk in supporting LIGO, its largest project commitment at the time, but nevertheless that was its function, to support science and to advance technologies and learning. A brief video-introduction to gravitational-waves was then presented.
THE PEOPLE Dr. Córdova then moved to the head table to join Prof. Gabriela González, Spokesperson, LIGO Scientific Collaboration, Professor of Physics and Astronomy, Louisiana State University; Prof. Rainer Weiss, Professor of Physics Emeritus, MIT; and Prof. Kip S. Thorne, The Feynman Professor of Theoretical Physics, Caltech.
GRAVITATIONAL WAVES Executive director at Caltech of the Advanced Laser Interferometer Gravitational-Wave Observatories (aLIGO), experimental laser physicist Prof. David Reitze, took to the podium and smilingly announced "Ladies and gentlemen, we have detected gravitational waves. We did it!" to which there was tumultuous applause. He then concluded his beginning, after the noisy pause, with a modest “I am so pleased, to be able to tell you that.”
He then explained that what LIGO had detected was the merger of two Black Holes that had occurred about 1.3 billion years ago. He then went on to stress the enormity of the technological achievement by stating “LIGO is the most precise measuring device ever built.” While explaining the character of the received waveforms, he mooted one of the experiments achievements as “Exactly …what Einstein’s theory of relativity would predict for …two Black Holes …inspiralling …merging together.” Prof. Reitze remarked that it had taken months of careful analysis with the collected data to be assured that what was being announced today “…was a gravitational wave.” then calmly adjusted the events focus from the now “This is not just about Gravitational Waves; that’s the story today”, then pointed to the future, with “what’s really exciting is, what comes next?” Drawing a reference from the history of the sciences he explained “400 years ago, Galileo turned a telescope to the sky and opened the era of modern observational astronomy.” and continued with the conviction that “I think we are doing something [as] equally important today. We are opening a window on the universe, a window of gravitational astronomy.” A video of the inspiral of two black holes, demonstrating the gravitational waves produced, and how they are propagated through space-time to the LIGO detectors on Earth; was shown, with Prof. Reitze providing explanations. While beginning his closing statements Prof. Reitze reiterated the staggering precision of the LIGO interferometers by comparing their sensitivity to the distance of the nearest star to the sun, Alpha Centauri as “…to the width of a human hair at the distance of 4.4 light-years.” He commented on the audio promises of the experiment with “…we may hear things that we never expected,” and asserted the possibilities of this new gravitational astronomical window with “…we may see things that we never saw before.” Prof. Reitze concluded with a lauded 20th Century analogy “This was …a scientific moon shot. We did it. We landed on the moon!” and in behest to the LIGO scientific collaborations, thanked the NSF, the US Congress and the US tax payers, for supporting such a risky project.
Next were presentations from the aLIGO team to deliver the gist of the science and some meaning to the projects discoveries.
HEAR THE SONG OF GRAVITY Spokesperson, LIGO Scientific Collaboration, astrophysicist Prof. Gabriela González started by emphasising that the effort for the discovery was an international effort “…a World wide village” with the LIGO collaboration and the VERGO collaboration from Europe, with over 1,000 international members. She then briefly described the LIGO detectors at the NSF’s Livingston (L1) and Hanford (H1) facilities; and noted that the planning specified two instruments, for comparison, to allow confidence in the verification of any received signals. With an enthusiastic “So, this is it! This is what we saw.” Prof. González displayed two waveforms of “Strain”, the magnitude of the gravitational distortion of space-time, verses “time”, the period over which the signal appeared; first received at L1, and then ~ 7 mille-seconds later by H1, in confirmation of the event. “This is it!” she explained “That’s how we know we have gravitational waves.”
“But we know a lot more than that” she went on to explain, indicating the diagrams of oscillating waveforms with a rise in amplitude, together with a rise in frequency to a peak, and then the drop off. “That’s exactly the predictions that we know from solving Einstein’s equations on computers, for the coalescence of two Black Holes; …into one.” She then graphed the predicted matching relativistic overlay onto the received signals diagrams, and then exclaimed “ …this is the fantastic news!” Presenting a new overlay diagram of the two received waveforms, time shifted to match both signals, Prof. González went on to explain “From these waveforms, you can tell a lot more.” From the frequencies within the signals, the masses of the initial black holes can be estimates as 29 and 36 Solar masses. From comparison with the relativity solutions, the resultant larger single black hole has a reduced total mass of 62 Solar masses. Where 3 Solar masses were converted to energy in the merger and emitted as gravitational waves; were Prof. González further explanations. “We can tell even more than that” Prof. González expressed, saying that from the amplitude of the waveforms, the time of the event could be deduced as “1.3 billion years ago; when multi-cellular life, here on Earth, was just beginning to spread.” Prof. González then alerted the audience to the fact that all the relevant scientific information about this gravitational wave discovery could be found in a paper on-line; published this day in Physical Review Letters (DOI: 10.1103/PhysRevLett.116.061102) - (See below). Other papers on related scientific and technical details were also now available on-line and from other sources. A coloured plot of the time vs frequency characteristics of the received gravitational waveforms was displayed by Prof. González, with the note that the amplitude gets brighter as time advances on the plot. She then emphasised the fact that these generated frequencies were within our auditory sensing range, the human hearing range. “We can hear gravitational waves, we can hear the universe. …That’s one of the beautiful things about this, we are not only going to see the universe, we are going to be listening to it.” she then looped a video interactive audio recording of a slowed down version of the gravitational waveform for the audience to observe and hear “…do you hear that? The rumbling noise, then the chirp?” asked Prof. González, replaying the display with a restrained show of obvious excitement, then exclaimed “That’s the chirp we’ve been looking for!. This is the signal we have measured.” “We can even tell more. Because we have two detectors, it’s like having two ears.” Prof. González drawing from the ‘All-Sky’ aspect of these GW telescopes, then displayed an image of the southern sky, with a graded probability plot of location overlaid onto the Magellanic cloud region of the MY galaxy. “Not very good” she conceded, “but this will get better” over time as the network of more GW telescopes came on-line. She then displayed a world map with the location of operating, under-construction and planned GW telescopes to explain. The two LIGO instruments at Livingston and Hanford, and the technology demonstrator GEO600 in Germany, were now functioning. VIRGO in Italy was expected to come on-line later this year, in mid 2016, “...so we will have three ears” she explained. The underground Japanese detector KAGRA (formerly the Large-scale Cryogenic Gravitational wave Telescope, LCGT) now under-construction, should be on-line some time in 2018. A LIGO India project awaited approval.
Wrapping up her presentation, Prof. González stated “This is just a beginning, We discovered gravitational waves. …from the merger of black holes. It’s been a very long road, but this is just the beginning. This is the first of many (discoveries) to come” she predicted. With the present detectors and as more GW telescopes become operational, she beamed with gleeful enthusiasm “…we begin listening to the universe!” she concluded.
PRECISION TO EINSTIN’S LEGASY co-Founder LIGO, experimental astrophysicist Prof. Rainer Weiss began his explanations from a historical perspective, with the reminder that, recently celebrated in Centenary, Einstein had first formulated the field equations for gravity in 1915. They was a complete departure from previous understandings about ‘forces’, to instead consider ‘distortions’ in space-time. An un-scaled diagram representing the 2D ‘distortion’ in space-time by the masses of the sun and earth was shown. In 1916 Einstein applied the field equations to finding a way for these ‘distortions’ to communicate the dynamics of movement, for which he described as gravitational waves, propagated in space-time at the speed of light. He elucidated that gravitational waves were ‘strains’ in space. Prof. Weiss then demonstrated changes in space ‘strain’, by stretching a piece of green plastic netting, illustrating that it was this change in ‘shape’, as each node in the distorted netting showed, that represented the ‘strain’ change in space; that the LIGO instruments were attempting to measure. Prof. Weiss then alluded to the fact that whereas Einstein was a good experimenter; 100 years ago, astronomers had not as yet discovered massive objects compact enough, nor was the technology available advanced enough, for any experimental test that Einstein may have envisaged or designed, to have been workable. Einstein thus remained doubtful that gravitational waves were at all detectable. Prof. Weiss stressed that it has been the discovery and development over the past 100 years, of such things as black holes, neutron stars, and advanced technologies; that has allowed us these new discoveries. Prof. Weiss then went on to express some idea of the finesse of the LIGO instrumentation. The enormously tiny measurements they make. He expressed this with “Start with (the measure of) a meter. Divide it by a million, three times over. …that’s a thousandth the size of a nucleus.” and if that wasn’t enough of a head bender “So how do we do it?” he challenged. “We do it by timing light” he offered. He then went on to show an animation of the basic principles of a working Michelson interferometer; a principal component of LIGO; an instrument attuned to measure changes in the wavelength of monochromatic (Laser) light. Prof. Weiss went on to explain that there were a lot of things necessary to make to reduce noise sources in the instruments, one of which was vibration from the earth. He then demonstrated with a hand-held pendulum, that represented the interferometers mirrors, how controlled lateral high frequency movements of its supporting structures could remove one aspect of the perturbating noise sources. A diagram of the mirrors actual suspension system was shown as example (However its intricate functions were not here explained any further). Prof. Weiss continued by describing that there were very many other noise sources, as examples thermal and quantum noise, which had to be overcome. He then speculated that had all of this technology been available to Einstein in 1916, that Einstein himself would probably have designed LIGO. He qualified this by stating that Einstein was smart enough to do it, and then with witty conviction, threw a wry carrot at his good colleague Thorne with “He (Einstein) wasn’t just a theorist!” which brought a peal of laughter from the high table. In a masterful move to quench his jest, he turned the attentions onto Prof. Thorne by relating a story (Home) taken from the book Black Holes & Time Warps - Einstein’s Outrageous Legacy, written by Thorne, in which intrepid explorers visit the event of the merger of a pair of 24 Solar-mass black holes. Taking up the story at the moment of the black hole merger, Prof. Weiss in good animation recalls “…and the universe gives a little burst, when that is over.” pausing, then “That’s all in that book, written in 19(9)3.” he states, pointing a finger at Thorne. Then dramatically declares “And we actually have seen it!”
Prof. Weiss then called Prof. Thorne to his turn at the podium, with a warm gesture and the words “So, Kip.”
Real 3D ==> 2D space-time surface membrane simulation.
Relativistic Binary Black Hole merger computer simulation. Count-down time == before (rising chirp), to merger [freeze], and after (Ringdown). By Simulating eXtreme Spacetimes (SXS) Project - LIGO
Colors depict the rate at which time flows; arrows in the normal direction of time.
In the green regions outside the holes, time flows at its normal rate. In the yellow regions, it is slowed by 20 or 30 percent.
In the red regions, time is hugely slowed. Far from the holes, the blue and purple bands depict outgoing gravitational waves.
Below picture is a chirp waveform that gets progressively covered in blue over time.
NEW WINDOW TO SURPRISES co-Founder LIGO, theoretical relativist Prof. Kip S. Thorne began his segment with the reminder that Prof. Weiss has been a principal designer of the LIGO laser systems together with the absent co-Founder LIGO, Scottish experimental physicist, laser stabilisation, Prof. Ronald Drever, post Professor of Physics Emeritus, Caltech, who had sent well wishes to all, but regretted to be presently medically indisposed. Prof. Thorne continued with a brief history of LIGO, citing past pioneer Joseph Weber (1919 - 2000) at the University of Maryland; and later laser research conducted at Caltech, MIT and in Scotland and Germany, as crucial contributions. He noted that the LIGO, who’s results are displayed today, was upgraded to Advanced LIGO roughly between 2010 and 2015; and provided these spectacular results almost as soon as the improved instruments started. He then demonstrated a 2D relativistic computer simulation of a binary black hole (BBH) merger, illustrating the resulting distortions to space-time; and how they matched the signals received at aLIGO. Prof. Thorne then speculated on other gravitational phenomenon that aLIGO could possibly detect; spinning neutron stars, BH and neutron star mergers, binary neutron star mergers, supernovae events and cosmic-string signatures from the early inflationary expansion period, just after the birth of the cosmos. Prof. Thorne continued his speculations in comparing progressive discoveries made by astronomers as they moved through the spectrum provided by optical, radio and x-ray telescopes, in suggesting to expect “bigger surprises” from the new gravitational wave window. He concluded that gravitational wave telescopes would, in the future, improve their time domain sensitivity from mille-seconds to include, minutes, hours, days, years, decades and finally even billions of years; “its really remarkable that LIGO is such a fantastic beginning.”
He then turned to Dr. Córdova, and on behalf of the LIGO collaboration, thanked the NSF, Dr. Córdova and her predecessors, for providing “A fabulous 40 year partnership” and ended his discourse with “…a great triumph. A whole new way to observe the universe.”
AMAZING SCIENCE BY COLLABORATION Dr. Córdova, Director of the NSF, returned to the podium to round off proceedings before question time by the media. “Einstein would be beaming, wouldn’t he.” she started with a smile. Unabashedly moved by the historic significance of the proceedings, in which her student field of interest had been an early investment in what had been at the time, only dreamy speculation; to have had a hug from “…a faculty mentor …when a grad student at Caltech” set her to reminisce that both Kip Thorne and past pioneer Joseph Weber (whose wife she courteously acknowledged as present in the gathering) had filled her student head with imaginings by stories of black holes. “And look where we’ve come now!” she nodded “Amazing!” Transforming herself back again into a functionary of the NSF; addressing the full membership of the LIGO collaboration, she noted “Mark this day as truly historic. I commend each of you.” She moved on to commend past programme directors of the NSF for their steadfast support for the LIGO project, over the past 40 years; and called for a show of gratitude. To which there was strong applause in reply. Dr. Córdova then delivered an impassioned summary of the entire project. She acknowledged astronomer, astrophysicist and historian science and astronomy Dr. Virginia Trimble, as an invited guest, in witness to her late husband Joseph Weber’s pioneering influences on the LIGO project; and noted that some of his instruments are now housed at the NSF LIGO facility at Hanford, Washington. Dr. Córdova continued her summary speckled with words like, visionary, drive, persistence, commitment. She noted that this was not a single persons achievement, but that of many, and that its success achieved only through collaboration. That this applied as well at a national level, where the support with funding and scientific expertise, by other national participants, was a significant and necessary component. She then called on the invited respective representatives of the supportative national Science Councils of Germany, the UK and Australia, to please stand and be accounted. To which again, there was strong applause. She reminded everyone that all these national participants had all contributed directly to Advanced LIGO’s success; and reminded the media to consult them as well, to get a full perspective of the discoveries presented.
Dr. Córdova then turned proceedings over to questions by the media.
The NSF LIGO 11th Feb 2016 anouncement at the National Press Club, Washington, DC, USA.
Gravitational Waves Detected 100 Years After Einstein's Prediction - Caltech Media Assets: HERE All relevant videos to GW Discovery + About LIGO
UpDate: tobagojo - San Fernando, Trinidad, TT. 22nd October 2017.
Observation of Gravitational Waves from a Binary Black Hole Merger
Physical Review Letters PRL 116, 061102 (2016)
B. P. Abbott et al.*
(LIGO Scientific Collaboration and Virgo Collaboration)
(Received 21 January 2016; published 11 February 2016)
ABSTRACT On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0 × 10-21. It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203 000 years, equivalent to a significance greater than 5.1σ. The source lies at a luminosity distance of 410+160-180 Mpc corresponding to a redshift z = 0.09+0.03-0.04. In the source frame, the initial black hole masses are 36+5-4 Msol and 29+4-4 Msol, and the final black hole mass is 62+4-4 Msol, with 3.0+0.5-0.5 Msol*c2 radiated in gravitational waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.
* Contributors listed in source
GW150914: Observation of Gravitational Waves from a Binary Black Hole Merger factsheet.
The LIGO Observatories, L1 + H1, USA, historic 1st gravitational wave detection called GW150914; 14th September 2015 @ 09:50:45 UTC.
The LIGO Scientific Collaboration and VIRGO Collaboration; A collaboration for this 1st effort of 133 internationally significant Scientific Institutions; with over 1,004 noted individual members from 15 contributing nations, of all disciplines listed, including posthumous citations. Phys. Rev. Lett. 116, 061102 – Published 11 February 2016; Abstract, PDF.
This was certainly some event, and as stated; the first detection of gravitational-waves and the first detection of a binary black hole merger. It was also the first time that gravitational waves were used as a tool for observational astronomy.
It also provided another direct confirmation of Einstein’s field equations of General Relativity, roughly 2 months short of 100 years after they were first proposed on 25th November 1915. Without further unnecessary superlatives; this was a commendable and historic achievement.
A few things of note in retrospect to the detection event; is that the expected binary neutron star merger was not the first event detected as was first anticipated. As there is no previous history of BBH mergers recorded on which to base a prediction on the likelihood that a merger would be found, the chance of finding a BBH merger however was more surprising than unexpected.
Another thing is that as neutron stars are less massive than black holes, and BBH mergers generate larger GW signals than BNS mergers, BBH mergers are easier to detect. A more sensitive instrument would help to find the BNS mergers. But all of this is sort of speculative; as the abundance of BBH and BNS mergers in the near and far field is not yet well enough known to tell. But these new GW instruments are sure to put a finger on the problem.
An interesting aspect of the LIGO/VERGO collaboration is their attitude as to how they publish their critical research documentation. It has long been speculated that if LIGO ever did get to detect gravitational waves, that because of the noted significance of such an achievement, some person(s) associated with the project would likely be nominated for a Nobel prize. However, prior to the LIGO GW discovery in 2015, declared in 2016; back around 2014, the scientific community were voicing some disquiet about the narrowness of only a few people being acknowledged with a Nobel, and sometimes some significant person had been left out, and certainly no ‘team’ group as a whole had ever been acknowledged with a Nobel. While the general arguments may not be without merit, and where the-few-who-were-left-out syndrome could be moderated to correction by a Nobel committee applying a bit more diligence; the real facts of the matter are a little more stark. The Nobel committee are only following the wishes and letter of the last will and testament left by Alfred Nobel when he bequeathed the Nobel Foundation. Each prize is limited to 3 recipients in any one category or to 4 or 5 at most, if one can cleverly reason a legal split of category; but certainly no more. It’s as simple as that. Oh, and also by writ, no posthumous Nobel’s are awarded; unless the recipient has unfortunately died after being officially publicly awarded. In a sort of oblique application of the currently in vogue euphemism of push-back; the ‘big science’ project community, moderately aware of the limitations of the Nobel committee, have come to be very diligent when preparing their papers for publication. In ever hopeful but mild protest for a group prize, they carefully list all who have contributed to their projects. To be sure, it was not always so, but the community has certainly become more responsible recently in this regard. As to whether the trend is driven by wistful Nobel push-pack or by sheer better practice, which has other benefits; is debatable.
Notably, the LIGO/VERGO collaboration were astutely vigilant in this regard, in that they carefully listed around 1,004 significant member contributors to their first GW detection achievement; and also diligently cited posthumous members. Whether this may be a record in itself or not, is probably not that significant; but what is, is that it represents peer acknowledgement of valid team effort and puts a high value to its human resources. This has the unusual benefit of a win-win for all. If they succeed, which they have, they all win. If any one of them alone is specially acknowledged, then implicitly they are all acknowledged and they all win again. Isn’t that cute! (see later)
Official List of Gravitational Wave Detections - 12 September 2015 to 23 October 2017
Observation of Gravitational Waves from a Binary Black Hole
The first observation of gravitational waves was made on 4
September 2015 at 09:50:45 UTC (GW150914, merger BBH) announced 11 February
2016. Observed by the L1 and H1 LIGO detectors in the USA, just before Advanced LIGO's first observing run "O1"; started on 18th September
2015; to end 12th January 2016.
Phys. Rev. Lett. 116, 061102 (2016) - Published 11 February 2016; Abstract, PDF.
Observation of Gravitational Waves from a 22-Solar-Mass Binary
Black Hole Coalescence
The second observation of gravitational waves was made on 26
December 2015 at 03:38:53 UTC (GW151226, merger BBH) dubbed "the Boxing
Day event" and announced on 15 June 2016. Observed by the L1 and H1 LIGO
detectors in the USA, near the end of Advanced LIGO's first observing run
"O1"; started on 18th September 2015; to end 12th January 2016.
Phys. Rev. Lett. 116, 241103 (2016) - Published 15 June 2016; Abstract,PDF.
Observation of a 50-Solar-Mass Binary Black Hole Coalescence at
A third observation of gravitational waves was made on 4 January
2017 10:11:58.6 UTC (GW170104, merger BBH) and announced on the 1 June 2017.
Observed by the L1 and H1 LIGO detectors in the USA. During Advanced LIGO's
second observing run "O2"; started on 30 November 2016; to end 25th
Phys. Rev. Lett. 118, 221101 (2017) - Published 1 June 2017; Abstract, PDF.
The European Advanced VERGO detector comes on-line in Pisa, Italy, 1st August 2017
A Three-Detector Observation of Gravitational Waves from a
Binary Black Hole Coalescence
A fourth observation of gravitational waves was made on 14
August 2017 10:30:43 UTC (GW170814, merger BBH) and announced on the 22
September 2017; but significantly observed by the L1 and H1 LIGO detectors in
the USA and also for the first time by the European Advanced VERGO detector
that had come on-line in Pisa, Italy on 1st August 2017. Significantly, with
3 detectors now on-line, much tighter spatial coordinates of the observed BBH
merger could be given and additional science on gravitational wave
polarisation was newly explored. During Advanced LIGO's second observing run
"O2"; started on 30 November 2016; to end 25th August 2017.
Phys. Rev. Lett. 119, 141101 (2017) - Published 6 October 2017; Abstract, PDF.
On 3rd October, the 2017 Nobel Prize for Physics is awarded:
'For decisive contributions to the LIGO detector and the observation of gravitational waves'
Observation of Gravitational Waves from a Binary Neutron Star
A fifth observation of gravitational waves was made on 17
August 2017 at 12:41:04 UTC (GW170817, merger BNS) announced on the 16
October 2017; observed by the L1 and H1 LIGO detectors in the USA and by the
European Advanced VERGO gravitational-wave detectors made their first
observation of a binary neutron star inspiral. During Advanced LIGO's second
observing run "O2"; started on 30 November 2016; and just before
the end of the run scheduled 25th August 2017, for system updates.
The association with the γ-ray burst GRB 170817A, detected by
Fermi-Gamma-Ray Burst Monitor (GBM) 1.7 s after the coalescence, corroborates
the hypothesis of a neutron star merger and provides the first direct
evidence of a link between these mergers and short γ-ray bursts. This
unprecedented joint gravitational and electromagnetic observation provides
insight into astrophysics, dense matter, gravitation, and cosmology.
Phys. Rev. Lett. 119, 161101 (2017) - Published 16 October 2017; Abstract, PDF.
‘For decisive contributions to the LIGO detector and the observation of gravitational waves’
The recipients were:
Barry C. Barish, Ronald and Maxine Linde Professor of Physics, Emeritus, Caltech; Principal Investigator of LIGO, 1994-97; Director, LIGO, 1997-2006.
Kip Thorne, theoretical relativist, Richard P. Feynman Professor of Theoretical Physics, Emeritus, Caltech. co-Founder LIGO.
Rainer Weiss, experimental astrophysicist, Professor of Physics, Emeritus, MIT. co-Founder LIGO.
Barish & Thorne shared award of ½ the prize
Weiss awarded ½ the prize
It is speculated that, had the Nobel prize for Physics been given for LIGO/Gravitational Waves in the earlier period 2015/2016, instead of in 2017; Ronald William Prest Drever (26 October 1931 – 7 March 2017) Scottish experimental physicist, laser stabilisation, co-founded LIGO project, co-inventor of the Pound–Drever–Hall laser stabilisation system, Professor Physics, Emeritus, Caltech, would have been accounted to share in the Nobel prize.
Nobel’s are not offered posthumously.
UpDate: tobagojo - San Fernando, Trinidad, TT. 24st October 2017.
GEO600 - German Advanced Laser Interferometer Gravitational Wave Observatory, Hannover, Germany - 600 m arms
Max-Planck-Institut für Gravitationsphysik and the Leibniz Universität Hannover.
YouTube - Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut)
GEO600 is a German-Anglo research and development project, a test bed for developing advanced laser technologies for use with gravitational-wave detection instruments which are called Dual Recycled, Fabry-Perot Michelson Interferometers (DRFPMI). GEO600 scientists are part of the international team which comprises the LIGO Scientific Collaboration (LSC).
Under the jurisdiction of the Max Planck Institut für Gravitationsphysik (Albert-Einstein-Institut) and the Leibniz Universität Hannover, with partners in the United Kingdom; it is funded by the German Max Planck Society and the UK Science and Technology Facilities Council (STFC). Technologies developed by GEO600 scientists, together with a team at the Laser Zentrum Hannover (LZH), supplied the laser equipment for Advanced LIGO.
The GEO600 provided advances in laser stabilization, absorption-free optics, relevant control engineering to provide vibration damping, and improved techniques for data acquisition and processing. They developed techniques for the amplification of laser light and signal called "dual recycling" and by using newly highly reflecting mirrors, constructively superposing the laser beam flow with itself, to enhanced the beam intensity in a process called "power recycling". For tuning control of frequency stabilisation they used an additional mirror to superpose the signal with itself, to provide a process call "signal recycling" in the control loop. In order to improve sensitivity of the system they developed a technique called "squeezed" laser transmission.
GEO600 developed improved vibrational damping with mirrors suspended from glass fibres.
Gravitational-Wave Observatories Across the Globe @ 2017 LIGOH1 (Hanford), L1 (Livingston); GEO600 (Germany); VERGO (Italy); KAGRA (Under Mount Ikeno, Kamioka mine, Kamioka cho, Japan); LIGO India (India).
By LIGO Scientific Collaboration