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Always called it LIG-WO in the voice of Joey from Blossom, but that's a detail.

fyi:
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Don't get confused

I was waiting for the actual presentation tomorrow (Thursday Feb 11 2016) to be certain but since you created the thread, hoping its the real thing, here is again what i posted in the random topic thread yesterday (since it belongs best in a proper Gravitational Waves thread anyway);

http://www.independent.co.uk/news/sc...-a6862611.html

Rumors that there might be an announcement on a scheduled LIGO update within days.

Regardless of rumors though the important detail is that under current advanced LIGO run (upgrade) since last fall they ought to be getting something like a few events per year for the first time since the LIGO program started and therefore a detection ought to be kind of inevitable at these numbers within a year.

An older video on the logic behind the LIGO detectors;




Also here on the official site;

http://www.ligo.org/news/media-advisory.php (thursday)

https://www.ligo.caltech.edu/page/facts

https://www.ligo.caltech.edu/page/faq


(In order to get to the ridiculous 1/10000 the size of proton sensitivity they use a massive system of mirrors that essentially convert the 4km arms to thousands of km effective distance traveled by the laser beams but all within the same geometric region of space probed eg 4km - ie back and forth many times increasing the effective length but not leaving the area of interest creating an additive effect basically. This also works because of the particular low frequency and relatively long wavelength these waves targeted appear to have.)

Some more recent videos of the actual interior site also;

yeah, hoping this is not a BICEP2 pt 2

Well they have 2 main labs here in different locations across the country so if they get something at the same general time frame its hard to be a systematic error or something local (plus the general form of the signal will have to match in many other ways too).

Also the substantial improvement in place since last fall made it possible to acquire measurable waves from very far say within a few hundred million light years radius sphere for typical astrophysical origin candidates, resulting in 10^-18 m maybe 10^-19 m change in the actual lengths of the 2 arms. So it was at least conceivable that they would be getting (based on the frequency such things ought to be happening in such vast sphere of space covering millions of galaxies ) way over 10 events per year, making it entirely plausible to have had something within the first 3-6 months already.

Plus this is more like old classical General Relativity and not connected at this level at least with more speculative physics. So if observed its easier to basically check it for the expected properties.

see more on the math here;

https://en.wikipedia.org/wiki/Gravitational_wave

http://fanfreluche.math.univ-tours.f...tz/GravRad.pdf

http://elmer.tapir.caltech.edu/ph237...Materials.html

Sry, may jump into conclusions, but does this guy look trustworthy to you?

Are you joking or what lol? Both guys seem reasonable in their explanations but they could do a bit more to describe the 10^-18 - 10^-19m sensitivity that ought to shock the hell out of any serious person given that proton is 10^-15m and there is so much optics in the beams that pose all kinds of potential fluctuations etc, but those explanations require a much longer documentary and a real lecture/seminar/few courses on the machines. The real triumph here is not the detection of waves itself that was inevitable eventually given that we know from all kinds of other phenomena that they exist and exactly how they are described, but the methodology used to remove all those sources of noise and read the real signal from it all and of course what can be learned about the processes that cause/generate these waves and which can reveal details or test, based on simulations of the assumed compact object structure/interactions, the various theories that describe them. They have been trying to detect them for over 50-60 years now. Even these observatories/labs have been going on for over 16-17 years.

Do you mean the glasses for the invisible laser beam (has to wear them because he cant see if his eyes get attacked by laser light etc) or the easy going style of the first guy outside?

Maybe it was the tinfoil hat . Look at the apparent plastic extension going down from his right ear, resembling Santa. Those guys need to step up the PR section

LIGO is confirming detection. Einstein still GOAT.

Surfing the universe on laser beams

https://www.ligo.caltech.edu/detection

https://www.ligo.caltech.edu/news/ligo20160211

http://www.ligo.org/news/detection-press-release.pdf

"The gravitational waves were detected on September 14, 2015 at 5:51 a.m. Eastern Daylight Time (09:51 UTC) by both of the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, Louisiana, and Hanford, Washington, USA. The LIGO Observatories are funded by the National Science Foundation (NSF), and were conceived, built, and are operated by Caltech and MIT. The discovery, accepted for publication in the journal Physical Review Letters, was made by the LIGO Scientific Collaboration (which includes the GEO Collaboration and the Australian Consortium for Interferometric Gravitational Astronomy) and the Virgo Collaboration using data from the two LIGO detectors.

Based on the observed signals, LIGO scientists estimate that the black holes for this event were about 29 and 36 times the mass of the sun, and the event took place 1.3 billion years ago. About 3 times the mass of the sun was converted into gravitational waves in a fraction of a second—with a peak power output about 50 times that of the whole visible universe. By looking at the time of arrival of the signals—the detector in Livingston recorded the event 7 milliseconds before the detector in Hanford—scientists can say that the source was located in the Southern Hemisphere."

https://www.ligo.caltech.edu/image/ligo20160211a



The Physical Review Letters submitted paper;

http://journals.aps.org/prl/pdf/10.1...ett.116.061102

"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+5−4M⊙ and 29+4−4M⊙, and the final black hole mass is 62+4−4M⊙, with 3.0+0.5−0.5M⊙c^2 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."


https://en.wikipedia.org/wiki/Binary_black_hole

Surprised they submitted the paper to PRL and not Science or Nature.

I'm proud of humanity right now.

Now I'm waiting for the next observations! How often are the events supposed to be found?

It depends on how close to their threshold was this event they recorded. In principle it should be around 10 + a year from what i had read but a big black hole merger like that is very rare event (top of the candidates that can be hoped to see). I will study their paper in better detail to see how close to their threshold this was. That would tell a lot about what else can be seen.

The good question is if they can see a merger of 2 neutron stars or a black hole and neutron star or a star and a neutron star at closer distance (the last at very close though). I think it should be close and possible to start seeing these things.

In some binary systems they even know the period and how soon it is about to happen (the last in-spiral merger part) so we may get lucky even to anticipate something happening within weeks if we can find a case that the projected time-frame is years and not centuries.


Of course the ultimate bonus is the merger of 2 galactic size black holes that might be felt from anywhere in the visible universe given that its millions of solar masses. But that requires to have galaxies colliding that is not very frequent and takes millions of years anyway to happen or would require real getting lucky there. Of course the phenomenon has 2 important aspects to gauge its severity. The total mass of the system gives an idea for the energy released (so much larger in a galactic core black hole merger) but some times smaller more compact systems can take place faster and be more prominent briefly. So one has more energy and duration and the other may be more dramatic spike. It depends on how the amplitude of the wave is affected by the 2 masses distributions and the absolute size. I might have to study this better to see how it depends on the masses and the orbit radius that in the end is comparable to the Schwarzschild radius which is proportional to the mass also.

For example the power of 2 objects rotating goes like (just before the most violent endgame);



So for the orbit radius approaching the size of Schwarzschild radius a (couple times over their sum say) it may turn out the peak of the power is universal more or less for all systems of near equal (for the pair) masses (regarding the last second i mean) . It may also mean that a big galactic size and small merging is not as impressive at all in the peak. I will have to check this better though to be more confident. One can see these things also from the second law of black hole thermodynamics (that forces a limit on how much can go into gravitational waves - to keep the entropy rising i mean) . https://en.wikipedia.org/wiki/Black_hole_thermodynamics


A close supernova also may be lucky because that way we can also optically see it and even detect neutrinos completing a trifecta of observations lol. But its not as impressive in amplitude in our location as the merger unless it is originating in our galaxy.

I think in the next 5 years many of these will be observed.


Can you imagine what the space-time felt like 100 astronomical units from the merger of the 2 holes?

Basically that system if accurate in description converted 3 solar masses to pure mc^2 in gravitational energy in only 0.5 second or less. Our sun during all its life will have converted only 0.1% of its mass to energy in photons. And this system did 3000 times than in <0.5 sec rather than 10 bil years. The universe is a very violent place. The 2 holes orbiting before merger were moving close to the speed of light in rotation. Basically speeds that you see for elementary particles were shared by ~60 solar masses type system.

Just pure madness in terms of violence. Completely unfamiliar to our experience environments even at a significant distance lethal.

I'm just starting to take in how basic this thing is. Electromagnethic radiation comes in different flavors. There are the various particles. And then you have this. A totally new way of detecting and measuring. A new era. You can say the warm up started in 1915, but now you have an instrument.

So it's legit, huh?

The way Einstein is held to this godlike status even among physicists, not to mention laypersons and the general public, while other great minds are largely ignored, is one of the few things that makes me nerdrage and has always made skeptical of the gravitational waves business. I know it's irrational but I can't help it. I'm an Einstein hater.

Be serious for a while. Einstein was made into a legend in serious exaggeration mode very often but never forget that even without the exaggeration he is still the best mind in history for Physics. All you need to do is read his original papers (over many topics) to witness a remarkable style of genius that is shared also by Archimedes and Newton in its elegance and confident positive economical thinking, its ability to derive magnificent results from very basic ideas, its relentless pursuit of a coherent honest understanding of the world. Have no doubt this is reached bravely after the era of misery and depression is defeated by the glorious synthesis of a truly restless mind...


Genius in the end is the ability to produce miracles from the obvious that everybody else is missing their deeper importance.

The other greats are not very far and many of them are exceptionally brilliant and less familiar to people. Some are even smarter but it gets pretty rare to witness his exact honest style over so many paradigm changing topics.

Fair enough, and I don't want to go off on a tangent/hijack with the thread.

But my avatar is Tycho Brahe, with some slight MSPaint embellishments, so that should give you an idea about how much I champion the unsung heroes. Sure, Brahe is mentioned in the books but the average person would still say "huh, who?" It's a topic that's came up much more than average this past year, I'm guessing due to the 100th anniversary of GR and the Interstellar movie, and I've been shocked at the number of highly educated people that had trouble placing names like Poincare or Lorentz or Riemann or Gauss. It's just bizarre.

Also, and the last point I have about this, concerning the thread topic it seems LIGO and the LIGO personnel are the heroes in this story. Gravitational waves could be considered a logical extension of spacetime curvature but actually testing for them is an engineering marvel, yet they're getting a backseat to 'Einstein's predictions'. Nothing else in science is ever described and reported on in a similar fashion as it is when Einstein is somehow even tangentially involved, and it's actually more than just annoying and disrespectful, it's a detriment to progress. Generations of kids are growing believing they can't contribute to the combined knowledge of the world because they're taught the fallacy that it's not a huge group effort by many intelligent people, it's one really smart guy and everybody else sits around waiting.

Ok, got that off my chest. Obviously I'm speculating and extrapolating to a significant degree, but it's an articulation of my partly irrational nerdrage.

Notice in post #7 when i said though;


"The real triumph here is not the detection of waves itself that was inevitable eventually given that we know from all kinds of other phenomena that they exist and exactly how they are described, but the methodology used to remove all those sources of noise and read the real signal from it all and of course what can be learned about the processes that cause/generate these waves and which can reveal details or test, based on simulations of the assumed compact object structure/interactions, the various theories that describe them."


So those that care definitely do not trivialize the effort of many recent people because we already know Einstein will fail at some point anyway (the glory of these predictions was already established in early 80s with pulsar binaries say) and if some experiment or observation helps to find the proper range of failure it will be remarkable. Probably Einstein would be the first to offer credit to them too.

The gift of Einstein at this point is in showing how to do it. What style and integrity in thinking can deliver the miracle.


Of course very often the media and society at large focuses on superficial story lines and hero worshiping etc lol. Nobody of course was there to help Einstein when he was trying to get there to the synthesis. The heroes were others then. The game stupidity plays is always the same. The only recognition that matters is that which nature provides when she smiles back at you after a great idea, revealing you finally some secret she had kept from your emerging awareness.

So long term would it be possible to manipulate gravity waves for communication or other things as we do with electromagnetic waves? If so could this happen in our lifetime or is there no way of knowing?

I doubt that unless we can find a different way to do things including new physics that manipulates the connection between QM and gravity without requiring enormous energies.

You see the creation of gravitational waves by even this system of earth around the sun (the orbit generates them) is so tiny that it cannot be detected by the same LIGO detectors if they were placed a bit far out of the orbit of earth or in any position actually. So if you need such massive objects to even try to get to that sensitivity in less than a light year distance imagine how hard it becomes.


The only hope is in trying to generate mini black holes that collapse to one fast and create an intense pulse. That however will be so brief in its properties even if in principle detectable at some distance that it will fail to have again any practical application moreover the insane technology required to generate the wave itself.

To see what i mean you simply imagine what radiation can a technologically doable system produce with say 10^9 kgr with another 10^9 kgr merging. If you can show its possible to generate a signal that is detectable then in principle it becomes possible to at least sense it from a distance that way even if you are completely shielded and light cannot go through (so there is one application). But what exactly have you gained even if that was possible with such expensive manner of creating the waves?

Additionally such small systems radiate fast enough and are unstable even faster than they take to merge (need to play with numbers to see better). So you might need to go higher to 10^12 kgr (in fact probably even more if Hawking radiation is as significant as thought at this mass level eg see here ; http://xaonon.dyndns.org/hawking/ ) or more mass and better contain it but again what is the benefit of transferring waves/information that way at such profound expense? It might become more interesting if one could manipulate the properties of the wave (the kind of wave i mean) generated to be very very deliberate in how the energy is radiated out in what form of waves (ie other than spherical) . But still its such a hardcore wave generation that uses enormous energy with limited control of the properties given how fast it all happens.

I need to do calculations to see how collapsing 2 small black holes behaves (and other properties of this difficult system - i considered small and massive and very close because only then the waves become significant) but clearly a lot of energy is released that way (likely still a decent fraction of the initial mc^2 mass and how it impacts the structure it passes through) and it could be destructive of the system that generates it even. I dont think anyone has ever done a calculation for mini black holes to see what the effects on the surrounding space-time is (say within 10 - 100 meters or the like eg on surrounding masses/structure when the amplitude is still significant. Its a curiosity really to do it and see what it does to surrounding masses structure it passes through. It may prove a terrible weapon or expose the difficulties with its implementation even.

Just play with numbers with these equations to see what they tell you;



(how long eg a system of 2 10^14 kgr mini black holes takes to merge if they start from 1 mm distance etc)

Here is the decay rate of the orbit;



Here is the power radiated;



Wave amplitudes;





(read more here to start appreciating what it would take to generate them
https://en.wikipedia.org/wiki/Gravitational_wave)




I do not have expressions yet for the radiation pattern at the last in-spiral merging moment where the power output would be insanely huge even for such small artificial holes.

Maybe a very advanced civilization that can manipulate mass that way and create small black holes can use the process to send information further than any radio/EM waves would go penetrating even through systems that radiation would be unable to pass through. But it seems there ought to be better ways to do this eg using neutrino beams etc.

Maybe in the very deep future if one can have amazing technology this ability can serve some function impossible to recognize yet but it does seem very extravagant way to communicate that way vs the alternatives available for the same energy. Its near term destructive properties appear more intriguing.

Pending on the numbers the above equations can yield maybe this is a very extravagant manner to show to the nearby universe you exist and have that technology lol. Lets put some numbers for fun and see what havoc eg 10^14 kgr type mini holes would generate. Of course how you create such holes and whether the theory that describes them allows this very thing (if what we think about them proves slightly wrong) is entirely another hard problem. But i used this example for wave generation because we really dont have anything else that is moving fast and has such large mass in such compact manner needed for the waves to be significant.

Michelson and Morley deserve a bit more love, iyam. LIGO more or less depends on their interferrometric methods.

Einstein would love that you doubt him. The reason why he is esteemed is because of all of the great nerds, he is one of the ones whose theories have stood the test of empirical testing.

So far, of course. As with all of science, he will go the way of Newton.

He could have been just a notch better, discovermagazine.com/2008/sep/01-einsteins-23-biggest-mistakes

That's a very weird article. I sure hope the book that's being advertised does a lot better job than that.