progress on S5 search

Winfried Weide
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Topic 192485

Was there already found a gravitational wave,or a hint on it?What is the progress of S5 search so far?

Reuben Gathright
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Bernd Machenschalk
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Nothing to report

Nothing to report yet.

Einstein@Home does only the first, most computation-expensive stage of the search, the "results" sent back from the clients still need to be analyzed to gain results in terms of science. Actually we haven't even finished the post-processing of the results from S4 yet; it already took us much longer than expected.

BM

BM

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I'm curious... what do you

I'm curious... what do you EaH define as "progress"? How do you know you are making progress? What were the objectives of S4 versus S5? Could we volunteers at Einstein simply be dillusional into thinking that we are accomplishing anything?

I just finished reading a book "Dark Cosmos, In Search of Our Universe's Missing Mass and Energy" written by a physicist Dan Hooper (I think he works at Fermi). In a chapter called "Visions of the Future" he makes (an admittedly) wild prediction that we discover gravity waves in the 2030s. I will be pushing up daisies by that time and am depressed.

Can the project give me some hope that we have a more aggressive schedule than that? If it will take until 2030s to have detectors of sufficient sensitivity to detect gravity waves then I'll devote my cpu cycles to Rosetta where there is the probability of solving diseases like HIV in my short life time?

Zhang Chi
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When can we find it?

When can we find it?

Hello everyone!I'm Zhang Chi from China.I am 16 and I am a middle school student.And I love science. I want to be a scientist in the future!

Chipper Q
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RE: I'm curious... what do

Quote:
I'm curious... what do you EaH define as “progress�? How do you know you are making progress? What were the objectives of S4 versus S5?


In order to more fully appreciate the progress, you have to know as much as you can about the physics, and that's not easy. While in the process of trying to learn as much as I can about it, I know enough to mention the progress being made in these areas:

Limits are being placed on the stochastic background of gravitational waves, with each new Science run (currently doing S5 run); this applies, in a general way, to cosmological models, and to figuring out which new theories (e.g., String theory) might be the correct ones.

Two of the three LIGOs (whose data we're crunching) are co-located (at Hanford, WA) where one interferometer has 2 km arms, and one has 4 km arms; this means they're more sensitive at different frequencies. The third is located some distance away (Livingston, LA) has 4 km arms. The data from all three provide the scientists with a higher level of confidence that a signal detected at one, and then subsequently detected at the other, is an actual gravitational wave signal. The times when all three LIGOs are up and running is referred to as 'triple coincidence' time (3C) and it is the goal of the S5 science run to collect one full year's worth of 3C time.

Then there's the progress that's being made with the LIGOs: various upgrades are scheduled to take place, to increase the sensitivity of the instruments, as there is a transition from 'Initial LIGO' to 'Advanced LIGO'. See the Detector Watch threads for links about this.

Quote:
Could we volunteers at Einstein simply be dillusional into thinking that we are accomplishing anything?


There are probably some important things I've failed to mention; after seeing the post about E8, I think I'm getting n-llusional. :)

Mike Hewson
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Probably the vital point to

Probably the vital point to make is that no-one has ever done this before! :-)

It is truly an entirely new area of physics measurement, coming to fruition after decades of incubation in theoretical thinking and smaller scale testing and technical development.

You can think of the LIGO's as extra-ordinarily sensitive surveying instruments, using light to measurement tiny changes in the dimensions of our surroundings that should occur as a moving distortion of spacetime, a gravity wave, passes hereabouts. Shortly after formulating his theory of General Relativity, Einstein predicted that this type of thing ( gravity waves ) should occur, but quickly despaired of ever measuring it when he calculated the expected magnitude of them. He moved on to consider other things. These disturbances are created by colossal events occurring, fortunately for us, at immense distances from here. What we hope to detect is tiny wiggles of a signal which would be devastating if actually felt up close.

It is pretty true to say that modern materials science had to arrive before such an enterprise could be seriously contemplated. This refers both to instruments of detection and the electronics and computing which is vital to the whole enterprise. What the data analysis does is take the signal from our surveying LIGO's and tries to identify patterns within it. Most patterns found will probably be unrelated to the astronomical events of interest ( say black holes and whatnot colliding ), and in fact be somewhat annoyingly banal - like earthquakes, trains, weather, power surges and such. Einstein At Home - which is all of you out there, at whatever level of involvement - is absolutely crucial to any seriously confirmed results that maybe obtained.

I say 'confirmed', as there are several important issues to settle upon:

- General Relativity mathematics is a real sod to solve exactly for the scenarios of interest. So the formulae for expected waves are approximate. It's a bit like listening for the call of a new unknown bird - you don't quite know what to listen for, but you have a rough idea based upon some Bird Theory. :-)

- the uninteresting/nuisance/non-astronomical signals have a far greater magnitude than the ones of real concern. There's a lot of local non-bird squabbling going on which may drown out that unknown call.

- some of the noise is from the listening device itself, so you have to learn as you go with regard to it's behaviour as well. A lot of special effort is devoted to this aspect, and indeed future upgrades of the LIGO's depend on that. The E@H effort helps calibrate the devices leading to a better bird call recorder.

- inevitably there will be some absolutely novel, never expected, phenomena occurring. Like we wind up listening to some Exploding Pig instead of a bird say! :-)

- the numerical analysis done by E@H is highly redundant ( ie. quorums ) to eliminate or minimise spurious errors.

It is crucial to realise that ALL E@H contributors will 'find' any subsequently confirmed wave even if the data making up the wave is sampled only by a few computers. The reason is that the confirmation of some future detection depends upon ( largely statistical ) comparison between cases/samples - and we all touch upon that.

So the shorter answer is nothing firm yet, as Chipper says some 'bounds' on certain signal types have/will be defined. My personal optimism is that the gravity waves are already in the data, but we just have to find them! :-)

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

Nothing But Idle Time
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I have a degree in Chemistry

I have a degree in Chemistry even though I did computer programming for a living before retiring. I'm fascinated with cosmology. But I'm not traveling to Proxima Centauri or even the moon in my life time and I'm not expecting to find gravity waves any time soon either. I think this is just a needle in the proverbial haystack; doesn't mean we shouldn't look only that we need to keep expectations in check. Gravity has been a tough nut to combine into all our theories -- at least from what I've been able to understand in the written literature.

One has to be a stalwort believer to spend hundreds of dollars year-after-year on computer electricity looking for that needle. Seems like the real project objectives, IMO, relate more to designing and improving search methods and instrumentation rather than "discovering" gravity waves. But gravity waves makes for better public relations. I can live with that. But some people think we are going to discover ET over at SETI and discover gravity waves here; we will have our pictures on the front page of Science magazine. That is what I find dillusional because the probability is quite low relative to the amount of capital expended.

OTH, I could spend the same money on bio projects like Rosetta and reasonably expect that my contribution will make a difference in the next few years toward curing something I might contract during that same timeframe. Being unable to ignore gravity (around the wasteline!) while worrying about my biomedical future I have decided to contribute to Rosetta and Einstein equally. I DO take EaH seriously despite my rhetoric to the contrary.
--NBIT

tullio
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Latest news from VIRGO/EGO

Latest news from VIRGO/EGO site in Tuscany:
PASADENA, Calif. and CASCINA, Italy-The Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Virgo interferometric gravitational-wave detector of the European Gravitational Observatory (EGO) near Pisa, Italy, have agreed to join in a collaborative search for gravitational waves from sources in and far beyond our galaxy. The collaboration will link the three LIGO detectors, which are in the United States, and LIGO's partner, GEO600 in Germany, with the Virgo detector to increase the likelihood of detecting the elusive phenomenon first predicted over 90 years ago by Albert Einstein in his general theory of relativity, and pinpointing the source of the signals.
Tullio
PS This will imply a data sharing mechanism after a given date. Maybe we shall crunch also VIRGO data in Einstein@home.

Chipper Q
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RE: That is what I find

Quote:
That is what I find dillusional because the probability is quite low relative to the amount of capital expended.


I guess part of my optimism in crunching for E@H comes from the fact that the expectations are based, not on capital, but on General Relativity (GR), and I don't see any delusion in that. Since the expectations are as realistic as is GR, a great deal more optimism comes from the fact that these gravitational waves pass unhindered right through things like clouds of gas and dust (unlike electromagnetic [EM] radiation, which gets absorbed and scattered), hence providing the expectation of a new 'window to the universe', whereby objects can be detected and measured that are otherwise impossible to observe directly using observations of EM radiation.

Another exciting aspect is evident when you consider the internal structure of black holes, which can't be “seen� because even light gets trapped within them. However, when two black holes merge, the gravitational wave signal from an event like that will help scientists discern better, just what the condition of things are like inside a black hole. What I find most impressive is that the scientists have been working hard with models and simulations based on the various newer theories (extensions of the Standard Model), in preparation of detecting gravity waves from such events. They already have a pretty good idea of what to expect, and in fact are using the results of these various simulations as templates, for patterns of what to look for in the LIGO (and VIRGO and GEO 600) data. So the data is being crunched in lots of different ways, by lots of scientists, and when you learn some of the finer points, it's hard not to share in their excitement, about the progress of physics these days.

And there's not really a down side to the effort. As Ben Owen pointed out here early on, if gravity waves aren't detected, then that will actually be bigger news, regarding the underlying physics and our understanding of it. Hopefully you'll find this a cool place to spend some of that idle time. :)

Bruce Allen
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RE: Latest news from

Message 61272 in response to message 61270

Quote:
Latest news from VIRGO/EGO site in Tuscany:
PASADENA, Calif. and CASCINA, Italy-The Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Virgo interferometric gravitational-wave detector of the European Gravitational Observatory (EGO) near Pisa, Italy, have agreed to join in a collaborative search for gravitational waves from sources in and far beyond our galaxy. The collaboration will link the three LIGO detectors, which are in the United States, and LIGO's partner, GEO600 in Germany, with the Virgo detector to increase the likelihood of detecting the elusive phenomenon first predicted over 90 years ago by Albert Einstein in his general theory of relativity, and pinpointing the source of the signals.
Tullio
PS This will imply a data sharing mechanism after a given date. Maybe we shall crunch also VIRGO data in Einstein@home.

The LIGO/VIRGO data sharing agreement will begin on May 18, 2007. Starting from that date, LIGO, GEO and VIRGO data will be pooled and jointly analyzed. So yes, I am hopeful that in the future we will also be crunching VIRGO data!

Bruce

Director, Einstein@Home

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