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Thread: Big day in science today - gravitational waves are discovered

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    Big day in science today - gravitational waves are discovered

    Einstein's gravitational waves found at last

    LIGO 'hears' space-time ripples produced by black-hole collision.



    11 February 2016


    Chris Maddaloni/Nature
    Gabriela Gonzalez, Rainer Weiss and Kip Thorne (L-R) applaud as LIGO executive director David Reitze announces the detection of gravitational waves.


    One hundred years after Albert Einstein predicted the existence of gravitational waves, scientists have finally spotted these elusive ripples in space-time.
    In a highly anticipated announcement, physicists with the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) revealed on 11 February that their twin detectors have heard the gravitational 'ringing' produced by the collision of two black holes about 400 megaparsecs (1.3 billion light-years) from Earth1.
    Ladies and gentlemen, we have detected gravitational waves,” David Reitze, the executive director of the LIGO Laboratory, said at a Washington DC press conference. “We did it!”
    Gravitational waves: 6 cosmic questions they can tackle



    One black hole was about 36 times the mass of the Sun, and the other was about 29 solar masses. As they spiralled inexorably into one another, they merged into a single, more-massive gravitational sink in space-time that weighed 62 solar masses, the LIGO team estimates.
    These amazing observations are the confirmation of a lot of theoretical work, including Einstein's general theory of relativity, which predicts gravitational waves,” says physicist Stephen Hawking of the University of Cambridge, UK. Hawking noted that Einstein himself never believed in black holes.
    This is the first black-hole merger that scientists have observed. The violent event temporarily radiated more energy — in the form of gravitational waves — than all the stars in the observable Universe emitted as light in the same amount of time.
    Nik Spencer/Nature
    Expand


    When played as an audible sound, the waves make an unmistakeable ‘chirp’ — a rapidly rising tone — followed by a ‘ringdown’, the radiation pattern from the merged black hole. The 'loudness' of the recorded signal also provides a rough measure of when the merger occurred: between 600 million and 1.8 billion years ago.
    The work will be published in a series of papers in Physical Review Letters1 and the Astrophysical Journal.
    The historic discovery — which physicists say will probably lead shortly to a Nobel prize — opens up the new field of gravitational-wave astronomy, in which scientists will listen to the waves to learn more about the objects that can produce them, including black holes, neutron stars and supernovae.
    “This is just the first step in a much larger and more exciting development,” says Ilya Mandel, a theoretical physicist at the University of Birmingham, UK. Gravitational waves will join γ-rays, X-rays and radio waves as "part of the toolkit that we have for understanding the universe", he says.
    It is also a long-sought victory for the LIGO experiment, which had spent a decade searching for the signal in the 2000s before a US$200-million upgrade improved the sensitivity of its twin detectors, one in Livingston, Louisiana, and the other in Hanford, Washington.
    Wave of discovery

    The discovery itself was made before the upgraded version, Advanced LIGO, had officially begun to take scientific data. At 11:50 a.m. Central European Time on 14 September, during the experiment's first observing run, LIGO physicist Marco Drago at the Max Planck Institute for Gravitational Physics in Hannover, Germany, saw a strange signal on his computer.
    Software that analyses data in real time was indicating that both interferometers had seen a wave resembling the chirp of a bird with a rapidly increasing pitch. Within an hour, the news had reached Drago's boss, physicist Bruce Allen. The recording looked too good to be true. “When I first saw it I said, 'Oh, it's an injection, obviously,'” Allen says.
    LIGO
    The gravitational wave signals detected by the twin LIGO stations.
    Expand


    It was an oscillation that began at 35 cycles per second (hertz) and rapidly increased to 250 hertz. It then became chaotic and rapidly died down; the whole thing was over within one-fourth of a second. Crucially, both detectors saw it at roughly the same time — Livingston first and Hanford 7 milliseconds later. That delay is an indication of how the waves swept through the Earth.
    Other gravitational-wave detectors — the Virgo interferometer near Pisa, Italy, and the GEO600 interferometer near Hannover — were not operating at the time and so could not confirm the signal. Had Advanced Virgo been on, it would have probably detected the event as well, says its spokesperson, Fulvio Ricci, a physicist at the University of Rome La Sapienza. LIGO scientists have run a series of careful checks to ensure that the signal is real and means what they think it does.
    In the past, a few senior members of the LIGO team have tested the group's ability to validate a potential discovery by secretly inserting ‘blind injections’ of fake gravitational waves into the data stream to test whether the research team can differentiate between real and fake signals. But the September detection happened before blind injections were being made, so it is thought to be a signal from a real astrophysical phenomenon in the Universe.
    To pinpoint the source of gravitational waves, researchers have to triangulate a signal spotted by different machines spread around Earth. When both LIGO detectors are operating along with Virgo or GEO600, scientists expect to be better able to locate future gravitational-wave sources. Another interferometer in Japan is under development, and a third LIGO site in India has been proposed. A greater geographic spread of detectors would strengthen confidence in any signals.
    Nature Special: Gravitational Waves


    Direct detection

    Einstein’s general theory of relativity predicts that any cosmic event that disturbs the fabric of space-time with sufficient force should produce gravitational ripples that propagate through the Universe. Earth should be awash with such waves — but by the time they reach us, the disturbances that they produce are minute.
    In 1974, physicists Joseph Taylor and Russell Hulse at the University of Massachusetts Amherst indirectly confirmed the existence of gravitational waves by watching radio flashes emitted by a pair of neutron stars whirling around one another; the shifts in the flashes’ timing matched Einstein’s predictions of how gravitational waves would carry energy away from the event. That discovery won them the 1993 Nobel Prize in Physics (see: ‘The hundred-year quest for gravitational waves — in pictures’).
    Adapted from Andrew Z. Colvin/CC-BY-SA 3.0
    Expand


    But direct detection of the waves had to await the sensitivity achieved by Advanced LIGO, which can detect stretches and compressions of space-time that are as small as one part in 1022 — comparable to a hair’s-width change in the distance from the Sun to Alpha Centauri, the nearest star to the Solar System.

    LIGO’s twin interferometers bounce laser beams between mirrors at the opposite ends of 4-kilometre-long vacuum pipes that are set perpendicularly to each other. A gravitational wave passing through will alter the length of one of the arms, causing the laser beams to shift slightly out of sync.
    Paid for by the US National Science Foundation, the machines were designed and built by teams at the California Institute of Technology (Caltech) in Pasadena and the Massachusetts Institute of Technology (MIT) in Cambridge. Caltech’s Kip Thorne and Ronald Drever, along with MIT’s Rainer Weiss, were the original founders.
    More than 1,000 scientists now belong to the LIGO collaboration. By studying gravitational waves, this next generation of researchers expects to probe entirely new realms of physics, including strong-field gravity, the very early Universe and how matter behaves at extremely high densities.
    Hawking says that he would like to use gravitational waves to test his area theorem: that “the area of the final black hole is greater than the sum of the areas of the internal black holes.” He adds: “This is satisfied by the observations.”
    “It’s the very real dawn of a new era,” says Mansi Kasliwal, an astronomer at Caltech.

    Nature
    doi:10.1038/nature.2016.19361


    http://www.nature.com/news/einstein-...TWT_NatureNews

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    Re: Big day in science today - gravitational waves are discovered

    Short video explanation:


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    Re: Big day in science today - gravitational waves are discovered

    No this wasn't caused by two fictional black holes colliding 1.3 Billion light years away. I believe the compression of the tunnel was caused by a teenager closing her door really hard in anger a fraction of a lightsecond away...

    If they had had the other 'gravitational wave' detectors on they could have disapproved my theory...

    These psychopaths (or is it physicopaths) are just telling stories children. They have to tell an interesting one once in a while, otherwise their funding is cut...

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    Re: Big day in science today - gravitational waves are discovered

    Quote Originally Posted by Neuro View Post
    No this wasn't caused by two fictional black holes colliding 1.3 Billion light years away. I believe the compression of the tunnel was caused by a teenager closing her door really hard in anger a fraction of a lightsecond away...

    If they had had the other 'gravitational wave' detectors on they could have disapproved my theory...

    These psychopaths (or is it physicopaths) are just telling stories children. They have to tell an interesting one once in a while, otherwise their funding is cut...
    I thought it might might have been a live-streamed Donald Trump rally myself, but didn't want to speculate.

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    Re: Big day in science today - gravitational waves are discovered

    you just have to list the names to know it's another Pied Piper BS exercise.

    Scammers gotta keep scamming. What was the measurement that enabled them to detect these?

    ok so it was a collision of black holes? Which they discovered the location of, how?

    What the flip is a final black hole? anyway completely new ways of bilking the public became viable today.

    And einstien didn't beleive in black holes but we need them to confirm his theory, which didn't need them apparently.

    How long ago did this collision happen?

    They heard ringing?

    ok so I should read the article.

    And the physicist are expecting a nobel prize as well. So we now know it's 100% credible.

    In the past, a few senior members of the LIGO team have tested the group's ability to validate a potential discovery by secretly inserting ‘blind injections’ of fake gravitational waves into the data stream to test whether the research team can differentiate between real and fake signals. But the September detection happened before blind injections were being made, so it is thought to be a signal from a real astrophysical phenomenon in the Universe.
    Sounds a lot like the running of moon mission. Simulate the telemetry. Who would be any the wiser?

    But direct detection of the waves had to await the sensitivity achieved by Advanced LIGO, which can detect stretches and compressions of space-time that are as small as one part in 1022 — comparable to a hair’s-width change in the distance from the Sun to Alpha Centauri, the nearest star to the Solar System.
    Also the original work from 1993 is based on assumption as to the source of the wave. unproven.
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    Re: Big day in science today - gravitational waves are discovered

    Apparently they discovered this on 14th of September, which is an interesting date, because it is one day BEFORE the LIGO started measuring gravitational waves... It seems time-space distortions are way bigger than previously thought...

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    Re: Big day in science today - gravitational waves are discovered

    Confirming Einstein's Theory


    — By Jim Barlow, University Communications




    Had UO scientist Robert Schofield kept working at 4 a.m. last Sept. 14, physicists might not yet be hailing the detection of a gravitational wave triggered in the last second of two colliding black holes a billion light years away. Schofield was at LIGO’s site in Livingston, Louisiana, working with Anamaria Effler, a scientist based there. They’d put in a long day injecting noises from Earth-bound environmental sources to analyze their effects on the sensitive detectors. Rather than shut down the detectors to begin another test, Schofield and Effler chose to leave them operating and get some sleep.

    “The signal came in about 45 minutes after Anamaria and I left,” Schofield said. “If I had been in the control room, I wouldn’t have seen it. It lasted one-tenth of a second. Had I been in the control room an alarm would have sounded, and I could have seen it by looking back at the data. But I was at my motel.”

    ...At about the same time of the gravitational wave's arrival, Schofield said, a massive lightning burst occurred over Burkina Faso in Africa. Some LIGO collaborators worried that a resulting electromagnetic wave, rather than a gravitational wave from deep space, had been recorded.

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    Re: Big day in science today - gravitational waves are discovered

    http://www.newyorker.com/tech/elemen...lly-found-them

    The LIGO team includes a small group of people whose job is to create blind injections—bogus evidence of a gravitational wave—as a way of keeping the scientists on their toes. Although everyone knew who the four people in that group were, “we didn’t know what, when, or whether,” Gabriela González, the collaboration’s spokeswoman, said. During Initial LIGO’s final run, in 2010, the detectors picked up what appeared to be a strong signal. The scientists analyzed it intensively for six months, concluding that it was a gravitational wave from somewhere in the constellation of Canis Major. Just before they submitted their results for publication, however, they learned that the signal was a fake.


    This time through, the blind-injection group swore that they had nothing to do with the signal. Marco Drago thought that their denials might also be part of the test, but Reitze, himself a member of the quartet, had a different concern. “My worry was—and you can file this under the fact that we are just paranoid cautious about making a false claim—could somebody have done this maliciously?” he said. “Could somebody have somehow faked a signal in our detector that we didn’t know about?” Reitze, Weiss, González, and a handful of others considered who, if anyone, was familiar enough with both the apparatus and the algorithms to have spoofed the system and covered his or her tracks. There were only four candidates, and none of them had a plausible motive. “We grilled those guys,” Weiss said. “And no, they didn’t do it.” Ultimately, he said, “We accepted that the most economical explanation was that it really is a black-hole pair.”

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    Re: Big day in science today - gravitational waves are discovered

    yes I also picked up on that JQP. I posted about how this was just like the Luna projects where they would "inject" flight telemetry into the training sequences.

    How would any one in ground control know the difference? The whole point is to convince the team that its real. This is not a Drill!. So the whole moon program was probably just a telemetry program playing out.

    I think they have provided a large number of clues in the story for the people who know the Space BS know it for what it is. A highly incredible story.
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    Re: Big day in science today - gravitational waves are discovered

    Quote Originally Posted by Glass View Post
    yes I also picked up on that JQP. I posted about how this was just like the Luna projects where they would "inject" flight telemetry into the training sequences.

    How would any one in control know the difference? The whole point is to convince the team that its real. This is not a Drill!. So the whole moon program was probably just a telemetry program playing out.

    I think they have provided a large number of clues in the story for the people who know the Space BS know it for what it is. A highly incredible story.
    Sounds a bit like:

    1. Dick Cheney playing "war games" the day of 9-11;
    2. The consultant in the London underground doing a terror attack simulation during an underground "terror attack";
    3. The emergency evacuation team for Netown CT just happening to be at a staged school terror drill at the same time as the Sandy Hook "shootings"'

    etc., etc.

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