Third Gravitational Wave Detected From Black-Hole Merger 3 Billion Light Years Away (bbc.com) 83
sycodon quotes a report from The New York Times (Warning: may be paywalled; alternate source): Astronomers said Thursday that they had felt space-time vibrations known as gravitational waves from the merger of a pair of mammoth black holes resulting in a pit of infinitely deep darkness weighing as much as 49 suns, some 3 billion light-years from here. This is the third black-hole smashup that astronomers have detected since they started keeping watch on the cosmos back in September 2015, with LIGO, the Laser Interferometer Gravitational-Wave Observatory. All of them are more massive than the black holes that astronomers had previously identified as the remnants of dead stars. The latest detection was made at 10:11 GMT on January 4, and is described in a paper accepted for publication in the journal Physical Review Letters. "The analysis suggests the two black holes that coalesced had starting masses that were just over 31 times and 19 times that of our Sun," reports BBC. "And when they finally came together, they produced a single object of a little under 49 solar masses. It means the unison radiated a simply colossal quantity of pure energy."
So, it happened in a galaxy far far away (Score:1)
and a long long time ago.
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far far away and a long long time ago.
Pleonasm.
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I do wonder what "pure energy" means. There are lots of kinds of energy but they are always tied to something physical (matter, photons,...). So what exactly is "pure energy"? Does that even mean anything?
Re:So, it happened in a galaxy far far away (Score:5, Informative)
"pure energy" = anything other than the energy due to the rest mass of a particle. So kinetic energy, gravitational field energy, and electromagnetic field energy (including photons) are "pure energy". An electron is not a form of "pure energy". A proton isn't pure energy either (although strictly speaking, most of the mass of a proton is due to the energy in its gluon field, which really is pure energy by the definition I gave. But just ignore that.)
In the end, pure energy is just to distinguish between matter and everything else. There is no deep meaning behind it. Consider an atomic bomb explosion. The light, heat, and sound produced is pure energy. The fallout is not pure energy.
Organic Aisle (Score:5, Funny)
Not sure, but you will find it on the Organic Aisle and it will cost twice as much as regular energy.
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Re:So, it happened in a galaxy far far away (Score:5, Funny)
"I felt a minuscule disturbance in the gravitational force. I fear something terrible has happened."
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Re:So, it happened in a galaxy far far away (Score:5, Interesting)
A collision briefing putting out more power than the rest of the observable universe, wiping out who knows how many intelligent civilisations in an instant. Kind of puts the Trump thing in perspective, I suppose.
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A collision briefing putting out more power than the rest of the observable universe, wiping out who knows how many intelligent civilisations in an instant. Kind of puts the Trump thing in perspective, I suppose.
When nations collide, they wipe out who knows how many innocent lives in an instant.
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Ha! I am in no way as rabidly anti-Trump as some of the people around here, but even I have to ask "Which Trump thing?"
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Re:total bullshit (Score:5, Informative)
What they "detected" was random noise. Nothing to see here.
They have two detectors now, one in Washington and the other in Louisiana. If they both trigger at nearly the same time, it's not random noise. This summer they'll add a third station in Pisa, Italy, which should not only help to collaborate the results, but also allow to triangulate the source.
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How triangulation works for objects 3 bill. lightyears away. Wouldn't any triangle on Earth seem like a single dot for such a distance?
Re:total bullshit (Score:5, Insightful)
The difference in distance to the event that caused the waves on different places on Earth is indeed much smaller than the measurement uncertainty of the distance, but the detectors are receiving the same waves with different delays, so the relative distance can be measured very precisely. In addition, the detectors are not equally sensitive to signals from all directions, so the relative amplitudes measured by different detectors provides some information too.
Re:total bullshit (Score:5, Informative)
The waves travel at light speed. The earth is sufficiently big to give noticeable delta in detection times, which allows you to find the place in the sky where the source of the waves is, no matter how far the object.
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Using the time delta with only two detectors means the source "location" is defined by a cone.
That's why they're adding a 3rd detector.
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It works because the speed of light delay in the signal changes the phase of the gravity waves, between different detectors.
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BTW, I have a question: how close would you need to be to actually *feel* this black hole collision. Would you feel something rattling your bones if you were close enough ?
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The likelihood of random noise creating a chirp consistent with a BH merger is very close to nil. The fact that two separate stations recorded the same chirp at the same time make this explanation very unlikely indeed.
GW170104 is consistent with general relativity. (Score:2)
That https://journals.aps.org/prl/a... [aps.org] was one hard read, here's one from LIGO explaining gravity waves and their detection http://ligo.org/science/Public... [ligo.org]
The second LIGO detector is like 20 miles away, so when a gravity wave comes by I know I felt it :)
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The second LIGO detector is like 20 miles away, so when a gravity wave comes by I know I felt it :)
The second LIGO detector is like 20 miles away, so when a gravity wave comes by I know I caused it :)
"He who felt it . . . dealt it!"
Wow (Score:2)
One solar mass of energy.
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The important thing though is how many libraries of congress this would represent... or cow farts. Honestly I'm not sure what the proper silly reference measurement would be appropriate here. I mean solar mass should be it, but that is what is actually being used already. I'm so confused.
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Swimming pools
It is always swimming pools...
Not to cause doubt, but... (Score:1)
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What makes you think the experiment depends on the gravitational constant being stable? What makes you think the folk at LIGO are waiting for you to explain the correlation/causation fallacy to them? What makes you think that gravitational waves are somehow linked to "electrical activity"? What makes you think that scientific projects with no immediate utility can survive without grants? What makes you think the entire purpose of science is to avoid doubt?
I have a lot of questions.
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The electrical activity part was alluding to how inventions often utilize zeitgeist as efficacy without much proof. But to answer your out-of-context question, electromagnetic waves can show-up by tugging of massive bodies the same way that gravitational waves are produced. However, gravitational waves are ridiculously weaker than electromagnetism, so it does not surprise me if there are confounding variables between Earth and 3 BILLION LIGHT YEARS away. But, it's okay because I've learned that AC's typical
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Question (Score:2)
"The analysis suggests the two black holes that coalesced had starting masses that were just over 31 times and 19 times that of our Sun," And when they finally came together, they produced a single object of a little under 49 solar masses
So, as a non-physicist, I have to ask what happened to the one remaining unit of solar mass since you started off with just over 50 units? I'd appreciate a serious answer, but I'm grabbing popcorn in anticipation of the normal /. replies.
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Re:Question (Score:4, Interesting)
The missing mass was radiated away as waves in the gravitational field of the black holes. Think of it this way: when a black hole is static (relative to the total mean gravitational field of the rest of the observable universe) nothing much happens. If, somehow, a black hole were to start vibrating back and forth, it would be tugging at EVERYTHING, and moving EVERYTHING, back and forth. So the movement of the black hole is radiated out into movement of the universe, through dilations in space-time.
Now, every mass that moves does the same thing, but most masses are small enough that they don't much affect anything beyond a small distance. Black holes are big enough that they do have a measurable effect, even at enormous distances.
Think of the energy that gets released by an earthquake: it gets turned into shaking of big, massive things. That energy eventually turns into heat, but during the release: low-frequency shaking of things with great mass, mostly through semi-rigid coupling (which, ultimately, mostly means through electric fields). The same is happening with two black holes as they merge: they shed energy in the form of shaking everything else as they spiral inward.
At least that's as much as my non-physics-PhD head has been able to understand. I hope that someone who actually knows will be able to correct it.
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M&A fees charged by Goldman Sachs.
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+1 sir
ridiculous (Score:2)
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The distance can be derived from the combination of the amplitude and the degree of redshift of the signal. The direction can be extracted (to some extent) from the delay between the arrival times at the two detectors. When the third detector in Italy is added, they will be able to to pinpoint it to a spot on the sky.
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<pedantry style="Well, technically, ...">
Three detectors would allow for narrowing the location to two points in the sky. Imagine three spheres surrounding the detectors with radii equal to the delay in their measurements of the same event: 0 for the first, c*t1 for the second, and c*t2 for the third with c being the speed of light. The line perpendicular to the plane that is tangent to all three spheres indicates the direction of the gravity wave's origin. But, there are two planes that fit the spher
To understand why this is so exciting (Score:2)
physicists stumped by second marriage (Score:2)
Second detection
Date: December 26, 2015
Mass of first black hole: 14.2 solar masses
Mass of second black hole: 7.5 solar masses
Merged mass: 20.8 solar masses
Third detection
Date: January 4, 2017
Mass of first black hole: 31.2 solar masses
Mass of second black hole: 19.4 solar masses
Merged mass: 48.7 solar masses
LIGO snags another set of gravitational waves [sciencenews.org]
weighing as much as 49 suns (Score:2)
I can't even get my head around what "weight" actually means in the context of a black hole, but assuming it even has weight, it seems to me that 49 suns must be a massive underestimate for a supermassive black hole given that both black holes that formed it have already been vaccuming up stars, suns and everything else for millions if not billions of years.
Hyperbole much? (Score:2)
Pit of infinitely deep darkness, huh? There's some serious hyperbole.
Wrong too [wikipedia.org] But why let facts get in the way of over the top hyperbole.
pit of infinitely deep darkness (Score:2)
Sounds just like my ex-wife's soul! Ba dump dump spish!
Anyway just laughing a bit of the creative description... How is it any more of "pit of infinitely deep darkness" than one black hole. Infinity x 2 bitches! Sounds like something you say as a kid to one up your friend who just said shotgun times infinity to get the front seat....
Suns (Score:2)
"The analysis suggests the two black holes that coalesced had starting masses that were just over 31 times and 19 times that of our Sun," reports BBC. "And when they finally came together, they produced a single object of a little under 49 solar masses. It means the unison radiated a simply colossal quantity of pure energy."
I'm calling bullshit that Superman can hold one of these in his hand.