Gravitational waves: LIGO Does It Again - A Second Robust Binary Black Hole Coalescence Observed - Polidicks

[QUOTE]The two LIGO gravitational wave detectors in Hanford Washington and Livingston Louisiana have caught a second robust signal from two black holes in their final orbits and then their coalescence into a single black hole. Like LIGO's first detection, this event was identified within minutes of the gravitational wave's passing. Subsequent careful studies of the instruments and environments around the observatories showed that the signal seen in the two detectors was truly from distant black holes – some 1.4 billion light years away, coincidentally at about the same distance as the first signal ever detected. The gravitational wave arrived at the two detectors at almost the same time, indicating that the source was located somewhere in a ring of sky about midway between the two detectors. The two merging black holes in the Boxing Day event were less massive (14 and 8 times the mass of our sun) than those observed in the first detection GW150914. While this made the signal weaker than GW150914, when these lighter black holes merged, their signal shifted into higher frequencies bringing it into LIGO’s sensitive band earlier in the merger than we observed in the September event. Source: [URL]https://www.ligo.caltech.edu/news/ligo20160615[/URL] Journal: [URL]http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.116.241103[/URL][/QUOTE]

Wow from Boxing day last year? I guess they need time to analyse the data before releasing it.

How do they detect variations in gravity?

[QUOTE=Alxnotorious;50527804]How do they detect variations in gravity?[/QUOTE] They basically fire two lasers over two different, 4km paths, and detect minute changes in their phases when reflected by mirrors at the ends of the paths and return to their origins. They have two wholly different paths specifically to rule out any other environmental factors, since the changes are so, SO small that a passing truck's own gravitational field could alter it (perhaps not quite that, but either way, the whole experiment is ridiculously sensitive).

[QUOTE=SweetSwifter;50527818]They basically fire two lasers over two different, 4km paths, and detect minute changes in their phases when reflected by mirrors at the ends of the paths and return to their origins. They have two wholly different paths specifically to rule out any other environmental factors, since the changes are so, SO small that a passing truck's own gravitational field could alter it (perhaps not quite that, but either way, the whole experiment is ridiculously sensitive).[/QUOTE] if I remember correctly, it's the passing truck makes the ground vibrate. After all, the difference is length of the lasers we're measuring is on the scale of atoms

[quote]...gravitational waves that originate tens of millions of light years from Earth are expected to distort the 4 kilometer mirror spacing by about 10−18 m, less than one-thousandth the charge diameter of a proton.[/quote] From the Wikipedia article. Yeah, that's a stupidly small change, making LIGO all the more awesome.

death stranding ARG??? [highlight](User was banned for this post ("Why reply" - Novangel))[/highlight]

Holy shit. We recorded the gravitational result of two black holes merging. Science is beautiful

[hd]https://www.youtube.com/watch?v=6Uy7Pp9OZDM[/hd] Good video if somebody doesn't know what they are or how they are detected.

I still wonder what black holes would look like when observed inside the event horizon. And now I heard of something even crazier, two black holes merging. Crazy stuff

[QUOTE=Recurracy;50528635]I still wonder what black holes would look like when observed inside the event horizon. And now I heard of something even crazier, two black holes merging. Crazy stuff[/QUOTE] Well here you go [video]https://youtu.be/eI9CvipHl_c[/video]

[QUOTE=Mitsuma;50528616][hd]https://www.youtube.com/watch?v=6Uy7Pp9OZDM[/hd] Good video if somebody doesn't know what they are or how they are detected.[/QUOTE] This video is really cool! Thank's for sharing, it helps to explain exactly what they're doing.

LIGO is killing it. Step it up, LHC! Detect supersymmetry already, nerds.

[QUOTE=mecaguy03;50528658]Well here you go [video]https://youtu.be/eI9CvipHl_c[/video][/QUOTE] I will never stop being fascinated by black holes. Even when we continue to know more and more about them, there's still so much weirdness surrounding them. I mean, I know why light bends, and I know why gravitational lensing occurs, but there's just something collosal and frightening that I can't explain about this effect. It's intimidating as hell, I simply cannot explain. It's just this well that seems to suddenly appear in space, and the only way we can discover their existance is by looking at the light around them, and nothing can escape from it, not even light. Also, they break the rules of physics as we know, and that's that you can see everything of a black hole at once, which means both poles, the front, and even the back. It's so weird and fascinating. And the closer you get to the singularity, the weirder things become. Things are probably even weirder when it has spin, too. I also find it extremely fascinating that not even the world's best scientists know what the singularity looks like, or what happens inside one. Neutron stars are another kind of weird. It's just an extremely dense plasmic soup, where not even the strong forces between atoms exist anymore. It's just neutrons.

physics is fucking scary i love it

In case you're wondering how they've processed the data, they've created a comprehensive tutorial on it: [url]https://losc.ligo.org/s/events/GW150914/GW150914_tutorial.html[/url] They also released their raw data if you want to play around with it!

So what does this mean for humanity? Is there a way for us to utilize this in some way or is it more of something for understanding physics in general? Not at all trying to detract from how fucking awesome this is, just genuinely curious.

[QUOTE=hippowombat;50539846]So what does this mean for humanity? Is there a way for us to utilize this in some way or is it more of something for understanding physics in general? Not at all trying to detract from how fucking awesome this is, just genuinely curious.[/QUOTE] It's the latter, mostly. Consider this: the first gravitational wave signature that LIGO detected a few months ago was put out by an event which, for a few fractions of a second, radiated more power than all of the stars in the observable universe combined, and it took some of our most advanced technology for us to recognize that it was even there. What on earth could we harness? The one thing we pretty much do get out of it is gravitational wave astronomy. We would probably not know these events were happening unless we could detect the gravitational waves from them.

I dont think there will be any engineering applications that come directly from discoveries in gravitational wave astronomy, however in the process of building and designing these instruments some new technologies may arise. They will be really specific to this sort of field, but maybe someone for example will figure out how to build laser interferometers that are much more sensitive.

[QUOTE=mecaguy03;50543554]I dont think there will be any engineering applications that come directly from discoveries in gravitational wave astronomy, however in the process of building and designing these instruments some new technologies may arise. They will be really specific to this sort of field, but maybe someone for example will figure out how to build laser interferometers that are much more sensitive.[/QUOTE] Presumably the tech that lets you build a massive inferometer using a constellation of craft could be utilized for all sorts of other applications where a swarm of craft would be useful as well. If we ever found a pair of black holes that regularly sent out waves it might lead to more accurate measurements of time or something

[QUOTE=Sableye;50546705]If we ever found a pair of black holes that regularly sent out waves it might lead to more accurate measurements of time or something[/QUOTE] It wouldn't.