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#20 by Star One on 05 Feb, 2016 19:46
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I don't think the announcement will be long now.
http://www.sciencemag.org/news/2016/02/woohoo-email-stokes-rumor-gravitational-waves-have-been-spotted -
#21 by birchoff on 07 Feb, 2016 23:20
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I wonder how far this has progressed.
Same here. If it becomes accepted that gravity waves are a physical thing. The next question becomes how do we generate them today within either existing technology or technology we already have on the drawing board but havent funded the engineering for yet. -
#22 by Star One on 08 Feb, 2016 06:22
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I wonder how far this has progressed.
Same here. If it becomes accepted that gravity waves are a physical thing. The next question becomes how do we generate them today within either existing technology or technology we already have on the drawing board but havent funded the engineering for yet.
I can't see how it would be possible to generate these in our foreseeable future at a level that would be useful, considering what it takes in nature to produce them. -
#23 by Star One on 08 Feb, 2016 23:05
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New Scientist has been having a dig around into the background of this latest rumour and seems to feel we may have some reason to hope for a positive announcement soon.
https://www.newscientist.com/article/2076754-latest-rumour-of-gravitational-waves-is-probably-true-this-time/ -
#24 by sanman on 09 Feb, 2016 02:09
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Well, we all know that New Scientist leans towards pop-sci and tends to hype news stories.
But if Gravity Waves are really a thing, then it should be possible to constructively or destructively combine many tiny such waves together in superposition, shouldn't it?
The Mach Effect apparatus of oscillating masses should be able to produce many tiny waves, and perhaps these waves or their constructive combination could be detected by atom interferometry.
It seems to me that atom interferometry is the key to better detection and analysis of gravity waves. If this budding field of science could be developed, then it would allow gravity waves and their nature to be studied in greater detail.
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#25 by ChrisWilson68 on 09 Feb, 2016 02:38
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Well, we all know that New Scientist leans towards pop-sci and tends to hype news stories.
But if Gravity Waves are really a thing, then it should be possible to constructively or destructively combine many tiny such waves together in superposition, shouldn't it?
That's not a "superposition" in the sense of a quantum superposition, so it's better to use a different word to avoid confusion.
Yes, it's possible, but that doesn't really help anything. You need just as much energy to produce two waves that you combine to a particular magnitude as it would take to just create a wave of that magnitude in the first place. There's no such thing as a free lunch.The Mach Effect apparatus of oscillating masses should be able to produce many tiny waves, and perhaps these waves or their constructive combination could be detected by atom interferometry.
Don't bring up the Mach Effect, it has nothing to do with gravitational waves.
Oscillating masses produce tiny waves. But they're so tiny that you can't produce a measurable gravity wave by combining them without have an impractically large number of them -- as much oscillating mass as if you just had one enormous mass you were oscillating. Either way, the energy involved is impractical.
That's why nobody has been able to detect gravity waves until now.
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#26 by Robotbeat on 09 Feb, 2016 02:40
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With enormous black holes. I'm not entirely sure this is that "new physics"-y (in the sense of upending existing physics), but if confirmed, has a good chance of a Nobel Prize anyway.I wonder how far this has progressed.
Same here. If it becomes accepted that gravity waves are a physical thing. The next question becomes how do we generate them today within either existing technology or technology we already have on the drawing board but havent funded the engineering for yet. -
#27 by Star One on 09 Feb, 2016 06:32
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Well, we all know that New Scientist leans towards pop-sci and tends to hype news stories.
But if Gravity Waves are really a thing, then it should be possible to constructively or destructively combine many tiny such waves together in superposition, shouldn't it?
The Mach Effect apparatus of oscillating masses should be able to produce many tiny waves, and perhaps these waves or their constructive combination could be detected by atom interferometry.
It seems to me that atom interferometry is the key to better detection and analysis of gravity waves. If this budding field of science could be developed, then it would allow gravity waves and their nature to be studied in greater detail.
I am not sure commentary on what New Scientist does or doesn't do is warranted in this case, especially in light of the wider background on this story. I'd rather be positive that they've actually done a bit of extra legwork in this case. -
#28 by birchoff on 09 Feb, 2016 16:41
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I wonder how far this has progressed.
Same here. If it becomes accepted that gravity waves are a physical thing. The next question becomes how do we generate them today within either existing technology or technology we already have on the drawing board but havent funded the engineering for yet.
I can't see how it would be possible to generate these in our foreseeable future at a level that would be useful, considering what it takes in nature to produce them.
Dont think I am as pessimestic. "OBSERVED" Nature has not needed to do the things we want to do. Therefore I feel its safe to argue that the way nature generates G-Waves is more a side effect of other things it needed to do. Now, My next question is, How hard have we honestly looked at the possibility for generating Gravity waves. How much curiosity has been road blocked in the quest to generate them, because we didnt know if they were simply a mathematical artifact or a physical object?
In addition if g-waves are simply vibrations of space time and all mass deforms space time. Then Energy deforms space time since all mass is energy. Now that c2 part of the calculation leads to you needing alot of energy to equal the changes that asteroids, comets, planets, stars and black holes make to space time. However, energy at least in the form of EM can do something those other forms cant or at the very least havent been observed to do. Resonate. The first question I would love to see an answer to is if there is a frequency at which EM can resonate that would amplify the small changes to space time that it naturally makes.
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#29 by Star One on 09 Feb, 2016 20:51
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If this is confirmed and current testing of the technology in space goes well is there any room for the development and launch of LISA to be moved up?
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#30 by sanman on 10 Feb, 2016 00:40
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That's not a "superposition" in the sense of a quantum superposition, so it's better to use a different word to avoid confusion.
"superposition" can be used to describe behavior of either waves or particles ("quantum")
https://en.wikipedia.org/wiki/Superposition_principle#Wave_superposition
Anyway, we can say "wave interference" if that sounds better.QuoteYes, it's possible, but that doesn't really help anything. You need just as much energy to produce two waves that you combine to a particular magnitude as it would take to just create a wave of that magnitude in the first place. There's no such thing as a free lunch.
Well, we manipulate EM waves for various purposes, so likewise we could theorize at how to analogously manipulate gravity waves to study how gravity waves behave.QuoteDon't bring up the Mach Effect, it has nothing to do with gravitational waves.
Alright, "Mach Effect" is an unverified conjecture, while Gravitational Waves are classical physics predicted by General Relativity. I was simply referring to the apparatus that uses oscillating masses, and not the conjecture itself. However, as a side-note, once Gravitational Waves are fully verified as real, then it would impact the theoretical conjecture around the possible Mach Effect.QuoteOscillating masses produce tiny waves. But they're so tiny that you can't produce a measurable gravity wave by combining them without have an impractically large number of them -- as much oscillating mass as if you just had one enormous mass you were oscillating. Either way, the energy involved is impractical.
That's why nobody has been able to detect gravity waves until now.
Whether a wave is tiny depends on what means you're using to detect it - as Einstein said, everything is relative.
That's why I mentioned atom interferometry - that method is capable of much greater sensitivity than LIGO.
It's a newer method, but one which now deserves to be developed further to help shed more light on things that light doesn't do as well on through classical interferometry.
While the Gravitational Waves LIGO is purported to have detected were generated by very large astrophysical phenomena (ie. colliding black holes), LIGO is detecting the waves from those phenomena across a very large distance of many lightyears. So while a man-made experimental apparatus that oscillates some masses is far smaller than massive black holes, at least the apparatus could be operated much closer to the detector, so that the falloff from R^2 isn't happening across many lightyears of distance. Yes, size matters - but distance matters too.
But if atom interferometers could be developed further, not only could they be used to detect the Gravitional Waves generated by large astrophysical phenomena that LIGO is detecting, but their high sensitivity could be used to one day measure man-made gravitational waves (ie. like from a tabletop apparatus with oscillating masses).
Learning how to manipulate gravity by exploiting its wave nature might not necessarily be for pulling objects. Perhaps we might learn how to create and modulate gravity waves for communications purposes, for example, just as we do with EM waves. -
#31 by ppnl on 10 Feb, 2016 06:58
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Detecting gravity waves may be new physics but it isn't unexpected physics. What would be surprising is if they didn't detect gravity waves. And if you are hoping for a gravity based propulsion system then it may be better to hope that gravity waves are not detected. That at least gives you a mystery that may resolve into an unexpected finding that gives you your gravity drive.
Anyway they are expected to announce on the 11th. -
#32 by Star One on 10 Feb, 2016 08:06
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Detecting gravity waves may be new physics but it isn't unexpected physics. What would be surprising is if they didn't detect gravity waves. And if you are hoping for a gravity based propulsion system then it may be better to hope that gravity waves are not detected. That at least gives you a mystery that may resolve into an unexpected finding that gives you your gravity drive.
Anyway they are expected to announce on the 11th.
Yes this is a big discovery, but one of the main things it does is reconfirm what a genius Einstein was, but then we already knew that.
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#33 by eeergo on 10 Feb, 2016 10:03
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I wonder how far this has progressed.
Same here. If it becomes accepted that gravity waves are a physical thing. The next question becomes how do we generate them today within either existing technology or technology we already have on the drawing board but havent funded the engineering for yet.
I can't see how it would be possible to generate these in our foreseeable future at a level that would be useful, considering what it takes in nature to produce them.
Dont think I am as pessimestic. "OBSERVED" Nature has not needed to do the things we want to do. Therefore I feel its safe to argue that the way nature generates G-Waves is more a side effect of other things it needed to do. Now, My next question is, How hard have we honestly looked at the possibility for generating Gravity waves. How much curiosity has been road blocked in the quest to generate them, because we didnt know if they were simply a mathematical artifact or a physical object?
In addition if g-waves are simply vibrations of space time and all mass deforms space time. Then Energy deforms space time since all mass is energy. Now that c2 part of the calculation leads to you needing alot of energy to equal the changes that asteroids, comets, planets, stars and black holes make to space time. However, energy at least in the form of EM can do something those other forms cant or at the very least havent been observed to do. Resonate. The first question I would love to see an answer to is if there is a frequency at which EM can resonate that would amplify the small changes to space time that it naturally makes.
If we consider the rumored 36+29=62 solar mass merger to be near our detectable threshold, then 3 solar masses were emitted as gravitational waves. Even if this is conservative and surely the merger emitted something else, it's probably safe to say the order of magnitude is right. This equates an energy release on the order of 10^30 kg = 10^30 eV/c^2 = 1,000,000 YeV/c^2 = one-hundred (short-scale) septillion TeV. Nowadays, we are able to produce ~10 TeV of center-of-mass energy with protons, around a factor of 10000 more in the lab frame: 10^17 eV. So just rounding things up to the largest measured energies, let's say we can in the foreseeable future control beams of ~10^20 eV=0.1 ZeV (not really, but just for the sake of argument). Of course, you need overtones to create resonance, so this is an unrealistically optimistic number.
We are a factor of 10 quintillion (10^19) away.
The largest Q factors achieved (for systems that in principle have nothing to do with the hypothetical high energy beams above) are ~10^11, so even in the most wildly optimistic case, we'd still be incapable of resonating anything hard enough to create gravitational waves, by a factor of almost a billion. And in any scenario approachin reality, by much, much more. -
#34 by RotoSequence on 10 Feb, 2016 10:11
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We are a factor of 10 quintillion (10^19) away.
It's probably less extreme than that once you factor in the (as yet unknown) distance losses. -
#35 by eeergo on 10 Feb, 2016 11:31
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We are a factor of 10 quintillion (10^19) away.
It's probably less extreme than that once you factor in the (as yet unknown) distance losses.
Current theories give a spacetime damping characteristic time greater than the age of the universe. -
#36 by Star One on 10 Feb, 2016 21:20
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Some details on the expected announcement tomorrow.Quote
This year marks the 100th anniversary of the first publication of Albert Einstein’s prediction of the existence of gravitational waves. With interest in this topic piqued by the centennial, researchers from UK universities in Glasgow, Birmingham, and Cardiff will discuss their ongoing efforts to observe and measure cosmic gravitational waves for scientific research at the Science Media Centre in London starting 3pm GMT on Thursday, 11 February.
Simultaneously in the US, the National Science Foundation is gathering scientists from Caltech, MIT, and the LIGO Scientific Collaboration (LSC) at the National Press Club in Washington, DC for a status report on the effort to detect gravitational waves — or ripples in the fabric of spacetime — using the Laser Interferometer Gravitational-wave Observatory (LIGO).
http://astronomynow.com/2016/02/10/scientists-to-provide-update-on-the-search-for-gravitational-waves/ -
#37 by Rocket Science on 11 Feb, 2016 13:57
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Announcement 10:30am ET
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#38 by Rocket Science on 11 Feb, 2016 14:22
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We're live!
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#39 by Rocket Science on 11 Feb, 2016 14:34
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We did it!!
