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New Kind of Gravitational Wave Source Detected? (nature.com)
"Scientists possibly detected an entirely different type of gravitational wave [source]," writes schwit1. "Gossip over potential detection of colliding neutron stars has astronomers in a tizzy," reports Nature:
Astrophysicists may have detected gravitational waves last week from the collision of two neutron stars in a distant galaxy -- and telescopes trained on the same region might also have spotted the event. Rumours to that effect are spreading fast online, much to researchers' excitement. Such a detection could mark a new era of astronomy: one in which phenomena are both seen by conventional telescopes and 'heard' as vibrations in the fabric of space-time. "It would be an incredible advance in our understanding," says Stuart Shapiro, an astrophysicist at the University of Illinois at Urbana-Champaign...
The Laser Interferometer Gravitational-Wave Observatory (LIGO) in Louisiana and Washington state has three times detected gravitational waves -- ripples in the fabric of space-time -- emerging from colliding black holes. But scientists have been hoping to detect ripples from another cosmic cataclysm, such as the merger of neutron stars, remnants of large stars that exploded but were not massive enough to collapse into a black hole.
One astronomer tweeted last week that "merging neutron-neutron star is the initial call," while Nature adds that the same rumor had already been circulating privately, according to "some astronomers who do not want to be identified."
Friday Ligo announced cautiously that "We are working hard to assure that the candidates are valid gravitational-wave events, and it will require time to establish the level of confidence needed to bring any results to the scientific community and the greater public. We will let you know as soon we have information ready to share."
The Laser Interferometer Gravitational-Wave Observatory (LIGO) in Louisiana and Washington state has three times detected gravitational waves -- ripples in the fabric of space-time -- emerging from colliding black holes. But scientists have been hoping to detect ripples from another cosmic cataclysm, such as the merger of neutron stars, remnants of large stars that exploded but were not massive enough to collapse into a black hole.
One astronomer tweeted last week that "merging neutron-neutron star is the initial call," while Nature adds that the same rumor had already been circulating privately, according to "some astronomers who do not want to be identified."
Friday Ligo announced cautiously that "We are working hard to assure that the candidates are valid gravitational-wave events, and it will require time to establish the level of confidence needed to bring any results to the scientific community and the greater public. We will let you know as soon we have information ready to share."
But a new reason for them being formed.
If builders built buildings the way programmers wrote programs, then the first woodpecker would destroy civilization.
But only when it collides with stars.
But a new type of source.
NO, NO, NO! A gravitational wave is a gravitational wave. The correct title of the article should have be "New source of gravitational waves detected". The new source is binary neutron star merging as compared to binary black hold merging.
DGDanforth
Things more popular than Trump: HIV
I am afraid that you are wrong, they are real. I have even surfed them, here a picture of myself doing it:
http://cdn3.theinertia.com/wp-...
Everything I write is lies, read between the lines.
A Wave Motion Gun.
Browsing at +1 - no ACs, I ignore their posts. So refreshing!
I agree. Some of those scammers deserve jail time. It's not nice to rob the people.
Consider that a wave implies that something is oscillating, otherwise you don't have a wave at all. Scientists can't even explain what is oscillating when these supposed gravitational waves occur, which is a huge problem
Um, they can and have. The curvature of spacetime is what's rippling, and the observable effect is changes in distance and/or timeflow. It's a consequence of the general theory of relativity.
[citation needed]
Your eye can measure the energy of an individual photon. It doesn't get much smaller than that.
The crudeness of the observing equipment doesn't make measurements impossible.
LOL. Did you know that spacetime is a block universe in which nothing happens?
That your mind is to small to accept that our four normal dimensions are local phenomena that vary, and that there is no universal distance or clock to satisfy your belief in them, well, that's no skin off my back. Just don't run for congress, 'k?
Why don't you go get hit by a bus, worthless flat earther.
Given a (candidate) detection, what can they say about the direction to the source? To be able to identify a single galaxy you need to be accurate to minutes of arc, which surprises me in a device operating so close to the bounds of detectability. How does this work?
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
Pearls never look good on a swine.
Nope. I remember reading that the human eye needs at least 6 photons per second in order to trigger depolarization of nerves.
Seven puppies were harmed during the making of this post.
ALSo, this is only newly confirmed/discovered! It has been theorized this was possible for a while now!
Are Jedi born to be able to detect these gravitational waves?
by TheSpoom (715771) Uncaring Linux user here. I have nothing to add to this but please continue. *munches popcorn*
Nope. I remember reading that the human eye needs at least 6 photons per second in order to trigger depolarization of nerves.
The latest study from 2016 seems to show that a single photon can, indeed,be enough.
Of course, many photons hit the layers before the receptors (in part due to the eye being suboptimal in that the receptors are at the wrong side or the retina - so much for 'intelligent design"), or miss. But when lucky, we appear to be able to detect single photons.
Luck multiplied with a high number of repetitions approaches certainty, which is also how most of our scientific equipment works.
In a more simplistic way, IMHO, their name is self-explanatory.
Water waves are variations in the height of water. A kind of shock-wave is variations on the air pressure around you, etc.
So, gravitational waves are variations on the gravity field around you and, of course, this has an impact on space time as we understand it nowadays and it can be measured now that we have more precise instruments.
At least, that's how I understand it without much research on the subject. Please elaborate if I am too simplistic since I assume that you are better documented than myself on the topic.
Anyway, there is a classical story on the NTP forums of a guy measuring time going slower; he had 2 atomic clocks and was going on a trip across the States. He left one home and he put the other one in the trunk of his car. When he got back home, he could see that the clock that had been accelerated and decelerated physically had gone slower compared to the one that was left home while the clocks wouldn't diverge when left side by side.
-thx
Everything I write is lies, read between the lines.
I used to read that that comic when I was knee-high to a gravitational ripple. That's the famous Silver-haired Surfer!
If we can observe neuron star collision both with LIGO and conventional telescope, then we can compare the speed of propagation of gravitational and electromagnetic waves.
Both should travel at speed of light, but we already observed from supernovas that photons traveled slower than neutrinos. An explanation was quantum fluctuations: each time a photon fluctuates back and forth into an electron-positron pair, it moves much slower than the neutrino.
The three binary black hole mergers that have been observed so far are unlikely to be the same source. The correct title should be "New kind of source of gravitational waves detected". Oh wait, that's what the title already says with a different word order.
Consider that a wave implies that something is oscillating, otherwise you don't have a wave at all.
Nope, shock waves caused by an explosion or earthquake have nothing oscillating as the source. I assume it must the same for most gravitational waves but I am not well versed on the subject.
Waves caused by something oscillating are just many and they tend to have regular patterns.
Everything I write is lies, read between the lines.
First for the record LIGO scientist made the claim in a press conference and it's on their web page. Second , So what? A proton is orders of magnitude shorter than the smalle wavelength photons. A 1/10000th of a proton radius is .88X10^-18 meters.
A femtometer is 10^-15.
Gamma wavelength photons are 1 picometer.... which is 1000 X 1 femtometer
In short,
They are saying the can measure in units a millionth of the shortest wavelength of a photon.
It will not perturb the proton to enough to measure what it did. Much less a displacement of 1/10000th of the protons radius.
I won't even get into the various types of "noise" whose range is well beyond that tiny scale.
I'm not a gravitational wave astronomer (or any other kind) but I know some physics and I am interested in the details of highly precise astronomical instruments. LIGO can, and does, measure variations in the length of the arms of the interferometer of the order of 10^-18 meters. There are many techniques needed to achieve this accuracy -- extremely stable laser sources where neither the power level nor the phase varies by much more than the inevitable statistical variation due to the beam being made up of photons; very powerful lasers so that that statistical noise is as small as possible in comparison with the total signal; the path is between very solid quartz mirrors VERY carefully suspended in a vacuum, with active damping of some vibration frequencies and active control of the mirror temperature; the beam bounces up and down the tunnels many times, so that the effective path length is longer; etc. etc.. In normal operation the paths are adjusted until the signals from the two arms precisely cancel one another out (destructive interference) and then any change in path lengths, even if only a very tiny fraction of a wavelength, shows up as a small fraction of the very powerful beams not interfering destructively, but instead being detected by a very sensitive detector, etc. etc,
It's a triumph of laser engineering and should be celebrated.
When the first LIGO detections were confirmed there was mention in the news that additional LIGO sites, potentially in Europe, were in the planning phase. Anyone have a source that discusses the timeline for additional LIGO sites coming online?
Considering that Newton's Universal Gravitational Force equation is ...
Have you read The Electro-Magnetic Radiation Pressure (EMRP) Gravity Theory, specifically Speed of Gravity?
--
I give it another quarter of a century before these priests ^H^H^H^H scientists ^H^H^H^H clowns discover the 2 missing forces: #5 strong intergalactic force, and #6 the weak intergalactic force, and the white hole at the center of the galaxy.
Mod this up.
Truth isn't Truth - Guliani
I heard they don't have enough detectors to triangulate the source based on speed of light delays. Also the reason we can't find meteors headed towards us is because we can't watch 100% of the sky at a time; not even close in fact. So combine those two facts and how do they have any remote idea whatsoever what the source might have been?
It's a triumph of laser engineering and should be celebrated.
With alcoholic beverages? I can drink to that!
Better known as 318230.
Check any standard textbook on general relativity. You derive the gravitational waves by linearizing the Einstein field equations, and what you end up with, is that in the weak-field limit you get a wave solution which makes the metric tensor oscillate. That is interpreted as a ripple in spacetime itself, since the metric tensor describes the curvature of spacetime.
That's what we learned in high school. When you get to uni level physics, and specifically relativity, you'll learn how it was discovered that's not the case after all.
Your source goes wrong even in the first paragraph of the main text:
If changes in gravity traveled at the speed of light, as relativists claim, Newtonian gravity equations would not work at all and all planetary orbits would become unstable. [...] The reason is that it would take more than eight minutes for changes (caused by its motion around the Milky Way galaxy) in the sun's gravity to reach the earth and even longer for the more distant planets. So the earth's orbit around the sun would depend on where the sun was eight minutes ago, the time it takes changes in the gravitational field to reach the earth, and not on where it is now. This is not observed.
Firstly, the assumption itself is wrong. Since the Earth orbits the Sun at a speed 10,000 times lower than the speed of light, the Earth only moves a negligible amount over the time it takes gravity to propagate to it. That's hardly destabilizing, and in fact you'll have to so very precise measurements to notice it at all.
Secondly, it is incorrect that "this is not observed". In fact, this was the first test of General Relativity; read up on the measurements of the precession of the orbit of Mercury, and how they found that its orbit deviated slightly from the predictions of Newtonian mechanics, but very closely matched the predictions of general relativity.
Well, yeah. But the point is that Newton's gravitational law is wrong, so using it to "debunk" the theory that superceded it doesn't make much sense. Newton's gravitational law is a very good approximation to general relativity as long as you're looking at low-mass objects moving at low-speed (both low compared to cosmological scales not human scales). General Relativity is needed to explain modern phenomena like time dilation, black holes, gravitational waves, etc. In this case, the equation F=GMm/r is insufficient to describe what's really going on, and is replaced by Einsteins field equations.
I had not seen that before.
That was a fascinating read.
Thanks.
Relativity deals nicely and rather beautifully with this problem if you take the time to follow the mathematics. The key conclusion is that if something is moving at the speed of light, it is measured as doing so, relative to themselves, by EVERY inertial observer. This is very counter-intuitive, but it tests out extremely accurately in experiments.
Proof by assertion. How quaint...
Sorry to hear your a gravitational wave astronomer.That's the gov't grant industry they some are attempting to create. A whole new avenue of money and glom to bilk the taxpayers out of.
If an experiment isn't falsifiable it's pseudo-science.
Another very interesting read is the complete clusterfuck of the universal constant G -- except it isn't constant -- it oscillates!
Final Demystification of the gravitational constant variation
Disclaimer: Spring-And-Loop Theory is also an alternative model of how things work at all scales.
The theory GP linked to has been discredited. In essence it says there is a push everywhere, and that one atom/mass blocks another from this push, and this is what (somehow) attracts the two things together. Even intuitively this sounds bizarre/non-workable.
Spring-And-Loop Theory also thinks gravity is a push, not a pull. But there the similarities end. Perhaps the introduction is the best place to start.
I come here for the love
Relativity does not deal with it, otherwise the Doppler effect would not exist.
Er what. Firstly I said I'm NOT a gravitational wave astronomer. Secondly, what do you think I'm trying to prove by assertion? The parent asserted that LIGO couldn't work as described for reasons I wasn't really able to make sense. I mentioned some of the techniques (which are widely described on the LIGO website and in the technical literature which are used to make it work as described.
LIGO is precisely the experiment which could have falsified GR, but didn't. GR (and some other things) together predicted that there should be gravitational waves of a certain magnitude. A lot of very detailed analysis of the instrument predicted that LIGO should be able to detect them. They built LIGO and it did. Theories stand up to another test.
What are you saying is not falsifiable.
LIGO is precisely the experiment which could have falsified GR, but didn't. This is so not true. LIGO was not designed to falsify GR but to corroborate it. A null result would not have falsified GR. It would have been attributed to noise, inadequate technology, etc. In fact, a team of Danish physicists have already written a paper to show that those LIGO wave detections are indistinguishable from noise.
and that paper is presumably being peer-reviewed as we speak -- hopefully an interesting debate will ensue among those who have invested the effort to understand the physics and engineering, and we will all learn something.
Regarding falsification, you are right, but also wrong. Real life is never as clearcut as the philosophy of science would like it to be. GR has already had a lot of predictions tested and they have so far not falsified it. Given that, if one experiment appeared to contradict it, the first assumption would be that the experiment or the analysis was flawed. Much effort would be spent checking it and trying to come up with independent experiments that probed the same aspects of the physics of GR. Eventually a conclusion would emerge. So more precisely it's an experiment which might have started a process that could lead to the falsification of GR, but didn't. It was interesting because it probed a part of the predictions of GR that had not previously been explored.
You are apparently not familiar with the science. Laplace proved a long time ago that the speed of gravity would have to be thousands of times faster than the speed of light in order for the solar system to remain stable. Look it up.
Moreover, the precession of Mercury argument is irrelevant to a discussion about the speed of gravity. In fact, relativists were forced to add complex terms to the equations of GR in order to make it act like Newtonian gravity which assumes that gravity is instantaneous. In other words, relativists are claiming that gravity acts as if it is instantaneous even though it isn't. This is pseudoscience because it cannot be falsified by experiment.
The light detecting cells indeed get triggered by a single photon.
But there are two obstacles: the photon could be absorbed by the lense or protective skin over the eye lense. Or it simplybdoes not hit cell, but fluids around it.
And: usually single photon events are filtered out by the nerve system.
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Not finding gravity waves with LIGO would not have 'falsified' GR theory.
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Continuing to not find them with more sensitive instruments certainly would.
In an essay titled "Objective Knowledge", Karl Popper wrote "... this is a field from which the observer was exorcised, slowly but steadily, by Einstein himself."
The main relativist claim that LIGO depends on is the claim that gravity propagates at the speed of light. There can be no gravitational waves if this claim is falsified. The problem is that GR makes it impossible to falsify the claim because it is essentially saying that gravity acts as if it is instantaneous (like Newtonian gravity) even though it isn't. This is pure pseudoscience because no experiment can be conducted to falsify it. LIGO cannot falsify it, only corroborate it with dubious results.
I am convinced that most of Einstein's physics is a scam for this reason and many others. The public is being deceived on a massive scale. I am not the only one. Unfortunately, science is more politics than science.
Some predictions of GR (which differ from those of Newtonian gravity) have been accurately tested -- precession of orbit of Mercury; part of the GPS calculation; decay of binary pulsar orbits, etc. There's a wikipedia page https://en.wikipedia.org/wiki/...
GR may not be perfect (and indeed, we know that either it or QM breaks down at very high energies and very small scales because they contradict, but do know that Newtonian mechanics is not correct and that in a number of experiments where GR poredictions differ from Newtonian gravity that difference is right to within a few percent.
I have to disagree. The noise to signal ratio makes it impossible to ascertain the results regardless of the sensitivity of the instruments.
Relativists cannot falsify a major claim (gravity propagates at c) and you complain about minor errors in Newtonian physics? Those errors exist only because Newton could not have known about the Michelson-Morley experiments on the speed of light that were conducted centuries later.
Thanks for the exchange.
The theory GP linked to has been discredited.
While I did only have time to skim a chunk of the website GP linked to, one clear difference between his EMRP theory and Le Sage's theory was the speed of the propagation of gravity (partly due to variation in 'c', if I read it right). So I'd hardly say his theory has been discredited, even if Le Sage's (and others') was ... although I'm not convinced the author addressed the thermodynamic issues with Le Sage's theory - like I said, I only had time to skim it.
In essence it says there is a push everywhere, and that one atom/mass blocks another from this push, and this is what (somehow) attracts the two things together. Even intuitively this sounds bizarre/non-workable.
Well, it might sound bizarre and unworkable to you, but it does kind of make intuitive sense to me. Funny thing about intuition is we don't all intuit the same things. Besides, even 'regular' physics has the idea of a sea of virtual particles (with their anti-particle pair) continuously popping into existence and, in most cases, popping out again as they 'annihilate' each other. Vacuum energy? I'm not sure that the idea of a universal non-local EM radiation is any more bizarre than this.
Spring-And-Loop Theory also thinks gravity is a push, not a pull.
But there the similarities end. Perhaps the introduction is the best place to start.
There I shall start then.
And thanks for the input! I look forward to reading your papers.
I'm so tired of stupid fucks on the Internet.
It also has to do with the incredible density of the source.
No it would not :D
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Got a cite on that? I don't know much GR, but I've never seen anything like that. It would be a way to transmit information faster than light if it existed.
You also don't get waves when propagation is instantaneous, so that makes no sense. LIGO proves that gravity has finite-speed propagation.
It would appear that you don't know it very well, and therefore can't have an informed opinion on whether it's a scam. Moreover, if it's a scam, please explain
among a large number of other things.
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
You can hear the Doppler effect by listening to a siren go past you. That's because the siren is moving relative to you. If you were in the emergency vehicle, the siren would not be moving relative to you, and you wouldn't get any Doppler effect. Relativity in action.
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
Pearls do not look good on swines. See you around.
I'd like to tackle a few points raised here.
Gravity is a wave, not a particle. Crazy, but makes a lot more sense.
We know through observation that Earth and the moon response to the exact position of where the sun is at this precise moment - not as it was 8 minutes ago (speed of light).
This inconvenient fact alone is evidence that the effect of gravity (not hypothetical gravity waves) travels at a near instantaneous speed. For it to do that as a wave, it would need a medium to travel though.
The very medium that Einstein did away with - Ether.
So although these thoughts fly in the face of conventional scientific beliefs still taught in education, that will change in time, as the truth is slowly revealed through experimentation.
The issue here though, is to not missinterpret the data, and try to make it fit your beliefs. This is the mistake they're making with LIGO. No one's saying they didn't detect something - but what they've detected is pure guess-work, and isn't science - it can't be re-created. There's no lab the size of the universe. It isn't imperical. Where's the science in wild speculation and fairytale stories?
So, Gravitational lensing. I read an aricle not so long ago that contrasted the idea with amospheric light refraction - and found this worked just as well (if not, better) than the idea of gravitational lensing. If photons have no mass, (light as a particle) then gravity can't have any effect. If light propogates as a wave, then we can expect interference, and refractions - basically a better fit for our observations. But not the accepted theories, at the moment.
Basically, a wide open argument that could go on generations, until observations meet expectations, which can be backed up by historical data, and ideally repeatable experimentation. The moment we stop experimenting, it isn't imperical, and it isn't science. If we're not doing science, we may as well go home,and dream that the wizard of Oz will explain it all, if only we can make it to the end of the yellow brick road.