Astronomers Strike Gravitational Gold In Colliding Neutron Stars

a reply to: BELIEVERpriest

The difference is that Oliver Heaveside was an incredibly gifted and hard working chap who, although was without formal education, still stuck to the scientific method and published many journal articles through formal channels. He was no outsider or crank, he was very much an active researcher in his field(s).

It is staggeringly naive to think that uninformed speculation is on par with the academic output of someone like Oliver Heaviside.

Indeed exactly my point. It isn't about kissing peoples bum or sucking up, it is about listening and comprehension. Many commenters here want their points to be heard, and more than that, to be considered. What invariably happens in these kinds of discussions is that someone is completely stuck in an idea and refuses to consider or comprehend the opposing idea. We are all guilty of that. BUT we all bring different things to the table.

The scientific method isn't simply about opposing the 'standard model' for the sake of it, just in spite. It is about knowing where the holes are in models, finding more holes and working to replace it should there be good and strong motivation to do so.

What my rather rude post was a reflection of, was pure exhaustion at second and third order questions and statements that are built upon incorrect assumptions. I and others have tried to explain the 'standard' reasoning behind how the measurement works, we haven't gone into the in depth details on exactly how the instrument works, there are lots of videos explaining the crux of how it works. And then statements are questions come flying in saying things like "Oh so gravitational waves are just light and they don't know what they are measuring"

Exactly how do you come to this thinking? What part of the instrument, explain to me, given that it is an optomechanical system do you think can effect it to give this false positive? 5 times now.

The concept of how the gravitational waves propagate, or can be 'visualised' I have explained probably twice using different language... both times I was accused of using incorrect scientific language from people who's only argument against what i was explaining was "I don't like the words you used because I have a fixed idea in my mind what those words mean" And then later go on to say that I am closed minded in some way.

For any discussion to be useful and not pointless, parties must be willing to put in similar effort. What is happening here is people clearly don't understand the Model, the experiment, or the interpretation and any attempt to do so, they go against for the sake of 'alternative thinking'... so exactly what is the point?

I can say the sky is pink as much as I like...is it pink? or is by all standard definition is it blue for some parts of the day. Cant argue against people who make statements that are 'not even wrong'

Wonderful discovery. It's simply amazing that they could map minute space-time distortion on earth to an event some 100 million light years away. From what I have read it soon will be possible to determine distance of events by the differing amplitude of the waves. So it's a new exciting field that might one day witness a far bigger universe than our current day telescopes can see.

originally posted by: Pilgrum
a reply to: intrptr

Gravity and light may propagate at the same speed but gravity has no relativistic mass so it can radiate unimpeded which goes against the notion of gravity being carried by any form of particle.

A question for the astro-physicists among us:
2 massive chunks of matter colliding violently would result in a lot of activity at the nuclear level. Would the detected 'wave' or fluctuation in detected gravity be related to the volume of matter instantly converted to energy? IE less mass = less gravity and the ejected matter is also dispersed adding to the change in the local gravity well, sufficient to be detected at a vast distance.

No the simple answer is matter is energy.so theres no real change caused in space time.

a reply to: ErosA433

Spacetime is difficult for people to grasp. They want it to e made of something and its difficult to see it as coordinates where things can happen.

The Universe doesn’t have a completely flat space-time… Instead space-time warps and flows around massive objects, wich provides a sliver of hope for alternate theories of gravity… For the versions of MOND [Modified Newtonian Dynamics, an idea that you can modify the law of gravity so you do not have to rely upon dark matter for an explanation of measured observations] that we are interested in today, the basic idea is this: there is no dark matter, but two different metrics—metrics are space-times coupled to matter.

The light and the gravitational waves travel along the direct line of sight to us, curling around the gravity wells of intervening galaxies along the way. As a result, the initial burst of light and gravitational waves hid a little gem: the time difference between the arrival of the gravitational waves and the light. All 1.7 seconds of it. Yes, that was the recorded delay between the two signals.

The measured delay was so much shorter than the difference predicted by double metric theories that the researchers didn’t even bother performing more detailed calculations. There is, in their view, simply no way to include the intervening galaxies and exclude dark matter. This is a dead MOND theory.

Arstechnica.com, Oct. 25, 2017 - Colliding neutron stars apply kiss of death to theories of gravity.

The headline should read, “kiss of death to some alternative theories of gravity”.

In addition to space-time being where things happen there is interaction with space-time itself when moving through it. The alternate theories still have to account for how this interaction works out. So they invented two different ones (it is a theory, you can do that).

The version they are talking about is one where gravity-waves follow one measuring standard while light follows another (the “double metric theories”) due to interacting with different space-times . That is a family of theories covered by the name MOND. GWs have a rougher time travelling though their space-time than light waves through theirs. The articles says that under the theories people were pursuing the difference would be, “three years” (same source).

In trying to remove dark matter from a coherent picture of the universe the line of thinking has lead them to a dead end.

The paper shows that the difference between the two waves being at such a vast distance and only being 1.7 seconds apart means the error-rate of these types of theories has to beat their observation of Einstein’s weak equivalence principle (WEP) where the laws of motion are the same for the frame of reference they are in. In this case, us observing the collision do not see a huge difference means only one space-time is where it took place (and pretty much interacted the same upon both).

The paper itself at arXiv.org: GW170817 Falsifies Dark Matter Emulators.

Scientists have hotly debated the cosmic expansion rate ever since 1929, when the American astronomer Edwin Hubble first established that the universe is expanding — and that it therefore had a beginning. How fast it expands reflects what’s in it (since matter, dark energy and radiation push and pull in different ways) and how old it is, making the value of the Hubble constant crucial for understanding the rest of cosmology.

And yet the two most precise ways of measuring it result in different answers, with a curious 8 percent discrepancy that “is currently the biggest tension in cosmology,” said Dan Scolnic of the University of Chicago’s Kavli Institute for Cosmological Physics. The mismatch could be a clue that cosmologists aren’t taking into account important details that have affected the universe’s evolution.

In an expanding universe, the farther away an astronomical object is, the faster it recedes. The Hubble constant says how much faster. Edwin Hubble himself estimated that galaxies move away from us 500 kilometers per second faster for each additional megaparsec of distance between us and them (a megaparsec is about 3.3 million light-years). This was a gross overestimate; by the 1970s, astrophysicists favored values for the Hubble constant around either 50 or 100 kilometers per second per megaparsec, depending on their methods. As errors were eliminated, these camps met near the middle. However, in the past year and a half, the Hubble trouble has reheated. This time, 67 stands off against 73.

The crashing stars serve as “standard sirens,” as Holz and Scott Hughes of the Massachusetts Institute of Technology dubbed them in a 2005 paper, building on the work of Bernard Schutz 20 years earlier. They send rushes of ripples outward through space-time that are not dimmed by gas or dust. Because of this, the gravitational waves transmit a clean record of the strength of the collision, which allows scientists to “directly infer the distance to the source,” Holz explained. “There is no distance ladder, and no poorly understood astronomical calibrations. You listen to how loud the [collision] is, and how the sound changes with time, and you directly infer how far away it is.” Because astronomers can also detect electromagnetic light from neutron-star collisions, they can use redshift to determine how fast the merged stars are receding. Recessional velocity divided by distance gives the Hubble constant.

From the first neutron-star collision alone, Holz and hundreds of coauthors calculated the Hubble constant to be 70 kilometers per second per megaparsec, give or take 10.

Quantamagazine.org, Oct. 25, 2017 - Colliding Neutron Stars Could Settle Cosmology’s Biggest Controversy.

The article is great read! For those that don't know, Quanta Magazine is an on-line science site written by writers and fact checked by scientists; they go beyond the "golly gee" headline and situate the news within historic, scientific developments.

The colliding neutron stars provided an alternative method to determine the Hubble constant. One method gives a high reading of 73; the other method gives a lower value, 67. With one measurement of gravity waves at LIGO and Virgo their calculation put them smack in the middle, 70.

They will need further observations to reduce the error (the, +/- 10, in the article) but it is good that it fell in the middle!

ETA: I read in Scientific America that 3,000 astronomers/astro-physicists have worked on the data the colliding neutron stars has produced. That represents 15% of the entire community! Also, we are on the back side of the sun and won't get another look until after Winter Solstice in December. You can bet they are going to look again!

originally posted by: BELIEVERpriest
a reply to: intrptr

I just confronted LIGO with these questions on twitter. They say a moving dipole creates EM radiation, so they ASSume a moving quadrupolar mass creates gravitational waves. They're treating gravity as a form of radiation. It makes no sense, but I can see why they came to that conclusion. They think its logical symmetry.

Not just logical symmetry.

They come to that conclusion because it is a consequence of the laws of general relativity as discovered by Albert Einstein, and those laws predict amazingly obscure, unintuitive and strange phenomena, and repeatedly, especially in the last couple of decades, these laws have been demonstrated to be quantitatively accurate---and competing theories falsified---in extraordinarily heroic experimental observations.

Don't #ing bet against Einstein

But in reality, a dipole has an expanded magnetic field. A quadrupole, which has two canceling dipoles have a collapsed magnetic field (magnetic attraction is really destructive interference between poles). So if a moving dipole causes EM waves, then a moving quadrupole should produce anti-EM waves. We know that Photons are their own anti-particles, so anti-light is still light.

No, that is wrong in both electromagnetism, and gravitation.

I maintain that LIGO is misinterpreting their own observations, else they would realize that their findings just unified Gravity with Electromagnetism.

Unified how? What do you mean by "unified"? Do you think charges make gravitational waves and electromagnetism makes gravity (beyond what Einstein said)?

originally posted by: intrptr


Turn off the motor the field disappears, turn it on, its back. Since this field attracts matter to each other, then its hard to explain the propagation at light speed when we consider the number of stars in an average galaxy spinning about the core singularity. Doesn't make sense that the propagation outward of gravity (at the speed of light) is 'pulling' matter towards it.

Doesn't work like that. Think of an isolated charge. It can attract other charges of opposite sign inward, while sitting alone doing nothing. But if you were to oscillate that charge in space a little bit and do it quickly, then the effects of that oscillation result in EM waves which propagate outwards. Gravitational waves are like those oscillations. Regular 'gravity' is like the electrostatic attraction.

Nothing else in the electromagnetic spectrum behaves this way.

Probably why Einstein tore his hair trying to 'see' a grand unified field theory. My only take on that is that the weak, strong, magnetic and gravimetric 'fields' are the same thing, just on different scales.

Yeah, how do you make that work? As in quantitatively and reproduce what we know already? EM is sensitive to charged particles and is infinite range. But the strong force totally ignores those electrons, and only works on short range---really different from EM in all sorts of ways. And gravity couples in completely different way from every other field and force and nobody knows why the rest masses have such unusual sizes. They look as different not as apples and oranges, but apples and kangaroos and hemorrhoids.

a reply to: mbkennel

Yeah, how do you make that work? As in quantitatively and reproduce what we know already? EM is sensitive to charged particles and is infinite range. But the strong force totally ignores those electrons, and only works on short range---really different from EM in all sorts of ways. And gravity couples in completely different way from every other field and force and nobody knows why the rest masses have such unusual sizes. They look as different not as apples and oranges, but apples and kangaroos and hemorrhoids.

Comparing atoms, that are mostly empty space containing little tiny whizzing bits of matter, to the solar system, which is mostly empty space containing little whizzing bits of matter, they are the same just different in scale, thats my apples and hemorrhoids link.

If someone would just do the math, we might find a unification between the 'weak force' on an atomic scale and gravity on the solar scale. The strong force would be the gravity of the nucleus, i.e., the sun.

About EM fields holding a 'charge', is that particle or wave theory discussion? Same with gravity, is it a field, as in particles, or wave of particles?

originally posted by: intrptr
a reply to: mbkennel

If someone would just do the math, we might find a unification between the 'weak force' on an atomic scale and gravity on the solar scale. The strong force would be the gravity of the nucleus, i.e., the sun.

If you just knew how many theorists have been 'just doing the maths' this is something that has quantifiably been disproven long long ago. the two forces are absolutely unrelated at our current energy regime.

a reply to: mbkennel

Well, if I'm so wrong, then please do explain how. Cuz so far your explanation is, "Don't #ing bet against Einstein".

That's more like religion than science.

a reply to: ErosA433

If you just knew how many theorists have been 'just doing the maths' this is something that has quantifiably been disproven long long ago. the two forces are absolutely unrelated at our current energy regime.

Considering nobody has actually seen the nucleus of an atom, or seen inside of a star directly, I find that statement somewhat suspect. They are 'doing the math' preceding from estimates of both realms.

Edit: You said it yourself, "theorists".

a reply to: mbkennel

They come to that conclusion because it is a consequence of the laws of general relativity as discovered by Albert Einstein, and those laws predict amazingly obscure, unintuitive and strange phenomena, and repeatedly, especially in the last couple of decades, these laws have been demonstrated to be quantitatively accurate---and competing theories falsified---in extraordinarily heroic experimental observations.

Do you realize how unscientific that sounds. We have an obscured, unintuitive theory, so when our results seem obscure and unintuitive, well, that's just confirmation of our obscured and unintuitive religion...oh, I'm sorry, I meant to say theory.

No other branch of science operates under those principles. Its more likely that there's a much simpler, intuitive explanation out there, but that would dethrone Relativity. We can't have that.

a reply to: BELIEVERpriest

Just because you don't understand the science, that doesn't mean it as no validity.

a reply to: GetHyped

I'm just saying other, more intuitive possibilities should be explored. I don't understand why that is such a decisive concept?

originally posted by: intrptr
a reply to: ErosA433

If you just knew how many theorists have been 'just doing the maths' this is something that has quantifiably been disproven long long ago. the two forces are absolutely unrelated at our current energy regime.

Considering nobody has actually seen the nucleus of an atom, or seen inside of a star directly, I find that statement somewhat suspect. They are 'doing the math' preceding from estimates of both realms.

Edit: You said it yourself, "theorists".

The problem with this kind of thinking, is that if you took it to its purist level, we would still be in the stone ages, because we wouldn't be invited to think or wonder about anything that we cannot physically touch and break apart with our hands.

Your supposition completely halts any kind of scientific investigation, since in your own words, no equipment other than our own touch or eyes are acceptable forms of scientific data taking. Your dismissal of science in this manner is extremely short sighted and closed minded. Have you seen inside a CPU? have you seen the electrons jiggling around? Well then how can you possibly believe a computer works? why are you writing about science on the internet?

See?

So lets look at one or two of these statements and tell you about what we DO know.

Considering nobody has actually seen the nucleus of an atom,

No, but, more than 100 years ago, we managed to take photographs of high energy particles bouncing back from thin gold films, most of the particles would pass through and deflect a little, but every so often one would ping off at high angles.

While no we don't 'see' the nucleus, that observation was the starting basis that shows that an 'Atom' as a small dense core and that most of the atom is empty space. Since then, scientists have found lots of different ways of probing the atom and have been able to show that the nucleus has size, and is a composite object made up of protons and neutrons, which has been probed using electron beams.

So no, we cant use a microscope to 'see' an atom, but, if like i said, your supposition was to be followed, we might as well have stopped 100 years ago, and yeah, so much for all this interesting technology we have developed since right because, if you cant 'see it' its obvious that we cant know anything about it right?

or seen inside of a star directly, I find that statement somewhat suspect. They are 'doing the math' preceding from estimates of both realms.

No we haven't seen inside of a star directly... or have we? Well theory of fusion says you can smack a bunch of protons together and make helium, the process of which releases energy. (Oh wait, yeah, we cant say that right because we should of stopped looking at atoms and nuclear stuff back when we couldn't zoom into things with microscopes right?)

Regardless we Soldiered on and did lots of different experiments to figure out if we can see anything coming from the sun that isn't just the light from the photosphere. Well interestingly, scientists thought "Well, we think that the sun is driven by nuclear fusion, so we did some calculations and here is what we expect to be happening, and the great news is this... neutrinos are produced in great abundance! and neutrinos interact so weakly that most of them will come out of the sun unperturbed! So all we need to do is detect and measure the properties of those neutrinos.

So we did. Scientists built several huge detectors in order to give them eyes that could see neutrinos.

Oh yeah and guess what? After some interesting results, it was discovered that... yep... the Sun's core does work in exactly the way theory predicted and that neutrinos have very small mass.

But... thats unimportant right? because we cant go there and scoop some out and put it in the lab... ah i forgot, whats the point in science if you cant poke it directly with a stick! silly me.

Edit: You said it yourself, "theorists".

And that is supposed to be some kind of "Ha, told you so?"

"its just a theory man" is perhaps the most intellectually bankrupt rebuttal to anything iv ever had to read... since most of the time the people talking about theories will offer up several and tell you that they might not be right.

Those who offer up garbage lack of logic however seem to be quite certain their prophecy / belief is 100% irrefutable..


So yeah.... theory right... dumb dumb dumb scientists with their theories! the moon is made of cheese and stars are long dead kings right.


The point is this... If you are going to argue against scientists, you should actually have some good information or propositions as to why they are wrong... trying to pull what is essentially sticking your fingers in your ears and saying "I don't believe you because its just a theory, and ha you haven't been there have you" doesn't mean that making random things up as you go makes you somehow correct.

a reply to: BELIEVERpriest

likely that there's a much simpler, intuitive explanation out there, but that would dethrone Relativity.

What part of relativity you consider wrong? Postulate about speed of light?

originally posted by: BELIEVERpriest
a reply to: GetHyped

I'm just saying other, more intuitive possibilities should be explored. I don't understand why that is such a decisive concept?

Its not... and science does it all the time... just because you need more than an armchair an afternoon, a pensil and paper to do science, doesn't mean other people don't actually do exactly what you are asking. Its just that, they often come to the same conclusion as the original publications.

And once again... saying the opposite for the sake of being different isn't to be correct or somehow be a wise open minded thinker. More often than not it means a massive lack of understanding or a willingness to make up realities to fit your own bias.

I said it before... for all the opposite thinking in this thread, neither one of you arguing about the validity of these results appear to understand how the experiment actually works, or what they are detecting... so how exactly can you argue against it?

Its like reading the statement "Der Himmel heute ist blau" and knowing only its a reference to the sky and saying "Wrong!" not because what it is saying is subjective, and that no the sky might not necessarily be blue, but because you don't understand German...
(for the record, i dont understand German either... just a lazy example to explain my point)

a reply to: intrptr

Considering nobody has actually seen the nucleus of an atom, or seen inside of a star directly, I find that statement somewhat suspect.

You saying that we should not believe anything until we see it with our own eyes?