It's a chirp obtained by running a gravity wave through a loudspeaker. It chirps because as the black holes spiral closer they spin faster sending out a higher frequency gravity wave. Starts off at 35 hz and gets to 250 hz prior to the collision. The two colliding black holes were 29 and 36 times the mass of the sun. That's a big collision!
This is the first confirmed gravity wave signal from the LIGO device.
Select to expand quotelog man said..
I know Ian, like when you fart in the bath
Good observation Log man.
en.wikipedia.org/wiki/Scale_invariance
Wow. Einstein may have been correct again. I mean gravity obviously 'propagates' through space and time. Now we need to work out how it propagates and what gravity is. Those answers could have the most significant scientific ramifications ever.
Umm..
Didn't Einstein theorize that gravity propagates through space as a bend in the space-time continuum and that gravity is simply that bend in the space time continuum ?
So I thought the point of finding the waves was to prove that part of the theory.
So now they have detected them it shows that gravity propagates as a bend in the space time continuum and it is a bend in the space time continuum.
So I'm not sure the next step is work out how it propagates or what it is. Isn't that the whole point of what they have done already ?
The next step presumably is to observe it some more and then eventually work out how to utilise it for some benefit.
Maybe producing electricity and killing solar pv ? (Just joking, don't get all upset again).
Select to expand quoteIan K said..
.... The two colliding black holes were 29 and 36 times the mass of the sun. That's a big collision! ...
The only way I can even begin to imagine a collision of that magnitude is to picture a SUP at Trigg Point.
A SUP trying to surf travelling on an unstoppable trajectory through the crowded density of the Trigg space-time continuum, obliterating smaller objects that happen to be in its path before finally colliding with another SUP paddling out.
The almighty noise and profanities then yelled out across the universe are finally detected by the scientists of Seabreeze.com.au.
(don't get red-thumby, it is just the mental images that help me understand the enormity and complexity of the issue)
BTW why to you have the say the same thing twice in each sentence? Is it deliberate prose? 
.
When you said
I mean gravity obviously 'propagates' through space and time. Now we need to work out how it propagates..
I was just pointing out we don't.
Gravity propagates by bending the space-time continuum. Einstein told us how it propagates. The science is in on how it propagates.
We just couldn't show it actually happening. Now they have.
Have a nice Friday
You're making the fundamental mistake of confusing cause with effect, observation and measurement with fundamental understanding.
What are the mechanisms that give rise to gravitational waves? What is gravity? You claim to have the answers?
To date, we only know gravity and gravitational waves exist and its observable relationship with space-time. We don't know what it is and how it works - let alone how gravity waves propagate.
Einstein did not "tell us how gravity waves propagate" at all. His theory of GR predicted that a small side effect of the phenomenon of gravity is that it would produce a wave, like a shock wave that rippled through space. He had no idea what the precise mechanism behind all this was because he was dealing only in the phenomenological aspects, rather than the empirical. The key is understanding what the wave and what gravity IS.
We have a few theories about what space-time is but again, we know scant little about what is behind these phenomena.
You claim that we will be able to make use of gravity someday and that all we need do is "observe it some more". Well that would be great, but is a bit fanciful to think we are anywhere near a proper understanding required to bend gravity to our will.
Have a nice Friday indeed!
Select to expand quoteAdriano said..
....We don't know what it is and how it works - let alone how gravity waves propagate.....
It is a bend in the space-time continuum and it propagates by bending the space-time continuum
I put it in bold to make it easy for you to read.
And I'll repeat it again below (so don't read it if you get upset by repeated sentences, but do read it if you continually fail to read the sentence in the first place) :
Gravity is a bend in the space-time continuum and it propagates by bending the space-time continuum
And, by the way I make use of gravity everyday already. I don't have to either wait until tomorrow or to understand it anymore, or to find out what it is. Why, I am even using it right now to stop me floating away.
You should try using it sometime as well. It is pretty simple to get the hang of the basics. Maybe you could start by trying to ensure your arse points to the ground and doesn't keep floating up and swallowing your head.
What's always tripped me out is that you can't tell gravity from acceleration.
Put me in a box and I might be near a large body, or I might be accelerating. I can't tell. Either way I'm at 1g.
Select to expand quoteCarantoc said..
Adriano said..
....We don't know what it is and how it works - let alone how gravity waves propagate.....
It is a bend in the space-time continuum and it propagates by bending the space-time continuum
I put it in bold to make it easy for you to read.
And I'll repeat it again below (so don't read it if you get upset by repeated sentences, but do read it if you continually fail to read the sentence in the first place) :
Gravity is a bend in the space-time continuum and it propagates by bending the space-time continuum
And, by the way I make use of gravity everyday already. I don't have to either wait until tomorrow or to understand it anymore, or to find out what it is. Why, I am even using it right now to stop me floating away.
You should try using it sometime as well. It is pretty simple to get the hang of the basics. Maybe you could start by trying to ensure your arse points to the ground and doesn't keep floating up and swallowing your head.
You still don't get my point.
Until we know what the Space Time Continuum actually is, how can you claim to know what gravity is? It's pretty fundamental. Yes that's what Einstein said a century or so ago. It's old news. What he couldn't tell us is HOW and WHAT any of this stuff is. Space-time is a concept, but we know very little about it's inner workings.
If we knew, we wouldn't need rockets to escape the Earth would we?
My word this is unbelievable. I mean I've heard of slow cogs but....you mean to say you know HOW these phenomena are working, rather than our theoretical calculations to explain the phenomena we see? Really.?
Hand this man a Nobel Prize right away and close down all rocket propulsion labs.
^^evlpanda
Never thought of it like that before.
What I don't get about the whole theory (and probably because I don't understand it at all really) is that they detected a change in space (a difference in length the laser beam travelled).
But if you are seeing a bending of space-time would time not also be changing, so the laser beam not only travelled a different distance but also for a different length of time. Hence any change in distance travelled in a certain time is related to two unknowns and therefore cannot be solved ?
I guess it could be answered if either you knew the relationship between space and time, so you could just do some maths for it, or if time is universal in all directions of space, so the time bending part of the wave affects both the x and y axis equally (unlike the space part of the bending).
Which I guess would then be part of sasquash's point, that space is not hard-wired to time and so you can travel in one and not the other ?
Select to expand quoteAdriano said..Carantoc said..
Adriano said..
....We don't know what it is and how it works - let alone how gravity waves propagate.....
It is a bend in the space-time continuum and it propagates by bending the space-time continuum
I put it in bold to make it easy for you to read.
And I'll repeat it again below (so don't read it if you get upset by repeated sentences, but do read it if you continually fail to read the sentence in the first place) :
Gravity is a bend in the space-time continuum and it propagates by bending the space-time continuum
And, by the way I make use of gravity everyday already. I don't have to either wait until tomorrow or to understand it anymore, or to find out what it is. Why, I am even using it right now to stop me floating away.
You should try using it sometime as well. It is pretty simple to get the hang of the basics. Maybe you could start by trying to ensure your arse points to the ground and doesn't keep floating up and swallowing your head.
You still don't get my point.
Until we know what the Space Time Continuum actually is, how can you claim to know what gravity is? It's pretty fundamental. Yes that's what Einstein said a century or so ago. It's old news. What he couldn't tell us is HOW and WHAT any of this stuff is. Space-time is a concept, but we know very little about it's inner workings.
If we knew, we wouldn't need rockets to escape the Earth would we?
My word this is unbelievable. I mean I've heard of slow cogs but....you mean to say you know HOW these phenomena are working, rather than our theoretical calculations to explain the phenomena we see? Really.?
Hand this man a Nobel Prize right away and close down all rocket propulsion labs.
But equally until you know what the space-time continuum is you don't know what ANYTHING is.
You can't explain what energy is, what forces are, what electro-magnetism is, what dark matter isn't, you can't even explain what what is.
You can't explain how Bonominator's conscience worked (if it ever did).
But that still hasn't stopped me from using gravity.
I still haven't floated away.
Have you tried using gravity yet? Go on give it go. I bet you'll eventually come to like it and find it quite useful.
I'll even give you a free lesson. We'll start by trying to pull your head out of your arse using the unknown science of gravity.
Come on, give it a go. Use gravity to oppose the force sucking your head in and to make sure the muscles in your arm don't instaneously fly apart.
Has it popped out yet ?
Well mate, you said we would only need "observe it some more" and we could utilise gravity. It's your claim. A laudable claim - but it belies your fundamental misunderstanding of the complexity of what we're discussing. I don't claim to understand it either, but I'm not making silly statements like the aforementioned.
This is my point, you can't utilise gravity until you understand it's fundamentals. It's secrets lie at the very fabric of the universe. It's nothing like electrical engineering for instance. We know what an electron is and what it does. It's an elementary particle. Gravity on the other hand is part of everything.
Are you getting it yet?
We understand Newtonian Mechanics fundamentally and we work with it. Einsteinian mechanics is another matter. Observing a wave is just the beginning and no where near a fundamental understanding.
Do let me know when you've cracked it and I'll be the first to nominate you for a nobel prize.
Select to expand quotewho knows ?
.. well OK so it hasn't popped out yet.
Are you sure you're trying ? It can't be stuck up there that hard can it ?
Mmmm maybe this is a trickier problem than I first thought.
Maybe we need the large nuclear force (I am not sure the small one would be enough) to assist gravity to free it ?
In the words of garynoel "it seems to be stuck harder than an Ezy 430 left at the pond" (OK maybe garynoel didn't actually say that, but he might have)
I'm laughing. Really. So many punch lines.
Just focus on the nobel prize and let us get back to enjoying this wonderful discovery...
Select to expand quoteevlPanda said..
What's always tripped me out is that you can't tell gravity from acceleration.
Put me in a box and I might be near a large body, or I might be accelerating. I can't tell. Either way I'm at 1g.
Interesting. There is a difference though. If you mean accelerating like an external constant force is pushing the box then you will feel it through the box on one side of your body as acceleration and pressure on tissues.
Gravity acts on every bit of matter in your body and that's why it is different - pulling at various amounts depending on density. Muscles more than bones for instance.
F = ma
Wonderful stuff.
Select to expand quoteAdriano said..
Well mate, you said we would only need "observe it some more" and we could utilise gravity. It's your claim. A laudable claim - but it belies your fundamental misunderstanding of the complexity of what we're discussing. I don't claim to understand it either, but I'm not making silly statements like the aforementioned.
This is my point, you can't utilise gravity until you understand it's fundamentals. It's secrets lie at the very fabric of the universe. It's nothing like electrical engineering for instance. We know what an electron is and what it does. It's an elementary particle. Gravity on the other hand is part of everything.
Are you getting it yet?
We understand Newtonian Mechanics fundamentally and we work with it. Einsteinian mechanics is another matter. Observing a wave is just the beginning and no where near a fundamental understanding.
Do let me know when you've cracked it and I'll be the first to nominate you for a nobel prize.
I don't think it has any implications for GR. It's just the last unrealised prediction of GR, a sort of cultural foot note on the theory. The big deal is that the technical potential of the LIGO has been verified and that opens the door to gravity mapping of distant phenomena. Maybe there are other techy spin offs. Who knows?
Absolutely. It's a footnote for GR. My point was that a fundamental understanding of gravity would be incredible for humanity.
In the meantime, the LIGO will provide plenty of research hours and theorising. It's is but one small step on the long path to understanding how gravity works through space-time.
Carantoc misunderstood what I was saying and instead went on the usual HW style ad hominen diatribe when he's actually talking about a different thing altogether.
If those black holes orbit each other at 250Hz prior to collision they must be tiny. Is that what the signal represents?
How big is a black hole of 30 solar masses?
Black holes colliding? now someones's digging one.
It appears to me, not that I know much about the equations of general relativity, that Einstein's equations are to gravity waves what Maxwell's equations are to electromagnetic waves? Maxwell formulated his equations in 1861 and saw the light straight away. "Yes that checks out, good one Maxwell."
Einstein came up with the gravity wave propagation 100 years ago but it's taken until now to observe them.
We've been using Maxwell's equations way back since then, that doesn't mean we understand what EM radiation exactly is . To paraphrase Curantoc "What do we really understand?"
It's pretty big to confirm something so major though. The biggest confirmation in science for a long time.
Dunno but that is incredibly fast. I guess as they became denser and closer their spin increased with centripetal conservation of energy.
Select to expand quoteIan K said..
Black holes colliding? now someones's digging one.
It appears to me, not that I know much about the equations of general relativity, that Einstein's equations are to gravity waves what Maxwell's equations are to electromagnetic waves? Maxwell formulated his equations in 1861 and saw the light straight away. "Yes that checks out, good one Maxwell."
Einstein came up with the gravity wave propagation 100 years ago but it's taken until now to observe them.
We've been using Maxwell's equations way back since then, that doesn't mean we understand what EM radiation exactly is . To paraphrase Curantoc "What do we really understand?"
It's pretty big to confirm something so major though. The biggest confirmation in science for a long time.
Yes but given gravity lies at the very heart of the fabric of the universe, equations that predict their existence and and understanding of the mechanisms behind them are completely different things.
Remember in our discussion about steel skyscrapers, even after months it was apparent you thought light cold rolled steel was used in their primary structure, when in fact heavy hot rolled high tensile steel is used and has been for over 140 years. Our communications ended after that. What a surprise. 
Select to expand quoteNotWal said..
If those black holes orbit each other at 250Hz prior to collision they must be tiny. Is that what the signal represents?
How big is a black hole of 30 solar masses?
ClassMassSizeSupermassive black hole~10^5–10^10 M Sun ~ 0.001–400 AU
Intermediate-mass black hole~10^3 M Sun ~10^3 km ≈ R Earth
Stellar black hole~10 M Sun ~ 30 km
Micro black holeup to ~M Moon up to ~0.1 mm
Had to google it, looks like 30km if they were ~ 30 times the mass of our sun. (the sun is 332946 times the mass of Earth!)
Apparently as they started whipping around in tight circles they radiated gravity waves at increasing intensity, losing energy all the time, which means they fell into a lower orbit started spinning even faster, radiated more and more energy as gravity waves, ( runaway situation, got a bit of free fall going on here) . In the collision they lost so much energy to gravity waves that the final black hole was lighter by 3 suns (E = mc^2) than the sum of the two initial masses. Just amazing, hard to imagine.
More powerful during that fraction of a second than the EM radiation of all the suns of the universe put together. Who did the maths for all this?
Pity you didn't Google "structural design of steel skyscrapers" before you sent me a link to a PhD thesis on low rise light cold rolled steel failure in fire.
Here's what you wrote:
"The details don't matter to the physics once the point of collapse is reached. Understanding how and when that point is reached and how to prevent it is of course important for the future design of buildings and certainly justifies spending millions. Well done NIST. "
"Some light reading" eprints.qut.edu.au/15972/1/Jung_Hoon_Lee_Thesis.pdf
Sure was "light" reading and I don't mean "heavy" man.
Select to expand quotesasquash said..Adriano said...
Absolutely. It's a footnote for GR. My point was that a fundamental understanding of gravity would be incredible for humanity.
In the meantime, the LIGO will provide plenty of research hours and theorising. It's is but one small step on the long path to understanding how gravity works through space-time.
Carantoc misunderstood what I was saying and instead went on the usual HW style ad hominen diatribe when he's actually talking about a different thing altogether.
seriously....your gunna segway from gravitional waves in space to what happened on 911......all whilst berrating others about diatribe and HW..........you really are just completely void of dignity. ...quickly...tell yourself your smart....
so there you go, you can spin two objects about 200000times bigger than earth, the force between the two will create an opportunity to manipulate the gravity, hence space and time between these two spinning monsters
and..........then what ....you can jump onto one of those gravitional waves and have all your atomic matter displaced across space.....still that sounds like more fun than having to sit next to bominator on a long train/bus/plane trip
most people would be like....iill take the gravitational wave thanks...
notmillsey?
One may only ask one day what " wave" is, definition what it is if any even exist, or that is just our expression.
Any wave, not just gravitational.
I am skeptical about the fact that time changes as things speed up. Apparently, as we approach the centre of a black hole, time becomes longer because it got "stretched".
Imagine I have a mechanical watch with a pendulum time action. Wouldn't the gears turn as per usual regardless of where you are? I mean a gear is a gear. Why would a gear turn faster just because it gets moved along at the speed of light?
