That paper is damaged according to my computer but I found the one that Harry posted. Do you have information concerning the filtering that the signal plus noise is subjected to before it is interpreted? Also, do these events only take place at at low rate throughout the universe? I suppose that is true for super nova explosions and this is likely to be just as rare of an event.
These teams need to be congratulated if the detections continue to be confirmed. I remain weary of announcements that are produced so quickly. Dave -----Original Message----- From: Giovanni Santostasi <[email protected]> To: vortex-l <[email protected]> Sent: Fri, Feb 12, 2016 11:08 am Subject: Re: [Vo]:LIGO Gravity Waves... So what? Here is the paper: https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.116.061102 The detection statistics is 5.1 sigma, that corresponds to a p value of 3x10-7 or 1 in 3.5 million that the signal is due to chance. In the paper they discuss the background noise and what to expect from it. But what is more astounding is the waveform itself as detected by both detectors (with a small time shift expected by the fact the waves travel at the velocity of light). You have a beautiful time evolution of the signal. In fact you can separate the detected signal in 3 parts: inspiraling, merger and ring down. They use relativistic approximate equations (basically an expansion with correction at many decimal places) to find a model that fits the observed data and only a merger of black holes with certain masses, orientation towards the detector, spin and distance fits with high accuracy the data. It is almost incredible how well the model actually fits the data. Besides some non Gaussian noise that is always present in the detector the observed waveforms look like the solution of a GR graduate textbook end of chapter exercise problem. On Fri, Feb 12, 2016 at 10:57 AM, David Roberson <[email protected]> wrote: How can we be confident that this is not just a false alarm? It seems a bit premature to make this announcement since the claimed event is a billion light years away from Earth. Are we to assume that this particular event at that great distance is the only one that is showing up on the instrument? What proof is there that millions more are not present at closer distances which would be noise to filter out? Has anyone released information concerning the signal to noise for this discovery? Also, it is a bit difficult to believe that the device can tell the actual distance and direction of the black hole collision. Has this been replicated? There is much more evidence for cold fusion than for this discovery and I have a strong suspicion that it will be overturned one day. Big science making big claims again...I hope it is true but it is unlikely. Dave -----Original Message----- From: Giovanni Santostasi <[email protected]> To: vortex-l <[email protected]> Sent: Thu, Feb 11, 2016 9:28 pm Subject: Re: [Vo]:LIGO Gravity Waves... So what? By the way, gravitational waves were the topic of my dissertation so feel free to ask any question about the topic. It is very fascinating. On Thu, Feb 11, 2016 at 9:26 PM, Giovanni Santostasi <[email protected]> wrote: It opens a complete different window on the Universe. The analogy that is often given is imagine the cosmic show is like a TV show. Until now we had video but not audio. Finally we turned the audio on. Gravitational waves are a different but complementary way to observe the universe. We already learning things we could not learn before just using EM radiation. For example that there are black holes systems with such large masses. This has consequences in terms of galaxy evolution and how stars were formed. And this is just the beginning. The ultimate price is when we will see the gravitational waves from Big Bang. While the Microwave Cosmic Background tell us abut the universe at a very early stage (500 K years) we cannot receive any earlier information about the universe using EM radiation. The equivalent gravitational wave background when detected will tells information from a fraction of a second after the Big Bang. Only gravitational radiation can give us a picture of the universe that early. Also information from events like the one just observed eventually would give us clues on how gravity and quantum mechanics work together. The consequences of this discovery are enormous. On Thu, Feb 11, 2016 at 8:22 PM, Russ George <[email protected]> wrote: It seems the announcement of showing gravity waves are real is only of value to obscure academic discussions. Unless someone here might illuminate us about some practical derivatives that might be revealed due to the findings.
