LIGO boffins set to reveal grav-wave corker

Re: Is it a test?

I doubt they would open the envelope in front of the world, and with the paper already printed in Nature, just to find "that was a test". I suspect the envelope-opening ceremony happened in private at a LIGO meeting some weeks ago, given the time that rumours have been circulating.

Re: Is it a test?

I read another article that said they'd seen three signals. Surely they didn't inject three tests?

If there are three events that gives hope that when they add the third detector there will be plenty of candidate events. The third detector will allow triangulating the exact position so they can visually confirm the observations (I assume something like two black holes merging or a black hole swallowing a neutron star is going to leave some obvious evidence in the gamma or Xray spectrum)

Re: I'm glad to see they are taking their time.

No - it requires journalists to have some clue about what they are reporting on, or to take the scientists words and not ignore the ones they don't understand.

Since that isn't likely to happen they have to say nothing for a long while - because "initial results" gets translated to "confirmed discovery" when it really means "there was a squiggle in the data, we're not sure why yet"

a geodesic past the media

"...it needs a measured and careful approach to announcing findings with lots of cross-checking, otherwise they end up looking stupid."

But you can't do too much cross-checking without telling people about it. And the more people you tell, the more likely it is the media will hear and turn their spotlight your way. (IIRC this was partly what happened to BICEP2 -- it leaked to El Graun. But they were also in competition with the people they needed to cross-check with.)

_{You said *snigger* "hyperbolic" *snigger* In a story about *snigger* *snigger* relativity *snigger*}

Re: How many events ?

But it depends on what you mean by 'signal'. If you are just talking a 'blip' then yes coincidence would be difficult to rule out. However if you are talking timing, amplitude and signal characteristics (shape, frequency, rise and fall) then it is possible to be very confident with one even from two detectors.

Re: How many events ?

The article suggests a confidence level of 5.1 sigma, I hope science at that level would have considered the number of events required to back their findings.

I am afraid it is precisely this kind of analysis and speculation that leads to media embellishment of matters still part of the scientific debate.

They haven't actually announced anything yet. Lets wait for the paper to be released hey?

Re: How many events ?

I suspect it's unlikely that a false positive with the same shape would happen to both detectors, let alone happen to both simultaneously. The 5.1 sigma is the quantification of that; it's something like a 0.00003% chance it's down to chance (although the implementation of erf() I've just pulled off the internet looks suspect at high sigma).

Re: How many events ?

If there are two black holes gradually(?) orbiting in towards each other then both detectors will be picking up a synchronized sinusoidal perturbation with a phase shift between them introduced by the speed of gravity (assumed to be the same as the speed of light) and the motion of the Earth. Further, since the orbiting black holes are losing energy by gravitational radiation, the period of the gravity wave and its intensity will both gradually be increasing, on top of the modulations caused by the motions of the Earth.

Surely it's too much to hope for that they have observed the actual merger event? Really good test of GR and black hole theory, if they have.