LIGO Background for a Prediction
On November 10 I posted a prediction there will be LIGO detections around the span of Nov. 10 to 14. I predicted two other spans later in November.
I posted this prediction in a comment to a post in the LIGO Scientific Collaboration face book page. The post on November 9 asked whether there would be more detections in November. My comment predicted some detections in November with specific dates to get some interest. As of today there is no response from LIGO.
I will wait until Nov.15 to get any LIGO detections reported until then. I intend to post my prediction and the results at that time. It makes sense to post them together. If someone can't wait I just described where it is.
There were 2 detections later on November 10 after my prediction in the morning so initially I felt the prediction was already confirmed. However with these all on the same day some will treat this coincidence with skepticism. Any detections until the 15th bolster my case.
In the meantime this is the background for that prediction. This is better as a prelude than in one long post.
To understand why I would make a prediction for LIGO detections around specific dates, some background is helpful. I am sure some of this is already known but this presents a coherent version.
1) What are gravitational waves?
on October 21 I posted:
Gravitational Physics Had an Initial Crisis
That post described the initial story of gravitational waves (GW).
Wal Thornhill has at least one youtube video:
Big Science and the Impossibility of Gravitational Waves | Space News
The answer to the question is there are no gravitational waves.
2) it is critical to note LIGO has no mechanism to measure a GW directly.
This is only an indirect detection.
LIGO has an extremely sensitive set of laser interferometers (LI) to record any minuscule changes in Earth's crust near these LI's.
3) LIGO developed templates for the inspiral events they wanted to detect: a merger between the two most massive individual objects, a black hole or neutron star. There are 4 templates for all combinations of the 2. The merger is called an inspiral because the 2 would spiral into each other until the final merger.
4) with this extreme sensitivity LIGO is essentially gathering noise.
The design accepts that noisy context but its software looks for the template in this data. In other words, LIGO is based on finding a tiny signal in the LI's from a crust distortion caused by a tiny wave in spacetime and finally software declares a detection.
5) There has never been an observed actual inspiral event to record its data to verify the LIGO system handles that event correctly.
LIGO reports detections despite never having their process checked in any way,
6) The obvious problem here is there are no waves but LIGO has frequent detections.
7) It did not take long to discover what LIGO is doing.
The first time I saw the LIGO list I noticed the 4th event, GW170104, near the top. I have known for years the perihelion is on about January 4.
It took a little research to find all the detections are near moon and Sun events (MSE). Many are within only a day or two while others are a few days.
8) LIGO needs a trigger to execute its complex signal analysis.
9) it is critical to note the MSE does not have to mimic the GW signal.
When I posted my initial findings in another Facebook group that incorrect assumption resulted in an immediate criticism.
The MSE only provides a trigger for LIGO to analyze a possible detection.
LIGO detects its template not the MSE.
LIGO is gathering its data and when it detects a change in its system it reacts and begins its analysis. Their complex software must do its pattern matching and through many checks determine whether an event is a candidate for further analysis.
The LIGO site GraceDB shows all the detections since the O3 run began in April. Each possible detection event has the status flags for its progress through analysis. Some events in this list have not passed all the checks.
Wikpedia has a list of GW detections that completed the analysis far enough to assign probabilities to the two partners in the merger.
10 ) Each MSE is a possible trigger.
11) All the detections are near an MSE. In the 4 years since LIGO records began in September 2015 there has never been a detection of more than 7 days from an MSE.
However with a system based on noise there is not a consistent match of the detection date and the MSE date. The dates are usually 'close'.
12) My prediction had to find a middle ground between
a) general enough to address the randomness inherent in LIGO declaring its detections and
b) specific enough so it is not quickly discarded as just chance within probabilities.
Until the 15th I don't know how well my prediction fared over the entire time span.
Even if LIGO reports nothing else my prediction was still confirmed on November 10. Now it has an unfortunate coincidence on that date. I did not read the November 9 post soon enough for me to comment earlier with the same prediction which I wrote in a couple of minutes.
This is a challenge to predict an event coming from anywhere in the universe at any time.
The post resulted in this comment:
How do you know all these?
LIGO underwent several upgrades before discovering their recent g waves. Many have called LIGO's infinitesimal results absurd and shouldn't convince the awardment of the Nobel Prize. But here are you predicting LIGO. How?
I listed the few steps in the post.
I suppose I left out some details like a few months ago I read detailed descriptions of their pattern matching algorithm.
Once one knows how the LIGO software works it is easy to see why it declares a detection during a full moon.
I suspect few wish to read my critique of the LIGO design. I thought it important just to get to the connection to moon and sun events.
Hit back to go to previous page in history.
Here is the list of topics in this Cosmology Topic Group .
Ctrl + for zoom in; Ctrl - for zoom out ; Ctrl 0 for no zoom;
triple-tap for zoom to fit; pinch for zoom change; pinched for no zoom