LIGO events Near Celestial Events with an Earth Tide - Part 2
There are many coincidences among the 29 LIGO detected events and several celestial events.
On July 11 I posted about those coincidences, listing all 29 events. This is a follow up.
For some the coincidences present a possible mystery.
For others the coincidences solve a second mystery.
LIGO achieved what it was designed for and so the team was awarded the 2017 Nobel Prize in Physics for that accomplishment.
From the Nobel Prize press release:
"for decisive contributions to the LIGO detector and the observation of gravitational waves"
Gravitational waves finally captured
On 14 September 2015, the universe's gravitational waves were observed for the very first time. The waves, which were predicted by Albert Einstein a hundred years ago, came from a collision between two black holes.
From a Symmetry magazine article titled LIGO analysis:
The LIGO experiments use grid-computing technologies to handle the collection and analysis of data. This workflow analyzes data looking for inspiral signals, which can occur when two compact objects, such as neutron stars or black holes, form binary systems. Over time, the objects spiral in toward one another, producing gravitational radiation. This diagram illustrates the steps required to turn the raw data collected from those signals into interpretable observations.
Using parameters such as mass and spin, and accounting for detector sensitivity, theoretical models are used to make a bank of expected waveforms, or templates, for binary inspiral events.
Data recorded by LIGO are compared with the waveforms in the template bank and those that match within some statistical threshold are stored for further analysis.
Programs look for coincident events, observed at the same time and with the same mass parameters in two or more detectors.
The events that survive in coincidence from the Thinca program are converted back into template waveforms.
Additional tests are performed to verify that the data matches a template waveform. These tests are computationally costly, so they are only performed on candidate events observed in at least two detectors.
The coincidence step is repeated to find a final list of candidate events. The result of the series of programs is an upper limit on the expected rate of binary inspiral events within the surveyed portion of the galaxy. Once the statistics are calculated using the workflow, LIGO scientists begin to interpret the results. LIGO has performed four science runs since 2002 with the fifth scheduled for late 2005, during which the LIGO instruments will operate at design sensitivity and will collect one year of observational data.
LIGO is designed to detect binary inspiral events. Tests are repeated to make sure the data matches the template waveform for these particular events.
Each reported event is a binary inspiral, with either of the two bodies involved a black hole or neutron star.
LIGO has detected over 20 of these events.
For those convinced LIGO detected a merger of those two bodies:
the list of concidences present the first mystery but it can be discarded as just chance; the coincidences add nothing to LIGO reports. LIGO reports its inspiral events as designed; other possible crust disturbances, like an earthquake somewhere on the globe, are not part of this design.
Since the moon completes an orbit every 29 days lunar events are fairly frequent so coincidences could be expected.
A possible mystery can be dismissed.
For those not convinced LIGO detected a merger, there is a second mystery:
What did LIGO detect?
The answer is in those coincidences. The earth tides are periodically disturbing the Earth's crust and this LIGO system reacts with its 'template search and confirm' algorithm can find a match with one of its templates to report an event detection.
This second mystery is solved.
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