The LIGO team reported on June 15, 2016, their second confirmed detection of coalescing binary black hole pair generating a gravitational wave. This was published in Physical Review Letters,1 with an abstract that reads (with some editing in […]’s and emphases added):
We report the observation of a gravitational-wave signal produced by the coalescence of two stellar-mass black holes. The signal, GW151226, was observed by the twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) on December 26, 2015 at 03:38:53 UTC. The signal was initially identified within 70 s by an online matched-filter search targeting binary coalescences. Subsequent off-line analyses recovered GW151226 with a network signal-to-noise ratio of 13 and a significance greater than 5σ. The signal persisted in the LIGO frequency band for approximately 1 s, increasing in frequency and amplitude over about 55 cycles from 35 to 450 Hz, and reached a peak gravitational strain of [about] 3.4 × 10-22. The inferred source-frame initial black hole masses are 14.2 and 7.5 [solar masses, i.e. mass of the sun], and the final black hole mass is 20.8 [solar masses]. We find that at least one of the component black holes has spin greater than 0.2. This source is located at a luminosity distance of 440 Mpc [about 1.4 billion light-years] corresponding to a redshift of 0.09±0.03. All uncertainties define a 90% credible interval.
This result further strengthens the argument for stellar mass size black holes and for their correct prediction by Einstein’s general relativity. As I have written before this largely falls into the category of operational science. Some assumptions are necessarily required, but the waveform (see right) extracted from the received signal very precisely matches the expected waveform. Read What impact does the detection of gravitational waves have on biblical creation?2
But how do they know that it was a collision of 2 black holes, or that their masses are those reported or that the event took place at the reported distance, hence so long ago? Could it not be something else? For an answer to these types of questions see my article linked above (ref. 2) and also Impact of gravitational wave detection: A response to Setterfield’s response.3
It is important to understand how science operates. We should realise that there is no such thing as a proof, but only disproof. In the cosmos, because we cannot interact with distant sources, operational science is more difficult than in a lab environment. But gravitational wave detection, because of its now repeatable nature (2 detections are good, 3 would be a charm) it is developing into what can be classed as operational science. This is akin to detecting spinning neutron stars–radio pulsars. Jocelyn Bell detected the first one in 1968 and nobody doubts the validity of such detections now. Or it is akin to detecting any other astronomical object on a repeated basis. The historical science comes in when you try to apply the knowledge of their existence to an assumed evolutionary history of the universe.
Secondly, this detection adds further weight to the argument I put in my first article (ref. 2) that the speed of light (c) is unchanged since the two black holes merged, which would have had to have been a long time ago. How soon after creation depends on your cosmology. Thus the notion that the speed of light has decreased by more than a million times since creation cannot be entertained by biblical creationists. There are alternate potential solutions to the creationist starlight-travel-time problem.4
- B. P. Abbott et al. (LIGO Scientific Collaboration and Virgo Collaboration), GW151226: Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence, Phys. Rev. Lett. 116, 241103, 15 June 2016.
- J.G. Hartnett, What impact does the detection of gravitational waves have on biblical creation?, February 16, 2016.
- J.G. Hartnett, Impact of gravitational wave detection: A response to Setterfield’s response, March 1 2016.
- J.G. Hartnett, The lecture: Starlight and time—Is it a brick wall for biblical creation? January 29, 2016.