Impact of gravitational wave detection: A Response to Setterfield’s Response

The following is written as a rebuttal to an article titled “In Response to Hartnett’s Article”1, dated February, 2016, written by Mr Barry Setterfield. (This rebuttal is also available on The author states that he received the following email, along with a number of others with the same questions about the Hartnett article:2

I have a question regarding a CMI article by a Dr. John Hartnett entitled “What impact does the detection of gravitational waves have on biblical creation?”  Dr. Hartnett makes the claim that the recent discovery of gravity waves uses a modern value for the speed of light to calculate the masses of the two black holes which collided to produce those waves, so he concludes (a bit too quickly in my opinion) that “the cdk idea is [to be] thoroughly rejected”. I wanted your take on this issue. Here’s the relevant portion of the article:

“Interestingly, the calculation used to determine the masses of the merging black holes in the analysis of this week’s discovery employed the standard canonical speed of light, c. That is, it used the same constant value that we measure today. Does that tell us something? I think it does.

Inspiral of black holes and associated waveform. Ref. 3.

Inspiral of black holes and associated waveform. Ref. 3. Click image for enlarged view.

Some biblical creationists favour a much higher value for the speed of light in the past, from a time soon after creation of the universe, after which it decreased or decayed down to its current value (the concept is known as cdk, from c-decay). They use this supposed much higher value of c in the past as a solution of the biblical creationist light-travel time problem. But now this new discovery shows that, at a time in the past representative of a distance in the cosmos of 1.3 billion light-years, the value of the speed of [sic] (c) was identical to today’s current value. Regardless of which creationist cosmology you like, the gravity waves observed in September 2015 must have left their source very soon after Creation week. Thus the cdk idea is thoroughly rejected.”

To which Setterfield responds. So I respond to his response (indented black text) with my comments (blue text) interspersed below his. Continue reading