RESPONSE TO PGA2.0
This post is the promised response to the questions PGA2.0 asked me in the comments section of "The Universe is Older than 10,000 years." Sorry it took me like a month.
PGA2.0:
"How do you justify not use an exclusively natural as opposed to a supernatural view (thus, the presuppositions nature of your argument) in interpreting the evidence? What was faulty thinking on either Wesley's or my part regarding the speed of light argument, and I am interested in your view on how the expansion (fast or slow) of the Universe could adversely affect its age. I am also interested in how you would answer the Thomas Aquinas issue?"
PHILOSOPHY
Methodological Naturalism is not the same as Ontological Naturalism. Ontological Naturalism is the presupposition that all that exists in spacetime is physical. Whereas Methodological Naturalism is simply A Posteriori investigation, in an attempt to create/acquire synthetic knowledge about the natural world.
LAWYERS VS SCIENTISTS
Often people will say that "we are looking at the same evidence and coming to different conclusions." In theory, two lawyers could walk into a courtroom and flip a coin to see who takes what side of a case to argue. Their presupposition is assigned to them, and regardless of what the reality of who did what in the case, their job is to convince you of their side.
Scientists do not operate this way. A scientist's job is to construct a model of reality that best incorporates all the known data and makes testable predictions. They have to synthesize a model that most accurately describes reality. They don't come to the table with their conclusions assigned to them.
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QUALITIES OF A SCIENTIFIC THEORY
A scientific theory is an attempt to construct a model of some aspect of reality. A scientific theory must have three qualities.
1. It must be independently verifiable, preferably by making novel predictions about future data.
2. It must be potentially falsifiable, otherwise it can be discarded into the category of pseudoscience.
3. It must make as few assumptions as possible, the idea of Parsimony.
If a theory is not verifiable, or it's predictions fail, that is indicative that it is not a reliable model of reality. If a theory is not falsifiable, then it cannot be tested with the scientific method, and therefore is probably pseudoscience. And a theory that is not parsimonious will contain extraneous elements that limit the scope of its explanatory power, liable to be disregarded in favor of a model with less assumptions (Occam's Razor).
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THE SPEED OF LIGHT
The speed of light in a vacuum is constant [1]. A lightyear is a measure of distance. If we can measure light that is 10 million light years away, then that light necessarily had to travel 10 million years to get to us.
PGA2.0, you made a couple of critical errors with the following statements:
" We 1) see the stars out there and 2) measure the speed of light to and back from the stars for accuracy. You can't measure it accurately from one direction is the point here."
Response:
1. We see the stars as they were when their light was emitted, not as they are right now. That is a consequence of light having a finite speed.
2. We do not measure the speed of light to and back from the stars; we measure the speed of light in a vacuum experimentally, such as the experiment I provided.
We can measure the distance to galaxies far away by determining their recessional velocity. Their recessional velocity is Hubble's Law. According to my debate source [2]:
"Radial velocities are relatively easy to measure. Once we measure v for a galaxy, we can compute
d = v / H0 .
For instance, suppose a galaxy is moving away from us at 14,000 km/sec. Its distance, using the Hubble Law, is thus
d = (14,000 km/sec) / (70 km/sec/Mpc) = 200 Mpc.
The galaxy is 200 megaparsecs away (652 million light years), beyond the region where Cepheids can be used to compute distances."
PGA2.0:
"On top of that, it is assumed that the speed of light we witness now from an expanding Universe (matter in motion) is the same it was at the beginning of the Universe, or at least calculable (always the same constant - no miracles allowed, which creation week was said to be), AND that the current supposed rate accurately calculates the rate of/from expansion at the BB."
Science is inductive, and therefore will never deal in epistemic certainty. However, it does construct hypotheses to test, which can either be vindicated into a working theory, or falsified and discarded in favor of a more explanatory model.
That’s really the point, to construct models that can make predictions about reality as we experience it. The best inductive model for lights speed, that has been verified without exception, in innumerable tests, is the speed of light in a vacuum is approx. 300,000 km/sec. As for the Big Bang model, see this debate for my constructive.
The speed of light is so well known in fact that the standard unit of length (Metre) is based on light's speed [3]: "Since 1983, the metre has been internationally defined as the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second. This definition can be realised simply and accurately using modern techniques and the speed of light is regarded to be a universal constant, making it ideal as the basis for a length standard."
The speed of light is not assumed, it is experimentally confirmed. The expansion rate of the Universe has been experimentally confirmed. These go into calculating cosmic distances. If you are going to suggest that laws of physics were different in the past, then you need to predicate that on something other than conjecture.
Miracles aren't unnecessarily interjected into the model, because that would necessarily make it less parsimonious, by virtue of the many assumptions that claiming a "miracle" makes. Sure, technically they can be allowed, but you have to establish that this happened with some kind of verifiability, or else the explanation that works better and makes less assumptions (that light travels at a constant speed in a vacuum) will always be accepted instead. Side note, cosmic distances are adjusted for the effects of gravity on the light.
" With all the paradigm shifts in thinking will the currently thought of age of the Universe remain what it is now?"
The accepted age of the Universe has been getting nailed down as the error bars become smaller and smaller, but the age has always been calculated within a margin of error. So the accepted age will probably change a little as we zero down, but the answer is just getting more accurate.
Like here in 1998 [4], the age was calculated to be (tU ≥ 9.5Gyr). Gyr stands for gigayears, or, one billion years.
And in 2020, we get even more accurate measurements [5]: "We find that the average age of the oldest globular clusters is tGC=13.32 0.1 (stat.) 0.5 (sys.), at 68% confidence level, including systematic uncertainties from stellar modeling. These measurements can be used to infer the age of the Universe, largely independently of the cosmological parameters: we find an age of the Universe tU=13.5+0.16−0.14 (stat.) 0.5 (sys.) at 68% confidence level, accounting for the formation time of globular clusters and its uncertainty. This value is compatible with 13.8±0.02 Gyr, the cosmological model-dependent value inferred by the Planck mission assuming the ΛCDM model."
Notice how the older calculation is also correct, it's just less precise than the newer one.
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AQUINAS
As for the Aquinas arguments, please see this debate for objections I have to his argument from motion. But I'll throw some objections out there to all of them: they have no evidence, and assume what nobody actually knows. I can go more in depth If you'd like
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I hope that covers everything and there aren't too many spelling errors.