So according to you, if a given UV intensity is able to generate a given coloration of a piece of linen after say 60 s of exposure, then half this intensity is able to generate the same coloration after 120 s of exposure. Yet, Lazzaro has performed the experiments and he observed a threshold effect, meaning that linens are never colored when irradiated at lower than threshold intensity value, independent of the number of laser shots.
Not according to me, but to a point, yes. Ultimately the colouration is a chemical response to the incoming radiation. A susceptible molecule needs to absorb a photon within the correct energy range, which only depends on its wavelength. The actual reaction someone with more background in organic chemistry in general or textiles in particular can explain, but from what I understand, it is irreversible. Once a molecule underwent it, it will not spontaneously restore its former state.
More reactions happen when more photons of that energy come in. Whether that happens over a fraction of a second or several years is, for the most part, irrelevant on that level. Of course, there are other things to consider.
The reaction in question could be exothermic, or just the excess energy of a photon beyond the reactionâs needs could subsequently be released as low-frequency photons. Linen is of course a rather complex substance, both in its molecular makeup and more macroscopic structure. It is entirely possible that the heat released could facilitate other molecules in the region to undergo reactions of their own, be they of the same sort or another. Perhaps if more external radiation is coming in at the same time, yet different reactions can occur. So in that sense, once we are talking about intensities where the internal heat dispersion is too slow to decay before the next event due to external irradiation, yes, intensity does matter. After all, one could set the fabric ablaze with a sufficiently intense local pulse, and surely thatâs not something that would happen after a millennium of mere exposure to unfocused sunlight.
The fabricâs response to irradiation is not linear with intensity across the board, nor was I arguing that. What I said, and you quoted as much, is that it is a silly idea that there a minimal power output should be required to produce an image of one size or colour depth or another, absent any further qualification, as said in the passage you referenced, and repeated by yourself here. Sun bleeches (or tans, as it were) materials both on the Canaries and in Alaska, albeit at different rates, and both without the need of laser optics.
Yea, well, too bad the data he chose to display do not show this, then.
As an aside (and not to mock people who struggle to construct cohesive documents ready for publication), the paper is a delight just to look at. With units like âMegaWatt/cm²â at one point, but â10âś W/cm²â everywhere else, the wavelength symbol âÎťâ appearing in some places, but replaced with a question mark in several others, at times printed above an opening parenthesis, and yet at many more places replaced with just an empty blank or with nothing at all. Granted, the copy uploaded to ResearchGate doesnât have the missing lambdas, but still has the question-mark-parenthesis overlaps and odd spacing no typesetting software would have voluntarily yielded as recently as fifteen years ago. Iâd conjecture someone must have gone out of their way to make this look less competently crafted. But thatâs neither here nor thereâŚ
And yet, this is what Lazzaro has experimentally observed, a threshold effect regarding laser power output!
Now, I would like to understand something. Do you really think that the Shroud has been manufactured by a medieval forger that used sunlight to generate the image?
He also states that he has performed an experiment that shows that the coloring still appears after heating linen fibres that have been exposed below the threshold intensity.
A threshold intensity is usually required because multiple consecutive photons have to excite an electron in short succession, before it decays back to a lower energy level. If too low, the excited state will decay back to a lower level before the next photon hits. If too high, the electron is excited too many times in a row and an undesired chemical reaction results.
However the fact that heating can make the fibres colorize even when it has been exposed below the threshold intensity really undermines the idea that the threshold intensity is absolutely required to produce the image effect. He even says that simple time, that is natural aging of the cloth, will also bring out the coloring in fibres exposed below the threshold intensity.
So it is entirely possible that prolonged time in the sun has the combined effect of UV light and heat required to color the linen fibres.
Well, the data he chose to display in the paper do not seem to indicate it. I understand that he says as much, and youâll have to ask him, Iâm afraid, to explain what about his data gave him that opinion.
Thatâs certainly more likely, in my opinion, than that a medieval forger would have used a terawatt laser, for what itâs worth⌠What I cannot speculate about is whether either event is more or less likely than that God-magic would make it so the shroud yields a carbon date some twelve centuries younger than it actually is.
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In science, we donât accept hypotheses based on how straightforward their explanations are. We accept them based on successful PREDICTIONS of empirical measurements in the future.
Are there any for that hypothesis?
Consistency with extant data is required, so we can easily discard this hypothesis.
You donât have a hypothesis that does that, so you pretend that science is about arguments instead of evidence. If you thought for a moment that the evidence supported what you wish to be true, youâd be citing evidence, not arguments.
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Hi John
This is Ruckers hypothesis and not mine. His hypothesis does account for all the data as far as I can tell. It would be easily falsified if more carbon dating testing could be done on the Shroud. The problem is that this dating method is destructive.
Doesnât matter.
How far have you looked? It appears that you stop when you merely wish the hypothesis to be true. Thatâs pseudoscience.
What specific empirical prediction(s) does it make?
Yet itâs been done already.
I propose the hypothesis only because it fits the evidence. I am not sure it is true or not.
It makes the prediction that the carbon dates will vary across the shroud depending on how close you are the center of the body. It predicts that some dates will have C-14 levels that are greater than a new cloth.
On one small piece that is at the edge of the shroud. The carbon dating showed an increase in C-14 as you moved toward the center of the shroud. The third page below shows the increasing levels as you move toward the center.
The Shroud Ruckers theory.pdf (298.2 KB)
Was the increase statistically significant? Show your math.
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This is Ruckers claim. Look at his paper above that I have attached and see if you agree.
A Chi-squared statistical analysis can also be used to
determine whether the 12 subsample dates and their un-
certainties for the Shroud are consistent with each oth-
er, as they should be. This statistical analysis calculated
a significance level for the 12 Shroud subsamples of only
1.4% (Table 5 of [4]), which indicates there is only a 1.4%
chance that random errors alone can explain the spread
in the data listed in Damon. The 1.4% is below the usu-
al acceptance criteria of 5%.
Unlikely, considering that itâs based on three data points that are very close together. I do wonder, though, whether there is supposed to be enough 14C at the center of the shroud to show up on a geiger counter. Supposedly, if tested, it would give an age of 8500 AD, but Iâm not sure how much that would be or how much radiation to expect. Is that something like 20 times the proportion in the atmosphere?
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No, all that says is that the samples in the three areas are not homogeneous, i.e. not all sampled from the same distribution. And even for that, p = 0.014 isnât spectacularly impressive. It does nothing to illuminate the differences among samples, nor any directionality.
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Read the third page and look at the proximity of the samples to the center. Directionality is clear based on this drawing.
Well which is it, is it Ruckerâs hypothesis and you are mentioning it just to make us aware of it, or are you proposing it, and willing to defend it? Pick a lane.
And no, the hypothesis does not âfit the evidenceâ. In fact, the entire point and purpose of its existence is specifically to serve as an excuse for dismissing evidence. The evidence, as we have it, suggests that the cloth in question is from sometime around the thirteenth or fourteenth century. The âhypothesisâ is an attempt to not look like an outright evidence denier when saying that the shroud is actually some other age. It does not explain anything about the data, because frankly nothing about the data is anomalous to begin with. The inconsistency is not between some data and other data. The inconsistency is between the wish to believe something the data clearly conflicts with and the wish to not appear like a reality-denying lunatic for doing so. The dissonance, if you will, is of a cognitive kind here. The data is just fine as it is.
And this is well before considering whether the hypothesis is consistent with other evidence, like everything we know about nuclear physics, to start with. Of course it is not.
As far as you can tell, then, respectfully, seems to be as far as one data point, namely the carbon date, and the entirely baseless opinion that said data point is incorrect, actually. It is these two things that Ruckerâs hypothesis can barely harmonize: A data point, and an opinion that should conflict with it, if taken at face value. And the only price for that âachievementâ is just a little bit of contradicting pretty much the entirety of fundamental physics. A worthy tradeoff⌠as far as you can tellâŚ
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The question is whether the directionality is significant, if you recall. The chi-square test is not a test for directionality, only for homogeneity.
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Agree. Here is a florescence test that I posted earlier that shows variation across the shroud.
Shroud florescence measuremnts.pdf (2.0 MB)
If you take any three numbers and put them in random order, there is a 1/6 chance that they will show what you call âdirectionalityâ i.e. be ordered from lowest to highest.
Hardly a breathtakingly improbable occurrence.
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How is that in any way relevant to variation in 14C content?
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The patterns of the high florescence variation appear to follow Ruckers predictions according to McAvoy.