When you are testing a sample for chemical composition there is a detection threshold.
How is this equivalent or analogous with primary vs. secondary evidence, in the sense you communicate here:
All there are are secondary (or worse) sources and that should be acknowledged rather than the pretense of raising them to the rank of primary with no support except whining that they're the "best we got."
?
Given that measurements of any physical system are of necessity in some sense proxy measurements (i.e., the alignment of hydrogen nuclei for (f)MRI measurements/scans or even the necessity for photons to reach our eyes in order to see the results of some experiment), we always rely on a device (even if it is our eyes) to determine the value for all observables. We don't generally refer to these as proxies as the term is reserved for e.g., ice cores in paleoclimatology or MSU readings to determine global temperatures via satellite. However, we can't measure anything "directly" (something known so well before the sciences were distinct from natural philosophy that this notion has practically become indistinct from Kantian philosophy despite those who contributed to the view before him and the vast work after).
In QM (and extensions thereof: QFT, QCD, etc.), observables do not even have a one-to-one correspondence with some value obtained by measurement. In classical physics, an observable like momentum or mass is represented by a vector or scalar value which directly corresponds to the observable measured. In QM, observables are mathematical operators, not values. Our measurements are secondary on a level unprecedented as we don't actually know what our "observables" correspond to in a quantum system apart from a mathematical framework.
That is much the way I see the historicity question.
That doesn't address your misuse of "primary" vs. "secondary". Just as we don't describe the reliance on electromagnetic fields as "proxies" when we take X-rays or use a simple microscope, we don't describe as "secondary" sources that attest to the events of a period of time in which they lived. This is especially significant for ancient historians, who have to also take into account that the primary sources from any ancient historian or author are lost. We have (we hope) adequate copies of these. From this perspective, the NT is unparalleled in the amount of evidence we have to assert that the text that we have (based on the manuscripts which survive) have given us what we need to determine the content of the originals to a sufficiently accurate degree.
There are insufficient references to a historical Jesus
You refer to thresholds. Classically, we can measure some system arbitrarily gently such that the disturbance by the measurement is as small (or infinitesimal) as we wish. High-end steels (S30V, ZDP-189, VG-10, ATS-34, H1, etc.) contain specified percentages of particular alloying elements (carbon, chromium, nickel, molybdenum, vanadium, etc.). The metallurgical processes behind any steel means variations not simply among the "exact" amounts of any particular alloying element but also among the presence of trace elements. Differences in the percentage of carbon contend in the simplest (compositionally speaking) steels like the 10xx series that are less than a hundredth of a percent could be detected but there is no need. Likewise for trace elements. However, the precision required for carbon dating is quite different.
When you don't know how specialists view "thresholds" in a particular field or why, then you don't have a basis for asserting that the failure to meet your arbitrarily and uninformed threshold is meaningful.
those that there are are of such poor quality, so potentially contaminated with mistranslation, forgery and hope to be of much use.
If we had only the Latin manuscripts of the NT we have, our degree of confidence in our ability to assess the faithfulness of our manuscripts would be superior to basically any text by every author from antiquity both before and centuries after Jesus.
We have lots of forgeries of letters and works said to be by Socrates or Hippocrates and our manuscript evidence for the most famous classical authors exist in a handful of bad manuscripts from the middle ages or in translations from Arabic manuscripts.
Have you studied textual criticism? If not, how are you determining the quality of our manuscripts? As for the quality of the NT texts (i.e., the singular "texts" scholars via the use of textual criticism and our manuscripts) and their historical merit, what is your basis for determining their quality? Would you apply the same standards and the same skepticism (and are you aware of what this entails) to all evidence from antiquity?
In general, what is your basis for comparison and for your understanding of scholarship on these questions?
If you need to look under the detection threshold you need a different test, a different instrument, a lower detection threshold, but you will still need a sample with a detectable concentration.
If the evidence for the historical Jesus is under some threshold, than virtually all our knowledge of ancient historical events, persons, cultures, societies, religions, etc., is as well. There are precious few for which we have more evidence than for Jesus.
you tout of modern biblical scholarship, critical historical methods, and/or comparative linguistics make the "detectors" significantly more sensitive but do not raise them
These developments aren't unique to biblical studies but the study of history in general. Regardless, the evidence for the historical Jesus is so far beyond the threshold used by historians (biblical scholars, classical historians, more general historians, Near-Eastern specialists, etc.) that to claim it is beneath it is to write off our ability to know basically anything about antiquity.
and this is (ultimate) a judgement call
The question is the framework one uses to make such a call. If it is "I don't know how specialists whose work makes up the scholarship of the ancient world determine what they do or why, their methods, or their work in general" this hardly seems like a sound basis for any judgment.
at any where near a 90% confidence level the historicity of Jesus. Your results and conclusions may vary.
Given that the interpretation of CIs as well as whether they mean anything (e.g., confidence intervals/levels in hypothesis testing/NHST are flawed regardless of their values), and given that historiography doesn't lend itself to mathematical models in this way, such requirements are basically meaningless.
I make not claims, you are the one making claims.
So this isn't a claim:
I find the entire body of knowledge that is available inadequate to the task that it being put to.
You haven't indicated a basic familiarity with any of the "body of knowledge", so much so that basic definitions used by those who produce this body of knowledge you misuse and your comparisons regarding thresholds misconstrue the entirety of this body of knowledge. Hence by request for evidence that you have any basis for asserting what you do that is grounded in a foundation of familiarity with the body of knowledge you refer to. NOT a dismissal of a body of evidence you haven't indicated you know anything of but have demonstrated an ignorance of.
That's not true, you just have to be good enough and you sound rather bitter, which never helps you get a contract, better to just appear arrogant, I never seen bitter work.
Had I went into classics, who would give me a contract? What contracts exist? I didn't, so I'm not bitter. I chose to follow another interest which has allowed me to participate both in academia and serve as an independent consult in various capacities (mainly research methods consulting & statistical/data analysis).
If you're good enough, and lucky enough, there's always room at the top
Wrong. This follows simply from tenure and the fact that the majority of doctoral degrees can't be used outside academia.
Again, that nasty, bitter tone, you really can't brook anyone disagreeing with you, can you.
My apologies. It is an extreme irritation for me and pet peeve of mine when those who haven't really researched a topic make sweeping claims about it and related topics, as you do when you speak of thresholds in ancient history and our evidence for Jesus.
You rush headlong into insult and deprecation over honest differences of opinion.
I didn't. I asked repeatedly for you to give some indication that you had any basis for your views. So far, you've referred to some anonymous historian or historians who you won't name and don't cite. That's not an "honest" difference, that's an uninformed opinion.