Why are you asking for a source when I gave it, and you cut it out of your quote? Dishonest.
Who needs 'sources' in the form of descriptions of how big they imagined the stars to be during the 17th century when you can simply go out and have a look for yourself? In any case Tom your 'sources' are always just links to a page of your FE Wiki. Hardly what can be described as 'independent'. Just go outside, look through a telescope at any star and then look at Jupiter or Saturn even. See the difference? You can see the disk of Jupiter with a simple pair of binoculars but Sirius will only ever appear as a point source. Surprise surprise!
It is completely ludicrous to even suggest that Sirius is ever going to look much bigger in an eyepiece than the largest planet in the solar system. Don't you think? I don't know what telescopes they were using back in the 17th century but if that's the impression that Kepler got then there was something seriously wrong going on.
If you can see Sirius looking like a disk 3x the size of Jupiter through your telescope Tom then either it doesn't work, you are looking through the wrong end (only kidding) or it is seriously out of focus. A star out of focus is going to look like a big disk. I don't know about you but I always find telescopes perform better when they are in focus.
Yeah, claiming that the sizes of the stars are optical illusions definitely supports the narrative that the sizes of the stars and celestial bodies are not optical illusions.
I never said anything about optical illusions did I. I said the Airy disk is an optical
effect of how telescopes work. Lenses and mirrors are round and the focal plane forms a small circle. That is the Airy disk. Nothing to do with optical illusions.
You can do so, but it is not considered scientific knowledge. The US Supreme Court (1993) in Daubert v. Merrell made a determination of what qualifies as "scientific knowledge":
Good for them...I don't particularly give a damn what the US supreme court says about scientific knowledge. I tend to go with scientific organisations rather than the law courts to decide on a definition about what is or what isn't scientific knowledge. Count up how many times the word 'observation' crops up in this
source about what scientific knowledge is. Is the US Supreme Court a recognised scientific organisation? Scientific knowledge is gained from the data that we gather. How can we do that completely if we don't count the observations that we make of how nature works? Even when carrying out experiments we learn by observing the results of those experiments.
https://whatmaster.com/what-is-scientific-knowledge/or indeed this one.. this one even mentions about ancient beliefs about the world being flat!
https://www.visionlearning.com/en/library/Process-of-Science/49/The-Nature-of-Scientific-Knowledge/185We know the distance to Sirius and anyone with an ounce of common sense will realise that you are never going to see any physical disk on something that far away with
any telescope. The reason being the visible disk diameter is much, much less than the resolving power of any telescope. Hence we see them as point sources.
You may not accept modern methods of measuring the distances to the stars because they don't fall in line with what you want to believe, but that in itself doesn't make them any less valid. Mother nature decides what is true and what isn't, not you.
With regards to Keplers 'De Stella Nova' publication, I have downloaded the publication but I cannot find any reference to where he apparently addressed the size of the nova. As suggested by the Wiki article...
In On the New Star, Kepler addressed the size of the nova
He did describe the position of the nova relative to nearby stars (with excellent accuracy) and the brightness curve but not the 'size'. He also described how he imagined that all other stars to be giants. But it doesn't mention the size of the nova specifically. Perhaps you could provide a page number where he addresses that? Many people seem to describe brightness in terms of size. For example I have heard people say 'I saw Venus last night and it looked really big'. But of course what they mean is it looked really bright.
Obviously knowledge of the stars in general back in the early 17th century was not quite on a par with what it is today. Thanks largely to developments in spectroscopy and optics during the mid-19th century. You cannot really base your understanding of the stars now with what was known about them during the 17th century. Except perhaps if it helps your position on what you believe.