On rainbows. Part 4.

There is one particularly interesting little story that occurred in my former correspondence with Dr. Markus Selmke I don't think I ever mentioned on these pages before, so I'll do it today because it's certainly worth knowing (by the discerning mind). 

After a few intense weeks of being involved in a torrid exchange of emails with Dr. Selmke I was beginning to get a pretty confident picture of what the man in question might be really like and about, so one day I decided to put it to a certain test, for good measure. Specifically, in a short and seemingly unrelated email to any other since then I asked the good Dr. to put a percentage number on how confident he truly was that the conventional understanding of rainbows was correct. A short time later his answer was crying out from my inbox and under the cheeky gaze of my Greek I opened the email and wryly grinned aloud the (rather sadly, and quite disappointingly) unsurprising figure. The test was over and in an instant I was completely freed of any lurking sense of either guilt, regret, remorse or wonder.

I have been taking my time with this post. There's no need to hurry. I remember reading somewhere, a long time ago now, someone's answer to a question whether one who might harbour a belief in possessing some great scientific insight should be wary about how to expose it to the world at large, in order to prevent/avoid/insure that it won't be stolen or claimed by some one else, later. One, the answer went, should not worry at all about that, for if one's unspecified scientific insight should happen to really be "great" then one shall find that no one will even think about doing anything of the kind. 

Clever. More importantly, though, true 😎!😂 

Almost a year ago to the day I received the email below from Markus Selmke. Today I decided to answer it.

Dear Remus,

Your answer does not address the points I have raised. I take it that you have no meaningful response to offer.

Why don't you do all those things yourself

I did indeed, indirectly many times. The direct measurement is too simple to warrant a dedicated section in a lab course, but you will find it in the curricula of many schools with dedicated experimental setups. In my physics training I have for instance done many of the following experiments myself:

http://home.uni-leipzig.de/physfp/fprakt.html

You will find spectroscopy among them, which for dispersive spectrometers is based precisely on snells law of refraction and dispersion.

You may also remember that I have published research. I have used Snells law in combination with dispersion many times and found good agreement with experiments I have done myself. My latest contribution in this direction being the fairly simple deomstration experiment and its quantification here: https://128.84.21.199/abs/1608.08664 (to appear in the next issue of Am. J. Phys., after a vetting and partial rewriting within the due course of a proper and lengthy critical review process; in fact you will be able to notice the difference between the final version and the submitted manuscript according to the ArXiv version). I found the agreement with experiments only WITH the inclusion of dispersion, and inferior results without. Unsurprisingly, I should say, because dispersion is, contrary to your baseless and evidently uninformed claim, a century-old well-supported, understood, measured and quantified fact. It may even be derived and understood from more fundamental laws like the Maxwell equations together with an appropriate atomistic model for matter.

BTW: You again demonstrate that you lack a fundamental understanding of the concept of light altogether. There is simply no way to individually send a single wavelength through a prism in an experiment. You will always be concerned with spectral distributions, even for narrow bandwidth laser sources! But this is, admittedly, the smallest of errors you make, with the more grave one being that you lack an understanding of the scientific method.

Also, I am curious: Did you test yourself whether gravity works as Newton described it? Did you ever jump off a cliff to find your velicity to increase linearly with time? I’m afraid not, but other people tested it (well, not by jumping) and found precise agreement. They even made quantitativly testable predictions of experimental outcomes. Your car will use the mechanical principles so eloquently framed by Newton, yet you didn’t test them all, did you? And so does your camera use the different refrangibility of colors. Or binoculars for that matter which truly use prisms directly. They are color-corrected in fact to counteract the measurable color dispersion effect. It should be unneccessary to state it again, but of course there is abundant evidence in the scientific literature to support this (including my miniscule contributions) contrary to your laughable claim (again, abstracting from the fact that you can only send spectral distributions of colors through a prism).

You may now apologize if you understand the above and the previous email in full.

Frustratedly,

Markus

Dear Markus,

Last year when I received your email, cited in full above, I had a good look at your  usual array of childish assumptions and their commensurately stupid and even more infantile extensions, I smiled and then decided to leave you continuing to bask in your pompous ignorance for the time being. Today, however, when I happened to stumble across it once again I suddenly realised that it in fact would be the best starting cue for this particular post. So here I am, ready to address more points than you can even imagine--let alone raise.

Leaving aside your incoherent ranting about dispersion, Snell's law, spectroscopy, etc. let me first tell you why I asked you conduct a proper experiment in order to confirm once and for all that Snell's law is indubitably valid. 

If you google the most relevant terms concerned with the subject of colour dispersion you will find that basically all sites that cover the issue use one and the same setup in every case. Specifically, starting with a version of Newton's experimentum crucis they separate colours from a dispersed beam of white light and thereof proceed to pass them through prisms placed at minimum deviation and finally compare the results according with Snell's refractive equations. Now, to my mind that particular method was fraught with danger, especially when used exclusively, as it seemed to be to the best of my research. (Why fraught with danger I'll tell you in a moment.)

And there was an additional reason for my request. I knew you simply had not only the knowledge and expertise to address the issue properly: You also had far superior means than my Kmart laser pointers and prisms.

Now, regarding my suspicious outlook towards Snell you'd be wise to treat it carefully, for I not only have a much firmer grasp of the subject than you'd be willing to consider, but that I have also found such a beautiful and healthy reason for dispersion that will make your heart skip a few beats when you will hear it.

Being aware that Snell developed his law a long time before Newton himself came unto the scene made me wonder how the man could have possibly managed to conceive of such an apparently accurate tool of assessment without having a real understanding of how white light was dispersed by a prism in a full spectrum of colours. Had Snell developed his law after Newton I certainly wouldn't have had a problem with the idea. But before?! (These days Snell's law is stated to be derivable from Fermat's principle of least time, but we should not forget that Snell's law was created some 30 years before Fermat laid down that principle.) Nonetheless, in time I came to realise that one could rather easily begin with compiling empirical results from prismatic observations, combine then those with certain mathematical and geometrical principles, derive symmetries by relating observational results and variables, unite all of those via some binding coefficients and finally use the recipe to practically enforce, define and in the end 'standardise' the whole industry, so to speak. In fact that has been the mainstream practice since those very times. And that is a most perilous methodology. So perilous that by now it has contaminated your mob so chronically that you seem to have all become decidedly impotent to see, or even imagine, how blatantly wrong your celebrated optical doctrines are. 

...dispersion is, contrary to your baseless and evidently uninformed claim, a century-old well-supported, understood, measured and quantified fact. 

There is only one thing I can say about the above statement: that when all current facts are considered you have to be either a genuine prophet or a fair dinkum fool to make it. Time will undoubtedly reveal the truth of that matter. (And at this point I should also tell you now the percentage figure I got from Markus Selmke in regard to the little story I shared with you at the beginning of this post, even though I suspect that most of you guessed it already. The figure was, yes, exactly 100%.)

If Markus Selmke understands perfectly well what dispersion is he certainly knows more about it than at least one of the creators of QED ever did. I'm referring here to none other than Richard Feynman, who candidly admitted in these videotaped lectures that he did not understand what exactly happens in the interaction of light with different media. The only thing the great man admitted that he could say on the subject was what effects appeared to unfold under the eye of a careful observer. As my friend Michael Heffron pointed out to me not long ago, when it comes to the subject in question what a genuine physicist of these times can only say is what Sheldon Cooper said in one episode of The Big Bang theory: "I can explain it to you, but I can't make you understand".

Now that is one thing I have always known myself. Furthermore, that is exactly the reason why I have embarked all these years ago on my personal foray into the subject. As most laymen out there, I simply did not understand what our crop of physicists were talking about so I set out (on my own) to change all that. Yes, I know, it was rather typically arrogant from someone in my position to even imagine that I could do that, but that is the truth and that's what I did. Moreover, that's not all either, for these days I have become even more arrogant, if you will, for these days I am here claiming that I do understand what happens when light interacts with different media, creating the chromatic dispersion that is observed in prismatic experimentation and the atmospheric optics phenomena in the process. Moreover still, in contrast to what Sheldon Cooper said (and to what a genuine physicist should say on the subject of light-matter interaction) I am asserting here that I can not only explain the subject to you, but that I can also make you understand. Make of this what you will, just don't make it in haste. Stay with me.

-----------------------

Since I have always been a layman who dared to preach in the conventional temple you can imagine that my 'sermons' are vastly different to those that have pharisaically been preached to the world for a number of centuries now. For instance mine contain very little mathematics, while theirs are by and largely chanted in that language. Furthermore, my own presentations are routinely embedded in familiar pictures, while theirs are most of the time encrypted in complicated graphics, charts and other similar concoctions of arcane data. But perhaps the greatest difference between our two forms of expression is the fact that my own language is very simple while theirs is convoluted and alien to the majority of those listening. Then I must also mention that their expositions can often put a dizzying spell on their audience, while mine are most of the time noticeably un-impressing even the best of those genuinely trying to feign some  degree of interest. What can I say, the truth is that we have always come to the same temple, but always from the exactly opposite ends of the town: when I come from the South they come from the North, and when I happen to arrive from the East they invariably choose to do so from the West👍👎👉👈.

But let me give you next a number of other discrepancies between us that are more relevant to our current bone of contention.

As a concrete example, take Newton's famous experimentum crucis and compare it to mine. (Yes, I do have one of those myself--see below.)

In spoken language: I laid down on a flat surface a short message written on a piece of paper, I then positioned my eye on a line of sight running perpendicularly along the same plane and finally I slid a prism in between them. Hello.

That was my experimentum crucis,  in a nutshell. It was crucis because it was due to it that in a swift period of time I managed to learn the most important things about what happens (about what really happens) in all prismatic interactions between light and matter. See the pictures I will drop below and think a little, if you really want to see where I'm coming from and where I'm heading to. Alternatively, make an effort and read all my previous posts. Otherwise consider leaving this site (right now, please) for I'm surely not interested in your company either😎.

Let me now show you the main reason that had led and driven me to the entire process. See the picture below and remember one particular prismatic observation, which Newton had been well aware of but left  alone (without any explanation).

The observational fact in question is that when a beam of white light is looked at directly with the naked eye, which is a so-called subjective observation, the order of colours in the spectrum is reversed--VBGYOR instead of ROYGBV. As we know, Newton was well aware of that fact but he never left anything more  to us on that subject beside casually mentioning it in his Opticks. Now to my mind that showed that he did not have any plausible explanation for it and that he sure as hell wasn't going to admit it. And indeed that was to eventually become poignantly evident when he categorically refused to discuss that subject when Lucas mentioned it in one of his letters.