Have you thought of the language of poetry? Many Italian poets wrote about the sun in anthropomorphic terms, associating the quality of paleness or splendor with the interior ambiance.
Seems like the appropriate word would be some variant of "translucid sun". Except that adjective applies to the medium (the cloud) and not the patient (the sun or moon). Which sent me down a rabbit trail conjugating "lucere" -- but I think the closest thing to a patient form would be "transluctant sun"
It is not characterized by the exact phenomenon, since all it implies is that you can see the solar disc through the cloud. But the exact phenomenon is that Sun is attenuated enough that it is pale, moonlike, and comfortable to gaze at. I see clouds of the translucidus variety all the time, but in every case that I have personally come across, the Sun was still bright enough to cause me discomfort glare.
(Or "transluct", or "translucted"? The tricky thing is "lucere" apparently has no attested fourth principal part. But "ducere" has otherwise parallel morphology and has "ductus" as its perfect participle.)
Thanks! I had a similar train of thought (well, minus the rabbit hole about Latin!). As Ethan says, translucidus clouds are a somewhat broader phenomenon than what we're looking into here, but I agree it's a linguistically promising direction, if a bit too highbrow.
Love these deep dives, and I’m now sure I’ll notice this phenomenon for the first time within the next month — always how it goes when you put a name to this sort of thing. I wonder if there are any indigenous myths or folktales out there that feature pale suns, or superstitious magic and such. Seems like a natural candidate. Slightly tangential, but among the Mentawai, sun showers (when it starts raining on a clear day) are viewed as a sign of illness-causing spirits.
Here is where I am coming from with regards to this phenomenon:
Based on my research, it seems clear that you need to attenuate sunlight by at least 5 OOMs for comfort for average person, probably 6 OOMs for comfort for everybody in a large and diverse crowd. When you attenuate the direct beam by that much with typical clouds, the diffuse component of the illumination gets too large and isotropic relative to the direct beam to preserve the memory of a sharp disc. So, conceptually, we either want to suppress the diffuse component relative to ballistic component or have it go through few enough scatter events that it retains directional information.
As you point out, it is an empirical fact that is possible to do this with clouds as the attenuating medium. At first, I was pretty confused about how that was possible. To attenuate the direct beam by enough, it seemed like you needed a thick medium that would completely isotropize the diffuse component. In the comments on Scott’s article, Coda provided a radiative transfer simulation that seemed to demonstrate that you could only retain the memory of disc as a bright outline in a diffuse bright patch because of 0-scatter lottery winners from direct beam with a thick medium.
However, I realized that you could achieve the effect with a thin medium (matching the reports) when the Sun was low on the horizon, so the optical path is long (because then you could get a slant optical depth that is much greater than vertical depth). This seems to be corroborated by the most credible reports. I think the story with fog is quite different, having more to do with the absorptivity of the medium, but I havent devoted much time to it, since it is of less relevance to Fatima. My initial confusion was due to the fact that I was only analyzing the Fatima elevation, neglecting the possibilities for more oblique optical paths.
At present, I believe that it is not possible get this effect at a solar elevation of 42 degrees, but not with much confidence. The solar elevation is what is of most importance in testing the hypothesis that it is only made possible when there is a large delta between slant and vertical optical depth.
Thanks for the detailed reply! I believe the solar elevation when I saw it in December was about 14-15 degrees, definitely a far cry from 42 and thus probably not too relevant to Fatima, indeed. I haven't put much time in understanding the math behind the phenomenon though.
Have you thought of the language of poetry? Many Italian poets wrote about the sun in anthropomorphic terms, associating the quality of paleness or splendor with the interior ambiance.
Something too poetic wouldn't work as a mainstream phrase, but this is interesting! If you have concrete examples I'd love to see them
It appears "translucidus" is the cloud variety specifically characterized by the phenomenon you describe: https://en.wikipedia.org/wiki/Translucidus_(cloud_variety)
Seems like the appropriate word would be some variant of "translucid sun". Except that adjective applies to the medium (the cloud) and not the patient (the sun or moon). Which sent me down a rabbit trail conjugating "lucere" -- but I think the closest thing to a patient form would be "transluctant sun"
It is not characterized by the exact phenomenon, since all it implies is that you can see the solar disc through the cloud. But the exact phenomenon is that Sun is attenuated enough that it is pale, moonlike, and comfortable to gaze at. I see clouds of the translucidus variety all the time, but in every case that I have personally come across, the Sun was still bright enough to cause me discomfort glare.
(Or "transluct", or "translucted"? The tricky thing is "lucere" apparently has no attested fourth principal part. But "ducere" has otherwise parallel morphology and has "ductus" as its perfect participle.)
Thanks! I had a similar train of thought (well, minus the rabbit hole about Latin!). As Ethan says, translucidus clouds are a somewhat broader phenomenon than what we're looking into here, but I agree it's a linguistically promising direction, if a bit too highbrow.
Love these deep dives, and I’m now sure I’ll notice this phenomenon for the first time within the next month — always how it goes when you put a name to this sort of thing. I wonder if there are any indigenous myths or folktales out there that feature pale suns, or superstitious magic and such. Seems like a natural candidate. Slightly tangential, but among the Mentawai, sun showers (when it starts raining on a clear day) are viewed as a sign of illness-causing spirits.
Oh that's a great question. If you ever come across examples of traditions related to the pale sun, please do send them my way.
Is it like when you put solar eclipse glasses and you look at the normal sun? Filter sun? 😎
But the sun still feel very yellow/orange with the glasses and not white like with the clouds 🤔
Would it be best to name the phenomenon of a star or a celestial body that is filter through a natural mater? This would be more generic.
Or maybe I feel more like anthropomorphizing the sun! « Shy sun » or « modest sun » or « want to stay in bed under the cover sun »
Oh I like the anthropomorphic suggestions!
Great write-up! I also prefer "pale sun" or "pale sun disk".
Thanks for writing this! It is a great resource.
Here is where I am coming from with regards to this phenomenon:
Based on my research, it seems clear that you need to attenuate sunlight by at least 5 OOMs for comfort for average person, probably 6 OOMs for comfort for everybody in a large and diverse crowd. When you attenuate the direct beam by that much with typical clouds, the diffuse component of the illumination gets too large and isotropic relative to the direct beam to preserve the memory of a sharp disc. So, conceptually, we either want to suppress the diffuse component relative to ballistic component or have it go through few enough scatter events that it retains directional information.
As you point out, it is an empirical fact that is possible to do this with clouds as the attenuating medium. At first, I was pretty confused about how that was possible. To attenuate the direct beam by enough, it seemed like you needed a thick medium that would completely isotropize the diffuse component. In the comments on Scott’s article, Coda provided a radiative transfer simulation that seemed to demonstrate that you could only retain the memory of disc as a bright outline in a diffuse bright patch because of 0-scatter lottery winners from direct beam with a thick medium.
However, I realized that you could achieve the effect with a thin medium (matching the reports) when the Sun was low on the horizon, so the optical path is long (because then you could get a slant optical depth that is much greater than vertical depth). This seems to be corroborated by the most credible reports. I think the story with fog is quite different, having more to do with the absorptivity of the medium, but I havent devoted much time to it, since it is of less relevance to Fatima. My initial confusion was due to the fact that I was only analyzing the Fatima elevation, neglecting the possibilities for more oblique optical paths.
At present, I believe that it is not possible get this effect at a solar elevation of 42 degrees, but not with much confidence. The solar elevation is what is of most importance in testing the hypothesis that it is only made possible when there is a large delta between slant and vertical optical depth.
Thanks for the detailed reply! I believe the solar elevation when I saw it in December was about 14-15 degrees, definitely a far cry from 42 and thus probably not too relevant to Fatima, indeed. I haven't put much time in understanding the math behind the phenomenon though.
A few days later, I wonder if "moonlike sun" would work better than "pale sun"?