I always welcome the return of the rainbow season.
While a rainbow might appear on any occasion, the best of them usually arrive in late May or early June with the arrival of convective showers. The timing of this also corresponds to the spring freshet, so pictures of rainbows over the Lake at this time usually show high water: last year’s late-June rainbow panorama presented a rather satisfactory view of a rainbow reflected in the Lake. This observation shows many nice features of the rainbow, but the Lake was too ruffled to show a good reflection.
The rainbow on June 2nd shows many of the features of a well developed rainbow that forms in a summer shower.
1) The first feature to notice is that rainbow is a circle whose centre is the head of one’s own shadow. This means that the rainbow is a remarkably personal thing: each person sees his own rainbow—what you see is YOUR rainbow, not someone else’s.
2) The second thing to notice is that there are two rainbows: the primary (inner) bow, and the secondary (outer bow). The primary bow is explained by a single reflection of sunlight within a raindrop and has red on the outside; the secondary bow is explained by two reflections within the raindrop and has red on the inside.
3) The darkest region of the sky lies between the bows. This region is known as Alexander’s Dark Band.
4) Then there are the supernumerary bows, but more of that below with the next picture.
5) Well…, a rainbow aficionado will spot other nice features in this picture, but this will do for now.
I enhanced a small portion of the above scene to show the supernumerary bows. These are the bands that appear inside the primary (inner) rainbow. As I watched the bow, I could see three supernumerary bows. Certainly there is one (and maybe two) apparent in this photograph.
Alistair,
thank you, impressive pictures as usual. The human-like shadow in the forfront—is this you?
Michael, that is, indeed, my shadow at the centre of the rainbow. This, of course, makes it my personal rainbow: if there were someone beside me, that person would see a slightly different bow.
Thank you for posting all your terrific photos. I was drawn to your blog because of the pics of the train wreck but now find myself coming for your regular postings. I am entertained & educated with every visit.
Thanks again, Bob
I agree with Bob above….your pictures are addictive!
Yes, re Judy’s comment. Strangely, today was the 1st time I appropriated the term anent the blog: addictive. No matter how “…in disgrace with fortune and men’s eyes…” I may feel, my day is redeemed
with a visit to Alistair’s.
Not two, but four bows, since the reflection bows are not exactly reflections of the primary and secondary, but separate projections of colors. At/optics has a good explanation, though I expect you already know about this.
Martha, your point is a bit obscur. Yet, there is a distinction to be made between reflected bows (a reflected image of the bows seen in the lake), and a reflection bow (a bow where the light source is reflected in the lake). They look different for most solar elevations. Yet, they do not appear in my pictures.