Here’s a picture from the plane. In the past I’ve only seen them fleetingly, but this one stayed with us for a full hour. The Chinese call it Buddha’s Light.
Mundane, I know; But I thought it was kinda cool.
I’m unfamiliar with this, care to enlighten me as to what I’m seeing?
A better summary than I could make on my own: Glory (optical phenomenon) - Wikipedia
I saw one of these a few years back but wasn’t sure what to look up because I didn’t know what it was called.
I see them frequently when I fly.
It used to be that you had to go on top of a mountain and look down into a valley at sunrise to see it, as with the “Spectre of the Brocken”. Owen Wilson was supposed to have seen one that inspired his invention of the Cloud Chamber that bears his name, used for the study of subatomic particles. And Antonio de Ulloa saw one during his scientific survey in South America.
There are many places arounbd the internet that give explanations, including the OP’s Wikipedia article. I’d also recommend RAR Tricker’s Intro to Meteorological Optics and Greenler’s Rainbows, Haloes, and Glories.
In essence, the effect is really an interference effect caused by two slightly different optical paths that pass through media that scatters it back. In this case, the two paths (counterpropagating through the same scattering mist) have almost but not precisely the same path length, so they fall within the coherence length of sunlight and cause interference colors.
Much the same thing happens in a raindrop, forming a rainbow. The rainbow is usually explained as a refractive phenomenon – “The raindrop acts like a prism” – but, at a deeper level, it’s really an interference phenomenon, as Thomas Young first pointed out over two centuries ago.*
*If the rainbow were purely a refractive phenomenon, the size of the raindrop would have no effect on its appearance – but the width and number of colors in a rainbow is heavily dependent upon the drop size, with “fogbows” being completely white. See M. Minnaert’s book The Nature of Light and Color in the Open Air, or Tricker’s book, cited above. Or Greenler’s. You can tell the size of raindrops from the relative widths of the colors in a rainbow.
It’s not uncommon to see them on morning flights in the balloon but we’ve always called them halos. Note how the bottom of the shadow is brighter.
The lack of color separation, resulting in that bright spot with no “rainbow” bands, suggests that this might be the result of very small drops causing the effect. I’m a little surprised, because I haven’t seen anything on the relationship between droplet size and appearance of color bands in glories. But you still expect a relationship to be there. Your low-level ground mist might simply be too small to allow the colors to separate.
Nice photo.
Did you get on top or down legally? Bawahahahaha
Flyin is fun.
We used to see those a lot in Alaska from a Long Ranger looking down on low clouds on the slope. Yeah, sometimes they’d last a long time. Pretty cool, always wondered what the explanation was.
Wow, Owen is quite the renaissance man. I only knew about his background in theater. Or did you mean Charles Wilson?
Thanks for all the replies, though I just noticed the link in the OP:smack:
They are definitely cool. Proximity to the cloud can create some neat effects. The following were taken as we flew over cloud cover that we were gradually getting closer to.
When you get close enough to the cloud layer that the aircraft’s shadow is appreciably large, you’ll see that the halo is centered on where you’re sitting. Be that front, middle or back.
Looking at the other pictures here, we rarely see that color separation band. My guess is one of two reasons.
- We’re two low.
- We’re rarely above the clounds & don’t see the color separation as well against the green/brown/yellow ground as with a white background of a cloud.
This one has it. (Note: a thin but dense cloud layer rolled in after we were in the air; we wouldn’t have gone up if it had been there. It was about 700’ & only maybe 15’ high.)
Here’s another shot from the same flight; note that you can see ground below & blue sky above. The cool thing with this is, even rarer than a halo is a double shadow, both on the cloud, & looking just above the basket, you can see the whole balloon shadow on the ground.
I saw this effect once in new road construction of all places. The crews had just put down new crosswalk paint which was then heavily sprinkled with superfine reflective particles. There was a lot of these particles spilled around the painted area and it gave an overall faint “halo around my shadow” effect. Very cool.
Are you sure it was a glory effect? I’ve never seen that with glass beads on paint, but I have seen rainbows from that. To be a glory, you need tight circles directly around the shadow of the observer.
What I saw was more like heiligenschein now that I look it up. But I remember it because I had just read the APOD page on Glory a few days prior to seeing the effect in person.
Ah. Heiligenschein is something else altogether. No color sepoaration at all (Maybe that balloon picture earlier was due to heiligenschein), and the effect requires grass or something just behind the droplets or beads – the light is brought close to focus at the underlying surface, then it’s reflected by that surface, and is approximately re-collimated toward the viewer. It’s the perfect system for retroreflecting paint. If that’s what you saw it on, it was probably heiligenschein.
One aujthor calls cases of “almost heiligenschein” by the namne “sylvanschein” to emphasize that it doesn’t require spherical drops or beads.
I see those just about every plane trip. What I like more is when the sky is clear and you get this odd looking ring of light on the ground around the plane’s shadow.
That might be Heiligenschein, or it could be the Opposition Effect