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geonuc
2010-Sep-10, 09:33 PM
Not sure if this might belong in some other forum, but I guess I just wanted to share a cool experience, so babbling it is.

On the way to Raleigh-Durham airport, the plane I was on cast a shadow on the cloud cover just outside my window. The cool thing was the complete circular rainbow the shadow was in. Lasted for a minute or two. Lousy photo, but ya gotta make do with what you can at the moment:

http://farm5.static.flickr.com/4152/4977384877_117960963b.jpg (http://www.flickr.com/photos/49925617@N00/4977384877/)
Rainbow and a shadow (http://www.flickr.com/photos/49925617@N00/4977384877/) by geonuc (http://www.flickr.com/people/49925617@N00/), on Flickr

grant hutchison
2010-Sep-11, 12:48 AM
Nice picture. :)

It's not technically a rainbow, but a glory: a much smaller coloured ring, generated by reflection and diffraction in water droplets at the antisolar point.

The particularly nice thing is that you'll find it's centred precisely on your location in the plane, as projected in the shadow. Someone sitting elsewhere in the plane would see the glory ringing their own position in the plane's shadow.
Sometimes mountain climbers see the glory around their own shadow on a cloud layer in the valley below. Each climber sees the glory ringing the shadow of his/her own head. Somewhere I've seen a series of photos of this phenomenon, in which the camera was passed from hand to hand so that three climbers each captured their "own" glory (this dated from the days of putting your eye to a viewfinder in the back of the camera). And then (pièce de résistance), the camera was fired while held above one climber's head, so that the glory quite obviously surrounded the camera's shadow.

Grant Hutchison

geonuc
2010-Sep-11, 11:41 AM
Nice picture. :)

It's not technically a rainbow, but a glory: a much smaller coloured ring, generated by reflection and diffraction in water droplets at the antisolar point.

The particularly nice thing is that you'll find it's centred precisely on your location in the plane, as projected in the shadow. Someone sitting elsewhere in the plane would see the glory ringing their own position in the plane's shadow.
Sometimes mountain climbers see the glory around their own shadow on a cloud layer in the valley below. Each climber sees the glory ringing the shadow of his/her own head. Somewhere I've seen a series of photos of this phenomenon, in which the camera was passed from hand to hand so that three climbers each captured their "own" glory (this dated from the days of putting your eye to a viewfinder in the back of the camera). And then (pièce de résistance), the camera was fired while held above one climber's head, so that the glory quite obviously surrounded the camera's shadow.

Grant Hutchison

Cool. But why isn't that a type of rainbow?

Kaptain K
2010-Sep-11, 11:54 AM
Cool. But why isn't that a type of rainbow?

A rainbow has a radius of 22 degrees. A glory is much smaller.

HenrikOlsen
2010-Sep-11, 01:42 PM
Cool. But why isn't that a type of rainbow?
Technically because it's reflections inside ice crystals rather than in raindrops, so there's no rain involved:)

Oops, they are reflection in water droplets, but normally the droplets aren't falling as rain, they are rather clouds or fog/mist.

grant hutchison
2010-Sep-11, 02:35 PM
A rainbow has a radius of 22 degrees. A glory is much smaller.Rainbows are big effects: a primary rainbow has a radius of 42 degrees. You may be thinking of the common 22-degree halo around the sun.
Although it's often said that you can see a completely circular rainbow from an aircraft, you'd need to be sitting in an observation bubble under the plane to see the full circle from one vantage point: a high sun, and a low rainbow spanning 84 degrees on the clouds below. I don't think I've ever seen a report of such a thing being observed.

Grant Hutchison

grant hutchison
2010-Sep-11, 03:01 PM
In technical discussions, a rainbow is generated by internal reflection+refraction in water droplets. There are variants (like the fogbow) and superadded effects (like diffraction-generated supernumerary bows). So the word "rainbow" strictly applies only to the familiar 42-degree primary and 51-degree secondary, and their related phenomena. (There are theoretical higher-order rainbows which can be demonstrated in the lab with a laser, but they're too faint to be observed in the wild.)
A halo comes from internal reflection+refraction in regular ice-crystals. The most common is the 22-degree halo which can be commonly observed around the sun.
A corona is a set of coloured rings around the sun or moon generated by diffraction+interference. They're produced by small particles of any kind, and are typically pretty small: just a few degrees across, with the diameter of the coronal rings varying inversely with the particle sizes. Most commonly, this one is observed as a ring around the moon on a frosty night, or when a thin layer of high stratus gets between the moon and the observer.
A glory is a set of diffraction+interference rings occurring at the antisolar point. It's a rough antisolar analogue of a corona, though the physical theory behind it is horribly mathematically complicated, and there are observable differences (for instance, with regard to polarization) between the rings of a corona and a glory. Again, it's typically just a few degrees across, which makes it readily observable through a plane window.

So the different names are used strictly to differentiate between the underlying physical phenomena. Robert Greenler's book Rainbows, Halos, and Glories [sic] makes that distinction right up front in the title.

Grant Hutchison

Kaptain K
2010-Sep-11, 04:33 PM
Thank you Grant for the correction and clarification.

grant hutchison
2010-Sep-11, 05:03 PM
Thank you Grant for the correction and clarification.No worries. :)
I do seem to be Mr Picky on this thread, even by my usual standards ...

Grant Hutchison

kevin1981
2010-Sep-11, 09:32 PM
I have not seen one before and think it's pretty cool :)

KaiYeves
2010-Sep-11, 09:34 PM
Whatever it's called, it's beautiful!

grant hutchison
2010-Sep-11, 10:09 PM
Whatever it's called, it's beautiful!"Glory" is a good word for it. :) Like "halo", it's another word for the nimbus of light depicted around the heads of saints in Greek icons. When it was named in the days before air travel, the glory was most commonly seen surrounding the shadow of the observer's head, giving the appearance of a saintly icon.
In a neat parallel, there's another antisolar phenomenon called heiligenschein ("holy light"), also seen around the shadow of the observer's head, and nowadays also noticed by air travellers around the shadows of their planes. The lunar astronauts noticed very strong heiligenschein around the shadows of their helmets in the lunar dust.

Grant Hutchison

mike alexander
2010-Sep-12, 04:30 AM
I was once on a cross country flight and watched a glory out my window off and on for at least twenty minutes. I've seen several over the decades, and I agree it is totally cool.

Scientific American had an excellent article on the glory in July 1974.

grant hutchison
2010-Sep-12, 12:50 PM
Every time I catch sight of the title of this thread, I automatically parse it according to the great description of Bix Beiderbecke's cornet playing: "like bullets shot from a bell".
"He plays that electric guitar like circular rainbows shot from a plane."
Is that just me?

Grant Hutchison

megrfl
2010-Sep-12, 12:51 PM
Whatever it's called, it's beautiful!

What she said and thanks Geonuc for sharing and Grant et al for all the info.

Jeff Root
2010-Sep-12, 01:38 PM
In geonuc's photo I think I see a small inner bright area right around
the plane, and a second ring outside the main one.

I have a hard time with the notion of Grant mentioning electric guitar.
Harpsichord, violin, or kettle drum, sure. Does he know no limits???

-- Jeff, in Minneapolis

grant hutchison
2010-Sep-12, 02:50 PM
In geonuc's photo I think I see a small inner bright area right around
the plane, and a second ring outside the main one.The central bright patch is called the aureole. It has a reddish outer edge. Then there's a dark region of destructive interference, then the first bright set of constructive-interference rings. Beyond that, destructive and constructive interference alternate to generate a series of rings of diminishing intensity. (The same thing happens with coronal rings.) The more uniform the droplet size generating the glory, the more distinct the subsidiary rings are, and the easier they are to see. Lynch and Livingston include a photograph of five-ring glory in their book Color and Light in Nature.


I have a hard time with the notion of Grant mentioning electric guitar.Well, of course I've never actually heard one played, but I understand they can be quite effective in the right hands.

Grant Hutchison

geonuc
2010-Sep-12, 03:42 PM
What she said and thanks Geonuc for sharing and Grant et al for all the info.

You are so welcome. :-)

geonuc
2010-Sep-12, 03:44 PM
In geonuc's photo I think I see a small inner bright area right around
the plane, and a second ring outside the main one.

I didn't notice a second ring, but I may have missed it with the uneven cloud surface causing the shadow to move a lot.

geonuc
2010-Sep-12, 03:47 PM
Here's a second photo and I do see an aureole in this one.

http://farm5.static.flickr.com/4152/4983169824_83102ae872.jpg (http://www.flickr.com/photos/49925617@N00/4983169824/)
second plane/glory photo (http://www.flickr.com/photos/49925617@N00/4983169824/) by geonuc (http://www.flickr.com/people/49925617@N00/), on Flickr

George
2010-Sep-12, 03:50 PM
Harpsichord, violin, or kettle drum, sure. Does he know no limits??? What are those?

Jeff Root
2010-Sep-12, 04:14 PM
Limits are the title of a story by Larry Niven and the book which
includes that story. The story is the last story in the book, and it
is barely more than four pages long.

-- Jeff, in Minneapolis

Jeff Root
2010-Sep-12, 04:19 PM
I have a hard time with the notion of Grant mentioning electric guitar.
Well, of course I've never actually heard one played, but I
understand they can be quite effective in the right hands.
Oh, well that's all right, then. One may read of such things in books.

-- Jeff, in Minneapolis

grant hutchison
2010-Sep-12, 04:24 PM
Limits are the title of a story by Larry Niven and the book which
includes that story. The story is the last story in the book, and it
is barely more than four pages long.Yes, I know Limits.

Grant Hutchison

George
2010-Sep-12, 05:34 PM
You will find electric guitars without Limit.

Jeff Root
2010-Sep-12, 06:54 PM
I need a link for that, please.

I am aware that there are Limits on the City of Austin, but I do not
currently have a working TV. My last (and only) TV (given me brand
new by a friend as a gift, to use as a monitor for his computer which
he loaned to me for a couple of years, back in the 1980's) was failing
and I finally gave up on it on the first day of the *first* Gulf War,
under the *first* US president named "George Bush". (Although earlier
this morning I was looking at a list of TV's online and one looks very
promising, from the buyer's reviews: LG 32LD550 for $620. I started
looking because the new 24" Dell monitor I'm using has such teeny
pixels that I either have to enlarge everything or I have to lift up my
glasses to look through the bifocal part and lean close to see it. A 32"
monitor would have the same number of pixels as this 24" Dell, but
the pixels would be as large as on my old CRT set to 800 x 600.)
So I don't know whether electric guitars are permitted, prohibited,
pesumed, promoted, or promulgated within or without those limits.

-- Jeff, in Minneapolis

George
2010-Sep-12, 07:23 PM
I need a link for that, please.
Exhibit A - Phantom of the Opera (http://www.youtube.com/watch?v=rJXUchM_7eI).

Perhaps the more exotic instruments you mention will be introduced here (http://www.npr.org/blogs/therecord/2010/09/09/129749035/first-ever-klingon-opera-by-terrans-premieres).


I am aware that there are Limits on the City of Austin, but I do not
currently have a working TV. Yes, they are limited, no doubt, due to Austin being home of governmental rules.


My last (and only) TV (given me brand new by a friend
as a gift, to use as a monitor for his computer which
he loaned to me for a couple of years, back in the 1980's) was failing
and I finally gave up on it on the first day of the *first* Gulf War,
under the *first* US president named "George Bush". That's amazing. How do you play Halo?


(Although earlierthis morning I was looking at a list of TV's online and one looks very
promising, from the buyer's reviews: LG 32LD550 for $620. I started
looking because the new 24" Dell monitor I'm using has such teeny
pixels that I either have to enlarge everything or I have to lift up my
glasses to look through the bifocal part and lean close to see it. A 32"
monitor would have the same number of pixels as this 24" Dell, but
the pixels would be as large as on my old CRT set to 800 x 600.) I wonder if I can use this approach with my wife in my request for much larger aperture. :) [You know you can change your screen settings, right?]

Jeff Root
2010-Sep-12, 09:27 PM
Halo, glory, aureole, whatever.

Changing the screen resolution isn't really an option. The native
resolution is the only one one it does well. It does that very well,
indeed, but any lesser resolution doesn't use the whole screen,
and looks pretty crummy in comparison. I can increase the size
of fonts, of course, but some web pages tend to resist changes.
My own web pages don't have any tags or CSS for font size, so
they're displayed in the browser's default size. The fonts looked
rather big when I made them, using a 17" monitor at 800 x 600
pixels, but on this 24" monitor with 1920 x 1200 pixels, they are
about right. Most of BAUT's fonts are miniscule, diminutive,
measly, and dwarfish on it.

-- Jeff, in Minneapolis

George
2010-Sep-12, 09:49 PM
The fonts looked
rather big when I made them, using a 17" monitor at 800 x 600
pixels, but on this 24" monitor with 1920 x 1200 pixels, they are
about right. That makes sense.


Most of BAUT's fonts are miniscule, diminutive,
measly, and dwarfish on it. That's makes for an aesthitic fit for puns.

JohnD
2010-Sep-13, 08:22 AM
Glory, halo, how can this be mistaken for a saintly halo?
(Grant, in post 12)

You always see the glory around your own head.
To see one around the head, or shadow of the head, of another might lead to awe and worship.
But when it's around one's own head, only delusions of grandeur can result.

John

AndreasJ
2010-Sep-13, 09:49 AM
Glory, halo, how can this be mistaken for a saintly halo?
(Grant, in post 12)

You always see the glory around your own head.
To see one around the head, or shadow of the head, of another might lead to awe and worship.
But when it's around one's own head, only delusions of grandeur can result.


It's called a glory because it looks like (the artistic depiction of) a saint's glory. There's no need to assume anyone ever thought it actually was a glory in the religious sense.

grant hutchison
2010-Sep-13, 11:06 AM
Glory, halo, how can this be mistaken for a saintly halo?
(Grant, in post 12)

You always see the glory around your own head.
To see one around the head, or shadow of the head, of another might lead to awe and worship.
But when it's around one's own head, only delusions of grandeur can result.Sensible people simply noted the similarity in appearance to an iconic painting, as AndreasJ says, and ... um ... as I said in the post you reference.

Stupid people did indeed develop delusions of grandeur; like Benvenuto Cellini, the sixteenth-century sculptor. After observing the related phenomenon of heiligenschein (which produces a glory or bright patch around the shadow of the observer's head on a rough or wet surface), he wrote:
I will not omit to relate another circumstance also, which is perhaps the most remarkable which has ever happened to any one. I do so in order to justify the divinity of God and of His secrets, who deign to grant me that great favour; for ever since the time of my strange vision until now an aureole of glory (marvellous to relate) has rested on my head. ... This halo can be observed above my shadow in the morning from the rising of the sun for about two hours, and far better when the grass is drenched with dew.
Grant Hutchison

George
2010-Sep-13, 01:59 PM
Stupid people did indeed develop delusions of grandeur; like Benvenuto Cellini, the sixteenth-century sculptor. After observing the related phenomenon of heiligenschein (which produces a glory or bright patch around the shadow of the observer's head on a rough or wet surface), he wrote:You touch on a huge issue. Martin Luther made his switch from law to ministry due to a nearby lightning strike, but his heart was very heavy with his life's direction. There are subjective elements that may or may not be important factors in a religious sense, though I won't address them here, of course. I am agreeing with your view but with a caveat of hope. There are indeed many false religious claims made from pulpits regarding natural disasters that are ridiculous, unfortunately, since any given dramatic natural event is almost always indiscriminant. For example, the claim that hurricane Katrina was a judgemental Act of God, yet Bourbon St. "business" was not affected near as much as the impoverished areas. Once again, objective evidence answers the question better than the subjective, at least in the Katrina/New Orleans case.

grant hutchison
2010-Sep-13, 03:56 PM
Cellini was a singularly unpleasant and self-regarding individual, as his autobiography attests. There's a complacent lack of analysis in his interpretation of a commonly observed phenomenon as a personal communication from God.
Indeed, where I wrote "stupid" above, you might take as shorthand for "complacently non-analytical".

Grant Hutchison

George
2010-Sep-13, 03:59 PM
Cellini was a singularly unpleasant and self-regarding individual, as his autobiography attests. There's a complacent lack of analysis in his interpretation of a commonly observed phenomenon as a personal communication from God.
Indeed, where I wrote "stupid" above, you might take as shorthand for "complacently non-analytical". I wouldn't be surprised if he wasn't using common marketing hyperbole, and he seemed to know the his customer's interests.

grant hutchison
2010-Sep-13, 04:14 PM
I wouldn't be surprised if he wasn't using common marketing hyperbole, and he seemed to know the his customer's interests.Odd to choose a phenomenon that's easily observerable by anyone on a dewy morning. A singular lack of calculation in a calculating individual.

Grant Hutchison

Strange
2010-Sep-13, 04:23 PM
Every time I catch sight of the title of this thread, I automatically parse it according to the great description of Bix Beiderbecke's cornet playing: "like bullets shot from a bell".
"He plays that electric guitar like circular rainbows shot from a plane."

Or maybe like some sort of New Age weapon.

George
2010-Sep-13, 07:33 PM
Odd to choose a phenomenon that's easily observerable by anyone on a dewy morning. A singular lack of calculation in a calculating individual. Passion often trumps calculation, unfortunately. This is probably more true in the early 16th century.

Look at this aggressive behavior found in one of his quotes (per Wiki)...


"When certain decisions of the court were sent me by those lawyers, and I perceived that my cause had been unjustly lost, I had recourse for my defense to a great dagger I carried; for I have always taken pleasure in keeping fine weapons. The first man I attacked was a plaintiff who had sued me; and one evening I wounded him in the legs and arms so severely, taking care, however, not to kill him, that I deprived him of the use of both his legs. Then I sought out the other fellow who had brought the suit, and used him also such wise that he dropped it. ”

Parts of his tale recount some extraordinary events and phenomena; such as his stories of conjuring up a legion of devils in the Colosseum, after one of his not innumerous mistresses had been spirited away from him by her mother; of the marvelous halo of light which he found surrounding his head at dawn and twilight after his Roman imprisonment, and his supernatural visions and angelic protection during that adversity; and of his being poisoned on two separate occasions.
When did they start issuing the Artistic License? ;)

George
2010-Sep-13, 07:35 PM
Or maybe like some sort of New Age weapon. Hey, I can play both the cornet and trumpet! Admittedly, after 30 years or so, I sound just as bad playing them separately. ;)

Jim
2010-Sep-13, 08:02 PM
I was once on a cross country flight and watched a glory out my window off and on for at least twenty minutes. I've seen several over the decades, and I agree it is totally cool.

Totally.

The BW and I were on a SWA flight from Dallas Love to Houston Hobby. I looked out the window and spotted a glory on the distant clouds; it was far enough away that only the circle of color was visible. We watched it for 30 minutes or more. Toward the end, the plane moved closer to the clouds. We could see the black dot of the plane appear and grow larger until a silhouette was visible. Then we entered the clouds and the show was over.

grant hutchison
2010-Sep-13, 09:37 PM
Or maybe like some sort of New Age weapon.:)
One for the First Earth Battalion (http://www.scribd.com/doc/21926670/The-First-Earth-Battalion-Field-Manual).

Grant Hutchison