I would say it is from moister in the air. I have see one similar around the sun about 25 years ago. Beautiful site to see.

that usually results in an airborne rainbow

i have a second idea.. that its the flash from the camera. btw, the shadow is prof. lewin holding the camera.

its a Kirli, krillian, kroptkian erm magic body aura-thingy. or its a ghost. or its a scene from poltergeist. or its rainwater on the lens. its that thing that lived on the Holodeck in a particularly pants episode of Voyager. how the tanj should i know?

It's an oil skim on a water puddle with the sun almost directly overhead. Prof. Lewin probably was at the Big Dig in downtown Boston.

indy's is most plausible so far imho. is boston part of massachusetts? big dig was on june 20th ?

Boston, capital city and largest in the Commonealth of Massachusetts. The "Big Dig" is this gigantic political boondoggle of a construction project meant to create underground expressways and tunnels to connect the variousparts of the City and with its airport across the bay, etc., etc., etc. It has been going on for, I think at least 5 years, no end in sight and what budget there may have been has evaporated into that rarefied air known as politics.

<Edit>

Alternatively it is a skim of oil/liquid wax on a polished stone slab on a building somewhere and the sun is almost at perpendicular angle to the surface of that slab either directly or by reflection off of another building, likely made of reflective glass a skin.

Edited by - Indy11 on 9/13/2004 7:21:59 AM

reflection from the camera lens? or some glass above the camera man?

To take another shot at this. 1. It looks like snow in the picture 2. The taker has a dark shadow, ie bright sun over head. 3. A flash would have been too weak to weven be noticed in the light. 4. as the ring is not a complete circle, it is behind the shooter. And, more than likely, he saw the rainbow and atempted to get a picture of it. There for, moister can still be a factor in the shot and cause the effect. All this presuming, photo has not been edited.

Edited by - Finalday on 9/13/2004 9:25:21 AM

If it had flash - then why the shadow??? It would have illuminated from the camera - which is infront of him is it not?

The point source of light is behind him. I am struggling to get what we are looking at though - it almost looks like some sand in the center part - which would have made me think sand flats with shallow water on top. The colouration is due to the fact that the light is being reflected, but the individual colours (which comprise to give white light) travel at different speeds, and so at angles are being "bent" more (travels slower in water than in air) resulting in the light taking "different" paths coming out of the water (after reflecting off the sand underneath). The point source is directly behind the viewer - hence why its "whiter" in the center - as a verticle beam would not split into its component colours.....but would reflect straight back. The defraction for most of the center probabily combines with rays from other light waves "next" to them - so blue of one ray merges with red of another (one gets bent less, the other more - which at the edge gives the rings, but in the center clashes with another slow/fast combination - giving whiter light).
At the edge, the angle of reflection is suffiently diverse that not enough light is coming back to the viewer (camera) and therefore makes it look darker.

My thoughts have as many holes as ideas in them there, but its a kinda explanation.....just doubt its right

The uniformity of the rainbow is too nice and neat to be an oil slick, and it is also nice and round, meaning it probably is not a disorganised puddle of oily goo. My guess is it is an optical effect of some sort, although since the effect is interupted by the shadow, it cannot by on the camera's lense. Besides, he's looking straight down, which means he is photographing something, so I think we can safely assume that the effect is the result of light bouncing off something, not oil, not someting on the lense. --- VH16

I am Nobody; Nobody is Perfect; Therefore, I am Perfect

It's an artificial light source then and not the sun.

yeah, even if the surface was oily it wouldn't have produced such a uniform circle.

and i believe its sandstone that is in the picture.

so we conclude the effect is created not on the sandstone, but rather, projected onto it by the lightsource and possibly, some refracting item ?

edit: might be concrete. sandstone tradiationally has a more yellow hue.

Edited by - kimk on 9/15/2004 1:31:19 AM

Well, unless its fine oil seeping up through the sandstone

Hmm can't really be moist, since it is not a normal rainbow, the colours just aint right, was this indoors or outdoors?
Rainbows are usually caused due to the bending of light, right? Usually thru a prism shaped obj? or am I wrong?
It could be caused by sth lying on the floor reflecting? it would have to be a very big sth tho