Mudcat Café message #2902750 The Mudcat Café TM
Thread #129314   Message #2902750
Posted By: Ebbie
08-May-10 - 04:08 PM
Thread Name: BS: COLORED Shadow?
Subject: RE: BS: COLORED Shadow?
OK, I'll try again. I'm beginning to wish I had never noticed it! Not true, actually; I don't mind feeling dumb if I end up learning something.

Robin, it was not the effect of an after-image. Everyone older than 6 is familiar with that effect. This was a sustained, bright, crisp, sharp, Irish green image as clear as racing stripes on .

On the white paper it was a much more muted color- and the color was turquoise, tending to blueish.

On the newspaper it was even more diffused but still turquoise.

There is no other light source there. This is Juneau, Alaska; our streets are narrow and we don't have lamp posts on every corner.

It was not full dark either time (half hour difference, two different nights). The days of the month of May are rapidly lengthening. Soon the sun won't set until after 10:00 and the sky will be the shade of stone-washed blue jeans. As yet it is darker than that but even now it is twilightish.

So only one lamp. Most likely sodium; the emitted light is orangeish in shade. My question at this point: Are sodium lamps' lights made up of different colored 'cones' so that they break apart in prismlike fashion?