Wednesday, December 11, 2013

The Green...

...Flash!


I owe these pictures to Lewis.  Yesterday he asked me if I had ever seen a Green Flash.  We joked about how we had both been involved in discussions about whether Green Flashes existed or not.  But I have been around a few people who claimed to have seen them.  

So we looked on the Internet and quickly found multiple pages that described the very real optical phenomena behind Green Flashes.  It's very complicated!  It involves dispersion and atmospheric refraction and mirages.  (Have I mentioned that I did very poorly in Physics?)

But because of this conversation, when I happened to be walking by an ocean view near sunset, I decided to walk out the door to watch.  And what do you know, a Green Flash appeared as the sun dipped below the horizon!  I tried to take pictures but was disappointed that they didn't come out.

Because the conditions were similar tonight I decided to try again.  This time I had looked up some recommendations for photographing Green Flashes. 


It doesn't look as green as it did while I was watching, but I hope you can see the potential.  

I don't think I'm going to try to explain Green Flashes myself.  But I'll vouch for the existence of them and point you to these web pages by Andrew Young (Astronomy Department at San Diego State University) which I found very helpful for starting to learn about Green Flashes.


These cold, clear nights offer prime conditions for seeing Green Flashes.  But heed all of the warnings about not looking at the sun until it has set — you won't see the green until then anyway!

5 comments:

  1. if you stare at a candle flame (ie the sun) in the dark and then close your eyes you will hold the image of the flame but it will be green ??????????? bop

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  2. One Christmas Eve, while watching Sandhill Cranes come in to roost at dusk at the Woodbridge Wildlife Refuge near Lodi, I had my binoculars on a long string of the cranes as they came in for a landing, when to my surprise I caught the green flash as the sun set behind a mountain. I'd never seen it before, and was stunned by how beautiful and ephemeral it is.

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  3. PS - I *love* this post!!

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  4. Hi, Boppy! Regarding the candle -- I think this effect is called an afterimage. And it has been proven that green flashes are not afterimages. One thing I learned about this is that green flashes can also occur at *sunrise* -- before the sun has appeared above the horizon. It's harder to see green flashes then, because the location of the flash is more difficult to predict (i.e., exactly where the sun is going to rise), but it proves that the green flash is based on physics rather than eye physiology because the sun has not yet appeared.

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  5. Jackie - I caught a picture of the green flash this fall in San Diego! Mine is just a little blip (not zoomed in) because I wasn't even trying for it -- I was just taking pics of the sunset.

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