Sunday, January 18, 2009

The Green Flash, the Red Flash



Man oh man, I just love viewing and taking pics of sky phenomenon that sound like superheroes.
"Honey.. I'm going out to try and capture the "Green Flash". See, there is something about saying that. I have made it my goal to try and capture these elusive/seldom seen phenomenon the last couple months, and finally did.

There is only about a couple months I have to do it, you have to have a true horizon and in my area the Sun only sets on a true flat horizon December and parts of January. If you don't have a true horizon the green flash happens behind a hill or the grade of the landscape. You see, when you are looking at the Sun on the horizon, you aren't, you are looking at the apparent Sun, the real Sun is actually below the horizon but due to atmosphere refraction the real Sun is bent up, much in the same way when you put a straw in a glass of water, the medium, water, bends or refracts the straw, you see two straws , the actual and the apparent straw.

Everything in the sky, the sky being the medium, is bent to a degree, about a half, or the diameter of the Sun, the apparent or fake Sun is actually sitting on top of the real Sun, which you don't see.


The illustration above shows what happens. Because the color green has a higher frequency, it has a steeper curve, more so then the reds, and is the last color to be refracted up to be seen by you.


I've also found that regular temps don't do it. I've been out in temps anywhere from -20c to -35c. At -20c the Sun looks a normal round, and no green flash, at -35c, you see a funky Sun, parts missing, square top and the like, this is because when the Sun travels along our lower atmosphere at -35c it's sunlight goes through more atmospheric temperature extremes making the separation of the reds and greens more apparent. Sorry for getting too technical but I thought there might be some of you that would appreciate the whys.


The Red Flash above is caused by atmospheric inversions causing all of the light being blocked, again the extreme temperatures, so you get the red all by itself, this time the red's longer wavelength helps, it is able to sneak through the lower atmosphere, filled with more particles, like dust, the greens and the blues are scattered because of their higher frequency, they tend to bump into all the lower atmospheric dust particles and get scattered out of the light path. What is interesting about this image is you can actually see a tiny bit of green on top of the Sun, so I have actually captured a green and red flash in the same image.




Again, sorry for getting so technical, it's not like there is going to be a test after, so if you want you can just take a look at what I think are cool pics and move along and not having to worry about a quiz or anything.

I got a cool perigee atmospheric Moon from Ivanhoe, this one I thought I would animate, looks cool, thanks Ivanhoe for allowing me to post it, and if you want , you get a free pair of Hanna Montana/Miley Cyrus 3D glasses.


50 comments:

Anna said...

Bob I love technical stuff, lol, you got it all down. Great images. BTW you know I always look at the Sun just the Sun, never knew that there is so much to explore and to know. This is so cool - I will never look at the sun the same way I used to - of course not directly into the sun, as probably never see anything again, lol. Very nice picture from Ivanhoe, and ofcourse the animation, lol. And lastly, you got true horizon, that is so cool. You know I get the residential mountains (I meant the roofs), lol. Excellent post again! Anna :)

Stephanie Barr said...

I love playing with refraction. When I write science fiction on another planet, I play with the colors to denote difference thickness, pressures and compositions. I'm weird. I'm having fun at the moment since my planet is actually one of a pair revolving around a center of gravity which is, in turn, revolving around a sun. It messes with lots of things, including apparent gravity and tides.

I always love your explanations and store that data away for later use. That sort of thing is great to play with in fiction. And, yes, you still can read the book when I finish. *Hangs head* I'm working on it.

These shots are fabulous (of course). I admire the dedication it takes to get these. And the cloudy moon shot is also a winner.

Ruth said...

Thank you, Professor. You do a great job explaining, especially when it's about one or two simple things, like red and green flash. Way cool.

And Ivanhoe's image is gorgeous.

Hava said...

How cool! I absolutely love space and anything to do with the nighttime sky (check out my site for my reviews of books - I have reviewed several that have to do with space, science, etc) and so your blog is right up my alley. :-) Very cool - I'll add you to my EC favs and be back!

Have a wonderful day!

Hava
http://nonfictionlover.today.com

Cashmere said...

Thanks for sharing the video...
Plus the information is great.. :)

Bob Johnson said...

Thanks Anna, lol, I love your residential mountains, I have lots of those too, all snow capped right now, but it is an unbelievable +4c right now and the snow is melting.\m/\m/

Bob Johnson said...

Oooh Stephanie your planet sounds so cool. I can hardly wait for the book,the snippets you've been letting out are very interesting, something I want to be one of the first to read, thanks for selecting me.\m/\m/

Bob Johnson said...

Lol Ruth, glad you understood the explanations.\m/\m/

Bob Johnson said...

Thanks Hava, glad you like space stuff, I'll be over checking out your reviews,thanks for dropping by.\m/\m/

Bob Johnson said...

Thanks Cashmere, glad you liked the video.\m/\m/

Susanne49 said...

Hi Bob,

In Key West I have seen 2 or 3 times the green flash but never made it to capture it with the camera. This is once again a great post! I learn so much every time when I'm here, do I will get a diploma on the end...LOL... ?

Thank you very much for your wonderful words on my blog, very much appreciated! I'll be back soon! :)

Sue's Daily Photography

Ivanhoe said...

You made it look a 100% better with that animation - thank you. Awesome! I think I may steal it for my side bar (that is if you don't mind :o)

Genie said...

Way to set your mind on a goal and achieve it! You make it look effortless. I can only imagine the work you put into this, the time, effort, and patience. Then having to pour over your photos and look for a glimpse of green.

Most of the technical stuff goes over my head but I always read it on your blog because I'm hoping it will eventually sink in. It's still hard for me to conceive of some light getting scattered while other light doesn't. But I'll keep reading! And seeing a sun above the sun messes with my head a little too--but that's okay. I'll get there.

Excellent photo work! Excellent explanations. Awesome blog!

Bob Johnson said...

Hi Susanne, cool you have seen the green flash, lol, hey I'll make you up one.\m/\m/

Bob Johnson said...

No problem Ivanhoe, I thought it would look good as an animation, and it did, I always use curves on the images in the animations, it brings out the detail more.\m/\m/

Bob Johnson said...

Thanks Genie, I've seen you do the same thing with putting your mind to something and achieving the results you want, very cool. Don't worry about the tech stuff, it will come in time when you least expect it, "oh, that's what he meant",lol.\m/\m/

Peter said...

Hi Bob! Are we supposed to get the green flash downunder? I've only seen the usual colours.

Down here if the sun sets with a very bright red colour we know we're in for a sticking hot day the next day. Getting plenty of that at the moment with temps reaching 100.

Did you read about Australia's very recent involvement in the telescope marathon; Radio telescopes I believe.

"Telescopes in Asia, Australia, Europe, North America and South America will track three quasars [J0204+1514, 0234+285 and 3C395] as they rise and set with the rotation of the Earth."

It involves 17 telescopes and 28 data networks around the world and through e-VLBI (whatever that means) astronomers can generate images of cosmic radio sources with up to one hundred times better resolution than images from the best optical telescopes.

It all sounds very interesting and I just wonder what they will find?

Thanks for the lesson. Just one more thing. As for the sun and the moon, is there anything you haven't seen yet?

Take Care,
Peter

Majase Cyc said...

As always, a great post Bob. This is one of those interesting synchronizations that I enjoy.

Only moments before clicking onto your site, and reading this post, I had just finished 'A Flash of Green' by John D. MacDonald (a great book and phenomenal writer by the way).

In it he refers to the elusive quality of this phenomena in a roundabout way.

Hope all is going well for you and yours Bob; take care,

Majase Cyc

Bob Johnson said...

Thanks Peter, 100, wow must be nice, I love hot temps.

VLBI or Very Large Base Inferometry is a method they use to group different telescopes together to form one large one, point being to study quasar type phenomenon and to try and learn more about them and quasar jets as well as black holes, very interesting stuff.

And yes you guys get green flashes as well, they are very elusive and seldom seem as they last only a couple seconds at most.

As far as what I haven't seen in person but a will one day, and that is a total solar eclipse.\m/\m/

Bob Johnson said...

Thanks Majase Cyc, I took a peak at this book on Amazon, looks interesting, thanks. always a pleasure when you drop by Majase.\m/\m/

Roger said...

Good job as always Bob! :D

Max said...

Hey Lord of the Astropics!

Amazing video! Well, I will go farther and say that it is a magical video: you are a true wizard...one must say *bowing*!

I have witnessed a few green flashes (my flat is facing the sea, so when the sun sets in the horizon [mainly in summer] the view is fantastic)! But I never thought about taking a pic...I will this year (shall I send it to you?) :D!
Now, I have a question...to see a green flash, does it have (necessarily) to be low temps or can it be seen even in summer (because if they can't be seen during summer, I may not be seeing a green flash, but rather something else)?

Thanks for this explanatory image: I didn't know the name of this phenomenon, nor how it occurred...thanks :D!

Wow, marvellous pictures, Bob!! You are forgiven about being technical (I actually like it, for I am learning new stuff) :)!

This is one fantastic moon! Well done, Ivanhoe! You did a wonderful job by animating it, Bob!

This was a true gift; thank you so much...Lord of the Astropics *bowing*!

Have a great week, my friend!

Cheers

Don said...

Thank you Professor! Your explanation was not only understandable, but it was also very cool.

I read about the green flash in the Patrick O'Brian books, and hope to see one in person some day!

Sherer said...

Bob,

Very interesting. I must say light facinates me. I will be honest though... I did not see the green flash in the video. (sad Alien emoticon)

Very good and scientific post.

Jesse

Bob Johnson said...

Thanks a lot Roger.\m/\m/

Bob Johnson said...

Thanks max, hey having a flat sea is the best you could hope for. No you don't need extreme temps, but it does help, but you are set up perfectly, you have a true horizon plus you have the sea, as with oceans they cause a lot of air turbulence and atmospheric inversions and create the ideal conditions for these type of phenomenon, and sometimes wacky cool colors. \m/\m/

Bob Johnson said...

Thanks Don, I thought you being a teacher would appreciate and understand the explanation, cool,thanks, hope you guys get to one day see them.\m/\m/

Bob Johnson said...

Thanks Jesse, too bad you didn't see the flash in the video, that's why I posted the cropped image cause it doesn't show up that well on lcd screens.\m/\m/

GAGAY said...

Dropping by to say hi..happy Tuesday!

gagay

Psycho No Deal Zone said...

I saw a "Green Flash" from a ship in Baja California about a year ago - it was really quite bizarre. I was "prepped" prior that such an event was possible, but I didn't think much of it - I'd never even heard of it up until that point. It was actually pretty amazing.

Bob Johnson said...

Thanks for dropping by GAGAY, and a happy Tuesday to you too.\m/\m/

Bob Johnson said...

Thanks for dropping by Psycho No Deal Zone and sharing your experience with all of us, Green Flashes are actually quite cool to observe.\m/\m/

Max said...

Hey Bob!

Thanks for the answer...then I am all set indeed :D!

Cheers

Lynda Lehmann said...

Bob, your blog is always a pleasure to read, even when the content is a little...beyone me, ha ha, not to make a pun.

This one is a little techical but I get the idea about refraction and different colors showing at different wave lengths.

Minus 35? Egad, you must be hot-blooded, my Northern friend!

Interesting post, as usual. It's none of my business but how can you afford giving away all those binocs? You are generous, as well as passionate about your interest. :)

Ivanhoe's photo makes a lovely GIF.

Marvin the Martian said...

Very interesting! I have, up to now, dismissed the "green flash" as a figment of fevered imaginations. I'm glad you have spotted it, and proved it mathematically. I still have never seen it, despite sitting through countless sunsets. Of course, being color-blind presents a problem also.

Bob Johnson said...

No problem max, glad to be of assistance.\m/\m/

Bob Johnson said...

Lol, no worries Lynda, like I said no quiz after,lol.

I got 900 Hanna Montana/ Miley Cyrus 3D glasses given to me, I was, shall we say in the know, and was quite lucky to get them. I have since put them to some great use, sharing the wonders of the cosmos through 3D sites like NASA and how to make your own 3D images, been a hoot.\m/\m/

Bob Johnson said...

Thanks Marvin, you actually have to look at the right time and have all the proper conditions to see them, that's why some people don't believe they exist, plus the fact you are color blind would probably decrease your chances of seeing the green quite a bit,lol.

Swubird said...

Bob:'

The green flash is pretty cool. I had heard of the fake sun, but I never heard about the green flash. After reading your post it makes perfect sense. I wonder what the ancient people made of that? Green? It must have been confusing, but I've never read anything about it.

Happy stargazing my friend.

Bob Johnson said...

Hey swubird, interesting thought, it probably did raise a lot of questions for the ancients, actually come to think of it, they are still raising a lot of questions, there is a lot of misinformation out there about them.

notedscholar said...

I don't know, that's a lot of sun!

NS

GAGAY said...

dropping by at sunny wednesday!

gagay

Marilyn said...

This is a very cool post. You tube has changed on me though. I have dial up so it used to take forever to load a you tube video. Now they load quick but the quality is awful. This is an instance where I wish I could just wait for better quality.

Bob Johnson said...

Hey NS, you can never get too much Sun,lol.\m/\m/

Bob Johnson said...

Thanks for dropping by GAGAY.\m/\m/

Bob Johnson said...

Thanks Marilyn, I noticed the quality going down as well.

betchai said...

i have heard of green flash phenomenon but I personally have not seen it but I saw a lot of pictures from the web taken from this side of the coast, maybe because I do not have the patience to watch at the sunset completely, usually, my eyes would roam around other parts of the sky :( maybe i should pay more attention next time

your technical description actually is very helpful.

Bob Johnson said...

Thanks betchai, glad the explanation helped.\m/\m/

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