I am really excited about this video. This discusses my analysis of three shadow band videos along the path that were oriented with compass directions marked. It will give you ideas about how to video bands at your next eclipse. If you watch this video and my Shadow Bands Part 1 video you will have amazing knowledge about shadow bands.
@tstone1977
6 ай бұрын
I captured a video of shadow bands during the eclipse earlier today. We had no idea what we were seeing!
@mrchad97z49
6 ай бұрын
I saw many shadow bands rippling across the paved trail in Dallas at white rock lake. I happened just before total eclipse, like 99%. They were very distinct.. more than in this video
@yankees2655
6 ай бұрын
Great video! And very fair ultimate hypothesis. Were you perhaps able to find the atmospheric conditions at all three points and compare? Anyway, I hope you got to do something like this again today. I was so in awe of my first totality, I didn't even get a chance to look down - at the huge WHITE snowpack we had up here in Maine! But fortunately my friend noticed and was able to share the direction of the rows, which did seem fairly in line with the direction of the umbra. We had very tranquil weather here today.
@merrillthompson8248
6 жыл бұрын
I am also surprised at the different outcomes. But I did not take into account the upper atmosphere turbulence. I was thinking the only factor was the movement of the moon across the disk of the sun. But different movements of the shadow bands adds new evidence to there being more to it than I thought. Sure seems like the factor of upper atmosphere turbulence is a good explanation. I guess this means we will not be able to make accurate predictions about the direction of shadow band movement for future eclipses. But we can enjoy collecting the results. The 2017 eclipse was my first TSE. I experienced an annular eclipse that came close to my home back in 1984, but no shadow bands of course. With your help, I’ll be better prepared next time. Thanks again for all your efforts.
@solareclipsetimer
6 жыл бұрын
Merrill, this eclipse experience, and data make me believe the atmosphere is the biggest factor. I need more data. I found I guy who has another great video from Tennessee. It's not oriented, but I am trying to get in touch with him to see if he can give me a basic idea of his setup direction. Yes, I now think the movements are NOT predictable a head of time. Gordon
@chris24hdez
6 ай бұрын
Today I saw a rainbow colored phenomenon right after C3 around the time shadow bands would be observed. It was like waves of rainbow and white and shadow in about 3 or 4 fast waves moving from west to east. Maybe because of the high altitude clouds causing refraction. It was very distinct. I was the only one who saw them because I was facing away looking at others reactions to the diamond ring stage.
@chriswaskew89
6 жыл бұрын
Wow! It is awesome that we had the opportunity to have such a unique set of observations for this analysis. I had no idea that there have never been proper studies on multiple locations for a single eclipse. I’m so glad I could be apart of the data collection. Thanks for the great work on this series of videos.
@solareclipsetimer
6 жыл бұрын
Chris, yes is't actually a really big deal! A lot had to come together to get this analysis. A perfectly placed path, good weather, some preparation on my part and then some good old fashion luck. First, it was an eclipse path with a long land path, especially around the point of greatest eclipse. We had good weather in the southeast. I worked with my NASA friends and Michaela put the compass rose in her video. You watched the Smarter Every Day video about shadow band video setup that was uploaded just 2 days before the eclipse and reproduced the set up. And then I was able to get the videos so I could work on my theories about shadow bands. In 2024 I should have a ton of oriented videos to work with.! Thanks for letting me use your video Gordon
@chriswaskew89
6 жыл бұрын
Solar Eclipse Timer I am planning to attend the 2024 eclipse as well. I hope to work on getting a better shot of the shadow bands next time with more planning and possibly help from you with the technical aspects of setup and videoing. Thanks again for all the work you have done.
@RTew021
Жыл бұрын
Some comments 1. it occurs to me that the apparent direction the bands flow may be an artifact of shutter speed versus the actual speed of movement in just the same way as can be seen on a video of a passing car when sometimes the wheels appear to rotate backwards. It's a stroboscopic effect. So I think shutter speed is relevant and probably should be part of the data connected to any (moving) images obtained. 2. with no prior experience or knowledge, I accidentally noticed shadow bands during the 2017 eclipse from an excellent vantage place in Oregon. I was astounded. The flow appeared to be, to my eye, away from the position of the sun, and the alignment of the bands appeared to be at right angles to the direction of the sunlight at the time of the eclipse, around 10:00 in the morning as I recall. That was what my eye told me. I had no camera set up, but have been thinking since then about how to capture the phenomenon on a camera. Your video is wonderful in that it brings out a bunch of technical details that are certain to bear on how well the phenomenon can be captured as a video or image. I had the feeling at the time the phenomenon could be captured by a still camera (to measure shadow spacing and alignment), or by looking at single frames of a high quality video. I found the spacing between the bands interesting - to my eye a little less than half a foot wave peak to wave peak. The flow rate also intrigued me -- no more than a foot per second; that's an order of magnitude guess only -- and the fact that when it occurred it was visible everywhere I could see, which of course was only practically within a few hundred feet max of where I was standing ( a very open field with no obstructions above horizon by more than 10° in any direction). When I look at the setup you propose, I want to suggest at least one change, which is that a small stick be set up to throw its shadow across the sheet being photographed so that the alignment that is set up by whoever is creating that particular arrangement can show exactly the position of the sun relative to the sheet itself. 3. another thought that I have had about this is that it seems probably useful to underexpose the image slightly, or maybe a lot, and to use a fixed focus, to avoid the camera adjusting to the rapid environmental (light) change in a way that imposes artifacts on the image that's captured. I kind of want to try two kinds of image capture simultaneously but I'm not sure I can manage the cameras for this. One will be where the exposure value is set high(+EV) but s allowed to track the changing light levels, if that is possible (ie, fast enough); and a second that has a fixed exposure that is clearly too high at the beginning of the phenomenon (entering totality) but will capture an image well in the few seconds just prior to totality. I'm also interested to check if the phenomenon occurs the same entering totality as it does leaving it. In Oregon I only noticed it as the totality ended, alas. 4. someone commented about using a surface that's tilted up. That seems like a good idea in that it would allow the camera to focus well on more of the surface being photographed. Of course doing so (making the surface plain normal to the axis of the light beam ), then my stick idea will need to be changed slightly (include both the stick and its shadow in the image and measure the distance between the camera lens and the stick and surface to get the geometric data correctly). Also, a big issue is going to be the resolution of the camera being used, and whether it has a sufficiently high ISO and dynamic range to show contrasting details in very low light. I'll need to do some testing to sort that out if I can. 5. There was a comment somewhere the couple videos I just reviewed suggesting that the phenomenon was noticeable even minutes before totality. My experience in Oregon indicated that it was in the seconds just AFTER totality, and that it lasted only 10 or 15 seconds maximum. I assume it also can or will occur in the few seconds before totality. 6. as for what is behind the phenomenon, what is causing it, my thoughts immediately went to diffraction, or is it refraction, where the sun's light is split into two beams that interfere with one another, in this case while the light source is shifting (hence the movement). I wondered about mountains poking out from the edge of the moon splitting the last moments of direct sunlight into two beams (something connected to the necklace of diamonds effect that has been reported for a long time), and in a way quite like the interferometer experiments that were done decades ago to show interference patterns. If I managed to get to a place where I view this upcoming total eclipse in a clear sky and I manage to get any kind of useful images of the moving shadow bands, I will certainly send them your way with as much technical information as I have managed to get in that moment. Thanks for publishing what you are thinking and what you've managed to do yourself and gather. Who knows what exploring this will turn up? it's quite exciting!
@Laserblade
7 ай бұрын
Well Done analysis, thank you!
@scottperry2541
6 ай бұрын
Ok, is it me? I don't see squat............and we are living in the centerline of totality coming April 8th.
@ClevelandOh216
6 ай бұрын
Put white signs in your lawn casting a shadow then look at it after the eclipse 😊
@sporter555
3 жыл бұрын
Gordon, are you organizing more sites of shadow band data collection for 2024? Wouldnt it be helpful if the bedsheet were stretched across a flat 4ft x 8ft piece of plywood to remove the extraneous shadows added by the sheet wrinkles? I plan to try this in 2024.
@solareclipsetimer
3 жыл бұрын
Scott, yes I plan to try to capture shadow bands in 2024. I was in Argentina for the 2019 eclipse and we saw wonderful shadow bands! Unfortunately, I did not capture good video of them because it was a setting eclipse and the low Sun angle made the contrast on the white sheet poor. Especially due to the fact that I needed to point the camera toward the eclipse, the direction of umbra approach. I prefer to point the other way, in the direction of umbra exit, but with this low eclipse the tripods were casting big shadows on the white sheet, so I reversed things. This was a huge mistake on my part! I should have accepted the shadows and point the cameras the way I usually recommend. And yes, having the least amount of wrinkles in the sheet is preferred. But sheets make it easy to travel to the eclipse versus hard white panels of any type. I have not tried to organize capturing of shadow bands at different sites yet, but it is something I have thought about. The problem is that this eclipse, being in April, is going to be tricky with the weather and trying to plan a head. Read this article I wrote for AccuWeather. www.accuweather.com/en/weather-blogs/astronomy/total-solar-eclipse-on-april-8-2024-is-3-years-away/926730 Thanks for comment and question!
@MichaelQShaw
Жыл бұрын
Theory? It’s not a theory NASA explains it on their website. Shadow bands seen during the solar eclipse, look just like the rippling caustics at the bottom of water only inverted. Our atmosphere refracting light like water. I saw it and I am all the way down in Wichita Falls Texas. I wasn’t even in the umbra or penumbra. Seriously it looked like the rippling caustics you see at the bottom of a swimming pool only inverted the lines were dark. I saw it on everything. If you continue to use a white sheet maybe place it on flat level concrete?
@solareclipsetimer
Жыл бұрын
Michael, thank you for watching the video and making a comment. I hope you watch some of my other videos as you prepare for the 2024 solar eclipse. The theory behind the creation of shadow bands is probably some sort of refraction. I agree with that. The question that I don't think is answered is at what level or altitude in the atmosphere is causing the refraction. I don' like the pool analogy because the ripples at the surface of the pool, that cause the refraction, (air water interface) are completely random and the Sun is a full globe when most people see the effect on the bottom of the pool. I've seen shadow bands at three of the five solar eclipses I have been to and the are always relatively straight streaks that move in rows because the are caused by the straight slit of light of the final crescent phase. I watched dozens of shadow band videos on line and they always form some form a a repeating row pattern. They never look like the random patterns on the bottom of a pool. So although the refraction origin maybe the same, the visual end result looks different.
@RTew021
Жыл бұрын
Your comments are interesting, but make me think you may have been seeing a phenomenon different from what this video is discussing. Wichita Falls was within the penumbra of the 2017 eclipse. In a solar penumbra viewers can see a partial occlusion of the sun during the eclipse. Wichita falls is less than 650 mi from the line of totality, and the penumbra of a solar eclipse is usually well over 1500 mi on either side of the line of totality. So I think you were within the penumbra of that eclipse, but not the umbra which is the narrow area where totality can be viewed. As for the phenomenon you saw, I wonder whether you were seeing the strange shadowing that occurs as sunlight from an occluded sun passes through a tree or some other obstruction that functions like a pinhole camera lens and creates images of the sun on the ground that reveal the sun's appearance at that moment's solar occlusion -- each of the light spot(s) in the shadow of a tree or other shadow-causing object look like a crescent. This phenomenon can be seen by someone in a penumbra when the sky is clear. And if what you saw was something different from what is described above, it sounds interesting and possibly something new. I too like this site's author have a hard time understanding pre-totality shadows that move for to an atmospheric phenomenon if only because, in the swimming pool you reference, the atmosphere's outer edge is not a surface like a swimming pool has but instead is a progressively thinning density. It's hard to imagine how regular shadows could be projected from that diffuse density of air. I'll have to look into what NASA has published about this. Thanks for the information.
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