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Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram

astrodon.social

71–80 of 93 posts

Re: Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram

#71

This is fantastic, and like another commenter mentions, a beautiful continuation of an age old practice: measuring the sky. Very cool that their hardware keept chugging along for years without hiccup, too. If you want to do something kinda similar but far less involved: a very lo-fi, no computer involved thing to do is an ultralong photographic exposure (months, a year, longer) with a pinhole camera. The results are…

Wow that is a cool concept

Thanks for sharing

Re: Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram

#72

Earlier quoted context omitted.

This is something I mention to the younger kids at start parties. Way back then, there was no internet, no devices, no tv, no radio, no movies, and more importantly no easily accessible calendars. You couldn't help but look up at the night sky. There was really nothing else to do, and when the only thing available to know when to plant and harvest was based on the constellations visible at the time. It helps put thin…

> There was really nothing else to do Well, nothing to do except for storytelling, music, dancing, parties, games, plays, sports, eating, drinking, visiting, festivals, gossip... People have been pretty good at keeping themselves entertained for a very long time.

Obviously OP didn’t mean literally nothing else to do

Re: Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram

#73

I did much the same thing (and much more) 10 years ago. I used a RPi as well as a Canon point-and-shot out my window. My pics were 1 per minute. Here is a link to the keogram section (I didn't know the term), but watch the whole video, I did a bunch of other art: https://youtu.be/Mfo4hVc71Qw?si=3YKojggkTj2xehAB&t=2334

I really enjoyed your faces example! I’ll have to look at the rest of the video soon, but it’s so cool what you can do with a little imagination and ingenuity!

Re: Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram

#74
post #31

Annnd, this is exactly how humanity figured out astronomy before the telescopes: by taking multi-year observations and keeping detailed records! See Antikythera mechanism, Tycho Brahe, etc. Arguably the entire Greek epistemology was so solid because their astronomy turned out to be an early proving ground for the scientific method.

This is something I mention to the younger kids at start parties. Way back then, there was no internet, no devices, no tv, no radio, no movies, and more importantly no easily accessible calendars. You couldn't help but look up at the night sky. There was really nothing else to do, and when the only thing available to know when to plant and harvest was based on the constellations visible at the time. It helps put thin…

Like the sibling, I don't think people had trouble entertaining and distracting themselves. But there was no electrical light, and much less artificial lighting overall. Evenings and nights were dark. I'm sure many a walk home after a gathering was lit only by the night sky.

Meanwhile, I can see the moon and like ten stars on a typical night, because I live in a city and there is massive ambient light at night.

Re: Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram

#75

Earlier quoted context omitted.

This is something I mention to the younger kids at start parties. Way back then, there was no internet, no devices, no tv, no radio, no movies, and more importantly no easily accessible calendars. You couldn't help but look up at the night sky. There was really nothing else to do, and when the only thing available to know when to plant and harvest was based on the constellations visible at the time. It helps put thin…

> There was really nothing else to do Well, nothing to do except for storytelling, music, dancing, parties, games, plays, sports, eating, drinking, visiting, festivals, gossip... People have been pretty good at keeping themselves entertained for a very long time.

I guess he meant there was nothing else for nerds to do...

Re: Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram

#76

This brings to mind something I've wondered about for a while. Sunrise on the shortest day of the year is earlier than sunrise for several days after it. Sunset on these days after the shortest day is of course even later than sunset of the shortest day. On the beautiful image of the OP, you can see that after dawn of December 21, dawn continues to get later over the next few days. In my area, sunrise on 12/21/2024 w…

It’s partly because we have a standardised 24 hour clock and solar noon (when the sun is highest) is sometimes ahead and sometimes behind GMT noon. The sunrise and sunset times relate to solar noon so they vary accordingly.

See ‘equation of time’ and ‘analemma’ for underlying astronomical explanations, as hinted at by sibling posts.

Re: Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram

#78
the real technical achievement here is maintaining consistent camera sensitivity over 4 years. Most consumer CMOS sensors degrade significantly from UV exposure over that timeframe, which would show up as a gradual darkening in the composite

Re: Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram

#79

Earlier quoted context omitted.

> There was really nothing else to do Well, nothing to do except for storytelling, music, dancing, parties, games, plays, sports, eating, drinking, visiting, festivals, gossip... People have been pretty good at keeping themselves entertained for a very long time.

Obviously OP didn’t mean literally nothing else to do

The reason I bothered to respond is that there is a common tendency to look back at historical people and see them as extremely primitive -- with little knowledge, with little entertainment, with little going on. That they would have had nothing better to do than to look at the sky.

And that's what I'm pushing back on. No, that's just not true. Obviously some people were interested in the sky, and it was a tool for certain things, but OP literally said "There was really nothing else to do." That's a complete misunderstanding of human society in history. And it's important we don't reduce our ancestors to these primitive stereotypes.

It's also important to push back on the idea that there were no distractions. OP says "no internet, no devices, no tv..." but there was extensive village gossip, games, stories... fundamentally we had all the same kind of distractions. We're a lot more similar than OP thinks.

Re: Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram

#80

Incredibly cool. I love this so much, both artistically as well as how it demonstrate the equation of time [1] -- the fact that the changes in sunrise and sunset are not symmetrical. On the other hand, it's driving me absolutely crazy that he centers the image at 4:00 rather than midnight. Or maybe that's to show the shimmer of sunlight a little after noon on the right hand side? I can't figure out why it's "bluest"…

>he centers the image at 4:00[pm]

I think because the night sky offers interesting variation that looks nice stitched together. the sunny day, not so much. I will also point out, OCD notwithstanding, that 0hour/12am is an arbitrary time to start the day, and you should really look at the days/nights all strung together in a long continuous strip

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