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…
Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram
81–90 of 93 posts
Re: Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram
#82Wow this is really beautiful. Is there an algorithm (not api, but available calc method) that can calculate the full year based on a few variables? Like long+lat?
Re: Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram
#83The “stripes” in the keogram look very regular. A few days of clear skies followed by a few days of clouds. Is that what’s happening? Why the regularity?
Re: Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram
#84Earlier quoted context omitted.
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 c…
You're now assuming that I'm a bumbling idiot that thinks everyone before electricity were neanderthal cavemen. Although, I've met plenty of modern people that couldn't hold a flame to a caveman.
The fact that the ancients knew the coming of the seasons and developed their entire society based on what was visible in the heavens just shows how much they did pay attention to it.
There's a thing in story telling called hyperbole. It helps enhance the story by bending the truth just a bit to make the story more interesting and helps get a point across. It is especially useful in oral story telling.
But clearly, we're all bumbling idiots for not getting the minute details exactly right. Good to know. I'm glad you're so intelligent that you've set me straight
Re: Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram
#85Earlier 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…
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.
I initially had something referencing light pollution, but felt it wasn't as relevant to the point and took it out. When talking to kids, giving them the whole nine yards at every opportunity is overwhelming. Giving them just enough to get the point across is much more effective. Explain once without over explaining, demonstrate, and then let them experience it. Never been a teacher, but it works as a coaching technique that translates well in other areas. Giving too much info that's not relevant verges on mansplaining IMO.
Re: Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram
#86Earlier quoted context omitted.
Everything you listed as options to do are also available now, yet people still choose to stay home and look at their devices. Pedantry for pedantry sake is just boring
> Everything you listed as options to do are also available now That has no bearing on anything you or I said. > Pedantry for pedantry sake is just boring Perhaps you don't understand what pedantry is? Your entire point was a false description of what humanity was like. Just take this as a learning experience! :)
Perhaps you don't know what story telling is. Just because details were left out does not mean I'm implying they didn't happen. It's not a lie of omission. You're hell bent on making something out of nothing, for what point I have no idea. But you're free to continue to attempt to denigrate my intentions if that really makes you feel superior.
You've yet to dispute the actual point that the average person did not have a simple device that allowed them to see the future without any thought about what it took for that to happen. In order to know how much of a season was left was to look at the night sky to see what stars where visible. Not the day time sky. The only reason they knew what they knew because people very intently looked at the night sky and started to recognize the patterns. Their was no Hey Google! What is today's date? or Hey Siri, how many more moons until it's time to plant seeds?
But sure, let's focus on the irrelevant parts of whatever story you want me to tell. In fact, how about you go find a star party and volunteer your time to talk to kids and tell the story however you want. Then come back and we can all critique it to ensure you didn't leave out any irrelevant details. Maybe we should update the saying "those that can't do, teach" to add "those that can't teach, critique"
Re: Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram
#87This 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…
Thanks, very much appreciate the thoughts and pointers!
Re: Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram
#88This 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…
OK here is my attempt at intuition:
Here is an approximation that captures the main effect (the 23.5 degree tilt of the earth's rotation axis) and overlooks secondary effects.
Consider the equator. Imagine a circle on the X-Y plane centered at the origin. Angle the circle up 23.5 degrees, rotated around the x axis. The projection of this circle back onto the plane is an ellipse on the X-Y plane, with the vertical axis about 92% of the length of the horizontal axis. Now, consider a series of vectors in the X-Y plane starting on the X axis, with angles in steps of 0.986 degrees. (This is approximately the angle the earth progresses around the sun each day.)
Where each vector hits the unit circle, move the point up or down so that it hits the ellipse. The angle will change a bit for most of the rays. In some cases the angle will be a bit smaller, and in some cases a bit larger. These discrepancies are the variations in time of day of sunrise and sunset over the course of a year on the equator.
Re: Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram
#89So cool that the shape resembles an hourglass!
I work with a shorebird expert who has been tracking migrations (Latham snipe whose range extends from Russia/Northern Japan to Southern Australia). I think an early technique of tracking their migration before gps/chip/batteries were small enough was a primitive light sensor + data logger that would log day/night hours on the bird as it flew from island to island and the light data was enough to roughly estimate lat…
Snipe, huh? Will you be organizing a Snipe-Hunt any time soon?
Re: Combining 15s interval whole-sky-camera photos to form a 4y spanning keogram
#90Earlier quoted context omitted.
I work with a shorebird expert who has been tracking migrations (Latham snipe whose range extends from Russia/Northern Japan to Southern Australia). I think an early technique of tracking their migration before gps/chip/batteries were small enough was a primitive light sensor + data logger that would log day/night hours on the bird as it flew from island to island and the light data was enough to roughly estimate lat…
Snipe, huh? Will you be organizing a Snipe-Hunt any time soon?
nice. had no idea about that connnotation :) ... goes with black swan event as a saying that's ill fitting for these parts (in southern Australia all we have are black swans).