yeah, it's hard to explain it in text, visuals are essential, and it's one of my favourite things, figuring out how to express in words concepts that people get pictures from, because i think in pictures. that feeling of making a connection.
Discussion
Read full thing again. Got most of that. I guess what I had wrong was that the thing acting like a point source is only a small patch of the star. But why does the small patch twinkle exactly? My visual of it was the "line of photons" gets warped here and there and misses your eye entirely, but you mentioned dark spots etc as the cause.
Also makes me wonder why it wouldn't be a moving patch that you're observing since relatively the star must be moving.
I get the camera obscura better now. Trade off is lower intensity signal, thus longer exposure needed. Thanks!
you would have heard of sunspots, these can be seen using a camera obscura looking at the sun
when you increase the dynamic range you can see even more detailof the varying brightness of the surface, it's like a boiling pot of water, constantly, every so often a little flash here and another pop there
the reason why is because stars have very complex magnetic fields, and the upper atmosphere of the star, is basically on fire
Think I more or less get that. I was unsure if you were saying the twinkling/flickering of stars was the result of spots moving across the small patch we see, and not the atmosphere bending the line of photons. Seemed like you were but hard to believe. And upon further consideration I was wondering if the light we see is actually that of a small patch (our window of sight) moving across the surface of the star as it moves.
Not to drag this out too long, just wanted closure. I may look it up later to sort this out
this gives you some idea of the wide variance of light, especially note the ultraviolet, there is a wide difference between the darker and lighter parts, in general already there is sunspots but the bright areas are also quite varying in intensity around that, the dynamic range of the visible spectrum cameras is low, it would require a proper HDR capture to really see just how much the brightness varies
the UV also gives you some idea of how much the pops and zaps of those plasma filaments is constantly changing, on the Space Weather News channel he always starts the show with images of the sun as it is, animated, and the bright flashes that occur around the edges especially are easy to see how they would make what we see from far away fluctuate randomly
planets don't fluctuate in their bightness so much because they absorb a lot of the light and diffuse the light widely across the surface, so they appear not to flicker in the same way... they also get darker just like the moon, but being further away you just can't see them at all when they are at an angle where the bright side is facing away from you
Thanks. Still not entirely sure it's those irregularities which cause interruptions/flickering though, and not atmospheric distortion of a "point source." Quick gpt seems to indicate it's atmospheric distortions, and those don't apply to planets for reasons you mentioned (it's larger and thus distorted, so additional distortions from atmosphere are imperceptible (just more noise on top of a wide noisy signal).
Thanks for the knowledge dump. Learned lots 🧠
Side note - heard while discussing this with someone yesterday that there is some sort of eye strengthening exercise one can do with glasses full of small holes (or a screen you move back and forth in front of eyes) while staring at red light, that is supposed to help restore eyes... may have to look into it