i nerd sniped myself tonight and i imagine the NSA operative who is assigned to me is very confused by the increasingly erratic and frustrated google searches for HOW DO I CALCULATE THE MOON WHERE IS THE MOON
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@aeva oh boy. I went down the rabbit hole of calculating star positions a few years ago, and the whole thing is... convoluted. Step one was calculating the Earth Rotation Angle, and that was... urgg
@jon_valdes my hope was that the moon's position relative to the earth would be the one situation where geocentrism still holds enough water for a useful approximation, but I'm starting to think that this is a problem space where people don't typically seek useful approximations
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@jon_valdes my hope was that the moon's position relative to the earth would be the one situation where geocentrism still holds enough water for a useful approximation, but I'm starting to think that this is a problem space where people don't typically seek useful approximations
@aeva what I found is most methods for calculating these things are approximations that break down if you deviate from the year 2000 by more than 5 millenia or something. It just depends on what you consider a "useful" approximation 😅
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@aeva what I found is most methods for calculating these things are approximations that break down if you deviate from the year 2000 by more than 5 millenia or something. It just depends on what you consider a "useful" approximation 😅
@jon_valdes oh that's great. I figure for my use case it only has to be moderately accurate for the remainder of my lifespan however short or long that may be, and it's not really my problem if it accumulates a bit of drift after that
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@jon_valdes oh that's great. I figure for my use case it only has to be moderately accurate for the remainder of my lifespan however short or long that may be, and it's not really my problem if it accumulates a bit of drift after that
@aeva perhaps the easiest way would be to look at how other programs do it. I spent a bunch of time reading code for Stellarium, for example. Perhaps that, or a website like this could help you?
https://eyes.nasa.gov/apps/orrery/#/moon?time=2025-09-10T04:57:12.041+00:00 -
@aeva perhaps the easiest way would be to look at how other programs do it. I spent a bunch of time reading code for Stellarium, for example. Perhaps that, or a website like this could help you?
https://eyes.nasa.gov/apps/orrery/#/moon?time=2025-09-10T04:57:12.041+00:00@jon_valdes i found this a few hours ago http://www.geoastro.de/elevazmoon/basics/index.htm haven't had a chance to look at it in detail but it looked promising at first skim
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@jon_valdes i found this a few hours ago http://www.geoastro.de/elevazmoon/basics/index.htm haven't had a chance to look at it in detail but it looked promising at first skim
@aeva @jon_valdes I'm trying to remember what program we use to generate location accurate star charts in Avatar and Division... Maybe it can do the moon as well, will look it up later.
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@aeva @jon_valdes I'm trying to remember what program we use to generate location accurate star charts in Avatar and Division... Maybe it can do the moon as well, will look it up later.
@aeva @jon_valdes alright I think we just use data from sdss and reproject it for alpha centuri, blindly extrapolating for the correct date using the star velocity. so no complex orbital mechanics. However for the planetary bodies in solar system we use code derived from https://stjarnhimlen.se/comp/ppcomp.html
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@aeva @jon_valdes alright I think we just use data from sdss and reproject it for alpha centuri, blindly extrapolating for the correct date using the star velocity. so no complex orbital mechanics. However for the planetary bodies in solar system we use code derived from https://stjarnhimlen.se/comp/ppcomp.html
Word of caution about calculating these things on the GPU: implementations of trigonometric functions on the GPU are less accurate than you'd hope, and if you calculate a bunch of sin() and cos() for your view direction per pixel, they turn out not to be accurate enough for stable movement across a 60° fov on a 4K screen. Particularly Intel, which seems to barely pass the D3D precision requirements there...
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Word of caution about calculating these things on the GPU: implementations of trigonometric functions on the GPU are less accurate than you'd hope, and if you calculate a bunch of sin() and cos() for your view direction per pixel, they turn out not to be accurate enough for stable movement across a 60° fov on a 4K screen. Particularly Intel, which seems to barely pass the D3D precision requirements there...
@jon_valdes @aeva right, yeah I should also mention all that is done on the cpu, and with double precision. I'm not really sure if you can even squeeze it to work with f32.
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@jon_valdes @aeva right, yeah I should also mention all that is done on the cpu, and with double precision. I'm not really sure if you can even squeeze it to work with f32.
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@jon_valdes @dotstdy blessedly I'm planning on doing this on the cpu, but D:
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@jon_valdes @dotstdy blessedly I'm planning on doing this on the cpu, but D:
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@jon_valdes @dotstdy my laptop has a recent-ish Xe gpu
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@jon_valdes @dotstdy my laptop has a recent-ish Xe gpu
@jon_valdes @dotstdy it's bizarre seeing my 10 year old telephone's mali do better at... anything at all
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@jon_valdes @dotstdy it's bizarre seeing my 10 year old telephone's mali do better at... anything at all
@jon_valdes @dotstdy though I guess the corner the intel case is cutting is where the slope starts to level out so I guess that makes sense. are CPU trig functions just as bad?
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@jon_valdes @dotstdy though I guess the corner the intel case is cutting is where the slope starts to level out so I guess that makes sense. are CPU trig functions just as bad?
@jon_valdes @dotstdy would mollytime get a warmer, fuller sound if i switched to expensive software sine waves :3
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@jon_valdes @dotstdy would mollytime get a warmer, fuller sound if i switched to expensive software sine waves :3
@aeva @jon_valdes generally cpu trig is not so bad, but does vary between platforms if you're just calling the c stdlib functions (but we're talking differences of 1 ulp or so). so yes, absolutely you can get a warmer fuller soundstage by switching to a different sin.
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@jon_valdes @dotstdy my laptop has a recent-ish Xe gpu
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@aeva @jon_valdes generally cpu trig is not so bad, but does vary between platforms if you're just calling the c stdlib functions (but we're talking differences of 1 ulp or so). so yes, absolutely you can get a warmer fuller soundstage by switching to a different sin.
@dotstdy @jon_valdes maybe I'll call the expensive exact soft sin oscillator "gold plated sin" 🤔
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@stefano Close one. Glad you made! It had rear traction, right? A bugger to regain control if traction gets lost.
It's a bit like a certain subtle sound I'll never forget. A very large wood construction- and timber market center right before my window of my childrens bedroom completely went up into flames in the middle of the dead night when I was young.
Much later, when my wife and me were living together one night I woke up by that subtle sound again and knew right away something big lit up. It was the bikeshed of our neigbours. We were able to call the FD and alerted the neighbours, who were still asleep at that point, to get out.🤷♀️
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@robhardware excellent point Rob. I also feel that vanity metrics play a lot into it too... they are reluctant to leave behind a platform - and rebuild from scratch in a new place - if they had accumulated a lot of followers over the years.
IMHO it's all about optics and ego - even if X has armies of bots and engagement has plummeted for real users... when will they see the light?
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Ieri su Radio Popolare è andata in onda una chiacchierata con me.
Mi piace Radio Pop <3
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La logica dei cartoni
Il cerotto sul vestito
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@elena @404mediaco @Em0nM4stodon Absolutely agree. I imagine there are quite a few politicians who instinctively feel they should be off X being advised by their political parties comms teams that they are losing a huge advertising opportunity, especially during elections, if they leave, and that they would be at a disadvantage to their opponents. Until the stigma of using X outweighs the electoral cost, I'm just not sure how much change we'll see.
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@macfranc @lauramassera @eticadigitale beh, attenzione perché la Apple deve assolutamente garantire (quasi per contratto) ai suoi clienti la privacy e la protezione dei loro dati. Tanto da avvisare loro stessi diversi clienti che nemmeno si erano accorti di aver subito intrusioni e controlli attivi sui propri dispositivi offrendo persino assistenza legale. Difendono semplicemente il loro "feudo" dando protezione (finché conviene) ai loro protetti che continuano semplicemente a consumare gadget e giochini digitali. Della libertà e della privacy in sé non gliene importa nulla a nessuno, né a chi si lascia possedere né tantomeno alle grandi aziende come Apple.
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Lavoratore muore per il freddo nei cantieri delle olimpiadi a cortina. “lo specchio del lavoro tossico e nocivo dei grandi eventi”
@anarchia
È morto per il freddo all’età di 55 anni Pietro Zantonini, originario di Brindisi, durante un turno di vigilanza notturna nel cantiere delle olimpiadi Milano-Cortina.
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@lauramassera Hai assolutamente ragione, ma diciamo anche che nel 2025 è impossibile non riconoscere che la malvagità antisociale è il tratto distintivo di quelle Big Tech che spesso si presentavano eticamente candide.
L'unica eccezione è probabilmente quella di Apple che effettivamente ha deciso, sia anche solo per questioni di marketing e narrativa aziendale, di opporsi alle nuove tendenze del cattivismo trumpiano
