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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@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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@dotstdy @jon_valdes maybe I'll call the expensive exact soft sin oscillator "gold plated sin"
@aeva @dotstdy @jon_valdes start a new genre "deca-dance"
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@aeva @dotstdy @jon_valdes start a new genre "deca-dance"
@demofox @dotstdy @jon_valdes well so far I can't tell the difference by ear between the soft sin and the double precision sin that clang gives me
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@demofox @dotstdy @jon_valdes well so far I can't tell the difference by ear between the soft sin and the double precision sin that clang gives me
@demofox @dotstdy @jon_valdes assuming I didn't screw anything up adapting Jon's shader toy, the 30 iteration soft sin also has the surprising property of being able to clip out of the expected -1.0 to 1.0 output range https://github.com/Aeva/mollytime/blob/af58e9237903856b6193a116ae6408038dc47d4a/src/patch.cpp#L319
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@demofox @dotstdy @jon_valdes assuming I didn't screw anything up adapting Jon's shader toy, the 30 iteration soft sin also has the surprising property of being able to clip out of the expected -1.0 to 1.0 output range https://github.com/Aeva/mollytime/blob/af58e9237903856b6193a116ae6408038dc47d4a/src/patch.cpp#L319
@aeva @demofox @dotstdy @jon_valdes There's lots of versions of CPU sin/cos as well. The fastest is basically identical to the GPU one - about 12 bits of precision, IIRC. Then they do iteration internally if you want higher precision. There's no magic - everything costs!
As you noticed, sometimes it's better not to call sin-vs-cos, because you're not guaranteed to get magnitude 1.0. In those cases it's better to get sin and derive the other by doing sqrt(1-sin^2).
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@aeva @demofox @dotstdy @jon_valdes There's lots of versions of CPU sin/cos as well. The fastest is basically identical to the GPU one - about 12 bits of precision, IIRC. Then they do iteration internally if you want higher precision. There's no magic - everything costs!
As you noticed, sometimes it's better not to call sin-vs-cos, because you're not guaranteed to get magnitude 1.0. In those cases it's better to get sin and derive the other by doing sqrt(1-sin^2).
@aeva @demofox @dotstdy @jon_valdes Also, if you care about precision at all, do range reduction yourself beforehand. Otherwise you have no idea how it's being done internally.
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@aeva @demofox @dotstdy @jon_valdes Also, if you care about precision at all, do range reduction yourself beforehand. Otherwise you have no idea how it's being done internally.
@TomF @demofox @dotstdy @jon_valdes I already do the range reduction. I learned that the hard way once upon a time XD
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wikipedia: even the ancient babylonians knew how to use math to figure out what the moon is up to
me: great how do i do that
wikipedia: 😏
today's extremely basic astronomy question that i'm finding surprisingly difficult to find an answer to: are geographic coordinates and equatorial coordinates the same coordinate system except one is for looking up and the other is for looking down, or is there some essential conversion step needed to correlate them?
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today's extremely basic astronomy question that i'm finding surprisingly difficult to find an answer to: are geographic coordinates and equatorial coordinates the same coordinate system except one is for looking up and the other is for looking down, or is there some essential conversion step needed to correlate them?
i feel like i'm so close to getting this working. i found a simple implementation of ELP2000-85 that gives the approximate ecliptic coordinates and distance of the moon for a given julian century, i found math for translating between ecliptic and equatorial coordinates, and the math for working with the julian calendar looks easy enough, so i just need to figure out the missing conversions and decide on an internal time keeping standard
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i feel like i'm so close to getting this working. i found a simple implementation of ELP2000-85 that gives the approximate ecliptic coordinates and distance of the moon for a given julian century, i found math for translating between ecliptic and equatorial coordinates, and the math for working with the julian calendar looks easy enough, so i just need to figure out the missing conversions and decide on an internal time keeping standard
i think astronomy would be a lot simpler if ancient peoples didn't get so hung up on conceptualizing celestial bodies as spheres and simply invented linear algebra first
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i think astronomy would be a lot simpler if ancient peoples didn't get so hung up on conceptualizing celestial bodies as spheres and simply invented linear algebra first
@aeva On cosmology sequence breaks: Terence Tao noted that an ancient Greek heliocentrist got his arguments shot down because others said, hey, if the earth moves so much yet the stars seem to stay still, the universe would have to be *thousands* of times bigger than anyone figures it is. And how would you know, back then, it was way *more* than thousands of times bigger?
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i think astronomy would be a lot simpler if ancient peoples didn't get so hung up on conceptualizing celestial bodies as spheres and simply invented linear algebra first
@aeva a lot of things would be simpler if cults based on "perfect" shapes hadn't done all the [gestures] that they did
divine geometry is a helluva drug
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@aeva On cosmology sequence breaks: Terence Tao noted that an ancient Greek heliocentrist got his arguments shot down because others said, hey, if the earth moves so much yet the stars seem to stay still, the universe would have to be *thousands* of times bigger than anyone figures it is. And how would you know, back then, it was way *more* than thousands of times bigger?
@rf they were so close lol
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@aeva a lot of things would be simpler if cults based on "perfect" shapes hadn't done all the [gestures] that they did
divine geometry is a helluva drug
@aeva on the other hand getting extremely horny for triangles is both funny and kinda relatable, so
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@aeva a lot of things would be simpler if cults based on "perfect" shapes hadn't done all the [gestures] that they did
divine geometry is a helluva drug
@SnoopJ we're still using spherical trig in astronomy today despite earth being an ellipsoid
Gli ultimi otto messaggi ricevuti dalla Federazione
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@scripting this is a great post, Dave.
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Where is this on Mastodon?
I've been taking Ozempic for the last couple of years with dramatic effects.
But now for the last year my weight is stable at a reasonably healthy level for the first time in a long time. Getting prepared for the big decade, I just turned 70 this year. It's a daunting moment. I remember when my grandfather was 70. It seemed like an impossibly age. I was 15.
Anyway I haven't said anything about it on my main blog. Not sure how people would react.
But this blog, daveverse, is finding another audience. I haven't made sense of it, people are liking it somewhere, but we don't have a Like button on the site. I'm thinking they must be doing it on Mastodon, but where? This is something we have to work on for Mastodon. There need to be places, and I always assumed they were there but now I think they aren't. This is not a good thing to be confused about.
Anyway back to Ozempic. I realize now how it works. After two years, I don't get an emotional rush out of eating. It isn't about satisfying a need for love any more. It's just eating. And I swear I taste so much more of the food now than I ever did. Eating for nutrition and eating for sensation.
My old grandfather used to call this the Art of Living. Maybe this attitude toward food isn't only coming from the drug, maybe time does that too.
My message btw to people who feel 70 is impossibly old, you won't feel that way so much when you are 70 because you keep learning and seeing things you didn't see before. It's part of the trip. I almost died a few times earlier in life, glad I didn't so I get to do this.
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@joncruz I'm not sure what you mean.
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@glyph my strat was to make sure every person on my team had a different set of non-contradictory talking points to focus on
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@aeva it really doesn't take much experience for most people to understand what's going on. I would say most people wouldn't figure out the whole game on their *first* outing, but it doesn't take long :)
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@glyph I've never really felt the need to watch political debates after that. I know the score.
Also iirc my roommate's team of well practiced debaters who practiced for the debate took 4th and he was so mad lol.
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@glyph you can even have some fun with it. I once rolled into a debate competition hung over and with no prior debate experience with my also hung over partner at the time, formed a debate team with two other like minded hung over people we found, and took second. we lost to the team that took first because it's really hard for a mostly male appearing team to beat an emotional appeal from four young cis women arguing against their own bodily autonomy
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@hypostase I'm just trying to calculate the vector from the center of the earth to the center of the moon for a given time point, and the vector from the center of the earth to my current position on the earth. The common coordinate system is arbitrary, but I'm thinking it would be easiest to use the earth's ecliptic coordinates as the common coordinate system since I already found math that does the first half.
I'm not anywhere near the point where the results can be "wrong"
