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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@halcy the real problem here is that academic astronomy best practice is to tie everything into spherical coordinates on the firmament so they can factor out the earth enough that you can pretend it is a fixed vantage point that doesn't spin, and if god forbid you do need to tie an observation to geographic coordinates for some reason i guess you just burn an undergrad on it and not sully yourself with the indignity
@aeva i guess that feels to me like it makes sense historically but maybe not…. anymore?
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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?
@aeva geographic lat long is relative to the an ellipsoid. 0 degrees longitude is fixed to the surface of the earth.
Equatorial is a sphere and the longitude equivalent doesn’t rotate with the earth.
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@aeva geographic lat long is relative to the an ellipsoid. 0 degrees longitude is fixed to the surface of the earth.
Equatorial is a sphere and the longitude equivalent doesn’t rotate with the earth.
@jkaniarz where I currently am stuck is how do you convert between the three when it is not the vernal equinox
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@aeva i guess that feels to me like it makes sense historically but maybe not…. anymore?
@halcy well, historically astronomy was among other things at times significantly concerned with answering the question "where the hell am I", whereas modern astronomy seems to be more split between "what is that specific bright object" and "visible spectrum is cringe"
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ok so back to the moon thing, i found another resource and i think i understand the why behind the asinine coordinate systems a little better but it also glosses over the math so it's kinda useless at the same time. i'm tempted to just make shit up and move on, but it would bother me that the function was wrong if i did that
@aeva i have copies of the explanatory supplement to the astronomical almanac in case i ever get enough of an urge to write astronomical software – both the 1960s edition and the more recent third edition that takes into account modern atomic time and general relativity and 🤯
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@aeva i have copies of the explanatory supplement to the astronomical almanac in case i ever get enough of an urge to write astronomical software – both the 1960s edition and the more recent third edition that takes into account modern atomic time and general relativity and 🤯
@fanf I just put in an order for the 2025 Astronomical Almanac - what is this about an explanatory supplement?
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ok so back to the moon thing, i found another resource and i think i understand the why behind the asinine coordinate systems a little better but it also glosses over the math so it's kinda useless at the same time. i'm tempted to just make shit up and move on, but it would bother me that the function was wrong if i did that
after a good night's sleep and reflecting on what I've learned so far, I've decided to follow the classic computer science strat: when faced with a problem you don't know how to solve, simply do something else, and pretend that is what you meant to do all along.
not only are horizontal coordinates the choice reference frame for backyard astronomers, the "altitude h" angular measurement is probably closer to the solution I wanted than my earlier framing of the problem. narf
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@fanf I just put in an order for the 2025 Astronomical Almanac - what is this about an explanatory supplement?
@aeva https://aa.usno.navy.mil/publications/exp_supp roughly speaking it explains the mathematical models used to caclculate the almanac
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@jkaniarz where I currently am stuck is how do you convert between the three when it is not the vernal equinox
@aeva If you know the position at the previous equinox, I think it’s as simple as spinning the moon around the earth (in the plane of the moons orbit) for 2*PI*t/27.3 radians, then spinning the earth for 2*PI*t radians.
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@aeva https://aa.usno.navy.mil/publications/exp_supp roughly speaking it explains the mathematical models used to caclculate the almanac
@fanf that sounds useful. looks like it is out of print though?
Gli ultimi otto messaggi ricevuti dalla Federazione
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@dneary 1m? Seems right.
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How would you answer this question?
Using the appropriate number of significant digits and units, what is 1.0m plus 2mm?
__mVery frustrated with this answer!
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Ormai per l'Italia è tardi, ma da qualche parte nel mondo è ancora #silentsunday, quindi beccatevi 'sto tramonto.
#sunset
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Presentazione di “Diario da Gaza”
@anarchia
VENERDI’ 19 SETTEMBRE’025 alle 19 @ CIRCOLO GUERNELLI, VIA GANDUSIO 6 Wi’am Qudaih è una studentessa di diciannove anni della Striscia di Gaza. Il 7 ottobre 2023 la sua vita, come quella di ogni palestinese, viene stravolta; dopo i primi...Vedi l'articolo
https://www.rivoluzioneanarchica.it/presentazione-di-diario-da-gaza/
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@mcc @cthos ah :( I was hoping Blacksky found a way around that problem, but I have no idea whether or not that is even possible because I have no idea how AT works.
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@cthos @aeva Every Bluesky replica is, probably without realizing it, making a bet that Bluesky has already plateaued.
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@cthos @aeva I don't have an answer to this question. I've seen various claimed attempts to ballpark this number, but I expect it will change month to month, so even if I trusted the numbers I saw (I don't) there's no guarantee they're still accurate.
The Big Problem as I see it is since every "tower" contains the entire network, if the amount of traffic on bluesky doubles, the operating costs of each tower doubles. The "oh shit this is harder than I thought" problem is even worse than fedi.
