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astroalysa.bsky.social
Queer & disabled astronomer formerly at UofT & CITA. Dynamics, planets, & ballet. Posts reflect opinions of Sailor Galaxia, not my employer. She/her šŸ‘©ā€šŸ”¬šŸ’ƒ
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How did I beat this game on survivor+?????? (I died a lot - often intentionally)
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As a warm-up
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I should just do this in random spots in downtown Toronto
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I need to get back into this stuff because it brought me so much joy and I’m feeling a bit envious right now!
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Omg I miss going to cons (went to so many in my teens). I would’ve been so happy if I saw a rad astronomer at one!!! I hope you have a blast :)
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ā€œI understand there is a riskā€ Do you? ā€œBut the potential rewardā€ What reward? Subjecting marginalized mathematicians to a session of gross ā€œdebateā€ so that someone maybe sees that it’s not the end of the world if they get an email (which they can delete) about Black mathematicians in February?
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I picked a great year to cut back on my alcohol consumption (turns out it’s not good for you) because every time I check the news I want to pound back some shots and pretend this isn’t happening.
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Oh nevermind, it's just junk that a tabloid made up and other tabloids are running with.
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Wait what?
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I think I just need to own being evil and killing everyone. Maybe?
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:(
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What movement? I’m confused. I’m asking about the altitude of the NCP for a local observer. It should be L, but this figure depicts it as 90-L. It’s just geometry of triangles. There’s no motion involved.
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I actually remember our final exam had a question about when/where something was up in the sky, but it explicitly said we could use reasoning to provide a general explanation (so I said something along the lines of, ā€œsince the Sun sets in the south west during winter, which I’ve verified by eyeā€)
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Yeah, we touched on this in my observational astronomy exam. The textbook (which I still have) doesn’t cover it in great detail, though. It gives some coordinate conversion formulae, and basically just says ā€œhow you get this should be immediately obvious from these 2 diagrams, go!ā€
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Non-linear dynamics and chaos theory? Cool. Super fun. Love it. Basic geometry? Screaming and crying and throwing up.
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It’s the angle (altitude) between the NCP and the local horizon. So it should be L. If you’re at the equator, the NCP is at the horizon whereas it’s at zenith for someone at the north pole
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You’d need to worry about it e.g. for determining if/when an object’s visible at a site, but I imagine most people just use pre-existing calculators for that.
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I suspect more people aren’t familiar with the error because working with alt-az coordinates isn’t really a big thing in astronomy education?
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Someone else pointed out that replacing L with 90-L is indeed correct (since it’s then 90-(90-L)=L). Just seems an odd way of phrasing the correction and leaves room for ambiguity about whether you’re seeing a corrected version or not
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I can tell you that I’ve spent a grand total of maybe 5 hours of my entire astronomy education and career thinking about alt-az coordinates, so I hadn’t paid any attention to it until I was teaching it šŸ˜…
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I’m not even sure if digital copies of textbooks have corrections applied to them or not. So perhaps my concern about the ambiguity is irrelevant.
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Ha, that is indeed correct! It just seems like an odd way of phrasing it. I’d have written, ā€œreplace ā€˜90-L’ with Lā€ because that’s a bit more clear (or at least I think so)
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I looked up the errata to see if this is a known error. It says there's an error in the figure, except that the error is L and that the correct version is 90 - L. So it would seem that my copy of BOB has been "corrected". Is there a different convention for latitude that I'm unaware of?
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youtu.be/TjDEsGZLbio
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I feel like modern astronomy is sometimes just ā€œidk it’s how my supervisor did itā€ going back for 2000 years
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Of course that makes so much sense now that you’ve said it haha
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Bread, cheese, and wine are all nice things :)
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Seething with envy looking at radio astronomers just out there living their best lives with Janskys
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Haha I don't recommend this seriously because of this! (but also because I don't actually recommend drinking while teaching)
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"Yeah, and they're backwards, too!" (dying inside)