ptwiddle.bsky.social
American mathematician in the UK. Mellowing in middle age.
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I was going to recommend Alcock!
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Scene I love in Infinite Jest where kids at a tennis academy play a hilariously technical nuclear war sim where they need to lob tennis balls as missiles. Descends into complete chaos.
Hope the tennis is good at least.
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Team chaos checking in.
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Seen many places (here's a short version: adamcoster.com/blog/on-bull... ) bringing this point up and tying it to Frankfurter's wonderful essay "On Bullshit". Really fits.
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It's kinda continuation of The Ambassador (he toured them together, there's a bit in the lyrics) but totally different -- it's just him and a piano.
Joshua Redman covering Baltimore (jazzers doing contemporary is old and important!) is how I found Kahane, and it's still my favourite track.
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Glad The Ambassador landed! His self titled album from 2010 has both a track that sounds soooo much more like Sufjan, and a separate track that actually has Sufjan. But my second fav is actually Book of Travelers:
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Hot day for lasagna. Braver man than I am.
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That was clear, I think!
Keep meaning to recommend Gabriel Kahane's The Ambassador, but don't want to write an essay, so: my new obsession. Concept album about LA.. So many styles. Blade Runner speech as lyrics, title track's like Paul Simon, funny bits about Die Hard, Pulp Fiction.
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I will listen! But not until I've mentally recovered from end of term.
But I'm amused you stopped just before Ghosts V, as after an episode of The Bear was essentially a music video for Together I've actually listened to that whole album a few times, and Together many.
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Was really surprised when I got two weeks. It was in my head as "standard" but I figured it was an old, corporate American number, and that working for a UK Uni in the 21st century it would surely be better...
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This isn't making me feel any better.
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my fav edit of that
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Ah, that's interesting -- it's the only one I've read, had no idea the interiority wasn't her standard m.o., but now I'm very curious to see what she does with text messages.
I got hooked early on, when Peter thinks a line from one of my favourite poems:
www.poetryfoundation.org/poems/46461/...
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Know that album well thanks to my brother.
Nintendo with an album on also makes me think of my brother -- he got The Cardigan's First Band on the Moon the same birthday he got Donkey Kong Country, and after playing them together they're forever linked in my head.
(o.g. battle mode fav Mario Kart)
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Except it was me typing on my phone and supposed to be book 😬
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I don't understand metal. Fascinated in a slightly horrified way at its division into a million tiny subgenres.
Me being me, this is making me want to read an essay about the difference between metal and rock.
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Screaming at the end of Six Shooter was starting to great but then they pull me back with a song in 5/4.
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First thoughts as I listen while doing dishes: much more Metal than I expected from Nobody Knows, but not so Metal I've felt the need to switch it off. Yet...
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I have never listened to more than a few singles from QotSA but they were great so sensing maybe I should...
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Somehow I'm drawn to two, the most classic looking.
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Yeah, Desmos doesn't have great support of this, people have cudgeled it together like here: www.desmos.com/calculator/y...
But it is messy.
It's probably useful to simplify even further, and look at vector fields (x,0) and (y,0), where drawing just a handful of arrows gives a good understanding.
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Maybe also worth pointing out that "water being created" is sloppy, and really what's happening is "density of water is increasing at that point". Vector fields with divergence zero are called "incompressible flow" because the density of material at each point isn't changing.
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I'm a pure mathematician but I guess the units make sense that way -- vector field would have units kg m/s. The divergence takes x,y,z derivatives so should change the units by dividing by m, giving kg/s.
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The vector field would be measuring the direction and speed the water was flowing at each point; I guess more formally something close to the 'momentum' of the water? The divergence would be something like change in mass of water at that point with respect to time?
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And hopefully this story gives some heft to the intuitions that "divergence measures how much water is created at a point" and "curl measures how the water spins around a point" so that they have some meaning and aren't just empty slogans.
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And they're planar, so we can draw a bunch of vector fields of form (by,cx) for various b, c, or make a slider on Desmos, and see what they look like. And similarly, (ax,dy), and see what *they* look like. And add a few to see what the more general ones look like.
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Well, curl of this will point in positive x direction with size c-b. Doesn't actually depend on a and d! Though note the divergence of this will be a+d. So we can split our simple vector fields into the sum of two parts, one with curl=0, and one with div=0.
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Another assumption: what if components of v had convergent Taylor series? It'd just be the linear part that the curl sees. So, really we've reduced the problem of understanding curl to understanding what curl does on vector fields of the form (ax+by, cx+dy) for some constants a,b,c,d.
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Let's simplify further, and just try to understand this at the origin. So we've got a planar vector field, we're going to take some x and y derivatives of its components, and then plug in x and y equal zeroes. *Most* of the information of v isn't going to matter. Which part will?
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I think what was satisfying to me is related to this if vector you're dotting is (0,0,1), so we're just trying to understand the z component of curl.
This only depends on the x and y derivatives of the x and y components of our vector field, so we can look at a planar vector field.
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Watched it in the theatre, and there were some chuckles and groans at this point.
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No hurry, shipping it to my folks on the US to bring over here later this summer.
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Trollolol.
My answer in this vein:
youtu.be/q3frGahV51E?...
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Just ordered the sheet music! Never been a big singer so curious to see how I find it...