u/ExternalBoysenberry

It feels like the window of time where this myth could make sense is pretty narrow. It's hard to imagine this story having much appeal before or during, say, the Trail of Tears. Maybe I'm mistaken but it feels like policy in this time must have relied on racism and dehumanization of Native Americans being widespread. But waiting a generation past the Trail of Tears (so the myth imagines a princess in an then-intact-now-vanished society, rather than positioning grandma as a victim of forced displacement whose family is currently struggling in an unfamiliar reservation) basically puts you in the 20th century. Anecdotally, I encountered this myth more than once in the 1990s. So that leaves only a handful of decades, and fairly recent ones, for the idea to become appealing, take the specific form of a Cherokee princess, and become widespread in white families. How much do we know about how this idea crystallized and propagated?

Even when he was a young man, many parents would struggle with the idea of their asthmatic son taking breaks from medical school for eg a motorcycle trip around South America. And in this answer, u/police-ical quotes from a letter he wrote to his mother from Guatemala (after becoming a doctor but before becoming a revolutionary) where he basically says "well I could easily become rich here by opening an allergy clinic but that seems very uninspiring so no".

And then on top of that, to watch him ultimately decide that, instead of simply taking this professional success that offered safety and stability, to decide to become a guerrilla in an even more distant foreign country. And the. on top of THAT to watch him continue to raise the stakes and become a global revolutionary icon. AND STILL not enough, he then remains unsatisfied with his revolutionary success in Cuba, where he could have remained a minister and diplomat or even opened his clinic... but instead to go back to becoming a guerrilla in yet another country. And if I understand correctly, through all this his parents were basically going about their normal day to day lives in the suburbs in Buenos Aires or whatever.

Later in the thread, u/police-ical mentions that Che and his mother remained close, she probably encouraged his leftist tendencies somewhat, while his father was more regretful. Considering his worldwide fame, is that all we know? Did journalists or biographers (or spies?) try to find out how they felt about all this? Did his mother support his decisions and activities or did she more agree in principle ideologically but try to nudge him toward a safer path? What was it like being Che Guevara's parents?
https://www.reddit.com/r/AskHistorians/s/W0OKEh9Qvj

I don't mean: why are there so many people of Turkish descent in Germany? In general terms I'm aware of the Gastarbeiter history and so forth, as well as more recent immigration from the Middle East during the refugee crisis a decade or so ago. I'm more asking about the specific association between these groups and barbershops/hair salons.

For example there are also a lot of people with roots in Italy and Poland in Germany, and to a lesser extent Vietnam. And there are many jobs where people who are immigrants themselves or who have a migration background (Migrationshintergrund) in general are disproportionately represented, like construction or food delivery. My question is more: why is the ratio of (number of residents with Polish background):(number of Polish barbershops) seemingly so low relative to the same ratio for people with a Turkish background? (I am being a bit loosey goosey with the Middle Eastern aspect to my question because it's more anecdotal than A Familiar Cultural Reference). If this is common outside of Germany I would be interested to hear about whatever country you happen to know about.

Or more generally: how do certain immigrant communities come to be associated with certain professions, and other immigrant communities with other professions?

PS As a possibly unrelated association/side question: Turkey is a popular destination for medical tourists seeking hair transplants, including for people from the US who might go somewhere closer, like Mexico, for other procedures, like dental work . Is there some larger association with Turkey and being good at hair stuff?

Or for mass imprisonment generally, or Holocaust operations (sorry I don't know or can't think of the umbrella term for all the rounding up/shipping/numbering/locking up/etc going in during Nazi times)

I live in Munich. If I go to a bar/pub/Biergarten in normal tjmes and order a beer (ein Bier) I will receive half a liter (50 cl) unless otherwise specified. If however I'm at some Bavarian festival - spring (Frühlingsfest), a local town festival (Volksfest) or of course Oktoberfest/Wiesn - and I want a 50cl beer, I have to ask specifically for a "half" (eine Halbe), as in "[half of a standard] measure" (Maß).

When and how did this become the festival standard? Was it once the universal standard? If I take a classic Maß with me into a time machine, how far back can I travel before somebody says "That's a weird glass" either in terms of its shape or size? The Maß has to be older than Oktoberfest itself, right? If not in its current glass form then at least in its approximate volume?

(Note: I am not German. If you are German and feel I have some part of the premise wrong, before posting your correction, be kind to the mods and check this sub's requirements for top-level comments. If your correction doesn't qualify, PM me and I will edit it in)

When I read history, unless it's explictly about environmental change I tend to imagine natural landscapes as I know them and just adjust, like, people's clothes and the buildings and so forth. I imagine that since previous generations had their own baselines, outside of naturalists or travel narratives, mostly these qualitative differences would have gone unremarked upon but would really stand out to, say, a time traveler.

Do you tend to get hints of this in your area of study? Does it take special effort to remember or communicate that when someone mentions strolling through a grove of old American chestnut trees, they were possibly immersed in a world that was unremarkable to them but which might be difficult for us to imagine? If we could bring Caesar to a rural farm today in a location where had once camped on campaign, would he find it unsettlingly quiet—not enough insects and birds and frogs, rivers emptied of fish, etc.?

(To be clear, I don't assume we are currently at peak ecological degradation today at every single location on the planet. I'm sure some of you study periods where the local environment was much more degraded than in the same area today. But the general trend is toward dramatic biodiversity loss and environmental degradation.)

Not sure where it comes from but I've always had a bit of a anachronistic cartoon idea of pre-preacher Jesus: he works as a carpenter, has his own house or apartment where he lives with family members or roommates, works during work hours and does kinda domestic stuff outside of that. I guess sometimes goes for religious services in something like a temple where everybody shows up at a certain time in nice clothes, listens to a sermon, and then goes about their day. He gets baptized by John and starts to attend like a fairly intimate study group type thing where he gets some one-on-one tutoring with his new teacher, they debate stuff, hang out late into the evening, John takes a liking to him, Jesus is talented and maybe feels divinely inspired, eventually leaves his day job to go start a nee career as an itinerant preacher too.

AFAIK there's zero reason for that model! Might followers of an apocalyptic preacher like JtB have lived in an insular little culty group? Dressed in a way that marked them out, like Mormons or Hari Krishna? Had to be secretive? Did they travel around together, like organize trips to teach in other cities?

Is there any reason to think Jesus would have actually had a day job as a skilled laborer at any point in his life (before or after he started his movement)? Maybe his only interaction with JtB was this one single baptism and his info about what he preached was all second and third hand. Maybe John had his own office in the temple and had a professor like arrangement where even if he had his disagreements with the Pharisees and Sadducees the environment was collegial and they got preaching stipends or whatever, had scheduled time slots to preach where they debated and trashed each other. Or maybe the whole thing was more like a crazy homeless guy in NYC with a THE END IS NEAR cardboard sign type vibe.

My point with all this rambling is just to make it abundantly clear that I have really sincerely zero clue what the institutional and microeconomic context of this kind of occupation would have been, either for a well known guy like JtB or for an up-and-comer trying to break into the scene. Would they have some kjnd of small donor network? Patrons, wealthy benefactors?

I understand we probably don't have historical information answering this specifically, but do we have a general idea of what this kind of thing might have looked like on the ground in kind of a mundane day-to-day way?

This post is an attempt to entice u/gerardmenfin to add a third installment to his incredible two-part series addressing "Well [absurd action] my [body part] and call me [name]!" and "No way, José". As a followup to the main question, I'd also like to know: How much lag time was there between "see you later alligator" and "in a while, crocodile" or did they emerge more or less simultaneously?

And if serious geographers were pretty much on the same page, did it put to rest any popular conspiracy theories or urban myths?

I unfortunately joined this sub after purchasing lol and am constantl seeing posts telling people to get the 24GB. In terms of like my observed performance the 16GB M5 is totally fine for me, it does what I need no problem. But I see that it often uses swap so I don't want to like degrade the machine either. Not sure if I'll lose more value by doing an insta-trade-in just past the return window or if I should just try to go easy and keep it for as long as possible. What do you guys think?

Edit: To be clear the problem in this question is not THE problem I'm working on, its a calculation we are doing in the context of the larger problem. But it's an important calculation I'd really like to understand, even if it is very simple and obvious and trivial for you guys

Hi everyone, I’m a PhD student working on a problem in an economic subfield (but am not primarily an economist). We've approached it algebraically but I suspect that there is some kind of complex analysis answer, but I'm below average in formal math training and didn't feel I could specify with confidence.

The problem we're working on seen as a bit esoteric in our discipline but we feel we have a very simple resolution. We can get to a convincing (and numerically correct) result that's needed for the decision problem, but I'm uncomfortable with an intermediate step on the way to that result.

I am 100% sure that, mathematically, we have not done anything innovative. I'm hoping that this sub can help me figure out the term for the transformation we did, so that I can find applications/analogies in other areas to help explain/contextualize the weird intermediate value. Or, failing that, to at least learn something new lol

tl;dr

Given

S* = x/(1-(1+i)) = -x/i

how should I interpret the finite negative value

(-i)S* = (-i)(-x/i) = x.

when it is not the ordinary sum of a diverging series (which is infinity), but still lets me recover the correct annuity? I'd be incredibly grateful not only for explanations, but also any links to explanations, or even just a term that I could search for!

THE problem

We have a constant payment x > 0 each period over an infinite horizon. The standard move is to apply exponential discounting at rate r > 0, so the present value is

PV = ∑ x(1+r)^(-t) = x ∑ q^t

where q = 1/(1+r), so |q| < 1. (Sorry, couldn't figure out how to do the index and upper limit on the summation). Simplifying as a geometric series gives the closed-form expression:

PV = x/(1-q)

In our problem, these payments are compounded rather than discounted (equivalently, discounted at a negative rate). So instead of q < 1, we have

q = 1+i > 1

Summing up to horizon N

S_N = ∑ x(1+i)^t = x ∑ q^t

As the horizon extends, the undiscounted sum diverges to infinity, the compounded value of the last payment does too, and of course the compounded sum does as well. But there's nothing stopping you from just plugging the negative rate into the geometric series expression... except for the fact that, when you solve it mechanically, it gives you a finite negative number.

S* = x/(1-q) = x/(1-(1+i)) = -x/i

Initially, I interpreted this number as a weird algebraic artifact - just something that happens when you abuse the formula. This finite negative number is btw partly why this problem has been almost totally ignored by my discipline.

Then we had the bright idea that, even if the present value expression doesn't make any sense, why not just work with the annuity instead? To get that, you multiply the definitely-not-a-present-value finite negative number by the (negative) discount rate:

(-i)S* = (-i)(-x/i) = x.

This not only gives a finite positive number, but actually the correct finite positive number. We can confirm this by just picking some random horizon N, taking the present value of the compounded (i.e. negatively discounted) payment stream up to that horizon, and then dividing it up into equivalent annual payments.

So: when the rate is negative, the real present value is infinity, the geometric series expression still works, but yields a finite negative number, which we would typically just dismiss as an abuse of the formula... except for the fact that this finite negative number can always be used to get the correct annuity.

MY problem

WHY?? What is this number?

It's driving me crazy. It really feels like this finite negative number shouldn't mean anything... but it clearly contains some important information, because if you just multiply it with a constant everything is fine!

As you can see, there is no genius mathematical innovation happening here. I'm sure this is something I can just look up and learn about. I bet if I had taken complex analysis or understood, like, Ramanujan's oft-memed -1/12 result, then I would be in a much better position. But I haven't and I don't.

I also bet that other fields have to do a similar transformation. Finance? Actuaries? Economist-economists who have a broad view of the field (vs me looking narrowly at this one subfield that has collectively decided to ignore this topic)?

I posted this yesterday to r/learnmath and got some helpful comments from u/Bounded_sequencE and u/jdorje but I was not quite clever enough to get from them to actually figuring out what's going on. I definitely am tempted to read u/jdorje's take as a suggestion to just ignore it (and then to follow that suggestion). But I would love to have an intuition for what's happening.

Can anyone tell me the name for what we did? Is this an example of regularizing a diverging series? Is this a common move in any field of application that I can learn about by analogy?

(If anyone read this far down - thank you sincerely)

The premise is coming from a great recent thread from u/FriedaKilligan. I'm curious how music historians think about the evolution of how masculinity is performed in rock after grunge's challenge, particularly with respect to the emo/screamo years including more pop-emo acts like MCR and AFI.

Hi everyone, first time poster here, apologies in advance if I make mistakes or break the etiquette.

Full disclosure, I am asking a question that has something to do with my work. I'm a PhD student in a quantitative discipline (not math) who is not very mathematically sophisticated.

I'm working on a manuscript where we take up a problem that's seen as being a bit esoteric in our discipline but, we decided, actually simple. We provide an analytical treatment but I am uncomfortable with a key step. I am 100% sure that, mathematically, we have not done anything innovative - our contribution is purely that the question itself is somewhat novel. I'm hoping that this sub can help me figure out the term for what we did, so that I can find applications/frameworks/analogies in other subdisciplines to explain or contextualize the result.

I'm not primarily an economist but this problem is situated within economics. I don't know how to format equations here but I think the problem is simple enough that I can describe it narratively. If it's helpful, just let me know and I will write some equations in R syntax or something.

The problem

We have a series of identical periodic payments across an infinite time horizon. The sum of this series diverges to infinity. In the typical version of the problem, these payments are assigned an exponential discount rate (causing the series to converge) and simplified as a geometric series to give a closed-form expression that yields a finite present value.

In our problem, these payments are compounded rather than discounted (equivalently, discounted at a negative rate). As the horizon extends, the undiscounted sum diverges to infinity, the compounded value of the last payment does too, and of course the compounded sum does as well. If you do the compounding by just inputting a negative number for the discount rate, you can mechanically solve the closed-form geometric series expression, which yields a finite negative number.

Initially, I interpreted this number as a weird algebraic artifact that arises in an intermediate step - just a weird thing that happens when you apply the closed-form expression outside its domain (the actual present value, again, is unbounded).

What we ultimately want is an annuity of the diverging series. To get that, you multiply the definitely-not-a-present-value finite negative number by the (negative) discount rate.

This not only gives a finite positive number, but actually the correct finite positive number. We can confirm this by just picking some random horizon, taking the present value of the compounded (i.e. negatively discounted) payment stream up to that horizon, and then dividing it up into equivalent annual payments.

My problem

I don't know how to make sense of the intermediate step where the closed-form expression is applied outside its domain to yield a finite negative number. It's driving me crazy. Can't wrap my head around it. What does this number mean? It feels like it shouldn't mean anything, but it clearly contains some important information because we can use it as a vehicle to get to the correct annuity by doing nothing more than multiplying it with a constant.

Clearly there is no genius mathematical innovation happening here. I'm sure this is something I can just look up and learn about. I would love to have an intuition for what's going on in this step. Can anyone tell me the name for what we did? Is this an example of regularizing a diverging series? Is this a common move in any field of application that I can learn about by analogy?

(If anyone read this far down - thank you sincerely)

Is joining one a fun and exciting prospect or is it more like jury duty? Do I hate the idea of riding all day in the hot sun squinting at the horizon and hoping I don't get shot or hurt my horse or is like a cool pursuit? Am I motivated by anger like a lynch mob or am I just solemnly doing my manly duty to keep the community safe?

Anyways it's my daughter's birthday today, can I get off with a "Maybe next time fellas, good luck?" My friend has plans on Thursday he needs to be back for, so he can only join for a couple days, is that cool? The sheriff seems incredibly dumb, it's hot, my little brother is annoying the hell out of me, he didn't bring enough food and is eating all of mine, the excitement is wearing off, had to close my store and I really need the money, who's going to wrangle my cows, I really have to finish planting.

Is there anything stopping any of us from saying "This sucks, I'm headed back"? If my horse gets hurt do I get compensated? If I get killed who watches out for my family?

Maybe I'm cynical but it doesn't really feel like our thing. Was there something exceptional about the circumstances around this specific suspension?

Did he need to supplement his income as a physician, or take a sabbatical to do some photography, did it have some revolutionary aim, or what?