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jfzoid

51 karma · joined February 1, 2021

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jfzoid··on Airbnb nightly rates shot up 36% in 3 years
For what it's worth, I logged into AirBnb just now and it showed me an option to "Display total price: all fees before taxes"
jfzoid··on Ask HN: Great text based games to play?
Planetfall Enchanter Trilogy Starcross (took place inside a space station -- map was wrap-around) Suspended was harder but definitely very good
jfzoid··on Zoo Vadis, or how to breathe new life into a thirty-year-old classic
Reiner Knizia is my favorite game designer of all time. I love how he takes familiar games and "bends" [1] them into new games by applying the right incentives into other games. For example, Lost Cities starts off looking like Solitaire, but when I play it I feel like I am using skills of reading my opponents hands that I learned from my (brief) bridge days.

If you are a gamer, I cannot recommend highly enough Tigris and Euphrates, Ra, Lost Cities, or Samurai

[1] I am trying to make a General Relativity metaphor here.

jfzoid··on How transportation technologies shaped empires
Chinese saying: "the mountains are high, and the Emperor is far away" (山高帝遠)
jfzoid··on Ask HN: Why is the wait for the new iPhone or gadget not as rousing as before?
for me, after obsessing over this for a few model releases, I realized that most years the new model doesn't add that much I really need.

Usually it is a faster CPU, which matters less than it sounds because most things I do on the phone are messaging or talking to a web service, not CPU bound, or camera tweaks.

jfzoid··on Three things for the next 100 years of Computer Science
When I was in high school I used to dream about sticking high speed ethernet ports into my skull (because reading on a screen was too slow, plus this was the 80s and we though Neuromancer was really going to happen)

Now I realize 1. I don't want buggy hardware in my head 2. I don't want to go to the surgeon ("wetdoc" or whatever the Cyberpunk RPG called it) every time a new model comes out

jfzoid··on The Generation Ship Model of Software Development (2014)
that was a fantastic book, and the Arguing On the Internet in it was both very descriptive of it's time and very prescient of ours.

and the aliens (no spoilers) in it were very cool

jfzoid··on I quiz ChatGPT about math
I just tried doing this myself

JFZ: how do we know there are infinitely many primes

ChatGPT: One way to show that there are infinitely many prime numbers is to use the fact that the set of prime numbers is infinite to show that there must be an infinite number of composite numbers as well. Composite numbers are positive integers that have at least one positive integer divisor other than 1 and itself. For example, 4 is a composite number because it can be divided by 2 (and is not prime), and 6 is a composite number because it can be divided by 2 and 3 (and is not prime).

To show that there are infinitely many composite numbers, consider the sequence of numbers 2, 4, 6, 8, 10, 12, 14, 16, and so on. Each of these numbers is composite because it can be divided by 2. Now consider the sequence of numbers 3, 6, 9, 12, 15, 18, 21, 24, and so on. Each of these numbers is composite because it can be divided by 3. And so on. For every prime number, there is an infinite sequence of composite numbers that can be generated by multiplying that prime number by other positive integers.

Since there are infinite sequences of composite numbers, and each composite number is the product of at least two prime numbers (for example, 12 is the product of 2 and 6, which are both prime numbers), there must be an infinite number of prime numbers as well. This is one way to show that there are infinitely many prime numbers, though there are other ways to prove it as well.

(seems hand wavey, and probably wrong though I can't figure out where the flaw is)

JFZ: is A5 a solvable group

Yes, the group A5 (also known as the alternating group on 5 elements) is a solvable group. A group is solvable if it can be constructed from simpler groups using only group extensions and group quotients, and if it has a composition series in which each factor is a simple group. (wrong)

The group A5 is the group of even permutations of five objects. It has 60 elements, and it is isomorphic to the group of rotations of a regular dodecahedron. A5 is a simple group, which means that it has no proper normal subgroups (subgroups that are normal in the group but not equal to the group itself). This means that A5 cannot be constructed from simpler groups using group extensions or group quotients. However, it can be shown that A5 has a composition series in which each factor is a simple group, so it is solvable.

In general, many groups that arise in mathematics and physics are solvable, and the study of solvable groups is an important area of research in group theory.

jfzoid··on Ask HN: What made you finally grok Git?
this video where he explains Git's dag with tinkertoys https://www.youtube.com/watch?v=3m7BgIvC-uQ
jfzoid··on Illegal host, electric shocks, slugs, leaks and no support – How Airbnb failed
> Just because some tech bros with sexist issues can make an app and a service without customer service does not mean jack shit.

this is an ad hominem attack and not helpful -- Kalanick's personal problems are separate from Uber's product and services

jfzoid··on The Raw Truth About Lox (2003)
According to this article, the word "lox" hasn't changed in 8000 years https://nautil.us/the-english-word-that-hasnt-changed-in-sou...
jfzoid··on Ask HN: YouTube Channels for the Intellectually Curious
PBS Spacetime (physics) PBS Eons (paleontology) Cody's Lab and Nile Red (chemistry) 3blue1brown (mathematics)
jfzoid··on Half of Americans anticipate a U.S. civil war soon
One thing that gives me comfort is that there is a difference between what they say on a poll, and what they actually do.

Plenty of people are willing to say "I am willing to commit violence" on social media. My gut feeling is that if 4% say they will shoot someone, < 0.4% will actually do it.

jfzoid··on Ask HN: What's your favorite board game?
The greatest ever. A true maestro
jfzoid··on Why roller coaster loops aren’t circular anymore
The book Curves for the Mathematically Curious ( https://press.princeton.edu/books/hardcover/9780691180052/cu... ) has a whole chapter about the shape used instead of a circle, complete with equations and derivation. Highly recommended
jfzoid··on Ask HN: What's your favorite board game?
for four players: Tigris and Euphrates

for three players: Ra

for two players: Quest for El Dorado or Azul

for solitaire: Agricola

Go is on my bucket list, I'll get "around to it" once I get some other stuff off my bucket list.

jfzoid··on Ask HN: Is there a TV on the market without “Smart TV” features?
and wouldn't it be great if the people on that committee acted in the consumers best interests?
jfzoid··on Citigroup plans to hire 4k tech staff
I live in NYC so many of my friends and colleagues have had tech jobs in the well known banks. Here are some of the data points I've collected.

Person 1 says there is a lot of politics, ass-covering, and throwing under the bus

Persons 2 and 3 says back in the 80s and 90s there were a lot of exciting projects, but now it's all maintenance work and making sure money train does not stop.

Person 4 says at his company they tracked how much money your bugs cost the firm, and at the end of the year if that number is too high, you're fired.

Person 5 corroborates what Person 4 said, adding that no one is allowed to touch production -- you touch production and you might cause an outage in some part of the company you never heard of, next thing that happens is Security shows up at your desk with cardboard boxes telling you to pack your stuff.

Person 6 says for the same reasons no one is allowed to touch the base classes you inherit from -- people just make their own copy of the base class and make their changes to it. The code base is littered with many copies of the same file each different in its own way.

Person 7 flat out told me "you are too nice, you will get eaten alive at a financial services firm"

Person 8 says he was not allowed to talk to or collaborate with a colleague because they worked for competing managers, they had to leave the office to collaborate

jfzoid··on Poll: How are you doing currently?
I voted Mostly Good -- I feel valued at work, and employer puts an emphasis on work life balance, which lets me spend time with my family, deal with things like doctor appointments. Took a vacation day today and trying to crack open a book about Galois Theory.

I tend to be "stubbornly optimistic" about the future, and I keep telling myself that on a long timescale (compared to 50-100 years ago) qualities of life are much better, but recent events have made me very concerned about my family's safety, and from there I started worrying about social media echo chambers and global warming.

jfzoid··on Apple Removes Flag Icons in Monterey 12.4
doubt it -- see my comment about how Chinese inputs are not using flags in Big Sur
jfzoid··on Apple Removes Flag Icons in Monterey 12.4
In Big Sur Apple was using a mix of flags and other icons. The flags seem to be for countries that use the Latin alphabet.

Playing around with the Keyboard Preferences, I've found:

Different Chinese inputs use different sinograms: the one for Pinyin uses the symbol for "Pin"

all Hebrew inputs use the Hebrew letter aleph

all Korean inputs use the same Korean symbol

all Thai inputs use the same Thai symbol

all Arabic inputs use the same Arabic symbol

Greek uses a lambda for one input and an epsilon for the other Russian curiously uses a Russian flag and not a Cyrillic letter

jfzoid··on Review of Lessons in the Fundamentals of Go by Toshiro Kageyama (2011)
I have a copy of this book, though I never got past the few pages. When I tried to read it I got through the first chapter, which says the first thing one should do is play many games, and I put the book down to do just that.

It also makes a great point that while amateurs play the game for fun, professionals will labor at it. I thought that was a fantastic point

For context, I occasionally play against the AI on an iPad app called SmartGo, probably 24-36 kyu rank.

jfzoid··on The Ur-Quan Masters
An absolute classic. Happy campers are the best.
jfzoid··on Urea prices increase 270% in 1 year
remember, https://en.wikipedia.org/wiki/Pecunia_non_olet
jfzoid··on Work/life balance should be difficult
> Personally, I know that I need a focus for my intellectual life. It needn’t be employment, but “work” is a fair way to describe it.

"It is difficult for a man who always has a full stomach to put his mind to some use. Are there not players of liubo and go? Even playing these games is better than being idle." -- Confucious

jfzoid··on Japanese Philosophies That'll Help You Spend Money Consciously
Fancy business terms that'll help you spend money consciously:

1. Return on ROI: will I use this enough to get my money back

2. BATNA: is there something I can use that is an alternative (yes, I know not exact definition)

3. Opportunity Cost: what else can I buy with this. As I am writing this comment I am thinking to myself "a croissant and latte every morning, or sushi once a week"

4. Time value of money: is this saving me enough time to be worth it

jfzoid··on A Collector of Math and Physics Surprises
There is a very nice, very accessible series of topology talks he did here : https://youtube.com/playlist?list=PLTBqohhFNBE_09L0i-lf3fYXF...

Very early on he covers Möbius Strips and Klein Bottles (what most amateur mathematicians want to hear when they go to a topology video) and later on he touches on how Brouwer’s Fixed Point theorem relates to Nash Equilibriums

I’ve tried to learn topology several times and was bogged down in definitions of open and closed (and of course “clopen” sets) every time. His lectures were very refreshing.

(Long time lurker, I lost my login and created a new one just to share this)