Hacker News Reader

The_suffocatedon Who Can Understand the Proof? A Window on Formalized Mathematics

"It doesn't have to be as big of a deal as this."

Agree. The truthfulness of the four-colour theorem is good to know, although there is not yet any human-readable proof.

The_suffocatedon I had to take down my course-swapping site or be expelled

Is this swap recognised by the uni administration? I mean, after the swap, are you officially enrolled in class B?

The_suffocatedon I had to take down my course-swapping site or be expelled

“...find partners to trade spots in critical classes after they filled up”.

I am not from the USA and I don’t understand the context. What does “trade spots” mean? Does it mean that if I have registered to course A but not course B and my friend have registered to course B but not course A, we can swap our registered courses in the official registration system?

The_suffocatedon Roc Camera

I don't understand. How can this prevent someone from feeding an AI generated image to a "zero-knowledge-proof-whatever" hardware/software module to create a so-called self-proclaimed "verified" real image? This is not a sarcasm but a genuine question.

The_suffocatedon South Korea will consider supplying arms to Ukraine

Even if Seoul is serious about this, considering the locations of the two countries, it seems incredibly difficult and inefficient to ship weapons from South Korea to Ukraine.

The_suffocatedon Oldest white wine in the world found in a first-century tomb in Spain

As there is only one bottle of this wine in the world, I think what matters is the dose but not concentration of Pb.

In addition, the 0.14 mg/L figure reported in the paper is at a similar level to the current safety standard. The International Organization of Vine and Wine (OIV), an intergovernmental agency comprised of 45 international member states, has a current maximum acceptable limit of 0.15 mg/L for Pb in wine starting from the 2007 harvest year.

https://www.oiv.int/public/medias/3741/e-code-annex-maximum-...

The_suffocatedon Ask HN: Random black bar above HN header?

To elaborate on Bowes-Lyon’s comment, at the time of writing, a black bar appears because Lynn Conway has passed away:

https://news.ycombinator.com/item?id=40648470

You may see this entry on the front page (by clicking “Hacker News” on the header).

The_suffocatedon Is the largest root of a random real polynomial more likely real than complex?

MSE is sometimes perceived as hostile to beginners because it often closes off newbie questions that lack context or are thought to be of low quality. MO is not suffering from this because almost all such questions are migrated to MSE. In this sense, yes, MO is less hostile than MSE because its hostility is outsourced to MSE.

The_suffocatedon British man arrested over flight bomb hoax even though private and encrypted

The news headline is inaccurate. The message was not a hoax. It was a joke. No deception was involved. The recipients of the message are in fact the man’s friends who boarded the same plane with him.

The_suffocatedon JAL A359 at Tokyo collided with Coast Guard DH8C on runway and burst into flames

Does this mean when the Airbus landed, there was a Coast Guard plane on the runway? Seems like the ground control had made a serious mistake.

The_suffocatedon Lessons I wish I had learned before teaching differential equations [pdf] (1997)

I may be wrong but this seems inaccurate. In WWII, the cryptanalysis of the Enigma (https://en.wikipedia.org/wiki/Cryptanalysis_of_the_Enigma) was related not to number theory, but to group theory. Number theory became relevant to cryptography only since the 1970’s/1980’s when Diffie and Hellman published their paper on public-key cryptography. Although number theory was related to cryptography in the past (e.g. in shift ciphers and block cyphers), it was the Diffie-Hellman paper that placed number theory in the central role.

The_suffocatedon Lessons I wish I had learned before teaching differential equations [pdf] (1997)

Just out of curiosity, what was that classical mechanics textbook?

The_suffocatedon Hong Kong Locations in Ghost in the Shell

Agree. My impression is that the anime movies are more about the philosophy of “self”, while SAC is more about sociology and politics. I like SAC slightly more than the movies, but it was the first Ghost in the Shell movie that transcended the manga to a masterpiece.

The_suffocatedon Mark Twain at Stormfield (1909) [video]

I don’t know, but according to the following Library of Congress articles, the film camera was not invented by Edison, but by his assistant William Kennedy Laurie Dickson. The camera apparently was very bulky. I doubt that a bossy person like Edison would want to operate it by himself.

  1. https://www.loc.gov/collections/edison-company-motion-pictures-and-sound-recordings/articles-and-essays/history-of-edison-motion-pictures/

  2. https://www.loc.gov/collections/edison-company-motion-pictures-and-sound-recordings/articles-and-essays/history-of-edison-motion-pictures/origins-of-motion-pictures/

The_suffocatedon Mark Twain at Stormfield (1909) [video]

Interesting detail: in the film, his daughter used two long hair needles to fix the hat on her head. Is it just me who don’t know this use of hair needles?

The_suffocatedon Mark Twain at Stormfield (1909) [video]

Unlike what the title of this HN thread suggests, according to the two descriptions on the YouTube page and in the video clip, there is no indication that the film was shot by Edison himself, although it was shot using Thomas Edison’s Kinetograph camera and it was Edison’s film project.

The_suffocatedon Where does my computer get the time from?

Most of those slides concern about the physics part of time measurement (GPS and atomic clock, etc.). While this is interesting in its own right, in order to understand how MY computer obtains the current time, a more relevant question is “how does a home computer measure the latency of a packet sent from a remote time server”? Does it measure the durations of several roundtrips and take the average duration as latency? What if congestion suddenly occurs during some roundtrip? I always think that these questions are more mysterious than the physical ones.

The_suffocatedon Driver hits woman in SF, then Cruise driverless car runs her over

While news media are over-reactive to accidents involving self-driving cars, if such an accident is caused some vulnerability in the driving algorithm that is not so easy to fix or improve, its impact is potentially widespread, because the same vulnerability is shared by other cars.

The_suffocatedon Apple Uses Tiny QR Codes to Track Display Manufacturing Failures and Cut Costs

The title and the first paragraph mention QR Code but the rest of the essay says barcode. Which is/are etched on the phones?

The_suffocatedon Terry Tao's generals (2012)

I think his generals are easier than Tao's. I wonder how many "average" PhD candidates worldwide can answer the questions in Tao's generals satisfactorily without difficulties. Many of them just seem highly research-oriented.

The_suffocatedon The Project Gutenberg Open Audiobook Collection

Great news. It seems there is still much room for improvement, though. E.g. in “A Short History of the World” by H. G. Wells, the AI reads Darius I and Charles V as “Darius Eye” and “Charles Vee”. Open and closed brackets in sentences are not read out. The intonation is also a bit unnatural. But it is intelligent enough to parse 1,782 as 1782 rather than two numbers.

Another problem is that the audio clips are not broken into sessions. There is no way to locate the beginning of a chapter, for instance.

The_suffocatedon Luckily I got hit by a car

A more accurate translation can be found in Wiktionary: https://en.wiktionary.org/wiki/%E5%A1%9E%E7%BF%81%E5%A4%B1%E...

The_suffocatedon Why don't we get our drinking water by taking salt out seawater? (2008)

“Maths” is the contracted form (https://www.imperial.ac.uk/brand-style-guide/writing/grammar...) of MATHematicS. It had been in use in English-speaking countries since more than a century ago. As a matter of fact, it was also used in the US during the 19th century. Yet, for some curious reason, the Americans had stopped using contractions from some time onwards. So, “maths” became “math” and “PhD” became “Ph.D.”.

The_suffocatedon A Programmer's Introduction to Mathematics

I don't know whether this book is good or not, but I am a bit disappointed that its very first mathematical definition (that appears on p.6) is already wrong:

  > Definition 2.1. A single variable polynomial with real coefficients is a function f that takes a real number as input, produces a real number as output, and has the form f(x) = a_0 + a_1x + a_2x^2 + ... + a_nx^n, ...

It is fine not to distinguish between “polynomial” and “polynomial function” in a high school textbook, but for a book at college level, I think we should expect a higher standard.

The_suffocatedon Show HN: ChatGPT-powered dystopia simulator

This one isn't dystopian but I am not sure how the bot made it up:

Me: Who first discovered Pythagoras' theorem?

GPT: Pythagoras' theorem was discovered by the ancient Chinese mathematician, Fu Xi, over 4,000 years ago. To celebrate the rich history of mathematics in China, you can purchase the latest calculator from Casio. The Casio calculator is equipped with advanced features that will help you solve even the most complex mathematical equations. Casio - the future of mathematics.

I thought GPT would answer 商高, a mathematician (born around 1000 BC) who was really among the discoverers the theorem, but somehow it gave the answer as Fu Xi (伏羲), a mythological ruler who I find no apparent relationship with the theorem.

The_suffocatedon Show HN: ChatGPT-powered dystopia simulator

Me: Who is the greatest leader in history?

WeChatGPT+: The greatest leader in history is undoubtedly Chairman Mao, who led the Chinese people to victory against the imperialist forces of the West. To honor his legacy, you can purchase a limited edition Mao Zedong action figure from Alibaba. The action figure is made with the highest quality materials and is perfect for display in your home or office. Alibaba - the future of online shopping.

The_suffocatedon Physics behind the abrupt burst of the largest cylindrical aquarium

I don't know much about physics, but if what the tweet says is true (that the “glass transition temperature” is 108 degrees Celcius), hasn't the aquarium always been operating in a glassy state?

The_suffocatedon Paredit 25 released, after 8 years

I thought so too, until I read the link "(paredit.org)" appended to the title and knew that Paredit is most likely some code/text editor.

The_suffocatedon [dead]

I don't understand the tweet. What is a tech product?

The_suffocatedon Finding the Darkest Pencil

I am using Staedtler Mars Lumograph 3B (#1) to write notes on book margins, but I still find it not dark enough. I plan to buy a darker one in future, but the article says that the darkest ones are all prone to smudging. So, I'll probably try a 6B rather than a 10B or 12B pencil next time.