1. A forged Apple employee badge
Total comment counts : 56
Summary
The article discusses a fake eBay auction for what was claimed to be Apple Employee #10’s employee badge. The author examines the pictures provided and discusses suspicions about its authenticity, which are confirmed by Apple Employee #8. The seller attempts to prove its authenticity with a German Red Cross proof, but the author points out inconsistencies and receives validation from the internet. The article concludes with the revelation that the item was sold before the post was finished, apologizing to the buyer who spent $946 on a fake item.
Top 1 Comment Summary
The article discusses the differences between typed text from electric typewriters and mechanical typewriters. The author explains that the smudginess of mechanical typewriters comes from the keys striking and releasing at the same speed the key is depressed, as well as the keys approaching the ribbon at an angle. In contrast, electric typewriters produce cleaner text by pre-buffering a line and using linear actuators and a rotating-ball type-head to apply high-viscosity ink onto the page. The article also mentions that the quality of the paper used can affect the appearance of the text.
Top 2 Comment Summary
The article highlights several issues with a faked Red Cross invoice. Firstly, the German date format is incorrect and should be written as DD.MM.YYYY. Additionally, the abbreviation for postal code (PLZ) is wrongly translated as ZIP. Moreover, the phrase “Wir danken für ihr Unternehmen” is a poor translation of “Thank you for your business” and actually means “Thank you for your company,” conveying a different meaning. Despite these flaws, the author acknowledges the effort put into creating the fake invoice and believes their friends would have unknowingly purchased the fraudulent Red Cross badge.
2. Computer scientists invent an efficient new way to count
Total comment counts : 51
Summary
The article discusses a new algorithm called the CVM algorithm that approximates the number of distinct entries in a long list. This algorithm is a significant step toward solving the distinct elements problem, which has been a challenge for computer scientists for over 40 years. The CVM algorithm works by relying on randomization and only requires remembering a small number of entries. The article uses the example of listening to the audiobook of Hamlet to explain how the algorithm works. By using this algorithm, it becomes easier to estimate the number of unique elements in a data stream without needing to store everything in memory.
Top 1 Comment Summary
The article discusses the implementation of the DNF volume counting version and provides links to a blog post and code related to this implementation. It mentions that approximately 30% of the time is spent on reading the file, highlighting the speed of the algorithm. The article also mentions that Knuth contributed to the algorithm and provides a link to Knuth’s notes on the subject. It notes that Knuth took a month off from TAOCP (The Art of Computer Programming) to work on this and describes him as “crazy good” and “mind-blowing.”
Top 2 Comment Summary
The article discusses a new algorithm called “CVM” that is similar to HyperLogLog in estimating values and tracking runs of heads or tails. CVM allows for efficient counting of distinct elements in a streaming case with a low error rate. HyperLogLog is praised for its ability to behave like a hash set, allowing for the addition of items, counting distinct elements, and merging sets while keeping memory usage low. The CVM algorithm has been reviewed by Knuth and is claimed to be easily implementable by undergraduates.
3. Exercises to Learn Rust
Total comment counts : 25
Summary
This article introduces a course called “100 Exercises To Learn Rust” that aims to teach Rust’s core concepts and syntax. The course assumes no prior knowledge of Rust or systems programming and covers topics such as memory management. It is designed to be interactive and hands-on, with exercises to reinforce learning. The course can be attended in a classroom setting or followed individually. Solutions to the exercises can be found in the GitHub repository. Each section of the course focuses on a new concept or feature of the Rust language and is accompanied by an exercise. The course provides a tool called “wr” to verify exercise solutions. It is recommended to clone the repository and work on a branch to track progress. The course was written by Luca Palmieri, an experienced Rust developer.
Top 1 Comment Summary
The article mentions a resource called Rustlings, which is a helpful tool for learning Rust programming. It provides files with todo statements that users need to fix in order to make the code compile and pass all tests. Rustlings offers an interactive learning experience and has been beneficial for many people who were learning Rust. The resource can be found on GitHub at https://github.com/rust-lang/rustlings.
Top 2 Comment Summary
The article mentions that the set of exercises in question was created by the author of “Zero to Production in Rust,” which is a well-reviewed book. The book has a cover depicting a human skull with a crab, and more information can be found at the provided link.
4. Visualizing algorithms for rate limiting
Total comment counts : 15
Summary
The article discusses the concept of rate limiting, which is used to control the rate of traffic that a service processes by blocking requests that exceed a set limit within a specified time period. Rate limiting is commonly used to prevent spam, brute force attacks, and resource monopolization by single users. The article explores three common rate-limiting algorithms: fixed window limiter, sliding window limiter, and floating window limiter. It also addresses the challenges of time zone considerations and daylight savings time in rate limiting. The article concludes by introducing the token bucket approach, which offers distinct burst and average capacities without the need for multiple rate limiters.
Top 1 Comment Summary
This article provides several considerations when implementing rate limits to protect against backend capacity issues and bad traffic. The main points are as follows:
Rate limits should be viewed as “policy” limits rather than complete protection against overuse of limited backend resources.
To protect against bad traffic, additional steps beyond rate limits may be necessary, such as traffic prioritization based on authentication status, user/session priority, or customer priority.
It is important to be prepared to communicate and take appropriate actions when rate limits are hit, especially from valuable customers or internal teams. Rate limits that are lifted only upon complaint are essentially advisory and do not effectively return a 429 error.
To avoid concertina effects, where many rate limits expire at the same time, a deterministic offset can be added to each user/session window to distribute the expiration times.
Overall, these considerations aim to improve the effectiveness and implementation of rate limits.
Top 2 Comment Summary
The article suggests that in a multitenant environment, implementing fair queuing is the best approach to prevent DoS attempts from affecting other tenants. Fair queuing involves assigning each client their own queue for incoming traffic. A background routine continuously goes through each queue, dequeues one request at a time, and serves it. This ensures that clients who spam requests will only impact their own queue and not disrupt other clients’ queues.
5. Growing sodium chloride crystals at home
Total comment counts : 14
Summary
The article discusses a method for growing transparent sodium chloride (table salt) crystals at home. The author explains that sodium chloride crystals can be challenging to grow because they are sensitive to temperature differences and can easily crystallize on dust particles, resulting in misshapen clusters. However, after multiple attempts, the author discovered a technique for growing large, high-quality sodium chloride crystals and shares the procedure in the article. The process involves preparing a saturated salt solution, filtering the solution, growing a seed crystal, and growing the main crystal in a container with a low rate of evaporation. The author provides detailed instructions and tips for each step.
Top 1 Comment Summary
The article discusses a prank that was posted on 4chan, where unsuspecting readers were instructed to create chloramine gas under the false promise of growing beautiful crystals. A screenshot of the post in question is provided.
Top 2 Comment Summary
The article discusses the author’s attempt to grow crystals after seeing a post on Hacker News (HN). Despite spending two months on the project, the author did not achieve satisfactory results. They managed to produce some crystals, but they were not comparable to the ones shown in the original post. The article emphasizes that growing crystals requires skill and experience, much like cooking a good carbonara or making decent croissants. Technique plays a crucial role in the process.
6. A transport protocol’s view of Starlink
Total comment counts : 8
Summary
This article discusses the characteristics of the Starlink service and how the TCP transport protocol interacts with it. It begins by explaining Newtonian physics and the concept of orbital velocity. Geosynchronous satellites, which sit at a fixed location in the sky, were used for early satellite-based communications services. However, these satellites have limitations in terms of signal capacity and latency. The round trip time for signals to geosynchronous satellites can range from 477 to 569ms, leading to the need for large buffers to hold unacknowledged data. TCP sessions in geosynchronous service contexts are more prone to instability and longer recovery times compared to terrestrial counterparts. To address the drawbacks of geosynchronous satellites, bringing the satellite closer to Earth is proposed as a potential solution. This approach offers benefits such as protection from solar radiation and improved signal capacity.
Top 1 Comment Summary
The article is missing references to two research papers, [1] and [2], that discuss Starlink performance and characteristics. These papers provide more detailed information on the 15-second reconfiguration interval and how it affects the one-way delay of Starlink. It is important to note that the dish itself does not handle the tracking, but rather a central orchestration system does.
Top 2 Comment Summary
The article discusses the analysis of ping times in Low Earth Orbit Systems. It mentions that most routers do not process pings quickly and instead rely on the router’s CPU, which is a lower priority task. Therefore, the high variation in latency cannot be solely attributed to Starlink.
7. Exit Strategy: The Case for Single-Stair Egress
Total comment counts : 15
Summary
This article discusses a barrier to design options for large multifamily buildings in the United States - the multiple egress routes mandated by American building codes. The argument is made to re-legalize single-stair apartment buildings, which would allow for attractive, light-filled multifamily housing to be built cost-effectively on urban sites that would otherwise be developed as single-family homes. The article compares the current “five over one” design, which is prescribed by regulations and results in long, windowless corridors, to the single-stair buildings commonly found in Europe. Single-stair designs offer more light, air, and acoustic privacy, as well as facilitate community building. They also unlock economically feasible multifamily development on small infill lots and can create park-like shared interior courtyards on large lots. Ultimately, building-code reform should complement zoning-code reform to allow for more diverse and neighborly multifamily housing options. The article also highlights the historical divergence between American and European fire-safety approaches as a reason for the difference in design regulations.
Top 1 Comment Summary
The author has mixed feelings about the idea discussed in the article. On one hand, visiting a friend’s Weimar-era home in Berlin impressed them due to the green space and community building opportunities. On the other hand, they are unnerved by the safety doctrine that focuses on either providing multiple paths of egress or fire-resistant materials. The author suggests having both multiple staircases and fire-retardant construction, citing the Grenfell Tower disaster as an example. They propose the idea of building fire-resistant steel and glass bridges between buildings as an alternative emergency exit option. They also address security and privacy concerns by suggesting safety-glass dividing doors with emergency hammers and mutual agreement for opening locks in non-emergencies.
Top 2 Comment Summary
The author agrees with a YouTube video that questions the US strategy of focusing solely on egress options to increase fire safety. They argue that Europe and other countries prioritize better fire suppression measures and materials instead. The author suggests that allowing builders to use a combination of approaches would be an obvious improvement for achieving a minimal level of safety.
8. Arch Linux RISC-V
Total comment counts : 5
Summary
This article is about an Arch Linux port to the RISC-V architecture. The supported hardware includes QEMU, HiFive Unmatched, HiFive Unleashed, and PolarFire SoC Icicle Kit. There is also experimental support for the Milk-V Pioneer (SG2042). The goal is to upstream the patches so that riscv64 (riscv64gc) could be added to Arch Linux itself as an alternative architecture. The article provides resources such as images, binary package repositories, patch repositories, and a Docker image. The progress of the port is also mentioned, along with thanks to contributors and organizations involved.
Top 1 Comment Summary
The article discusses the author’s experience using VisionFive 2, a version of the Arch Linux operating system for RISC-V architecture. The author mentions that the system works well and has most Arch packages. They express hope that the RISC-V port and other ports will be taken more seriously and eventually become fully supported. The article includes a link to the Arch Linux RFCs page where the RISC-V ports request for comments can be found.
Top 2 Comment Summary
The article mentions that Felix, an Arch Linux Developer, has the potential to fulfill the “merge back to Arch” plan. The author also expresses a desire for a similar initiative for ARM architecture, as ArchLinux ARM is currently underfunded. The author shares their personal experience of having to switch from ALARM to the Fedora remix.
9. Jike: The obscure social media app beloved by China’s tech scene
Total comment counts : 12
Summary
The article discusses the popularity of the social media platform Jike among tech workers and industry experts in China. Although Jike has a smaller user base compared to platforms like Weibo and WeChat, it is favored by big internet company founders and venture capitalists. Jike stands out with its tightly knit community and absence of in-app ads and algorithms. The platform was temporarily shut down in 2019 but made a comeback in 2020. With the rise of generative artificial intelligence, Jike has become the hub for discussions and ideas related to AI startups. The company also announced an AI hackathon as part of their accelerator program.
Top 1 Comment Summary
The article discusses the importance of having a high-quality discussion forum for every guild or community, similar to Hacker News. It then explores the question of how to achieve high quality in such forums by translating the learnings from Hacker News to other platforms.
Top 2 Comment Summary
The article highlights the remarkable resilience of a popular website that was shut down for a year and managed to regain its leading position without being overtaken by new competitors who had the opportunity to catch up during that time.
10. Non-Euclidean Doom: what happens to a game when pi is not 3.14159 (2022) [video]
Total comment counts : 20
Summary
The article discusses the use of incorrect mathematical values, particularly the value of pi, in the source code of the first-person shooter game Doom. It explores the consequences and changes that occur when math is subtly or not so subtly broken in the game. The author also raises the question of whether non-Euclidean geometries could create interesting gaming possibilities. The article concludes by providing links to other games and source code repositories that also use incorrect values of pi, as well as pointers for the audience to compile their own version of the game with incorrect math.
Top 1 Comment Summary
The article discusses a level in the video game Duke Nukem 3D called “Lunatic Fringe”. This level features a circular hallway ring that has two full rotations without intersecting. It utilizes the game engine’s ability to separate areas by room connections, which was groundbreaking at the time. This made for a fun multiplayer experience, and the illusion of the hallway held up well. The central chamber of the level has four entrances/exits, but only two are encountered in each loop around the outside. The article also mentions the author’s personal experience of building a level that solves a puzzle using a similar trick.
Top 2 Comment Summary
The article discusses the plot of Poul Anderson’s novel, “Operation Chaos.” The story is set in a parallel world where magic and science coexist and rapidly advance. The main characters’ child is kidnapped and taken to Hell, where they learn about a previous failed attempt by the army to investigate the dimension. They are given a clue that the space-time geometry of Hell is different from their world, making it possible to go back in time and rescue their child. Using this information, the scientists determine that Hell has non-Euclidean geometry and develop spells to safely navigate and retrieve their child. They hope to receive assistance from two 19th-century geometers to aid their mission.